ROLLED FIBER COMPOSITE RACQUET

BACKGROUND

[0001]Sports racquets may have a variety of different shapes and sizes depending upon the particular sport in which they are used. In some sports, the racquets may have other names, such as paddles. Examples of sports in which racquets are used include, but are not limited to, tennis, badminton, squash, racquetball, pickle ball, table tennis, padel and the like.

[0002]Tennis racquet frames are sometimes formed from discrete fiber composite pieces. Each discrete piece comprises a resin or polymer reinforced with fibers, such as carbon or glass fibers. The discrete fiber composite pieces are individually cut out of a sheet and manually laid upon one another on a mandrel prior to molding and fusing/curing of the fiber composite pieces to form the tennis racquet frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003]FIG. 1 is a front view of an example sports racquet at least partially formed by a rolled sheet.

[0004]FIG. 2 is a perspective view of the example sports racquet of FIG. 1.

[0005]FIG. 3 is a side the example sports racquet of FIG. 1.

[0006]FIG. 4A is a perspective view of an example fiber composite layer in the form of an example composite fiber ply arrangement.

[0007]FIG. 4B is a perspective view of an example fiber composite layer.

[0008]FIG. 5 is a flow diagram of an example method for forming a sports racquet from a rolled sheet.

[0009]FIG. 6 the diagram schematically illustrating an example layout of fiber composite pieces for placement upon an example sheet to be rolled pursuant to the method of FIG. 5 to form an example rolled tube for forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0010]FIG. 7 is a side view of a sheet rolled about a bladder and a mandrel to form a rolled tube about the mandrel.

[0011]FIG. 8 is a top perspective view of the rolled tube of FIG. 7 following removal of the mandrel, following the shaping of the rolled tube and the provision of an example yoke.

[0012]FIG. 9 is a top perspective view of the shaped and rolled tube of FIG. 8 joined to the example yoke.

[0013]FIG. 10 is an exploded perspective view of the joined rolled tube and yoke of FIG. 9 being placed into a sports racquet forming mold.

[0014]FIG. 11 is a flow diagram of an example method for forming a sports racquet from a rolled sheet.

[0015]FIG. 12 is a diagram schematically illustrating an example sheet to be rolled about an example mandrel and bladder pursuant to the method of FIG. 11 to form an example rolled tube for forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0016]FIG. 13 is a sectional of the example rolled tube formed by rolling of the example sheet shown in FIG. 12, wherein the rolled tube may be used to form the example sports racquet of FIG. 1 pursuant to the shaping and molding process shown in FIGS. 7-10.

[0017]FIG. 14 is a diagram illustrating an example sheet to be rolled about an example mandrel to form an example yoke for the example sports racquet of FIG. 1.

[0018]FIG. 15 is a diagram illustrating the example yoke of FIG. 14 following the rolling of the example sheet of FIG. 14 about the example mandrel, wherein the yoke may be included as part of a sports racquet such as the example tennis racquet of FIG. 1 pursuant to the process shown in FIGS. 8-10.

[0019]FIG. 16 is a sectional view of the example sports racquet of FIG. 1 taken along line 16-16, in one implementation where the example sports racquet is formed from the example rolled tube of FIG. 13.

[0020]FIG. 17 is a sectional view of the example sports racquet of FIG. 1 taken along line 17-17, in one implementation where the example sports racquet is formed from the example rolled tube of FIG. 13.

[0021]FIG. 18 is a sectional view of the example sports racquet of FIG. 1 taken along line 18-18, in one implementation where the example sports racquet is formed from the example rolled tube of FIG. 13.

[0022]FIG. 19 is a sectional view of the example sports racquet of FIG. 1 taken along line 18-18, in another implementation where the example sports racquet is formed from the example rolled tube of FIG. 13.

[0023]FIG. 20 is a flow diagram of an example method for forming a sports racquet from a rolled sheet.

[0024]FIG. 21 is a diagram illustrating an example lay up of pieces for placement upon an example fiber composite sheet to be rolled about an example bladder and mandrel pursuant to the method of FIG. 20 to form an example rolled tube for forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0025]FIG. 22 is a sectional view of the example rolled tube formed by rolling of the example sheet shown in FIG. 21 with the example lay-up of pieces, wherein the rolled tube may be used to form the example sports racquet of FIG. 1 pursuant to the shaping and molding process shown in FIGS. 7-10.

[0026]FIG. 23 is a diagram illustrating an example sheet to be rolled about an example mandrel to sandwich layer pieces to form an example yoke for the example sports racquet of FIG. 1.

[0027]FIG. 24A is a diagram illustrating the example yoke of FIG. 23 following the rolling of the example sheet of FIG. 23 about the example mandrel with the sandwiched layer pieces, wherein the yoke may be included as part of a sports racquet such as the example sports racquet of FIG. 1 pursuant to the process shown in FIGS. 8-10.

[0028]FIG. 24B is a sectional view of the yoke of FIG. 24A taken along line 24B-24B.

[0029]FIG. 25 is a diagram illustrating an example fiber composite sheet having example folded layers and placed layer pieces which are to be rolled about an example bladder and mandrel pursuant to the method of FIG. 20 to form an example rolled tube for forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0030]FIG. 26A is a fragmentary view illustrating a portion of another example implementation of the fiber composite sheet of FIG. 25, the portion comprising a folded layer, wherein an angle of the folded layer is controlled by cutting of the fiber composite sheet.

[0031]FIG. 26B is a perspective view illustrating the example fiber composite sheet of FIG. 25 with the placed layers underlying an example template for additional placed pieces prior to rolling.

[0032]FIG. 27 is a sectional view of the example rolled tube formed by rolling of the example sheet shown in FIG. 25 with the example folded layers and placed layer pieces, wherein the rolled tube may be used to form the example sports racquet of FIG. 1 pursuant to the shaping and molding process shown in FIGS. 7-10.

[0033]FIG. 28 is a diagram illustrating an example fiber composite sheet having cut portions for forming example folded layers which are to be rolled about an example bladder and mandrel pursuant to the method of FIG. 20 to form an example rolled tube for forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0034]FIG. 29 is a diagram of the example fiber composite sheet of FIG. 27 following folding of the cut portions to form the example folded layers.

[0035]FIG. 30 is a sectional view of the example rolled tube formed by rolling of the example sheet shown in FIG. 25 with the example folded layers, wherein the rolled tube may be used to form the example sports racquet of FIG. 1 pursuant to the shaping and molding process shown in FIGS. 7-10.

[0036]FIG. 31 is a diagram of example fiber composite sheets having cut and folded layers which are to be rolled about an example bladder and mandrel pursuant to method 22 form example rolled tube forming a sports racquet, such as the example sports racquet shown in FIG. 1.

[0037]FIG. 32 is a diagram illustrating an example method for rolling a sheet about an example bladder and an example mandrel.

[0038]FIG. 33 is an exploded view of an example sports racquet having an example head portion and an example throat portion formed by rolling a sheet to form a rolled tube and formed according to the example method of FIG. 5, the example method of FIG. 11 or the example method of FIG. 20, the example sports racquet further comprising a separately formed handle portion.

[0039]FIG. 34 is an exploded view of an example sports racquet having an example head portion formed by rolling a sheet to form a rolled tube and formed according to the example method of FIG. 5, the example method of FIG. 11 or the example method of FIG. 20, the example sports racquet further comprising a separately formed handle portion and a separately formed throat portion.

[0040]FIG. 35 is a front view of an example sports racquet formed by rolling a sheet to form a rolled tube and formed according to the example method of FIG. 5, the example method of FIG. 11 or the example method of FIG. 20.

[0041]FIG. 36 is a sectional view of one example implementation of the example sports racquet of FIG. 35 taken along line 36-36.

[0042]FIG. 37 is a sectional view of another example implementation of the example sports racquet of FIG. 35 taken along line 36-36.

[0043]FIG. 38 is a front view of an example sports racquet formed by rolling a sheet to form a rolled tube and formed according to the example method of FIG. 5, the example method of FIG. 11 or the example method of FIG. 20.

[0044]Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION OF EXAMPLES

[0045]Disclosed example sports racquets and example method for forming sports racquets. The example sports racquets and methods may be utilized to form racquets for a variety of different sports such as tennis, badminton, squash, racquetball, pickle ball, table tennis, padel and the like. In contrast to many existing tennis racquet frames, at least a portion of the example sports racquets comprises a rolled sheet wound at least 720° (at least two revolutions) about a centerline.

[0046]In some implementations, the rolled sheet comprises a fiber composite sheet. In some implementations, the fiber composite sheet comprises folded layers sandwiched between overlapping portions of the rolled composite fiber sheet. In some implementations, the rolled fiber composite sheet with the folded layers additionally comprises fiber composite pieces and/or non-fiber composite pieces. In some implementations, the rolled sheet comprises a fiber composite sheet supporting fiber composite pieces and/or non-fiber composite pieces which become sandwiched between overlapping portions of the rolled sheet. In some implementations, the rolled sheet comprises a non-fiber composite sheet supporting fiber composite pieces which become sandwiched between overlapping portions of the rolled sheet.

[0047]In some implementations, the rolled sheet forms the head portion of the sports racquet. In some implementations, the rolled sheet additionally forms a throat portion of the sports racquet. In some implementations, the rolled sheet further forms a handle portion of the sports racquet.

[0048]In some implementations the rolled sheet forms a beam which at least partially surrounds a racquet head opening. The racquet head opening may form a string bed (such as in the case of a tennis racquet, a badminton racquet, a racquetball racquet or the like), wherein a series of openings extend through the beam, wherein the strings are strung through the openings and across the string bed. In some implementations, a panel (perforate or imperforate) may be positioned across the racquet head opening (such as in the case of a pickle ball paddle/racquet or a padel racquet). In some implementations, one or more layers of material may at least partially fill the racquet head opening formed by the beam. The one or more layers may be foamed or non-foamed materials. The one or more layers may be formed by injecting or filling the racquet opening with a fluid material that is solidified or may be formed by securing an already solid layer or group of layers within the racquet head opening.

[0049]Because portions of the racquet are formed from a rolled sheet wound about a centerline rather than individual discrete pieces laid upon one another, the racquet construction is more unitary. This more unitary construction may provide enhanced performance for the racquet. For example, in at least implementations where the rolled sheet is a fiber composite sheet, this construction may offer enhanced torsional stability when employed to form portions of a tennis racquet frame.

[0050]Moreover, because portions of the racquet are formed from sheet wound about a centerline rather than individual discrete pieces laid upon one another, fewer discrete pieces need to be cut and individually placed. As result, this racquet construction facilitates faster and less labor-intensive manufacturing of the racquet. This construction may also facilitate more automation of the racquet construction and reduce human prone assembly errors and variability, resulting in a lower cost racquet with greater performance consistency from one racquet to another.

[0051]Forming at least portions of the racquet from a rolled sheet with folded layers eliminates or reduces the number of individual pieces which are typically manually located. As a result, manufacturing speed is enhanced to likewise improve manufacturing efficiency with less work in process. In addition, consistency from one racquet to another racquet may also be improved. In particular, stiffness and weight characteristics of a racquet are more uniform and more predictable with less variation. Skilled tennis players can often notice even a 1 g difference in a racquet or a shifting of a balance point of the racquet by as little as 0.1 mm. The example rackets can address such issues.

[0052]Moreover, because the example racquets and the disclosed example manufacturing processes eliminate or reduce the number of individual pieces (by folding portions of the sheet), the rolled tube which forms at least the racquet head has been found to include fewer voids or pits in the wound layers, ultimately reducing finishing or postprocessing time and cost. The elimination or reduction in the number of individual pieces has been further found to potentially reduce wrinkles in the rolled tube along an inner diameter of the racquet hoop. Such reduction of wrinkles further reduces the time and cost of finishing a manufactured racquet while enhancing final racquet appearance.

[0053]In some implementations, the rolled sheet is rolled so as to have an interior along the centerline. In some implementations, the interior is void or empty such that the beam provided by the rolled sheet is hollow and lighter in weight. In some implementations, the interior is filled with material for strength or noise dampening. For example, the interior may be filled or injected with a foaming material or other material.

[0054]In some implementations where the rolled sheet is a fiber composite sheet, wherein portions of the fiber composite sheet are removed or cut out. As result, when the fiber composite sheet is subsequently rolled and shaped into a portion of the sports racquet, corresponding portions of the sport racquet have fewer windings or overlapping portions. The fewer number of overlapping portions may alter the performance characteristics in such portions. For example, in implementations where the rolled fiber composite sheet forms a throat portion of a sports racquet, removing those portions of the fiber composite sheet prior to rolling at locations that correspond to the throat may result in the throat being less stiff and more flexible.

[0055]In some implementations, a second sheet may be rolled about the centerline by at least 360° and, in some implementations, by at least 720° (two revolutions). The sheet may be rolled about the rolled second sheet or the second sheet may be rolled about the rolled fiber composite sheet. The second sheet may have a physical composition different than that of the fiber composite sheet. The second sheet may not comprise a fiber composite sheet. The second sheet may omit fibers. In some implementations, the first sheet may comprise a first fiber composite sheet while the second sheet may comprise a second fiber composite sheet that may have other different material characteristics than that of the first fiber composite sheet. The two rolled sheets may have different thicknesses. The two sheets may have different ply arrangement angles. The two sheets may have different material compositions such as different fiber materials and/or different resin or polymer materials encapsulating the fiber materials.

[0056]In some implementations, construction and performance characteristics of the racquet are controlled and varied by additionally sandwiching at least one layer between adjacent overlapping portions of the rolled fiber composite sheet. The added layer or layers may vary material properties are performance characteristics of particular portions of the racquet. For example, a layer may be added to a particular portion of the fiber composite racquet to increase the stiffness or other properties of the particular portion of the fiber composite racquet.

[0057]In implementations where a plurality of layers are sandwiched or captured within the roll of fiber composite material, multiple layers may be sandwiched between the same overlapping portions of the roll of fiber composite material and/or may be sandwiched between different pairs of adjacent overlapping portions of the rolled fiber composite material. For example, two different layers may be provided between adjacent overlapping portions of the fiber composite sheet roll, wherein the two layers are at the same radial location (the same radial distance from a center or centerline of the roll), but at different axial locations along a centerline the row. A first layer may be provided between adjacent overlapping portions of the fiber composite sheet roll at a first radial position within the roll and a second layer may be provided between adjacent overlapping portions of the fiber composite sheet roll at a second radial position within the roll, radially outward of the first radial position. The different radial positions of the first and second layers may be at the same or different axial locations relative to the centerline of the roll.

[0058]The added layer or layers may have material or physical characteristics different than that of the material or physical characteristics of the fiber composite sheet. For example, the added layer or layers may have plies or ply arrangements that have different angles as compared to the that of the fiber composite sheet. A ply arrangement refers to a pair of plies having a respective pair of +/−angles. For example, ply arrangement may comprise a first ply having a positive 30° angle and a second adjacent overlapping ply having a −30° angle. In some implementations, the fiber composite sheet may have a first ply arrangement having a first +/−angle and the layer may comprise a second ply arrangement having a second different +/−angle.

[0059]In some implementations, the added layer or layers may have a different thickness than that of the fiber composite sheet. In some implementations, the fiber composite sheet may have fibers that reinforce a first resin or material while the layer or layers comprise the same fibers that reinforce a second different type of resin or material. In some implementations, the fiber composite sheet may comprise a first type of fiber that reinforces a type of resin or material while the layer comprises a second type of fiber that reinforces the same type of resin or material. In some implementations, the fiber composite sheet may comprise a first type of resin that reinforces a first type of resin or polymer while the layer or layers comprises a second different type of fiber that reinforces second different type of resin or material. In some implementations, the layer or layers may comprise fiber composite layers having multiple different types of fibers or fiber clusters. In some implementations, the layer layers may omit fibers.

[0060]In implementations where more than one layer is sandwiched between overlapping portions of the rolled fiber composite sheet, the different layers themselves may have different material characteristics. The different layers may have different sizes and shapes. The different layers may have different thicknesses. The different layers may have different ply arrangement angles. The different layers may have different material compositions such as different fiber materials and/or different resin or polymer materials encapsulating the fiber materials. In some implementations, some of the layers may be in the form of a fiber composite layer while other layers omit fibers. The different layers may be at particular locations to modify or control performance characteristics of different portions of the fiber composite racquet. For example, the fiber composite racquet may be provided with perimeter weighting by sandwiching two layers at locations corresponding to the 3 o'clock and 9 o'clock positions of the head of the racquet. The fiber composite racquet may be provided with a heavier weighted handle portion by providing or sandwiching additional layers at locations corresponding to the handle portion of the fiber composite racquet.

[0061]In some implementations, the sandwiching of the layer (or layers) between adjacent overlapping portions of the rolled fiber composite sheet comprises positioning a discrete panel (layer piece) of material on the fiber composite sheet prior to rolling of the fiber composite sheet. The discrete panel or layer piece may comprise a fiber composite panel or a panel having other constructions or formed from other materials. For example, the panel may omit fibers. In such implementations, indicia or markings may be formed on a surface of the fiber composite sheet to assist in the proper manual or automated (computer vision assisted) location and orientation of the discrete panel or piece of material on the fiber composite sheet. For example, the fiber composite sheet may be printed with printed outlines of the layer piece, the outline indicating both the location and orientation for the layer/piece. In some implementations, the printing may additionally include a text (numbers and such or words) or graphics (bar code, QR code or other images) identifying the particular layer piece that is to be positioned at the particular location. In some implementations, the marking may be scanned or otherwise captured with a computer vision system/camera to facilitate the subsequent automated positioning of the layer piece on fiber composite sheet prior to folding. In some implementations, the fiber composite sheet and/or the layer piece may be heated to a temperature such that at least portions of the fiber composite sheet and/or the layer piece is tacky to facilitate securement of the layer piece on the fiber composite sheet prior to rolling. In some implementations, the layer piece may be provided with an adhesive layer or film to facilitate its securement once positioned on the fiber composite sheet prior to rolling.

[0062]In some implementations, the sandwiching of the layer between adjacent overlapping portions of the rolled fiber composite sheet comprises folding a portion of the fiber composite sheet (and/or folding a portion of the second fiber composite sheet that is to be rolled when provided) along a fold to form the layer. For example, an edge portion or perimeter portion of the fiber composite sheet may be folded over and along a fold to form the layer. Portions of the fiber composite sheet may be cut or severed while leaving such portions connected to a remainder of the fiber composite sheet along a fold along which the portions are to be folded to form the layer. The cut may have endpoints that guide the folding to form the layer. In some implementations, the cuts of such portions may have aligned end such that the portion is folded along a fold that is perpendicular to a centerline of the portion that was severed. In some implementations, the ends of the cuts of such portions may be offset such that the portion is folded along a fold that is oblique to a centerline of the portion that was severed. In such implementations, despite the unfolded partially severed portion having the same ply arrangement angle as that of the remaining fiber composite sheet, the layer formed by the folded portion of the fiber composite sheet may be provided with a different ply arrangement (+/−) angle.

[0063]In those implementations where the layer is formed by folding of the fiber composite sheet, the number of separate or discrete layer pieces that must be cut is reduced, further reducing manufacturing time and cost. Moreover, in implementations with a layer is formed by folding of the fiber composite sheet, the angle of the fold and the resulting orientation of the layer as well as its ply arrangement (plus/minus) angle is further controlled or dictated by the alignment or offsetting of the ends of the cut that partially severed the portion to be folded. As result, operator or human induced error or variability during the manufacture of different sports racquets is reduced. In such example implementations, the forming of the beam/rolled tube that is to be fused and shape to form the head portion of a sports racquet may simply involve folding those partially severed portions of the fiber composite sheet and rolling the sheet about a centerline. The tedious, time-consuming and error-prone task of individually laying sometimes dozens of discrete fiber composite pieces on a mandrel is eliminated.

[0064]Disclosed are example fiber composite racquets and example methods for forming fiber composite racquets, wherein a sheet is wound or rolled about a centerline; and wherein a fiber composite layer is sandwiched between adjacent overlapping portions of the sheet. In some implementations, the sheet may not be a fiber composite sheet or may omit fibers, wherein the fiber composite layer is part of a piece that is discrete from the sheet and that is placed on a surface of the sheet prior to rolling of the sheet about the centerline. In some implementations, the sheet may comprise a marking or markings indicating a designated position and/or orientation of the piece to assist in assembly or manufacture of the racquet. In some implementations, the sheet may comprise a fiber composite sheet.

[0065]In some implementations, the fiber composite layer may have a length, extending along the centerline about which is sheet is rolled, that is sufficiently long to form an entirety of the head portion of the racquet. In some implementations, fiber composite layer has a length, extending along the centerline about which the sheet is rolled, that is sufficiently long to form an entirety of the head portion and a throat portion of the racquet. In some implementations, the fiber composite layer has a length, extending along the centerline about which issues rolled, that is sufficiently long to form an entirety of the head portion and at least portions (if not an entirety) of a handle portion of the racquet.

[0066]In some implementations, the example fiber composite racquet may comprise a second layer provided by a piece of material or a piece formed from one or more layers that is sandwiched between adjacent overlapping portions of the sheet. In some implementations, the second layer comprises a second fiber composite layer. In some implementations, the second fiber composite layer forming the second layer may have a material characteristic different than the material characteristic of the fiber composite layer. In some implementations, the second layer may comprise a material that is not a fiber composite layer or may omit fibers.

[0067]In some implementations, the sheet and the fiber composite layer are both formed from a fiber composite material. In some implementations, the sheet and the fiber composite layer are integrally formed as part of a single unitary body, wherein the fiber composite layer is joined to the sheet along a fold. In such implementations, the racquet may comprise a second layer sandwiched between overlapping portions of the sheet. In some implementations, the second layer is a non-fiber composite layer or piece. In some implementations, the second layer may be a second fiber composite layer. In some implementations, the second fiber composite layer may have a material characteristic different than that of the material characteristic of the first fiber composite layer.

[0068]For purposes of this disclosure, the term “rolled” refers to the winding, rolling or wrapping of a sheet, layer, panel or the like about the centerline or axis and about itself. The rolled sheet, layer, panel or the like may have multiple rounds or windings which may form a two-dimensional spiral where the overlapping portions do not translate along the axis or the centerline, or may form a three-dimensional spiral, a helix, where the overlapping portions additionally translate along the axis or the centerline. The rolled sheet, layer, panel or the like may have a cross-section similar to that of a jellyroll. In some implementations, the sheet, layer, panel or the like may be rolled about a mandrel having a circular, or oval cross-sectional shape. In some implementations, sheet, layer, panel like be rolled about a mandrel having a polygonal cross-section, such as a square, rectangle or the like which may or may not include protuberances and/or grooves or other cavities along or at least partially along its length which provides the centerline.

[0069]For purposes of this disclosure, the term “coupled” shall mean the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two members, or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature.

[0070]For purposes of this disclosure, the phrase “configured to” denotes an actual state of configuration that fundamentally ties the stated function/use to the physical characteristics of the feature proceeding the phrase “configured to”.

[0071]For purposes of this disclosure, the term “releasably” or “removably” with respect to an attachment or coupling of two structures means that the two structures may be repeatedly connected and disconnected to and from one another without material damage to either of the two structures or their functioning.

[0072]In each of the drawings of this entire disclosure, various mandrels are schematically shown for ease of illustration and may have other lengths, diameters and proportions other than those schematically depicted. Likewise, the number of revolutions or windings of the depicted sheets after being rolled about the mandrel, the proportionality of the length and width of each sheet, and the depicted thickness of each sheet are also schematically illustrated in that the exact number of windings, the compactness/density of windings, the lengths and widths of the sheets, and the thicknesses of the sheets (unless otherwise explicitly specified in each case) may vary from what is schematically depicted.

[0073]Referring to FIGS. 1 through 3, a sports racquet is indicated generally at 10. The racquet 10 of FIG. 1 is configured as a tennis racquet. The racquet 10 includes a frame 12 extending along a longitudinal axis 16 and including a head portion 18, a handle portion 20, and a throat portion 22 coupling the head and handle portions 18 and 20. The frame 12 is a tubular structure formed of a lightweight, durable material, preferably a fiber composite material.

[0074]The head portion 18 is a tubular structure that includes inner and outer peripheral walls 24 and 26. The head portion 18 can be broken down into regions, such as, a distal region 28, first and second side regions 30 and 32, and a proximal region 34, which collectively define a hoop 36 having a string bed area 38 for receiving and supporting the string bed 14. In one preferred implementation, the proximal region 34 includes a yoke 40. The string bed area 38 is also referred to as the head size of the racquet 10. In a preferred implementation, the head size or string bed area 38 of the racquet 10 is within the range of 93 to 120 square inches. In other implementations, the head size of the racquet 10 can be within the range 98 to 115 square inches. In other implementations, other head sizes can also be used and are contemplated under the present invention. The string bed area 38 has a maximum longitudinal dimension, a, and a maximum transverse dimension, b. The hoop 36 can be any closed curved shape including, for example, a generally oval shape, a generally tear-drop shape, a generally circular, a generally pear shape, and combinations thereof. In some implementations, the maximum longitudinal dimension a can be at least 1.2 times the maximum transverse dimension b (a≥1.2*b). In other implementations, the maximum longitudinal dimension a can be at least 1.25 times the maximum transverse dimension b (a≥1.25*b). In other implementations, the maximum longitudinal dimension a can be less than 1.2 times the maximum transverse dimension b.

[0075]The yoke 40 is an elongate tubular structural member that extends from the first side region 30 to the second side region 32 of the head portion 18. In one implementation, the yoke 40 is integrally formed with the frame 12 defining the proximal region 34. For example, the yoke can be formed of a fiber composite material and molded and cured with the frame 12 of the racquet 10. In alternative preferred implementations, the yoke 40 can be connected through use of adhesives, fasteners, bonding and combinations thereof. The yoke 40 is formed of a lightweight, durable material, such as a carbon-fiber composite material. Alternatively, the yoke 40 can be formed of other materials, such as, for example, other composite materials, metallic alloys, a polymeric material, wood and combinations thereof.

[0076]In a preferred implementation, the first and second side regions 30 and 32 downwardly extend from the head portion 18 to form first and second throat tubes 42 and 44 of the throat portion 22. The first and second throat tubes 42 and 44 converge and further downwardly extend to form the handle portion 20. Accordingly, in such implementations, the frame 12 can be formed of one continuous tube of material (e.g., fiber composite material) that is curved at its middle region to form the head portion 18 then each side of the continuous tube of material can converge toward each other in the throat region 22 and the end regions of the continuous tube can be arranged side by side to form the base structure of the handle portion 20. In such implementations, the frame 12 is formed as a one-piece integral structure. The handle portion 20 can further include a pallet 46, a grip 48 and a butt cap 50. In other implementations, the handle portion 20 can be a tubular structure that does not include an extension of the first and second throat tubes. In such implementations, the handle portion can be a tubular structure separate from either the throat portion or the head portion of the frame and attached to the throat portion through use of conventional fasteners, molding techniques, bonding techniques, adhesives or combinations thereof. In other implementations, the handle portion can be formed in the shape of an outer surface of a conventional pallet, thereby eliminating the need for the use of a pallet.

[0077]In other implementations, the head portion 18 can be directly connected to one or both of the throat portion 22 and the yoke 40 through the use of conventional fasteners, adhesives, mechanical bonding, thermal bonding, or other combinations thereof. In one implementation, the head portion 18 can be separated from one or both of the throat portion and the yoke by a vibration and shock absorbing material, such as an elastomer.

[0078]The racquet 10 is configured for supporting a string bed 14 and is formed by a plurality of main string segments 52 alternately interwoven or interlaced with a plurality of cross string segments 54. The string bed 14 is preferably generally uniform with constant spacing between the string segments 52 and 54. Alternatively, the string bed 14 can have some spacing variability provided that the spacing of the main and cross string segments of the string bed is most dense at the center of the string bed 14 (or near the geometric center of the string bed or string bed area). The main and cross string segments 52 and 54 can be formed from one continuous piece of racquet string, or from two or more pieces of racquet string. The racquet string is formed of a high tensile strength, flexible material. In preferred implementations, the racquet string can be formed of a polyester material, a nylon, a natural gut material and/or a synthetic gut material. The racquet string can be formed in a monofilament construction or in a multiple filament construction, and can be formed of various different diameters (or gauges). Preferably, the diameter of the racquet string is within the range 1.10 to 1.55 mm.

[0079]The inner and outer peripheral walls 24 and 26 of the hoop 36 can include string holes 59 for receiving the racquet string. The string holes 59 can be sized to be just larger than the diameter of the racquet string, or the combination of the racquet string and a grommet, or a size that is larger to accommodate movement or deflection of the racquet string and/or grommet. The head portion 18 of the racquet 10 can also include one or more grommets or bumper guards for supporting and protecting the racquet string as it extends from one string hole to another. Additionally, the number of string holes 59 can be varied to produce different string arrangements or numbers of main string segments 52 and cross string segments 54 resulting in different string patterns. Referring to FIG. 3, the inner and outer peripheral walls 24 and 26 of the head portion 18 can define a maximum beam height distance d measured from a forward hoop surface 25 to a rearward hoop surface 27. In one implementation, the maximum beam height distance d is at least 19 mm. In other implementations, the maximum beam height distance d can be at least 20 mm. In other implementations, the maximum beam height distance d can be at least 21 mm. In still other implementations, the maximum beam height distance d can be at least 22 mm.

[0080]Referring to FIGS. 1 through 3, the main and cross string segments 52 and 54 refer to the portions of the racquet string that make up the string bed 14. The string bed 14 extends about and generally defines a string bed plane 56 (or a first plane). The string bed plane (or first plane) 56 extends through the longitudinal axis 16. A second plane 58, perpendicular to the sting bed plane (or the first plane) 56, also extends through the longitudinal axis 16. The sting bed plane 56 exists on a racquet whether it is strung or unstrung.

[0081]Conventional tennis racquets are typically formed of fiber composite material and/or aluminum, and are typically formed to be stiff structures that resist deflection about the longitudinal axis of the racquet. A stiff racquet construction is generally considered to be desirable because it is believed to improve the power and/or control of the racquet. Conventionally, the stiffness of a racquet generally refers to the racquet's resistance to bending along the longitudinal axis of the racquet and with respect to the string bed plane in a forward/rearward direction with respect to the string bed. Racquet stiffness is typically measured in a forward/rearward bending test (or a racquet stiffness test) wherein the handle portion of the racquet is fixedly secured in a test fixture with the string bed (and the string bed plane) positioned generally horizontal to the ground, a load is applied to the distal region of the head portion in a direction that is perpendicular to the string bed plane. The load causes the racquet to bend, flex or deflect with respect to the longitudinal axis and the string bed plane. The amount of deflection is measured to ascertain the stiffness level of a racquet.

[0082]High quality racquets are also typically designed to provide high levels of torsional stability. A torsionally stable racquet resists rotational movement of the head portion of the racquet upon an off-center impact with a tennis ball which improves the control of the racquet. Accordingly, conventional racquet design seeks to produce racquets with high levels of racquet stiffness and torsional stability at a predetermined racquet weight or weight range.

[0083]The shape and geometry of the head portion 18 and the throat portion 22 of the frame 12 of the racquet 10 also contributes to the racquet's stiffness level and/or torsional stability. For example, racquets with high racquet beam heights are generally stiffer than racquets with lower racquet beam heights. The shape and geometry of the throat tubes 42 and 44 can also affect the stiffness of the racquet.

[0084]As used herein, the term “fiber composite material” or “composite material” refers to a plurality of fibers within and permeated throughout a resin. The fibers can be co-axially aligned in sheets, layers or plies, or braided or weaved in sheets or layers, and/or chopped and randomly dispersed in one or more layers. A single ply typically includes hundreds or thousands of fiber bundles that are initially arranged to extend coaxially and parallel with each other through the resin that is initially uncured. Each of the fiber bundles includes a plurality of fibers. The fibers are formed of a high tensile strength material such as carbon. Alternatively, the fibers can be formed of other materials such as, for example, glass, graphite, boron, basalt, carrot, Kevlar®, Spectra®, poly-para-phenylene-2,6-benzobisoxazole (PBO), hemp, flax, other natural fibers and combinations thereof. In one set of preferred implementations, the resin is preferably a thermosetting resin such as an epoxy or a polyester resin. In other sets of preferred implementations, the resin can be a thermoplastic resin. The composite material is typically wrapped about a mandrel and/or a comparable structure, and cured under heat and/or pressure. While curing, the resin is configured to flow and fully disperse and extend throughout the matrix of fibers. In multiple layer or ply constructions, the fibers can be aligned in different directions with respect to the longitudinal axis 16, and/or in braids or weaves from layer to layer.

[0085]Referring to FIG. 4A, a portion of a layer 60 of fiber composite material is illustrated. The layer 60 is formed by one or two plies 62 (62a and 62b) of fiber composite material. A ply 62 of fiber composite material refers to an arrangement of fibers 64 and fiber bundles 66 in a resin 68, wherein the fibers 64 and the fiber bundles 66 are arranged and aligned such that the fibers 64 and the fiber bundles 66 generally extend coaxially with respect to each other and are generally parallel to one another. The fibers 64 or fiber bundles 66 are preferably formed such that they extend along the ply 62 and form generally the same angle with respect to an axis, such as a composite axis 70. The plies 62 are typically identified, at least in part, by the size and polarity of the angle defined by the fibers 64 or fiber bundles 66 with respect to the axis 70. As shown in FIG. 4A, the ply 62a has fibers 64 and fiber bundles 66 aligned at a positive 45 degree angle ply, and the ply 62b has fibers 64 and fiber bundles 66 aligned at a negative 45 degree angle ply. In other implementations, the plies 62 can include fibers 64 or fiber bundles 66 defining a positive 30 degree angle ply, a negative 30 degree angle ply, a positive 45 degree angle ply, a negative 45 degree angle ply, a positive 40 degree angle ply, a negative 40 degree angle ply, a positive 35 degree angle ply, a negative 35 degree angle ply, a 90 degree angle ply (extending perpendicular to the axis), and a 0 degree angle ply (or extending parallel to the axis). Other positive or negative angles for plies can also be used. Accordingly, in the present application, a single ply 62 refers to a single layer of fiber composite material in which the fiber bundles 66 extend in substantially the same direction with respect to a longitudinal axis along the single layer, such as plus or positive 45 degrees or minus or negative 30 degrees. A layer 60 formed of a pair of plies 62 having fibers 64 of generally the same angle but arranged with opposite polarities is also referred to a ply arrangement. This pattern typically extends throughout a fiber composite material. The alternating angular arrangement of the fiber bundles 66 and fibers 64 is important to achieving and maintaining the structural integrity of the component or structure being formed of the fiber composite material. The overlapped region of the two plies 62a and 62b can be essential for ensuring that, once cured, the fiber composite material has the desired strength, durability, toughness and/or reliability.

[0086]During heating/molding and curing, the resin 68 can flow between plies 62 and within the fiber bundles 66. The plies 62 preferably typically have a thickness within the range of 0.002 to 0.015 inch. In other implementations, other thickness ranges can also be used.

[0087]Referring to FIG. 4B, in other implementations, one or more of the layers 60 can include a plurality of braided fibers 62c. The braided fibers 62c can extend at angles with respect to the lay-up axis 70 of at least 35 degrees with positive and negative polarities. In other implementations, the braided fibers 62c can extend at angles with respect to the lay-up axis 70 of at least 40 degrees (with positive and negative polarities).

[0088]Tennis racquets similar to racquet 10 described above are often formed with a lay-up of multiple discrete individually cut fiber composite pieces which are placed directly upon a mandrel, wherein the mandrel is subsequently removed to form a hollow fiber composite tube. The hollow fiber composite tube is then positioned within a mold where the discrete fiber composite pieces are fused/cured to form the frame of the tennis racquet. However, as described above, this process of placing discrete fiber composite pieces directly upon a mandrel is tedious, time-consuming and error prone.

[0089]In contrast, racquet 10 is formed by one of various below described methods which avoid or reduce an extent to which discrete individually cut fiber composite pieces need to be placed directly upon the mandrel. In contrast to typical racquet fabrication processes, racquet 10 is formed by one of various below described methods in which a sheet is wound or rolled about a centerline or about a mandrel. The use of the rolled sheet (1) may reduce manufacturing time, complexity and cost by reducing the number of, or eliminating the need for, individually cut fiber composite pieces and/or (2) may reduce manufacturing variability and error by assisting in ensuring that fiber composite layers and/or fiber composite pieces are more consistently and more accurately positioned and oriented when the racquet is being formed. It has been further discovered that in some implementations, racquet 10 formed from one of the various below described methods may have a more unitary construction that may offer enhanced stiffness characteristics and/or torsional stability.

[0090]FIG. 5 is a flow diagram of an example method 200 for forming a fiber composite racquet, such as racquet 10. As should be appreciated, method 200 may likewise be used to form other tennis racquets having other shapes or dimensions. Method 200 may be used to form other sports racquets such as those used for badminton, squash, racquetball, pickle ball, table tennis, padel and the like.

[0091]As indicated by block 204, fiber composite layer pieces are placed or positioned on a sheet. FIG. 6 illustrates an example lay-up 300 of individual, discrete pieces ready to be placed upon an example sheet 304. Lay-up 300 may comprise both fiber composite pieces and non-fiber composite pieces. Each fiber composite piece comprises a fiber composite layer. The fiber composite layer may comprise a fiber composite ply arrangement formed by a pair of adjacent plies having different fiber composite ply angles. In some implementations, the fiber composite layer may comprise a fiber composite ply arrangement formed by a pair of adjacent plies having a plus/minus (+/−) fiber composite ply arrangement angle. An example of such fiber composite ply arrangement is shown in FIG. 4A.

[0092]In the example illustrated, at least one of the fiber composite pieces has a longitudinal length L (which is to extend parallel to the axis about which sheet 304 is to be rolled) that is sufficiently long so as to extend along an entire perimeter of the head portion of the racquet. In some implementations, the length is sufficiently long so as to additionally form or extend along each of the beams of the throat portion of the racquet. In some implementations, length is sufficiently long so is additionally form or extend along at least portions of, if not the entirety of, the handle portion of the racquet 10 when formed. This length of the at least one fiber composite piece provides continuous uninterrupted fiber strength or fiber reinforcement along the length while serving as a continuous substrate, foundation or base along which and to which other, potentially shorter, pieces (whether fiber composite pieces or non-fiber composite pieces) may be secured, fused or cured.

[0093]In some implementations, at least some of the discrete pieces of lay-up 300 may omit fibers or may not comprise a fiber composite composition. For example, a piece may be a cut homogenous polymeric panel or a panel formed from multiple different polymeric layers. In some implementations, the non-fiber composite composition of the piece may be used to establish a desired weight or weight distribution or desired particular dimensions for particular portions of the racquet.

[0094]In the example shown in FIG. 6, lay-up 300 comprises discrete fiber composite pieces 320-1, 320-2, 320-3, 320-4, 320-5, 320-6, 320-7, 320-8, 320-9 and 320-10 (collectively referred to as pieces 320) and non-fiber composite pieces 322-1 and 322-2 (collectively referred to as pieces 322). In the example illustrated, each of pieces 320 comprises a fiber composite ply arrangement, a pair of individual plies of opposite polarity (+/−composite ply angles or orientations). For example, fiber composite piece 320-1 comprises a layer formed by a first ply having a +30° fiber orientation and a second adjacent ply having a −30° fiber orientation. Similarly, pieces 320-2, 320-3, 320-5, 320-6, 320-7, 320-9 and 320-10 each comprise a layer comprising a ply arrangement comprising pair of adjacent plies having a +/−30° fiber composite ply arrangement angle. Fiber composite piece 320-4 comprise a composite ply arrangement having a +/−45° angle or orientation. Fiber composite piece 320-8 comprises a ply arrangement having a 0/90 ply arrangement angle, wherein one ply is at 0° and the other ply is at 90°. As should be appreciated, other arrangements of pieces 320 including other numbers of pieces 320, other lengths of pieces 320, other widths of pieces 320, other shapes of pieces 320, other fiber angle values of pieces 320, other sequences of pieces, and combinations thereof are contemplated. The number of pieces 322 used to form a frame 12 can be within the range of 2 to 150. In a preferred implementation, the number of pieces 322 used to form the frame 12, or the head portion 18 and throat portion 22 thereof, is at least 10 plies. In other implementations, other numbers of pieces or other numbers of composite ply arrangements can be used.

[0095]In the example illustrated, pieces 320-1, 320-4, 320-9 and 320-10 each have a length (measured in a direction parallel to the axis about which sheet 304 is rolled) generally extending along an entire length of the lay-up 300, a length near or equal to the width of sheet 304. In some implementations, the length of the high angle layers (at least 35 degree angle layers, at least 40 degree angle layers, or at least 45 degree angle layers) extend over at least 40 percent of the total length of the lay-up the head portion 18 of the racquet 10. In other implementations, the length of the high angle layers extend over at least 50 percent of the total length of the lay-up the head portion 18 of the racquet 10. In other implementations, the length of the high angle layers extend over at least 70 percent of the total length of the lay-up the head portion 18 of the racquet 10. In some implementations, the length of the layers 60 or ply arrangements can be sufficiently long such that, when molded and cured, the high angle layers (at least 35 degree angle layers, at least 40 degree angle layers, or at least 45 degree angle layers) extend over at least the head portion 18 of the racquet 10. In other implementations, the length of the pieces 320 or ply arrangements can be sufficiently long such that, when molded and cured, the high angle layers (at least 35 degree angle layers, at least 40 degree angle layers, or at least 45 degree angle layers) extend over at least the head portion 18 and the throat portion 22 of the racquet 10.

[0096]In some implementations, at least 50 percent of the pieces 320 of a of lay-up 300 are be formed with carbon fibers. In another implementation, at least 75 percent of the pieces 320 in lay-up 300 can be formed of carbon fibers. In one implementation, each of the high angle layers (at least 35 degree angle layers, at least 40 degree angle layers, or at least 45 degree angle layers) in the lay-up 300 include a resin and have a fiber area weight of at least 100 g/m². In another implementation, each of the high angle pieces fiber composite (at least 35 degree angle layers, at least 40 degree angle layers, at least 45 degree angle layers, or at least 60 degrees) in the lay-up 300 include a resin and have a fiber area weight of at least 120 g/m².

[0097]Non-fiber composite pieces 322 comprise pieces formed from one or more layers of non-fiber or fiber embedded materials. Non-composite five pieces 322 may comprise one or more layers of polymeric material or materials (thermoplastic or thermoset), may comprise a polymer resin encapsulating fibers which are not oriented (randomly oriented) or may comprise metal layers or films, such as iron. In some implementations, layer 300 may comprise a fewer greater number of such non-fiber composite pieces or pieces 322 may be omitted.

[0098]In one implementation, sheet 304 is a ply arrangement of fiber composite material that serves as a table or platform upon which each of the pieces 320, 322 of layer 300 may be positioned and secured prior to rolling of sheet 304. Sheet 304 facilitates inspection to ensure that all of the pieces 320, 322 designated for the racquet 10 have been included prior to the pieces forming the fiber composite tube used to form racquet 10. Rather than the individual discrete pieces being wrapped about the mandrel and stacked on top of one another where such pieces may be placed at the wrong angles, out of order or completely omitted, a human assembler or a computer vision inspection system (trained to inspect sheets 304 with the positioned pieces 320, 322 of lay-up 300 prior to rolling of the sheet 304) can easily view and inspect the assembled lay-up 300 on sheet 304 prior to rolling of sheet 304.

[0099]Sheet 304 may comprise a thin sheet of fiber composite material including fibers extending at a predetermined angle and a resin or polymer (thermoset or thermoplastic) material. In some implementations, sheet 304 is formed from the same fiber composite material as contained in the fiber composite pieces 320. Sheet 304 may have a thickness sufficient to withstand rolling about a centerline or rolling about a mandrel, yet thin enough so as to not substantially alter the dimension or construction of the roll fiber composite tube used to form racquet 10. Sheet 304 has a length L so as to extend at least 720° about the axis 331 of mandrel 330 (at least two revolutions) when rolled or wound about mandrel 330. Sheet 404 has a width W (measured in a direction parallel to axis 331 of mandrel 330 when rolled or parallel to the centerline about which sheet 304 is rolled) sufficiently long so as to extend along an entire perimeter of the head portion of the racquet. In some implementations, the length is sufficiently long so as to additionally form or extend along each of the beams of the throat portion of the racquet. In some implementations, length and sufficiently long so is additionally former extend along at least portions of, if not the entirety of, the handle portion of the racquet 10 when formed. This length of sheet 304 provides continuous uninterrupted fiber strength or fiber reinforcement along the length of rolled tube.

[0100]As further shown may FIG. 6, in some implementations, sheet 304 may include windows or openings 307 which completely extend through sheet 304 and are completely surrounded by other portions of sheet 304. Such openings 307 may be provided on sheet 304 in regions where pieces 320-322 are not being supported to reduce cost and weight of the resin or other material of sheet 304. In some implementations, such multiple opening 307 may be provided between each location where a piece 320, 322 is to be supported by sheet 304. In some implementations, at least some of the openings 310 located between consecutive piece supporting portions of sheet 304 (and between pieces 320, 322 when positioned on sheet 304) may connect to one another. In some implementations, such openings 310 may continuously surround piece supporting “islands” 311 provided by sheet 304, wherein each of such islands 311 of sheet 304 are sized and shaped to support a piece 320, 322 and wherein such islands are connected to one another and to a remaining solid portion of sheet 304 by connecting bridges 313 such that all of the “islands” 311 supporting pieces 320, 324 are interconnected by the remaining portions of sheet 304 when sheet 304 is rolled about mandrel 330.

[0101]As further shown by FIG. 6, in some implementations, sheet 304 may be perforated throughout to reduce its weight, wherein such perforations 309 are sized and shaped such that an overlying piece 320, 322 may still be supported over such perforations. So long as sheet 304 is sufficiently strong to support pieces 320, 322 and be wrapped about mandrel 330 without tearing, perforations 309 may be as large as possible or may be highly concentrated to reduce the added weight of sheet 304. In some implementations, the size of the perforations, the shape of the perforations or the concentration of perforations in different regions of sheet 304 may vary. For example, the number, concentration or size of perforations may be reduced in those particular regions of sheet 304 where sheet 304 may be subject to tearing during rolling. In the example illustrated, regions sheet 304 which are to underlie a piece 320, 322 may have larger size perforations and/or a greater concentration of perforations to enhance weight reduction and to potentially facilitate a greater degree of fusing or curing between adjacent overlapping pieces 320, 322 during curing or fusing of the rolled tube when forming the racquet. An example of this is shown in FIG. 6 with respect to those regions to receive pieces 320-1, 320-6 and 320-7.

[0102]As shown in FIG. 6, sheet 304 may have formed thereon markings 326-1, 326-2, 326-3, 326-4, 326-5, 3286-6, 326-7, 326-8, 326-9, 326-10, (collectively referred to as markings 326) and markings 328-1 and 328-2 (collectively referred to as markings 328). Markings 326, 328 may each have a size and shape identifying or matching that of the particular piece 320, 322 that is to be received at the location of the marking. In some implementations, the markings 326, 328 may additionally include alphanumeric markings 329 or other graphics 335 (examples of which are shown) which further identify the particular piece to be positioned at the location of the particular marking. Each of such markings may further be provided with an orientation for the particular piece. Markings 328 may be printed upon a face of sheet 324. Markings 326, 328 further assist in the positioning or placement of the pieces 320, 322 of layer 300 on sheet 304 prior to the rolling of sheet 304. Such placement may be performed in a manual fashion with a human operator or may be performed with robotic system using robotic vision.

[0103]Referring to FIG. 5, once the pieces have been placed or positioned on a sheet, such as sheet 304, the sheet 304 is rolled about a mandrel as indicated by block 208. The rolling creates a two-dimensional in some implementations, the rolling forms a two-dimensional spiral (non-helical) cross-section of windings or portions wrapped about the mandrel 330. In some implementations, the rolling may have movement along a longitudinal axis of the mandrel so as to form a three-dimensional spiral, helical spiral about the mandrel.

[0104]FIG. 6 illustrates an example mandrel 330 about which sheet 304 and the positioned pieces 320, 322 may be rolled as indicated by arrows 337 and 339. In some implementations, as shown by broken lines, the mandrel 330 may be coated with a no-stick film or layer or may be enclosed with a thin bladder 332 prior to rolling of sheet 304 about mandrel 330. Because the individual pieces 320, 322 of lay-up 300 are secured in place upon the surface of 304, the individual pieces 320, 322 are likewise wrapped or rolled. In implementations where the mandrel is enclosed within a bladder 332 prior to rolling, a vacuum may be applied to bladder 332 to form a tight fit between bladder 332 and the internally received mandrel 330.

[0105]As indicated by block 212 in FIG. 5, following rolling the sheet about the mandrel 330, the overlapping portions (or windings) of the rolled sheet 304 (and the secured pieces 320, 322) are fused while the rolled sheet a sheet and a loop to form at least a head portion of the fiber composite racquet being performed, such as racquet 10. Such shaping may be carried out with the assistance of a mold which may then apply heat and pressure for a predefined period of time to facilitate fusing of the overlapping portions of the roll sheet. In implementations where the resin supporting the oriented fibers is a thermoset material, such fusing may be in the form of curing of the resin.

[0106]FIGS. 6-9 illustrate one example process or method by which the rolled sheet resulting from block 208 may be shaped and fused to form the head portion, the throat portion and portions of the handle portion of fiber composite racquet 10. Referring to FIG. 7, when the sheet 304 and the carried pieces 320, 322 are rolled about the mandrel 330 (over the bladder 332), the pieces 320, 322 are no longer arranged in a flat sheet, and therefore, the fiber bundles 66 and fibers 64 (shown in FIG. 4A) no longer follow or define generally parallel lines. Rather, the fiber bundles 66 and fibers 64 are

[0107]adjacent to one another, and are curved or otherwise formed so that they follow substantially the same adjacent paths. For example, when sheet 304 is rolled about the bladder 76 and the mandrel 74, pieces 320, 322 can take a generally cylindrical or tubular shape and the fiber bundles 66 and fibers 64 can follow the same cylindrical path or define a helical path (depending upon their angle within the ply arrangement). The fibers 64 remain adjacent to one another, are aligned with each other and follow substantially similar paths that are essentially parallel (or even co-axial) for example, when viewed in a sectional view in a single plane or other small finite segment of the plies of the piece 320.

[0108]In one implementation, the mandrel 330 may include a pull tab 338 for facilitating the pulling or removal of the mandrel 330 from the rolled sheet 304 and pieces 320, 322 wrapped about the bladder 332 and the mandrel 330. The lay-up 300 of FIG. 6 is uncured. In one implementation, the mandrel 330, using the pull tab 338, can be drawn, pulled or otherwise removed from the bladder and the lay-up 300.

[0109]Referring to FIGS. 8 and 9, once the mandrel 330 is removed from the bladder 332 and the rolled sheet 304 with lay-up 300, the rolled sheet 304 and the uncured lay-up 300 can be gently positioned into the shape of a racquet frame. An uncured yoke 350 of fiber composite material can be prepared for positioning next to the curved sheet 304 and lay-up 300. As shown in FIG. 9, the lay-up can be shaped to resemble a racquet frame, and the yoke 350 can be attached to the rolled sheet 304 and lay-up 300. In one implementation, additional relatively short ties or tying plies can be applied over the connection points of the yoke 350 to the roll sheet 300. In other implementations, the yoke may be replaced with a preformed yoke structure that is added attached to the rolled sheet 304 and lay-up 300 prior to molding.

[0110]Referring to FIG. 10, the uncured rolled sheet 304 with the internally wound pieces 320, 322 of lay-up 300 and the uncured yoke 350 is positioned within a mold cavity 388 of a racquet forming mold 390. A supply line 386 can be attached to the bladder 332 for supplying air or other gas to the bladder, and the pieces of the racquet forming mold 90 can be positioned around the lay-up 80 and the yoke 84. The bladder 76 can be pressurized by air or other gas to a predetermined pressure, and the racquet forming mold 90 can then be heated in an oven or furnace to a predetermined temperature. Once subjected to heat and pressure, the viscosity of the resin 68 in the lay-up 80 and the yoke 350 drops and the resin 68 (shown in FIG. 4A) flows through out the plies of pieces 320 of the lay-up 300 and yoke 350 in the mold cavity 388 creating a more uniform structure and the fibers 64 are positioned into the shape of the mold cavity. After a first predetermined amount of time, the racquet forming mold 390 is removed from the heat and the rolled sheet 304 with lay-up 350 and yoke 350 are allowed to cool. After a second pre-determined amount of time, the racquet forming mold 390 is opened and the racquet frame 12 is removed from the mold 390. The frame 12 of the racquet 10 can have a weight within the range of 260 gm to 355 gm. In

[0111]other implementations, the frame of the racquet can have a weight outside of the 180 gm to 370 gm range.

[0112]FIG. 11 is a flow diagram illustrating an example method 400 that may be used to form the example racquet 10 described above or other sports racquets. As indicated by block 408, a fiber composite sheet is rolled about a mandrel. FIGS. 12 and 13 illustrate an example fiber composite sheet 404 prior to and after being rolled about mandrel 330, respectively. As with the method shown in FIG. 6, in some implementations, the mandrel 330 may be enclosed within an inflatable bladder 332 (shown in broken lines). In some implementations, inflatable bladder 332 may be omitted.

[0113]The fiber composite sheet 404 comprises a panel or sheet of a fiber composite material, such as the fiber composite material shown and described above in FIG. 4A or 4B. Sheet 404 has a length L so as to extend at least 720° about the axis 331 of mandrel 330 (at least two revolutions) when rolled or wound about mandrel 330. Sheet 404 has a width W (measured in a direction parallel to axis 331 of mandrel 330 when rolled or parallel to the centerline about which sheet 404 is rolled) sufficiently long so as to extend along an entire perimeter of the head portion of the racquet. In some implementations, the length is sufficiently long so as to additionally form or extend along each of the beams of the throat portion of the racquet. In some implementations, length and sufficiently long so is additionally former extend along at least portions of, if not the entirety of, the handle portion of the racquet 10 when formed. This length of sheet 404 provides continuous uninterrupted fiber strength or fiber reinforcement along the length of rolled tube shown in FIG. 13.

[0114]Although sheet 404 is illustrated as a rectangular sheet without openings or perforations, in other implementations, sheet 404 may have other shapes and/or may include openings or cut outs. For example, as shown by broken lines in FIG. 12, in some implementations, fiber composite sheet 404 may have snipped corners 405, one or more notches 406 or may include windows or openings 407. Such corners, notches or openings may be cut from sheet 404 prior to rolling. Such corners, notches or openings may be via locations where fiber strength is less of a priority or where less stiffness or greater flexibility is desired. In the example illustrated, Windows 407 may be symmetrically provided applications corresponding to the throat portions of the racquet, such as the throat portions of racquet 10 described above where less stiffness may be desired.

[0115]FIG. 13 illustrates sheet 404 after being rolled about mandrel 330 with the overlying bladder 332. Before molding and curing, the fiber composite material has a natural tacky state such that the two-dimensional spiral roll maintains its rolled configuration. At such time, mandrel 330 may be withdrawn as described above and the two formed by the roll sheet 404 may be shaped as shown in FIG. 8 and nine in place in the mold shown in FIG. 10 to form the frame of the racquet. In some implementations where the racquet is to include a yoke, the yoke insert 350 described

[0116]above may be further positioned within the mold 390 in FIG. 10 as described above.

[0117]FIGS. 14 and 15 illustrate an example method by which the yoke 350 shown in FIGS. 8 and 9 may be formed in a similar fashion. As shown by FIG. 14, yoke 350 may be formed from a fiber composite sheet 504 which is to be rolled body centerline, such as about a mandrel 530. In some implementations, mandrel 533 is removed resulting in a hollow tube forming yoke 350. In other implementations, mandrel 530 is not removed, forming a core filling the otherwise hollow interior of the rolled yoke 350. Mandrel 530 may be a bendable or flexible piece configured to be bent into the shape of yoke 350 when placed in mold 390. In some implementations, mandrel 530 may comprise a foam piece about which sheet 504 is rolled. In other implementations, yoke 350 may have a non-circular cross-section and/or may be formed from other materials.

[0118]Sheet 504 has a length L sufficient long so as to wrap or extend about mandrel 530 by at least 720° (two revolutions). Sheet 504 has a width W corresponding to the length of yoke 350. In the example illustrated, sheet 504 is further shaped so as to form tie-ins 511. Tie-ins 511 comprise projections extending from a body of sheet 504, wherein the tie-ins are configured to facilitate enhanced connection of the yoke 350 to the throat portion of the racquet formed by sheet 404.

[0119]As indicated by arrow 513, mandrel 530 may be rolled or sheet 504 may be rolled about the centerline or axis 331 of mandrel 530. Such rolling occurs in the direction indicated by arrow 515. FIG. 15 illustrates the rolled sheet 504 and the internal mandrel 530. Once formed, yoke 350 may be incorporated into the racquet as described above with respect to FIGS. 8-10. As should be appreciated, 350 may be omitted in sports racks where yoke is not provided or the racquet may not include throat portion. As should further be appreciated, the yoke shown in FIG. 15 may be utilized as a yoke in racquet 10 or other racquets regardless of how the head portion, the throat portion (when provided) and the handle portion are formed. For example, the yoke shown in FIG. 15 may be utilized as a yoke in current conventionally formed racquets independent of whether the remaining portions of such racquets are formed pursuant to the methods of this disclosure.

[0120]Referring to FIG. 11, as indicated by block 412, following rolling the sheet about the mandrel 330, the overlapping portions (or windings) of the rolled sheet 404 are fused while the rolled sheet is shaped to form a loop to form at least a head portion of the fiber composite racquet being performed, such as racquet 10. Such shaping may be carried out with the assistance of a mold (as shown in FIGS. 8-10) which may then apply heat and pressure for a predefined period of time to facilitate fusing of the overlapping portions of the roll sheet. In implementations where the resin supporting the oriented fibers is a thermoset material, such fusing may be in the form of curing of the resin.

[0121]FIG. 16 is a sectional view of an implementation of racquet 10 formed pursuant to method 400. FIG. 16 is a sectional view of a head portion of racquet 10 taken along line 16-16 of FIG. 1. As shown by FIG. 16, in the example illustrated, the mold forms an outer recessed channel 57 in the rolled tube formed by sheet 404. After molding and curing of the assembly, string openings 59 may be drilled or otherwise formed in the rolled tube formed by sheet 404.

[0122]FIG. 17 is a sectional view of an implementation of racquet 10 formed pursuant to method 400. FIG. 17 is a sectional view of a throat portion of racquet 10, taken along line 17-17 of FIG. 1. As shown by FIG. 17, throat portion has a hollow interior or void 61. As indicated by broken lines, in some implementations, the hollow or otherwise empty void 61 may be filled with a filler 73. In some implementations, filling material may be a foam material. In some implementations, filling window may be injected into the void 61 through a fill port 75 which may be drilled and subsequently filled or closed. In some implementations, the fill ports and five may be omitted where or 61 is filled through an open end of the tube formed by sheet 404.

[0123]FIG. 18 is a sectional view of an implementation of racquet 10 formed pursuant to method 400. FIG. 18 is a sectional view of a handle portion of racquet 10, taken along line 18-18 of FIG. 1. As shown by FIG. 18, to end portions of the rolled tube formed by sheet 404 are shaped in mold 390 such that the mutually facing in her surfaces 490 of the two about one another and fuse or joined to one another. In the example illustrated, mold 390 further provides the outer facing surfaces of the end portions of the tube formed by the rolled sheet 404 with an octagon shaped outer profile 492. Each of the end portions of the tube have hollow interiors 63. During molding, pressurized air or other gas may be provided into the bladder 332 to force the end portions of the tube against the sheet forming surfaces of mold 390, producing interiors 63. As shown by broken lines, in some implementations, the otherwise hollow interior void 63 may be filled with a filler 73. The filler 73 may be the same or different than that of the filler, if applied, in void 61. The filler 73 may be a foam cereal or a foaming material. The filler 73 may be injected through end portions of the bladder 332 or end portion of the tube formed by the rolled sheet 404. In some implementations, filler 73 and/or filler 73 may be injected or otherwise provided to void 61 and/or void 63 prior to shaping of the tube or prior to the fusing step of block 412 (following movable of the mandrel 330).

[0124]FIG. 19 illustrates an alternative shaping of the tube formed by the rolled sheet 404 and an alternative configuration of handle portion 20 of racquet 10. In FIG. 19 is a sectional view of an implementation of racquet 10 formed pursuant to method 400. FIG. 19 is a sectional view of handle portion 20 of racquet 10, taken along line 18-18. As shown by FIG. 19, the two end portions of the tube formed by the rolled sheet 404 are substantially collapsed to form a pair of hairpins 77. Thereafter, a pallet 79 may be formed around the hairpins 77 form handle portion 20. The pallet may be formed from a foam material or other materials. In other implementations, the handle portion 20 may be formed in other fashions.

[0125]As with each of FIGS. 16-19, it should be appreciated that certain portions are omitted for ease of illustration. For example, additional outer coatings, lacquers, paint, varnishes or other materials are not shown. With respect to FIGS. 18 and 19, additional outer wrappings forming the grip or cushioning layers are omitted.

[0126]FIG. 20 is a flow diagram of an example method 600 for forming a sports racquet, such as the example supports racquet 10. Method 600 is similar to method 200 described above. Sheet 600 that is rolled about the mandrel is a fiber composite sheet. As result, the sheet 704 itself forms the continuous unitary fiber structure along the length of the rolled tube that is to form the racquet. As result, each of the discrete pieces of fiber composite material or non-fiber composite material may have lengths less than the length of the rolled tube that is to form the racquet. As indicated by block 608, a fiber composite sheet is rolled about a mandrel. FIG. 21 illustrates an example fiber composite sheet 704 prior to being rolled about mandrel 330 received within bladder 332. Sheet 704 may have the same fiber composite composition as described above with respect to fiber composite sheet 404. Sheet 704 also has a length and width as described above with respect to sheet 304. In some

[0127]implementations, sheet 704 may include any of the perforations or openings described above with respect to sheet 304. In some implementations, sheet 704 may omit openings 307, perforations 309, and/or island forming openings 310 which are optionally provided in the sheet 304. Although illustrated as a rectangle, sheet 704 may have other shapes.

[0128]As indicated by block 610 in FIG. 20, a layer (at least one layer) is sandwiched between overlapping portions of the rolled fiber composite sheet. The sandwiching of the layer occurs during the rolling of the sheet 704 as shown in FIG. 22. To facilitate such sandwiching, the layer is positioned on or formed upon a surface of sheet 704 prior to such rolling. In the example illustrated, a lay-up 700 of discrete fiber composite pieces and non-fiber composite pieces are positioned upon sheet 704 prior to sheet 704 being rolled.

[0129]In the example illustrated, lay-up 700 comprises fiber composite pieces 720-1, 720-2, 720-3, 720-4, 720-5, 720-6 (collectively referred to as pieces 720) and non-fiber-composite piece 720-7. In the example illustrated, each of pieces 720 comprises a fiber composite ply arrangement, a pair of individual plies of opposite polarity (+/−composite ply angles or orientations). For example, fiber composite pieces 720-1 and 720-2 may each comprise a layer formed by a first ply having a +30° fiber orientation and a second adjacent ply having a −30° fiber orientation. Likewise, pieces 720-3 and 720-4 may each comprise a layer formed by a first ply having a +30° fiber orientation and a second adjacent ply having a −30° fiber orientation. However, because piece 721-1 and 720-2 are positioned on sheet 704 at a different angle as compared to sheet 720-3 and 720-4, pieces 720-1 and 729-2 have a different resulting +/−fiber oriented paired to pieces 720-3 and 720-4. Pieces 720-5 720-6 each have +/−45 degree angle and have different shapes as compared to the other pieces which are rectangular.

[0130]Non-fiber composite piece 722 comprises a discrete piece formed from one or more layers of non-fiber or fiber embedded materials. Non-fiber composite pieces 722 may comprise one or more layers of polymeric material or materials (thermoplastic or thermoset), may comprise a polymer resin encapsulating fibers which are not oriented (randomly oriented) or may comprise metal layers or films, such as iron. In some implementations, lay-up 700 may comprise a fewer or greater number of such non-fiber composite pieces or piece 722 may be omitted.

[0131]As shown in FIG. 21, sheet 704 may have formed thereon markings 726-1, 726-2, 726-3, 726-4, 726-5, 726-6, (collectively referred to as markings 726) and marking 727. Markings 726, 727 may each have a size and shape identifying or matching that of the particular piece 720, 722 that is to be received at the location of the marking. In some implementations, the markings 726, 727 may additionally include alphanumeric markings 729 or other marking graphics 735 (examples of which are shown) which further identify the particular piece to be positioned at the location of the particular marking. Each of such markings may further be provided with an orientation for the particular piece. Markings 726, 727, 729 and 735 may be printed upon a face of sheet 704. Markings 726, 727, 729 and 735 further assist in the positioning or placement of the pieces 720, 722 of lay-up 700 on sheet 704 prior to the rolling of sheet 704. Such placement may be performed in a manual fashion with a human operator or may be performed with robotic system using robotic vision. Because sheet 704 is uncured, sheet 704 is inherently tacky or sticky state to retain each of the pieces 720, 722 once placed.

[0132]As shown by FIG. 22, once the pieces 720, 722 have been placed or positioned on sheet 704, the sheet 704 is rolled about a mandrel as indicated by block 608. The rolling creates a two-dimensional spiral (non-helical) cross-section of windings or portions wrapped about the mandrel 330. In some implementations, the rolling may have movement along a longitudinal axis of the mandrel so as to form a three-dimensional spiral, helical spiral about the mandrel.

[0133]As indicated by block 612 in FIG. 20, following the rolling of the sheet 704 with the pieces 720, 722 about the mandrel 330, the overlapping portions (or windings) of the rolled sheet 304 (and the secured pieces 320, 322) are fused while the rolled sheet is shaped to form a loop to form at least a head portion of the fiber composite racquet, such as racquet 10. Such shaping may be carried out with the assistance of a mold 390 which may then apply heat and pressure for a predefined period of time to facilitate fusing of the overlapping portions of the roll sheet. In implementations where the resin supporting the oriented fibers is a thermoset material, such fusing may be in the form of curing of the resin. In some implementations, the tube formed by the rolled sheet 704 may be shaped and molded, and combined with yoke 350, as shown in FIGS. 6-10.

[0134]FIGS. 23, 24A and 24B illustrate an example method by which the yoke 350 shown in FIGS. 8 and 9 may be formed in a similar fashion. The method by which yoke 350 is formed in FIGS. 23 and 24 is similar to the method shown in FIGS. 14 and 15 except that the yoke formed in FIGS. 23 and 24 additionally comprises discrete pieces 820-1, 820-2, and 820-3.

[0135]As shown by FIG. 23, yoke 350 may be formed from a fiber composite sheet 804 which is to be rolled about a centerline, such as about axis 731 of mandrel 530. In some implementations, mandrel 533 is removed resulting in a hollow tube forming yoke 350. In other implementations, mandrel 530 is not removed, forming a core occupying the otherwise hollow interior of the rolled yoke 350. Mandrel 530 may be a bendable or flexible piece configured to be bent into the shape of yoke 350 when placed in mold 390. In some implementations, mandrel 530 may comprise a foam piece about which sheet 804 is rolled. In other implementations, yoke 350 may have a non-circular cross-section and/or may be formed from other materials.

[0136]Sheet 804 has a length L sufficient long so as to wrap or extend about mandrel 530 by at least 720° (two revolutions). Sheet 804 has a width W corresponding to the length of yoke 350. In the example illustrated, sheet 804 is further shaped so as to form tie-ins 511. Tie-ins 511 comprise projections extending from a body of sheet 504, wherein the tie-ins are configured to facilitate enhanced connection of the yoke 350 to the throat portion of the racquet formed by sheet 704.

[0137]As further shown by FIG. 23, sheet 804 may additionally include markings 826-1, 826-2 and 826-3 (collectively referred to as markings 826) which are located, size and oriented to indicate the designated positions for discrete pieces 820-1, 820-2 and 820-3, respectively. Markings 826 functions similar to markings 326, 328 and 726, 728 described above. Markings 826 may be printed upon a face of sheet 804. Markings 826, 828 assist in the positioning or placement of the pieces 820 on sheet 804 prior to the rolling of sheet 804. Such placement may be performed in a manual fashion with a human operator or may be performed with robotic system using robotic vision.

[0138]In some implementations, the resin or polymer of sheet 804 may be in a tacky or sticky state to retain each of the pieces 820 once placed. In some implementations, the surface of sheet 804 or a surface of the discrete pieces 820 may be provided with a thin adhesive film or layer to facilitate retention and securement once a piece 820 is placed upon sheet 804.

[0139]In some implementations, each of pieces 820 comprises a fiber composite piece, a piece having a fiber composite layer. In some implementations, the fiber composite layer may comprise a ply arrangement in the form of a pair of adjacent plies having opposite polarities. In some implementations, some of pieces 820 may comprise non-fiber composite pieces as described above. Although FIG. 23 illustrates three discrete pieces eight, the yoke being formed in FIGS. 23 and 24 may alternatively comprise a greater or fewer number of such pieces. In some implementations, such pieces may be omitted.

[0140]As indicated by arrow 513, mandrel 530 may be rolled or sheet 704 may be rolled about the centerline or axis 331 of mandrel 530. Such rolling occurs in the direction indicated by arrow 515. FIG. 15 illustrates the rolled sheet 504 and the internal mandrel 530. Once formed, yoke 350 may be incorporated into the racquet as described above with respect to FIGS. 8-10. As should be appreciated, 350 may be omitted in sports racks where yoke is not provided or the racquet may not include throat portion. As should further be appreciated, the yoke shown in FIG. 15 may be utilized as a yoke in racquet 10 or other racquets regardless of how the head portion, the throat portion (when provided) and the handle portion are formed. For example, the yoke shown in FIG. 15 may be utilized as a yoke in current conventionally formed racquets independent of whether the remaining portions of such racquets are formed pursuant to the methods of this disclosure.

[0141]FIG. 25 illustrates another example of how a sports racquet, such as the tennis racquet 10 described above, may be formed pursuant to method 600 outlined in FIG. 20. In the method shown in FIG. 25 at least some of layers ultimately sandwiched between overlapping portion of the rolled composite fiber sheet 704 per block 610 are formed by folded over portions 924 of sheet 704 prior to sheet 704 being rolled about mandrel 330 (and bladder 332). The use of folded over portions of sheet 704 to form at least some of the layers that are alternately sandwiched between the roll sheet 704 further reduces manufacturing time, manufacturing labor, manufacturing cost, manufacturing complexity and manufacturing inconsistency. In addition, because at least some of the layers are formed by folded over portions 924 of the rolled sheet 704, the composition is more unitary. It has been found that, in some implementations, the resulting sports racquet may achieve enhanced torsional stability. In the example illustrated, the tube formed by the rolling of sheet 704 and the sandwiched layers comprises sheet 704, discrete pieces 920-1, 920-2, (collectively referred to as pieces 920), discrete pieces 922 and folded layers 924-1, 924-2, 924-3 and 924-4 (collectively referred to as layers 924).

[0142]Pieces 920 may be compositionally similar to pieces 720 described above. Pieces 920 may comprise a fiber composite layer which may comprise a fiber ply arrangement having adjacent plies of opposite polarity. Pieces 922 may be

[0143]compositionally similar to piece 722 described above in that piece 722 comprises a non-fiber composite layer. The provision of pieces 920, 922 on sheet 704 prior to its rolling may provide greater design flexibility. For example, pieces 920, 922 may have material compositions different than that of sheet 704 and/or fiber composite orientation/angles/polarities that cannot be achieved through the selective folding of portions of sheet 704 to form folded layers 924. Moreover, pieces 920, 922 may provide additional sandwiched layers at locations where the option to provide a sandwiched folded layer may not be available due to adjacent or proximal portions of sheet 704 having already been cut and folded to form other folded, layers. As should be appreciated, the example numbers, size, shape and locations of pieces 920, 922 on sheet 704 may be different from the illustrated example.

[0144]As with sheet 704 in FIG. 21, sheet 704 in FIG. 25 may additionally comprise markings 926-1, 926-2 (collectively referred to as markings 926) and 927 that serve as indicia indicating designated positions and orientations for pieces 920-1, 920-2 and 922, respectively. Such markings 926, 927 may be printed upon sheet 704. For example, in some implementations, sheet 704 to be run through a printer which print such markings on a surface of sheet 704 prior to the cutting and folding of portions of sheet 704 to form folded layers 924 and prior to the rolling of sheet 704. In some implementations, markings 926, 927 may be omitted. In some implementations, markings 926, 927 as well as one or more of pieces 920, 922 may be omitted.

[0145]As further shown by FIG. 25, in some implementations, sheet 704 may additionally comprise completely surrounded openings 906-1, 906-2 (collectively referred to as openings 906). Such openings 906 extend completely through sheet 704, wherein none of the edges of the openings 906 extend adjacent to or are bordered by a fold (in contrast to apertures 997). Such openings 906 may remove weight and stiffness from particular portions of the formed racquet without transferring weight or stiffness, in contrast to folded layers 924-3 and 924-4 which do shift weight and stiffness when forming apertures 997. Although not illustrated, in some implementations, sheet 704 may include edge notches or cutouts (similar to snipped corners 405 and/or notch 406 shown in FIG. 11).

[0146]Folded layers 924 comprise portions of sheet 704 which have been folded over so as to overlap other portions of sheet 704 prior to the rolling of sheet 704. In some implementations, such folded portions may comprise perimeter edge portions, such as corners or side edges, which are folded inwardly. In the example illustrated, each of folded layers 924 is formed by partially cutting sheet 704 to partially separate those portions of sheet 704 which are to be folded over to form folded layers 924. As

[0147]shown by FIG. 25, portions of the fiber composite sheet 704 may be cut or severed while leaving such portions connected to a remainder of the fiber composite sheet along a fold 945, 955, 965 along which the portions are to be folded to form the layer 924.

[0148]The cut may have endpoints that guide the folding to form the layer. In some implementations, the cuts of such portions may have aligned end such that the portion is folded along a fold that is perpendicular to a centerline of the portion that was severed. In some implementations, the ends of the cuts of such portions may be offset such that the portion is folded along a fold 945, 955 that is oblique to a centerline of the portion that was severed. In such implementations, despite the unfolded partially severed portion having the same ply arrangement angle as that of the remaining fiber composite sheet, the layer 924 formed by the folded portion of the fiber composite sheet may be provided with a different ply arrangement (+/−) angle.

[0149]In the example illustrated, folded layer 924-1 is formed by severing or cutting sheet 704 along its perimeter along cut lines 940-1 and 940-2 (collectively referred to as cut lines 940. Cut lines 940 partially cut out the portion 943 of sheet 704 which is to be folded, leaving an end portion of portion 943 overlying or integral with the remainder of sheet 704. As shown by arrow 946, the portion 943 is folded about and along a fold line or fold 945, wherein the folded layer 924-1 is connected to the remainder sheet 704 by and along the fold 945. In the example illustrated, fold 945 is oblique to axis 331 (in the example, at a 45 degree angle) and the folded layer 924-1 extends along an axis that is perpendicular to axis 331. The angle of the folded layer 924-1 may vary depending on the angles of the fold 945. Accordingly, by adjusting the size and length of the cut lines 940 and adjusting the angle of the fold 945, portion 943 can be sized and positioned at a number of different locations relative to the sheet 704.

[0150]Folded layer 924-2 is formed in a similar fashion as folded layer 924-1, but where the cut lines 940 mirror those used to cut out portion 943 to form layer 924-1. Folded layer 924-2 is formed by severing or cutting sheet 704 along its perimeter along cut lines 950-1 and 950-2 (collectively referred to as cut lines 950. Cut lines 950 partially cut out the portion 953 of sheet 704 which is to be folded, leaving an end portion of portion 953 overlying or integral with the remainder of sheet 704. As shown by arrow 956, the portion 953 is folded about and along a fold line or fold 955, wherein the folded layer 924-2 is connected to the remainder sheet 704 by and along the fold 955. In the example illustrated, fold 955 is oblique to axis 331 (in the example, at a 45 degree angle) and the folded layer 924-2 extends along an axis that is perpendicular to axis 331. The angle of the folded layer 924-2 may vary depending upon the angle of fold 955.

[0151]As further shown by FIG. 25, in some implementations, the folded layers, themselves, may be additionally folded to form a secondary folded layer. In the example illustrated, each of folded layers 924-1, 924-2 is to be folded about a fold line 925. In some implementations, the fold line 925 is designated on each of the folded layers 924-1, 924-2 by markings. For example, each of the fold lines 925 may be printed on sheet 704 prior to the folding of layers 924-1, 924-2. In the example illustrated, the printing is placed on the back face of sheet 704 (the opposite side or face as that of marking 729 or 730) prior to folding. In yet other implementations, the fold line 925 may be indicated by a scoring of the back surface of sheet 704. In the example illustrated, the fold lines 925 are perpendicular to the longitudinal axis of each of folded layers 924-1, 924-2 such that the folded portions of layers 924-1, 94-2 fold back on top of (or beneath) themselves with aligned side edges. In other implementations, the fold lines 925 may be angled or oblique to the longitudinal axis of folded layers 924-1, 924-2 such that the secondary folded layer or portion angles away from the primary folded portion that extends from fold 945 or fold 955.

[0152]Folded layers 924-3 and 924-4 are formed by cutting and folding interior portions of sheet 704. Folded layer 924-3 is formed by cut lines 960-1, 960-2 and 960-3 (collectively referred to as cut lines 960) within the interior of sheet 704. Cut lines 960 partially cut out the portion 963 of sheet 704 which is to be folded, leaving an end portion of portion 963 overlyng or integral with the remainder of sheet 704. As shown by arrow 966, the portion 963 is folded about and along a fold line or fold 965, wherein the folded layer 924-3 is connected to the remainder sheet 704 by and along the fold 965. Cut lines 960-1 and 960-3 have ends or endpoints 961 and 962 which are vertically

[0153]aligned relative to the axis 331 of mandrel 330. The endpoints 961 and 962 define the angle of the fold 965 and the angle of the layer 924-3 relative to the axis 331 about which the sheet 704 is to be rolled. In other implementations, the endpoints 961 and 962 may be horizontally offset such that the fold 965 is not perpendicular to axis 331, but is oblique to axis 331, resulting in the folded layer 924-3 also being oblique to axis 331. The angle of the folded layer 924-3 may vary depending on the angle of fold 965. Because the angle of the fold 965 is controlled by the offset between the endpoints 961, 962 of the cuts, the angle the fold in the angles of the folded layer may be controlled during the cutting of sheet 704, reducing the opportunity for errors in the orientation of layer 924-3.

[0154]Folded layer 924-4 may be formed in a fashion similar to folded layer 924-3, but wherein the cuts and folds mirror that of folded layer 924-3. Folded layer 924-4 is formed by cut lines 970-1, 970-2 and 970-3 (collectively referred to as cut lines 970) within the interior of sheet 704. Cut lines 970 partially cut out the portion 973 of sheet 704 which is to be folded, leaving an end portion of portion 973 overlying or integral with the remainder of sheet 704. As shown by arrow 976, the portion 973 is folded about and along a fold line or fold 975, wherein the folded layer 924-4 is connected to the remainder sheet 704 by and along the fold 975. Cut lines 970-1 and 970-3 have ends or endpoints 971 and 972 which are vertically aligned relative to the axis 331 of mandrel 330. The endpoints 971 and 972 define the angle of the fold 975 and the angle of the layer 924-4 relative to the axis 331 about which the sheet 704 is to be rolled. In other implementations, the endpoints 971 and 972 may be horizontally offset such that the fold 965 is not perpendicular to axis 331, but is oblique to axis 331, resulting in the folded layer 924-4 also being oblique to axis 331. The angle of the folded layer 924-4 may vary depending on the angle of fold 965. Because the angle of the fold 975 is controlled by the offset between the endpoints 971, 972 of the cuts, the angle the fold in the angles of the folded layer may be controlled during the cutting of sheet 704, reducing the opportunity for errors in the orientation of layer 924-4.

[0155]FIG. 26A illustrates an alternative implementation of that which is shown in FIG. 25 where an interior portion of sheet 704 is additionally provided with cut lines 980-1, 980-2 and 980-3 to partially cut out portion 983 which dangles from the remainder sheet 704. FIG. 26A further illustrates the folding of portion 983 to form a folding layer 924-5. In the example shown, cut lines 980-1 and 980-3 have horizontally offset endpoints 981 and 982 which result in portion 983 being folded about a fold 985 which is oblique to axis 331 and oblique to the centerline of the cut out opening in sheet 704. As should be appreciated, the relative positioning of endpoints 981 and 982 may have other offsets or positions relative to one another to form other fold angles which result in the folded layers extending at other angles.

[0156]The location of the layers and the location of the folds on sheet 704 control where additional fiber content is provided along the axial length of the rolled tube 900 shown in FIG. 27. Likewise, those regions where a portion of sheet 704 has been cut out folded over to create an aperture have less fibers. As shown by FIGS. 7-10, different axial segments of the tube, when shaped, form different portions of the racquet. In the example illustrated, the center 990 of sheet 704 corresponds to the longitudinal center of the rolled tube 900 shown in FIG. 27 which corresponds to the apex 989 of the head portion 18 of racquet 10 (shown in FIG. 1). The location of the layers and the locations of the fold on sheet 704 and along tube 900 control what part of the sports racquet is provided with additional layering of fiber composite material or non-fiber material to vary the performance properties of different portions of the sports racquet.

[0157]In the example illustrated where the rolled tube shown in FIG. 27 forms each of the head portion, the throat and the handle portion of the racquet 10, the closer positioning of layers 924-1 and 924-2 to center 990 results in greater fiber content in the head portion of racquet 10. In the example illustrated, folded layers 924-1 and 924-2 are each equidistantly spaced from a center 990 of sheet 704 and are spaced from center 990 such that when sheet 704 is rolled into the tube 900 shown in FIG. 27, and when the tube 900 is then shaped and molded as shown in FIGS. 7-10, the sandwiched layers 924-1 and 924-2 are at locations corresponding to the 3 o'clock position 991 and the 9 o'clock position 992 of the head portion of racquet 10 (both positions of which is shown in FIG. 1) to provide the racquet 10 with perimeter weighting.

[0158]The apertures 997 (formed by the cutting out and outward folding of portions 963 and 973) are at locations along the rolled tube, that when shaped in FIGS. 7-10, correspond to the throat portions 22 of racquet 10 and result in such throat portions 22 having less fiber content and being less stiff. The positioning of the layers 924-3 and 924-4 most distant from center 990 result in such layers forming end portions of the rolled tube shown in FIG. 26 to provide additional fiber content to the handle portion 20 of racquet 10 and to provide additional stiffness and weight to the handle portion 20.

[0159]As shown by FIG. 25, the example construction of the racquet formed by sheet 704 and pieces 920, 922 additionally comprises an outermost layer 998 of fiber composite material. In some implementations, the outermost layer 998 may comprise a ply arrangement having adjacent plies of opposite polarity. In some implementations, the ply arrangement may have the same +/−(opposite polarity) fiber composite ply orientation or angles as that of sheet 704. As shown by FIG. 25, layer 998 has a width less than that sheet 704. As shown by FIG. 27, layer 998 has a length sufficient to wrap about the rolled sheet 704 by at least 360° and less than or equal to 720°. In some implementations, layer 998 may be omitted.

[0160]In some circumstances, different variations of a racquet may have different weight distributions or degrees of stiffness in different portions of the racquet. The racquet variations may accommodate different preferences of different players. FIG. 26B illustrates an example of how an example fiber composite sheet folded portions and with the placed layers may be tweaked or modified using an example template which guides the placement of additional placed pieces prior to rolling. FIG. 26B illustrates an example template 704′ temporarily overlaid on top of sheet 704. In some implementations contemplate 704′ may include a bottom face coated with a tacky but releasable coating or adhesive permits template 704′ to be temporally retained in

[0161]place on sheet 704 as the additional pieces are placed, wherein upon placement of the additional pieces, the template 704′ may be released, peeled away, or lifted, leaving the additionally placed pieces in place on sheet 704, ready for being rolled.

[0162]In the example illustrated, template 704′ comprises window openings 931-1, 931-2, 931-3, 931-4 and 931-5 (collectively referred to as openings 931). Openings 931 extend completely through the sheet serving as template 704′. In the example illustrated, openings 931 each have a shape corresponding to that of the piece to be received by the particular one of openings 931. As result, the shapes of the openings 931 intuitively identify which piece goes in which opening.

[0163]In the illustrated example, opening 931-1, 931-2, 931-3, 931-4 and 931-5 are each sized and shaped to receive correspondingly shaped and slightly proportionally smaller sized supplemental pieces 933-1, 933-2, 933-3, 923-4 and 933-5, respectively. In the example illustrated, sheet 704 may include an additional piece identification marking 939 which is printed, scored upon or otherwise provided on the face of sheet 704 proximate to opening 931-5. In the example illustrated, the piece 933-5 includes a corresponding marking 941 printed, scored upon otherwise provided on the face of piece 933-5. As should be appreciated, the other openings 931 and pieces 933 may include similar corresponding pairs of markings to assist in identifying which piece goes in which opening. As should be appreciated, each of the openings in each of the pieces may have a variety of different sizes, shapes, locations and configurations other than the examples being illustrated.

[0164]In the example illustrated, openings 931-1 and 931-2 are located on template 704′ such that when template 704′ is aligned with and positioned on top of sheet 704 (such as with edge-to edge alignment or alignment of template 704′ with particular markings provided on sheet 704), openings 931-1 and 931-2 overlie folded layers 924-1 and 924-2, respectively. As a result, the placed pieces 933-1 and 933-2 will also overlie and extend across and beyond the side edges of folded layers 924-1 and 924-2. The additional pieces 933-1 and 933-2 provide enhanced stiffness and enhanced weight at their respective locations in the subsequently rolled tube and in the subsequently formed racquet. In some implementations, the openings 931-1, 931-2 and their associated pieces 933-1 and 933-2 may be sized smaller than the underlying folded layers 924-1, 924-2 so as to not extend beyond edges of folded layers 924-1, 924-2.

[0165]In the example illustrated, openings 931-4 and 931-5 are located on template 704′ such that when template 704′ is aligned with and positioned on top of sheet 704 (as shown) (such as with edge-to edge alignment or alignment of template 704′ with particular markings provided on sheet 704), openings 931-3 and 931-4 overlie and bridge across the openings 997 formed by folded layers 924-3 and 924-4, respectively. As a result, by folding portions to create an opening and then laying completely new or different pieces in such openings, completely different material properties may be provided by the supplemental pieces in such particular locations. In the example illustrated, opening 931-5 is located on template 704′ such that when template 704′ is aligned with and positioned on top of sheet 704 (as shown) (such as with edge-to edge alignment or alignment of template 704′ with particular markings provided on sheet 704), opening 931-5 overlies an unfolded or blank region of sheet 704. The piece 933-5 may then be positioned within the window opening 931-5. As a result, the weight or stiffness properties for the particular portions of the racquet corresponding to location of opening 931-5 may be increased. As noted above, following placement of pieces 933, template 704′ the way, leaving the pieces 933 in place on sheet 704, wherein sheet 704 is then subsequently rolled.

[0166]Although template 704′ is described as being overlaid upon sheet 704 that has folded layers, in some implementations, template 704′ may be laid upon a sheet lacking folded layers. Although template 704′ is described as being overlaid upon sheet 704 having markings 926, 928, in other implementations, template 704′ may be laid

[0167]upon a sheet lacking such markings 926, 928. In some implementations, rather than sheet 704 having markings 926, an overlying template, such as template 704′, may include piece designating openings for each of the pieces to be added or placed upon sheet 704. In some implementations, where the sheet 704 is to include folded layers, the template 704′ may include slits for guiding a blade or knife as well as indicating where cuts (such as cut lines 940, cut lines 950, cut lines 960, cut lines 970) are to be made in the underlying sheet 704 to facilitate subsequent folding form the folded layers are to form openings such as openings 906. In some implementations, the cut lines may be formed by a die or die cutter which concurrently cuts each of the cut lines.

[0168]FIGS. 28-30 illustrate the forming of an example rolled fiber composite tube which may then be shaped and molded to form a sports racquet, such as the tennis racquet 10 described above. FIGS. 28-30 illustrate an example where the rolled tube used to form a sports racquet is formed from a fiber composite sheet without the use of discrete fiber composite or non-fiber composite pieces. FIG. 28 illustrates an example fiber composite sheet 1004 with cuts forming various portions which are to be folded so as to form folded layers. FIG. 29 illustrates the fiber composite sheet 1004 after the cut portions are folded to form folded layers. Once such portions are folded, the fiber composite sheet 1004 is configured to be rolled about a centerline, such as a centerline of mandrel 330, to form a rolled tube shown in FIG. 30 which may then be flattened, shaped and molded as shown in FIG. 7-10. As further shown by FIG. 28, in some implementations, the mandrel 330 may be received within the bladder 332.

[0169]In the example illustrated, sheet 1004 comprises interior portions 1043-1, 1043-2 (collectively referred to as portions 1043), interior portions 1045-1, 1045-2 (collectively referred to as portions 1045) and interior portions 1047-1 and 1047-2 (collectively referred to as portions 1047). Each of such portions is cut on three sides with the fourth side uncut for forming folds about which such portions 1043, 1045 and 1047 are to be folded prior to rolling of sheet 1004 about the illustrated example

[0170]mandrel 330 and enclosing bladder 332. In some implementations, such cuts may be formed by a CNC cutting table or machine. In other implementations, the cuts of sheet 1004 can be made through other conventional means.

[0171]Portions 1043 mirror one another on opposite sides of a center 990 of sheet 1004 which corresponds to the longitudinal center point of the rolled tube be performed. As with the example shown in FIG. 28, the center 990 also corresponds to the apex 989 of the racquet 10 shown in FIG. 1. As indicated by arrows 1063 in FIG. 28 and shown in FIG. 29, portions 1043 are folded away from one another outwardly and away from centerline 990 to form folded layers 1063-1 and 1063-2 (collectively referred to as layers 1063) and apertures 1073-1 and 1073-2 (collectively referred to as apertures 1073), respectively. Such folded layers 1063 are at locations along the axial length of tube 1090 that when shaped into the frame of racquet 10, correspond to the 3 o'clock and 9 o'clock positions 991 and 992 of racquet 10 shown in FIG. 1. Folded layers 1063 provide racquet 10 with perimeter weighting.

[0172]Portions 1045 mirror one another and opposite sides of center 990 and are at locations so as to form folded layers 1065-1, 1065-2 (collectively referred to as layers 1065) and apertures 1075-1, 1075-2 (collectively referred to as apertures 1075) as shown in FIG. 29. Folded layers 1063 are locations corresponding to handle portion 20 of racquet 10 will apertures 165 are locations correspond to throat portions 22 of racquet 10.

[0173]Portions 1047 mirror one another on opposite sides of center 990 and are locations so as to form folded layers 1073-1, 1073-2 (collectively referred to as layers 1067) and apertures 1077-1 and 1077-2 (collectively referred to as apertures 1077), respectively, as shown in FIG. 29. Folded layers 1073 are at locations along the axial length of the rolled tube 1090 that when shaped, form handle portion 20 of racquet 10.

[0174]As shown by FIG. 28 the endpoints of the cuts forming portions 1043, 1045 and 1047 are longitudinally or horizontally offset such that each of the folded layers 1053, 1063 and 1073 are connected to the remainder of sheet 1004 along folds that are oblique to the longitudinal centerline of sheet 1004 and the axis 331 of mandrel 330 when sheet 1004 is rolled about mandrel 330. As result, the folded layers 1053, 1063 1073 are also oblique to axis 331 such that the folded layers have different fiber angles or polarities as compared to those portions of sheet 1004 which are not folded prior to being rolled. As with the above examples, once the sheet 1004 has been rolled about mandrel 330, mandrel 330 may be removed and the rolled tube formed by sheet 1004 may be shaped and molded as described above with respect to FIGS. 7-10.

[0175]The method described above of making discrete cuts in a sheet 1004 of fiber composite material before it is molded and cured, and then folding over portions of the sheet 1004 (folded layers 1053, 1063 and 1073) before applying the sheet to a mandrel and curing the fiber composite material provides an exceptionally efficient and cost-effective manner for making a fiber composite sports racquet. The cutting and folding of the folded layers 1053, 1063 and 1073 about the sheet 1004 allows for a great deal of design flexibility in designing a fiber composite racquet. The method also allows for material to be readily and consistently positioned at desired locations within the sports racquet construction. The method significantly reduces the likelihood of human error and inconsistencies in sports racquet production. The cuts can be made in a very consistent, fast and reliable manner, and the folding over of specific folded layers in specific directions also provides for a fast, consistent and reliable manner of producing a sports racquet. The method reduces the time to produce the sports racquet, and it significantly increases the accuracy and consistency of the sports racquet production. Sports racquet frames produced in accordance with the present invention allow for racquets to be produced within very tight specification and tolerances. The above-described method enables fiber composite sports racquet frames to be consistently produced within very tight specifications and tolerances, as low as plus or minus 1 gram as opposed to plus or minus 5-10 grams of many conventional racquet designs. The present method of producing a sports racquet also enables a sports racquet to be consistently produced in a significantly lower amount of time, thus allowing more racquets to be produced in a specific amount of time, at less cost and with fewer inaccuracies.

[0176]FIGS. 25-30 illustrate examples where a single fiber composite sheet is

[0177]rolled body centerline or rolled the body mandrel. FIG. 31 illustrates an example where a plurality of composite fiber sheet may be rolled about a centerline or about mandrel 330, one on the top of the other. Each of such sheets may be rolled so as to wrap or extend at least 720° about the centerline or mandrel. FIG. 31 illustrates an example where the fiber composite sheet 704 described above with respect to FIG. 25 is divided into two sheets, sheet 704-1 and 704-2. In such an implementation, pieces 920 and 922 may additionally be provided as shown in FIG. 25 or may be omitted. Such sheets 704-1 and 704-2 may be sequentially rolled about mandrel 330 (and bladder 332). In some implementations, sheet 704 may first be rolled about mandrel 330 followed by sheet 702. In other implementations, this order may be reversed. In yet other implementations, more than two fiber composite sheets having folded layers and/or pieces may be rolled about a centerline or about mandrel 330.

[0178]FIG. 32 further illustrates one example of how one or more sheets 304, 404, 704 or 1004 may be rolled about a centerline or rolled about mandrel 330. In some implementations, mandrel 330 may be releasably connected to a rotary actuator 1200 which rotates mandrel 330. Portions of the first sheet to be rolled about mandrel 330 may be secured to an exterior of mandrel 330 prior to and at the start of such rolling.

[0179]FIG. 32 is a schematic diagram illustrating another example method by which sheets 304, 404, 704 or 1004 may be rolled about a centerline or rolled about mandrel 330. FIG. 32 schematically illustrates a table roller which comprises a table 1202, and roller 1204. As shown by FIG. 32, mandrel 330 and the closing bladder 332 with the sheet 304, 404, 704, 1004 partially rolled about mandrel 330 are positioned between table 1200 and roller 1204. Roller 1204 is lowered to apply pressure to a top of mandrel 330 and is moved in the direction indicated by arrow 1208. During such time, mandrel 330 is rolled about its axis 331 in the direction indicated by arrow 1209. In implementations where the travel of roller 1204 is insufficient to fully roll the sheet about mandrel 330, table 1202 may be lifted as indicated by arrow 1210, retracted as indicated by arrow 1212 and once again lowered as indicated by arrow 12 14, wherein the cycle is repeated. In some implementations, table 1200 may concurrently move relative to roller 1204. For example, roller 1204 may be moved in the direction indicated by arrow 1208 while table 1202 may concurrently move in the direction indicated by arrow 1216. Once table 1202 is moved through its full travel distance, table 1202 may be lowered, retracted in the direction indicated by arrow 1208 and raised before repeating the cycle.

[0180]Although each of the above examples are described in the context of rolling a sheet to form a tube that is shaped and molded to form a head portion, through portion and handle portion of a tennis racquet, such as tennis racquet 10 described above, in other implementations, each of the above-described methods may likewise be utilized to form lesser extents of a sport racquet or lesser extents of a tennis racquet. In such implementations, the axial length of the tube formed by the rolled sheet is shorter, wherein those portions of the sports racquet or tennis racquet not formed by the shaped and molded tube or separately formed and attached to that portion of the sports racquet formed by the rolled and shaped tube.

[0181]FIG. 33 is an exploded view of an example tennis racquet 1310. Tennis racquet 1310 is similar to tennis racquet 10 except that the tube formed from the rolled sheet that is used to form head portion 18 and throat portion 22 is not used to form handle portion 20. In such an implementation, the axial length of the tube formed from the rolled sheet is shorter, being of sufficient length to form head portion 18 and throat portion 22, wherein the yoke 350 is added during the molding step as described above. In such an implementation, handle portion 20 is separately formed and is secured to throat portion 22 by adhesive, welds, fasteners and the like.

[0182]FIG. 34 is an exploded view of an example tennis racquet 1410. Tennis racquet 1410 is similar to tennis racquet 10 except that the tube formed from the rolled sheet that is used to form head portion 18 is not used to form throat portion 22 or handle portion 20. In such an implementation, the axial length of the tube formed from the rolled sheet is shorter, being of sufficient length to form head portion 18. In some implementations, the end portions of the tube formed from the rolled sheet come together to form a complete hoop, forming the complete string bed four tennis racquet 1410. In such an implementation, the additional yoke piece may be omitted. In other implementations, the end portion of the tube formed by the rolled sheet remain separated (having a generally U-shaped, wherein the racquet head interior or string bed is completed by the addition of a yoke piece, such as yoke 350 described above. In such an implementation, throat portion 22 and handle portion 20 is separately formed and is secured to the hoop or head portion 18 by adhesive, welds, fasteners and the like.

[0183]Although each of the above examples specifically illustrates a tennis racquet having the above-described constructions and formed by the above-described methods, each of the above-described constructions and methods may be equally employed to form other sports racquets. FIGS. 35 and 36 illustrate an example racquet 1510 that has a different frame shape and that omits a string bed. FIG. 36 is a sectional view of the racquet 1510 shown in FIG. 35 taken along line 36-36. Racquet 1510 may be formed according to any of the above-described methods and have similar constructions as the tennis racquet 10 described above. In some implementations, racquet 1510 may be configured as a pickle ball racquet (sometimes also referred to as a pickle ball paddle). In some implementations, racquet 1510 may be configured as a padel racquet or a ping pong racquet. As shown by FIG. 35, racquet 1510 comprises a head portion 1518, a handle portion 1520 and a throat portion 1522.

[0184]Head portion 1518 provides a hitting surface racquet 1510. Handle portion 1020 provides an extension configured to be gripped by a player's hand. Throat portion extends between and connect head portion 1518 to handle portion 1520. The head portion 1518, the portion 1520 is throat portion 1522 are each formed by a shape and molded fiber composite tube 1590 formed by rolling at least one sheet 304, 404, 704 about a centerline or mandrel pursuant to any of methods 200, 400 or 600 as described above with respect to FIGS. 6-28.

[0185]In the example illustrated, racquet 1510 additionally comprises the yoke 350 which may be formed pursuant to any of the above describe methods. In other implementations, the yoke piece may be omitted. As should be evident, the molded fiber composite tube 1590 (having a rolled fiber composite sheet and/or a rolled nine fiber composite sheet carrying fiber composite pieces) may be molded/fused with a different shape to form the racquet 1510 as compared to racquet 10. Although head portion 1518, handle portion 1520 and the throat portion 5022 are each at least partially formed from the fiber composite tube, in other implementations, smaller extents of racquet 1510 may be formed from the fiber composite to similar to the tennis racquets 1310 and 1410 shown in FIGS. 33 and 34. In some implementations, the fiber composite tube 1590 forms just the head portion 1518 and the throat portion 1522, wherein the handle portion 1520 is separately formed and attached. In some implementations, the fiber composite tube 1590 form just the head portion 1518, wherein the handle portion 1520 and the throat portion 1522 are separately formed and attached.

[0186]As shown by FIGS. 35 and 36, the portion of tube 1590 forming head portion 1518 form a racquet head interior 1530. In contrast to tennis racquet 10 which comprises a string bed, racquet 1510 comprises a pair of covers, panels or faceplates 1532 extending across and spanning the racquet head opening 1530. Such faceplates 1532 and extend opposite to one another across tube 1590. In some implementations, faceplates 1532 are imperforate. In other implementations, faceplates 1532 are perforate. Such faceplates may be formed from a variety of different materials such as a polymer.

[0187]FIG. 37 is a sectional taken along line 36-36 illustrating an alternative construction of racquet 1510. As shown by FIG. 37, the racquet interior 1530 may be filled with a filler 1534. The filler may be in the form of one or more foam layers or one or more layers of different combinations of materials. In some implementations, the filler 1534 may comprise a honeycomb material. In some implementations, filler 1534 may comprise a solid material. In some implementations, filler 1534 is injected as a fluid into interior of racquet head opening 1530 before after the application faceplates 1532. In some implementations, filler 1534 comprises a solid panel (of one or more layers) that is secured within racquet head interior 1530 prior to the positioning of at least one of 15 plates 1532 across the racquet head opening 1530. In some implementations, one or both of faceplates 1532 may be omitted, wherein the filler 1534 provides a hitting surface within the racquet head opening.

[0188]FIG. 38 illustrates another example sports racquet 1610 which may be formed pursuant to may be formed according to any of the above-described methods and have similar constructions as the tennis racquet 10 described above. In the example illustrated, racquet 1610 omits the yoke 350. Similar to racquet 1510, racquet 1610 is formed by the molded fiber composite tube 1590 (having a rolled fiber composite sheet and/or a rolled nine fiber composite sheet carrying fiber composite pieces) may be molded/fused with a different shape to form the racquet 1610 as compared to racquet 1510. Although head portion 1518, handle portion 1520 and the throat portion 5022 are each at least partially formed from the fiber composite tube, in other implementations, smaller extents of racquet 1610 may be formed from the fiber composite to similar to the tennis racquets 1310 and 1410 shown in FIGS. 33 and 34. In some implementations, the fiber composite tube 1590 forms just the head portion 1618 and the throat portion 1622, wherein the handle portion 1620 is separately formed and attached. In some implementations, the fiber composite tube 1690 form just the head portion 1618, wherein the handle portion 1620 and the throat portion 1622 are separately formed and attached. As with racquet 1510, the tube 1590 forms a racquet head opening 1630. In the example illustrated, the filler 1534 fills the racquet head opening 1630 and provides a hitting surface. In other implementations, the head portion 1618 of racquet 1610 may comprise faceplates 1532 extending across the racquet head opening 1630 without filler 1534 or faceplates 1532 extending across and covering racquet head opening 1630 with filler 1534 sandwiched therebetween as shown in FIGS. 36 and 37, wherein the faceplates provide hitting surface for the racquet 1610.

[0418]Although the present disclosure has been described with reference to example implementations, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the claimed subject matter. For example, although different example implementations may have been described as including features providing benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example implementations or in other alternative implementations. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example implementations and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements. The terms “first”, “second”, “third” and so on in the claims merely distinguish different elements and, unless otherwise stated, are not to be specifically associated with a particular order or particular numbering of elements in the disclosure.