TOP STOP FOR SLIDE FASTENER CHAIN

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application is based on and claims priority under 35 USC §119 from Great Britain Patent Application No. 2417578.8 filed on November 29, 2024, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

[0002]The present application relates to a top stop for a slide fastener, a slide fastener chain including such top stop, and a slide fastener including such slide fastener chain.

BACKGROUND

[0003]Conventional slide fasteners (or zips or zippers) include a pair of stringers and an opening and closing means commonly referred to as a slider. Each stringer includes a tape and a plurality of coupling elements. The coupling elements extend along a first edge of each tape and when the slider of the slide fastener is moved to a closed position, corresponding coupling elements of the stringers interdigitate, couple or interlock. When each tape of the slide fastener is attached to separate portions of an article, the separate portions of the article may be releasably joined by closing the slide fastener by moving the slider to the closed position, and thereby bringing the coupling elements into above interdigitating relationship.

[0004]Slide fasteners are therefore both useful and versatile and are employed in a range of applications including garments, furnishings and luggage. The slide fasteners of the related art are generally constructed as follows.

[0005]A coupling portion, usually in the form of a plurality of coupling elements (also referred to as teeth) is attached to a first edge of a tape to form a stringer. This first edge may be referred to as the coupling edge of the stringer. The tape can be woven or knitted and may be formed from, for example, polyester. The coupling elements may be attached to the tape by, for example, crimping or molding the coupling elements onto a reinforced edge of the tape. In some cases, the reinforced end may include a cord, and the cord may be sewn or woven into the tape. Alternatively, the coupling elements may be formed as a continuous coil. In this case, the coupling elements are most commonly stitched to a surface of the tape at the edge of the tape or, alternatively, are woven or knitted into the tape.

[0006]Two stringers are brought together, such that the coupling elements of each stringer can attach to one another, for example, by interdigitating, to form a chain. The chain is generally planar, and the chain (and the coupling elements which form part of the chain) extends along a longitudinal axis of the chain. A slider is mounted to the chain onto coupling elements of each respective stringer such that the slider can move along the chain between the two stringers.

[0007]The slider commonly includes a main body having upper and lower blades through which the coupling elements of each stringer pass. A pull tab or pull cord is attached to the main body which may be grasped by a user in order to effectively move the slider along the chain. The main body includes a guide post (sometimes referred to as a diamond) which, in part, defines a Y-shaped channel which is configured to carry coupling elements of the first and second stringers. The slider can include upper flanges and lower flanges which are disposed on each of the right and left side edge parts of the upper and lower blades, that is, the edges of the slider substantially parallel to a direction of operation of the slider. The flanges provided on the upper blade protrude downwards and towards the lower blade and the flanges provided on the lower blade protrude upwards and towards the upper blade. The flanges are configured for a sliding engagement with the coupling elements.

[0008]Movement of the slider along the chain in a first sliding direction along an axis of operation of the slider causes the coupling elements of the first stringer to attach to the coupling elements of the second stringer. When the slider is no longer able to couple elements any further in the first sliding direction i.e. substantially all the coupling elements of the first stringer are attached to substantially all the coupling elements of the second stringer, the slide fastener may be regarded as being in a fully closed configuration. Movement of the slider along the chain in a second sliding direction, along the axis of operation of the slider, opposite to the first sliding direction, causes the coupling elements of the first stringer to detach from the coupling elements of the second stringer. When the slider is no longer able to uncouple elements any further in the second sliding direction i.e. substantially all the coupling elements of the first stringer are detached from the coupling elements of the second stringer, the slide fastener may be regarded as being in a fully open configuration.

[0009]The chain is cut to a desired length to form a desired length of slide fastener. Stops (often referred to as top stops and bottom stops) may be attached to either or both ends of the chain. The stops limit the extent of movement that the slider can undertake along the chain. It is usually the case that a top stop limits movement of the slider in the first sliding direction and a bottom stop limits movement of the slider in the second sliding direction. Typically, stops may be used in order to limit the movement of the slider along the chain. Typically, the slider is no longer able to couple or uncouple elements, or move, when the slider abuts on a stop of some variety, such as a bottom stop or a top stop. The top stop may be configured to abut on a top portion of the slider, for example a top edge of a flange provided on the slider main body, and may limit the travel of the slider in the first sliding direction. The bottom stop may be configured to abut on a bottom portion of the slider, for example a bottom edge of a flange provided on the main body of the slider, and may limit the travel of the slider in the second sliding direction. Stops may also be configured to abut on the upper or lower blades of the slider.

[0010]Some slide fasteners may have a single bottom stop which is attached to both the first and second stringers. Other slide fasteners, which may be referred to as separating slide fasteners, may have two separate bottom stops each attached to a corresponding each one of the stringers. The two bottom stops may take the respective forms of a retainer box and an insertion pin. The insertion pin can be inserted into the retainer box in order to interlink the first and second stringers with each other. Conversely, the insertion pin can be removed from the retainer box when the slider is located adjacent the retainer box in order to pass through the slider and to separate the first and second stringers from each other.

[0011]Some slide fasteners may have two separate top stops, each being attached to a corresponding one of the stringers. The stringers of such slide fasteners can be separated at a top end of the slide fastener when the slider is in an open position. Examples of use of such slide fasteners are in trousers, skirts and boots. Other slide fasteners may have a single top stop attached to both of the stringers. In such slide fasteners, when the slider is in an open position, an opening is created between the stringers (and, in particular, between i) the coupling elements of the first stringer and ii) the coupling elements of the second stringer). However, with the slider in the open position, the stringers remain connected i) at one end of the slide fastener, adjacent the diamond of the slider; and ii) at the other end of the slide fastener at the top stop.

[0012]In certain applications, it is desirable for a slide fastener to be fluid resistant, for example liquid and/or gas tight (i.e. for the slide fastener to substantially prevent the passage of liquid and/or gas through the slide fastener when the slide fastener is in a closed configuration). By further way of example, in some applications, it is desirable for a slide fastener to be watertight, or more specifically, for an article (for example, but not limited to, a garment) of which a watertight slide fastener forms a part to be watertight when the slide fastener is in a closed configuration.

[0013]In applications of slide fastener including a top stop in which the slide fastener is watertight when the slide fastener is in the closed configuration (i.e. when the slider of the slide fastener is in a closed, or fully closed, configuration), the top stop will be required to facilitate a watertight seal between the stringers (in particular the portions of the stringers which are not joined together by coupled coupling elements) and the slider.

[0014]It is desirable to provide a top stop suitable for a liquid or gas tight slide fastener and a slide fastener chain including a top stop which provides a desired degree of liquid or gas tightness whilst at the same time being relatively easy and cost-effective to manufacture. It is also desirable to provide an alternative design of top stop suitable for a liquid or gas tight slide fastener and a slide fastener chain including such a top stop.

SUMMARY

[0015]According to a first aspect of the present application, there is a top stop for a slide fastener, the top stop including: a main body from which first and second legs depend, the first and second legs being spaced from each other in a width direction, and the first and second legs defining a central space therebetween which lies on a central axis perpendicular to the width direction, and which is configured to receive a connection post of a slider when the slider is engaged with the top stop in a fully closed position, the first and second legs extending away from the main body in a direction which has a component that is in a first direction along the central axis. The first leg has a first outer surface which is inclined towards the central axis, and a first compression lug protrudes from a lug portion of the first outer surface. The second leg has a second outer surface which is inclined towards the central axis, and a second compression lug protrudes from a lug portion of the second outer surface. The first compression lug includes a first compression lug outer surface which contacts a portion of a first side flange of the slider, in an offset plane parallel to a central plane and containing the first compression lug, the second compression lug and the central axis, when the slider is in the fully closed position. The first compression lug outer surface when not in contact with the first side flange, has a profile in the offset plane, which differs to a profile of the portion of the first side flange in the offset plane. The second compression lug includes a second compression lug outer surface which contacts a portion of a second side flange of the slider in the offset plane, when the slider is in the fully closed position. The second compression lug outer surface when not in contact with the second side flange, has a profile in the offset plane, which differs to a profile of the portion of the second side flange in the offset plane.

[0016]The first and second compression lugs each have first and second portions, the first end being axially closer to the main body than the second end. A maximum distance of the first portion of the first compression lug extending perpendicular to the lug portion of the first outer surface is less than a maximum distance of the second portion of the first compression lug extending perpendicular to the lug portion of the first outer surface. A maximum distance of the first portion of the second compression lug extending perpendicular to the lug portion of the second outer surface is less than a maximum distance of the second portion of the second compression lug extending perpendicular to the lug portion of the second outer surface.

[0017]The first outer surface is linear along a first outer surface axis. The first compression lug has a linear first compression lug outer surface along a first compression lug outer surface axis. In the central plane which contains the first compression lug outer surface axis, the first outer surface axis and the central axis, the first compression lug outer surface axis and first outer surface axis diverge, moving along the central axis in the first direction, such that a point of intersection of the first compression lug outer surface axis and the first outer surface axis is located in a third direction from the first compression lug outer surface which has a component in a second direction opposite the first direction, along the central axis.

[0018]An angle subtended between the first compression lug outer surface axis and the first outer surface axis in the central plane is between 0.5 degrees and 10 degrees.

[0019]The second outer surface is linear along a second outer surface axis. The second compression lug has a linear second compression lug outer surface along a second compression lug outer surface axis. In the central plane which contains the second compression lug outer surface axis, the second outer surface axis and the central axis, the second compression lug outer surface axis and second outer surface axis diverge, moving along the central axis in the first direction, such that a point of intersection of the second compression lug outer surface axis and the second outer surface axis is located in a fourth direction from the second compression lug outer surface which has a component in the second direction along the central axis.

[0020]An angle subtended between the second compression lug outer surface axis and the second outer surface axis in the central plane is between 0.5 degrees and 10 degrees.

[0021]A center point of the main body lies on the central axis and meets the central space. A maximum axial distance between the center point and a tip of the first leg which is distal from the main body is between 2 and 8 times an axial length of the first compression lug.

[0022]A center point of the main body lies on the central axis and meets the central space. A maximum axial distance between the center point and a tip of the second leg which is distal from the main body is between 2 and 8 times an axial length of the second compression lug.

[0023]The first leg has a first inner surface and the second leg has a second inner surface, the first and second inner surfaces defining therebetween an opening to the central space, the opening lying on the central axis and being located in the first direction along the central axis from the central space. A portion of the first inner surface which defines the opening and a portion of the second inner surface which defines the opening diverge, relative to the central axis, moving along the central axis in the first direction.

[0024]In the central plane containing the portion of the first inner surface, the portion of the second inner surface and the central axis, the portion of the first inner surface and the portion of the second inner surface are linear, lying along a first inner surface axis and a second inner surface axis respectively.

[0025]An angle subtended between the first inner surface axis and second inner surface axis in the central plane is between about 0.5 degrees and about 10 degrees.

[0026]The top stop includes first and second outer skirts which protrude from the main body in the first direction. The first outer skirt and first leg define a first recess therebetween, configured to receive the first side flange of the slider. The second outer skirt and second leg define a second recess therebetween, configured to receive the second side flange of the slider.

[0027]A first end, distal to the main body, of each of the first and second outer skirts includes an inward protrusion which protrudes inwardly, towards the central axis, and which is configured to engage with each of the first and second side flanges of the slider.

[0028]According to a second aspect of the present application, a slide fastener chain includes: a first stringer including a first tape having a first row of coupling elements mounted on a first longitudinal edge of the first tape; and a second stringer including a second tape having a second row of coupling elements mounted on a second longitudinal edge of the second tape. The first row of the coupling elements is configured to be interdigitated with the second row of the coupling elements along a fastener axis in order to secure the first stringer and a second stringer together. The slide fastener chain further includes the top stop according to the first aspect of the present application. The main body of the top stop is mounted to both the first and second tapes. The first leg of the top stop is mounted to the first tape, such that an end of the first leg distal to the main body is adjacent a first coupling element of the first stringer. The second leg of the top stop is mounted to the second tape, such that an end of the second leg distal to the main body is adjacent a second coupling element of the second stringer. The central axis of the top stop is co-axial with the fastener axis.

[0029]The first leg of the top stop is fused with the first coupling element.

[0030]According to a third aspect of the present application, a slide fastener includes: the slide fastener chain according to the second aspect of the present application; and a slider movably mounted on the first and second stringers, such that the slider is movable relative to the first and second stringers along the fastener axis in a first sliding direction in order to interdigitate the first row of the coupling elements of the first stringer with the second row of the coupling elements of the second stringer in order to secure the first stringer and the second stringer together and in a second sliding direction, opposite the first sliding direction, in order to decouple the first row of the coupling elements of the first stringer from the second row of the coupling elements of the second stringer in order to decouple the first stringer and the second stringer. The top stop is configured to, when the slider is engaged with the top stop, provide a limit of movement of the slider along the fastener axis in the first sliding direction.

BRIEF DESCRIPTION OF DRAWINGS

[0031]FIG. 1 is a schematic plan view of portions of a slide fastener of a related art.

[0032]FIG. 2 is a schematic perspective view of a slide fastener slider of the related art.

[0033]FIG. 3 is a schematic perspective view of a portion of a slide fastener including a top stop according to an embodiment of the present invention, with the slider in a fully closed position.

[0034]FIG. 4 is a cross-sectional view of a portion of a slide fastener including a top stop according to an embodiment of the present invention, with the slider in a fully closed position.

[0035]FIG. 5 is a schematic cross-sectional view of the portion of the slide fastener shown in FIG. 4, but with the slider in an open position.

[0036]FIG. 6 is a schematic perspective view of the portion of the slide fastener shown in FIG. 3, but with the slider removed for clarity.

[0037]FIG. 7 is a schematic perspective view of the top stop shown as part of the slide fastener in FIGS. 3 to 6.

[0038]FIG. 8 is a plan view of the top stop shown as part of the slide fastener in FIGS. 3 to 6.

[0039]FIG. 9 is a side view of the top stop shown as part of the slide fastener in FIGS. 3 to 6.

[0040]FIG. 10 shows schematic cross-sectional views of a portion a slide fastener according to an embodiment of the invention, in which the upper view shows a configuration in which the slider is not contacting the top stop, and the lower view shows a configuration in which the slider is in the fully closed position.

DESCRIPTION OF EMBODIMENTS

[0041]FIG. 1 is a slide fastener 10 of a related art. The slide fastener 10 includes a slider 20 and a pair of stringers 12a, 12b. Each stringer includes a coupling portion in the form of a row of coupling elements 14a, 14b which are attached to an edge of a tape of each stringer. The edge to which the coupling elements are attached may be referred to as the coupling edge 16. The tape may be woven or knitted and may be formed from, for example, synthetic fibres such as polyester, vinylon or polyurethane and/or natural fibres such as cotton. The coupling elements 14a, 14b may be molded, as shown in FIG. 1, or crimped teeth (not shown) or formed as continuous coils with coil elements forming the coupling elements (again, not shown). In this embodiment, the tape of the stringer 12a, 12b may be provided with a reinforced edge including a cord (not shown), onto which the coupling elements 14a, 14b are attached. The presence of the reinforced edge on the stringers 12a, 12b is optional.

[0042]The tape of each stringer includes a first planar surface and a second planar surface opposite to the first planar surface. The first planar surface and the second planar surface join at the coupling edge 16 including the coupling elements 14a, 14b and the cord to which they are attached so that the coupling elements 14a, 14b encompass the coupling edge 16 of both the first planar surface and the second planar surface. The coupling elements 14a, 14b include a head potion 14c which is provided with an engagement section which allows engagement with at least one head portion 14c of an opposing coupling element of a cooperating stringer. The tape also includes an outer edge 17 which is opposite and parallel to the coupling edge 16.

[0043]The two stringers 12a, 12b are brought together, such that the row of coupling elements 14a, 14b of each stringer 12a, 12b can attach to each other, by interdigitating. The slide fastener chain 18 includes the two stringers 12a, 12b and extends along a longitudinal axis A of the slide fastener 10. This axis is also the axis of operation.

[0044]The slider 20 is attached to the slide fastener chain 18 such that the slider 20 can move along the rows of coupling element between the two stringers 12a, 12b. The slider 20 includes a slider body 21.

[0045]As seen best in FIG. 2, the slider 20 includes a main body 21, through which the coupling elements 14a, 14b of each stringer 12a, 12b pass, and a pull tab 25 attached to the main body 21 via a bridge portion 22. The pull tab 25 may be grasped by a user in order to effect movement of the slider 20 along the slide fastener chain 18 (for example, in the first and second sliding directions E, D as discussed in more detail further below).

[0046]In more detail, the main body 21 of the slider 20 includes an upper portion 26 connected to a lower portion 28 by a post (not shown) extending in a direction perpendicular to the longitudinal axis A of the slide fastener (in the present case, the connection post extends in a direction perpendicular to the plane of FIG. 1). The upper portion 26 may be referred to as an upper wing or an upper blade. Likewise, the lower portion 28 may be referred to as a lower wing or lower blade. The connection post may be referred to as the diamond.

[0047]The upper portion 26, lower portion 28 and connection post co-operate to define a Y-shaped channel within the slider. The Y-shaped channel is also defined by upper lateral flanges 26a and lower lateral flanges 28a on either side (which may be referred to as the left and right sides) of the slider 20 which extend towards each other from the upper portion 26 and lower portion 28 respectively. The lateral flanges extend along the left and right sides of the upper and lower portions in a direction which is generally parallel to the direction of sliding operation of the slider. In FIG. 2, only one of each of the upper lateral flanges 26a and lower lateral flanges 28a is visible. Another one of each of the upper lateral flanges and lower lateral flanges is provided on the reverse side of the slider which is not visible in the figure. The Y-shaped channel has a first arm separated from a second arm by the connection post.

[0048]The slider 20 extends in direction D, when mounted to the slide fastener chain 18, from a head end 27 of the slider to a tail end 29 of the slider 20. The Y-shaped channel also includes a third arm which adjoins the first and second arms in the vicinity of the tail end 29.

[0049]The first arm and second arm have respective first and second openings (not shown) interposing the connection post at the head end 27 of the slider 20. The third arm has a third opening 29a at the tail end 29 of the slider 20.

[0050]In order to engage or disengage the slide fastener 10, the row of coupling elements 14a of the first stringer 12a passes through the first opening of the first arm and along the first arm portion of the Y-shaped channel. Likewise, the row of coupling elements 14b of the second stringer 12b passes through the second opening of the second arm and along the second arm portion of the Y-shaped channel. Once the row of coupling elements 14a of the first stringer 12a and the row of coupling elements 14b of the second stringer 12b pass the connection post, the row of coupling elements 14a of the first stringer 12a comes into releasably coupled contact with the row of coupling elements 14b of the second stringer 12b. The coupled coupling elements 14a and coupling elements 14b pass through the third arm portion of the Y shaped channel and through the third opening 29a.

[0051]In order to allow the slider 20 to move along the first and second stringers 12a, 12b (and hence along the rows of coupling elements 14a and 14b), there is an insertion gap 23 between the each opposing upper flange 26a and lower flange 26b. Each insertion gap 23 receives the tape of a respective stringer 12a, 12b.

[0052]Using a slider 20 having the above mentioned structure enables the smooth coupling and separating of the rows of coupling elements 14a, 14b of the first and second stringers 12a, 12b.

[0053]Movement of the slider 20 along the rows of coupling elements 14a, 14b in a first sliding direction E causes the coupling elements 14a of the first stringer 12a to attach or couple to the coupling elements 14b of the second stringer 12b. Movement of the slider along the slide fastener chain in a second sliding direction D, opposite to the first sliding direction E, causes the coupling elements 14a of the first stringer 12a to detach from the coupling elements 14b of the second stringer 12b. Attached coupling elements are also coupled coupling elements, engaged coupling elements or paired coupling elements. The process of attaching coupling elements is also referred as coupling, engaging or pairing.

[0054]Top stops 30 and 40 are provided at the top end 18a of the coupling elements rows 14a, 14b. The top stops may be formed from any suitable material, for example, they may include a polymer material such as polyester, polyacethal, or polyethylene, or they may be metal based, such as aluminium, nickel or the like, or alloys of such metals.

[0055]A retainer box 11 is provided at the bottom end 18b of the row of coupling elements 14a, 14b, into which an insertion pin 15 can be inserted in order to interlink the first and second stringers 12a, 12b. A box pin 13 provided on stringer 12a may be permanently fixed into the retainer box, therefore insertion pin 15 may be removed from the retainer box 11 when the slider 20 is located adjacent the retainer box 11, in order to pass through the slider 20 and separate the first and second stringers 12a, 12b from each other. The stringers 12a, 12b can therefore be separated. When the stringers 12a, 12b are separated, the slider 20 is retained on the stringer 12a to which the retainer box 11 is attached. The slide fastener 10 is therefore an example of an open ended slide fastener.

[0056]Although the example of slide fastener discussed above is an open ended slide fastener, the present invention relates to a top stop which is attached to both stringers 12a and 12b, which may be referred to as a closed ended slide fastener.

[0057]The top stop of the present invention is attached to the coupling edge of each stringer. The coupling edges may include a cord (or reinforced edge).

[0058]The top stop of the present invention may be integrally injected onto the fastener tapes of the stringers by injection molding.

[0059]FIGS. 3, 4, 5 and 6 show portions of a slide fastener including portions of a slide fastener chain according to the present invention and a top stop 50 according to the present invention.

[0060]FIGS. 3, 4 and 5 show the top stop 50 in combination with a slider 20. FIG. 6 shows the portion of the slider chain and slide fastener with the top stop 50 but without the slider.

[0061]FIGS. 7, 8 and 9 show the top stop of FIGS. 3 to 6 in isolation.

[0062]As seen best in FIG. 3, the slide fastener 110 includes stringers 112a and 112b having respective rows of coupling elements 114a and 114b. The slide fastener 110 operates in the same manner as the related slide fastener in which the slider 20 is moved along the stringers 112a, 112b in order to couple and decouple the rows of coupling elements 114a and 114b. As such, for the sake of brevity, details of the operation of slide fastener 110 are not repeated here.

[0063]Referring now to FIGS. 5, 6, 7, 8 and 9, details of a top stop 50 according to an embodiment of the invention are now discussed.

[0064]The top stop 50 includes a main body 52 from which first and second legs 54, 56 depend. The first and second legs 54, 56 are spaced from each other in a width direction W. The first leg 54 and second leg 56 define a central space 58 between them which lies on a central axis A. The central axis A is perpendicular to the width direction W.

[0065]The central space 58 is configured to receive a diamond (or connection post 59) of the slider 20 when the slider 20 is engaged with the top stop 50 in a fully closed position. The slider 20 is shown in the fully closed position in FIG. 4.

[0066]The first and second legs 54, 56 extend away from the main body 52 in a direction which has a component, that is in a first direction D along the central axis A. In particular, as shown in FIG. 8, the first leg 54 extends in direction 54A which has a component in the first direction D. In the present embodiment direction 54A also has a component that is parallel to the width direction W and to the left as shown in FIG. 8, i.e. towards the central axis A. The second leg 56 extends in a direction 56A which has a component that is in the first direction D. In the present embodiment direction 56A also has a component which extends parallel to the width direction W and to the right as shown in FIG. 8, i.e. towards the central axis A.

[0067]The first leg 54 has a first outer surface 54a which is inclined from the main body 52 towards the central axis A. A first compression lug 60 protrudes from a lug portion 54b of the first outer surface 54a.

[0068]The second leg 56 has a second outer surface 56a which is inclined from the main body 52 towards the central axis A. A second compression lug 62 protrudes from a lug portion 56b of the second outer surface 56a.

[0069]The first compression lug 60 includes a first compression lug outer surface 60a which, in use, in an offset plane OP, which is parallel to a central plane CP which contains the first compression lug 60, the second compression lug 62 and the central axis A, contacts a portion of a first side flange 26a of the slider 20 when the slider 20 is in the fully closed position (as shown in FIG. 4).

[0070]As previously mentioned, the central plane CP contains the first compression lug 60, second compression lug 62 and central axis A. As seen best in FIG. 9, the central plane CP extends through the center of the top stop 50 with regard to a height of the top stop 50 when measured in a height direction H, which is perpendicular to both the central axis A and width direction W. Again, as best shown in FIG. 9, the offset plane OP is parallel to and offset from the central plane CP. In particular, the central plane CP and offset plane OP are both perpendicular to the height direction H and the offset plane OP is spaced from the central plane CP in the height direction H.

[0071]The first compression lug outer surface 60a, when not in contact with the first side flange 26a, has a profile in the offset plane which differs to the profile in the offset plane of the portion of the first side flange 26a.

[0072]The second compression lug 62 includes a second compression lug outer surface 62a. When in use the second compression lug outer surface 62a contacts a portion of a second side flange 26a’ of the slider 20, the slider 20 is in the fully closed position (as shown in FIG. 4). When the second compression lug outer surface 62a is not in contact with the second side flange 26a’, the second compression lug outer surface 62a has a profile in the offset plane which differs to the profile, in the offset plane, of the portion of the second side flange 26a’.

[0073]In order to aid the understanding of the concept of the relative profiles of the side flanges and outer surfaces of the compression lugs, we will now discuss this with reference to FIG. 10.

[0074]FIG. 10 shows two separate schematic views of a portion of the top stop and a portion of the slider. The schematic views are both shown in the offset plane. The upper view within FIG. 10 shows portions of the first and second legs 54, 56 of the top stop, in particular, the outer surfaces 54a, 56a and the first and second compression lugs 60, 62.

[0075]The lower view of FIG. 10 shows inner surfaces of each of the first and second side flanges 26a, 26a’ when the slider is in the fully closed position. The upper view of FIG. 10 shows the top stop when the slider is not in the fully closed position, i.e. when it is located along the stringers of the slide fastener at a position remote from the top stop. In order to aid comparison between the upper and lower views of FIG. 10, within the upper view of FIG. 10, dashed lines DL1 and DL2 indicate the position of the inner surfaces of the first and second side flanges 26a and 26a’ respectively when the slider is in the fully closed position.

[0076]In order to explain the differences between the profile of the outer surfaces of the compression lugs and that of the inner surfaces of the side flanges, given that the figure is schematic, the profiles of the outer surfaces of the compression lugs have been exaggerated so as to enhance clarity.

[0077]As previously discussed, in the offset plane, the portion of the first side flange which contacts the first compression lug outer surface when the slider is in the fully closed position differs from the profile of the first compression lug outer surface 60a when the slider is not in the fully closed position. Referring now to FIG. 10, the lower view of FIG. 10 shows the slider in the fully closed position such that the first side flange 26a of the slider contacts the first compression lug outer surface 60a. It can be seen that when the slider is in the fully closed position and the first side flange 26a contacts the first compression lug outer surface 60a, the slider compresses the top stop such that the first compression lug outer surface 60a generally conforms to the profile of the inner surface of the first side flange 26a of the slider. The portion of the first side flange 26a (and in particular the inner surface of the first side flange 26a) which contacts the first compression lug outer surface 60a when the slider is in the fully closed position is shown in the figure bounded between the dashed lines indicated by p26a.

[0078]The upper view of FIG. 10 shows a view in which the slider is not in the fully closed position. In order to aid comparison between the profiles of the portion of the inner surface of the first side flange 26a which contacts the first compression lug outer surface 60a when the slider is in the fully closed position, and that of the first compression lug outer surface 60a when the slider is not in the fully closed position, the dashed line DL1 shows the position of inner surface of the first side flange of the slider when in the fully closed position and the portion of the inner surface of the first side flange which is contacted by the first compression lug outer surface 60a when the slider is in the fully closed position is bounded between the dashed lines p26a.

[0079]Considering the upper view of FIG. 10, it can readily be observed that the profile of the first compression lug outer surface 60a when the slider is not in the fully closed position (i.e. when the slider does not contact the top stop), differs from the profile of the portion of the inner surface of the first side flange 26a which is contacted by the first compression lug outer surface 60a when the slider is in the fully closed position. In particular, in the present example, an acute angle subtended between the profile of the first compression lug outer surface when it has not been contacted by the slider and the longitudinal axis of the slide fastener is less than an acute angle subtended between the profile of the portion of the inner surface of the first side flange 26a of the slider which is contacted by the first compression lug outer surface 60a when the slider is in the fully closed position and the longitudinal axis of the slide fastener.

[0080]Whilst the relationship in the offset plane between the profile of the first compression lug outer surface when the slider is not in the fully closed position and the profile of the portion of the surface of the first side flange of the slider contacted by the first compression lug outer surface when the slider is in the fully closed position has been discussed, the equivalent is also true of the profiles of the second compression lug outer surface 62a when the slider is not in the fully closed position and the portion of the inner surface of the second side flange of the slider which contacts the second compression lug outer surface when the slider is in the fully closed position.

[0081]In particular, as already discussed, in the offset plane, the profile of the portion (indicated between dashed lines p26a’) of the second side flange 26a’ (and, in particular, the portion of the inner surface of the second side flange 26a’) which contacts the second compression lug outer surface 62a of the second compression lug 62 has a profile which differs to the profile of the second compression lug outer surface 62a when the slider is not in the fully closed position (i.e. when the slider is not contacting the top stop). Furthermore, in the present example, an acute angle subtended between the profile, in the offset plane, of the second compression lug outer surface 62a and the longitudinal axis of the slide fastener is less than an acute angle subtended between the profile of the portion of the inner surface of the second side flange 26a’ which contacts the second compression lug outer surface 62a when the slider is in the fully closed position and the longitudinal axis of the slide fastener.

[0082]With continuing reference to the upper view of FIG. 10, the first and second compression lugs 60, 62 each include respective first portions 60b, 62b and respective second portions 60c, 62c. The first portions 60b, 62b of the compression lugs 60, 62 are axially closer (i.e. in terms of distance measured along the central axis A) to the main body 52 of the top stop 50 than the second ends 60c, 62c of the compression lugs 60, 62. A maximum distance the first portion 60b of the first compression lug 60 extending perpendicular to the lug portion 54b of the first outer surface 54a is less than a maximum distance of the second portion 60c of the first compression lug 60 extending perpendicular to the lug portion 54b of the first outer surface 54a.

[0083]In a similar manner, the maximum distance of the first portion 62b of the second compression lug 62 extending perpendicular to the lug portion 56b of the second outer surface 56a is less than a maximum distance of the second portion 62c of the second compression lug 62 extending perpendicular to the lug portion 56b of the second outer surface 56a.

[0084]Where reference is made to the lug portion of the first and second outer surfaces, what is meant is the portion of the relevant surface which is adjacent to the relevant compression lug and which is therefore a portion of the respective outer surface which does not include the relevant compression lug. In the present embodiment, the lug portion of the relevant outer surface may be considered to be a portion of the outer surface which is just above or below the relevant compression lug in the height direction H.

[0085]In an alternative embodiment, not shown in the figures, the maximum distance of the first position of the first compression lug extending perpendicular to the lug portion of the first outer surface is greater than a maximum distance of the second portion of the first compression lug extending perpendicular to the lug portion of the first outer surface. Likewise, the maximum distance of the first portion of the second compression lug extending perpendicular to the lug portion of the second outer surface is greater than a maximum distance of the second portion of the second compression lug extending perpendicular to the lug portion of the second outer surface.

[0086]As shown in FIG. 8, the first outer surface 54a is generally linear along a first outer surface linear 54B and the first compression lug 60 has a generally linear first compression lug outer surface 60a which extends along a first compression lug outer surface axis 60A.

[0087]In the central plane CP, which contains the first compression lug outer surface axis 60A, the first outer surface axis 54B and the central axis A, the first compression lug outer surface axis 60A and first outer surface axis 54B diverge from one another moving along the central axis A in the first direction D such that the point of intersection I1 of the first compression lug outer surface axis 60A and the first outer surface axis 54B is located in a third direction (in this case extending along the first compression lug outer surface axis 60A) from the first compression lug outer surface 60a. The third direction (i.e. the direction extending along the first compression lug outer surface axis 60A) has a component in a second direction E, opposite the first direction D, along the central axis A. For completeness, in the present example, the third direction also has a component extending perpendicularly away from the central axis A (i.e. to the right in FIG. 8).

[0088]In the present example, the angle subtended between the first compression lug outer surface axis 60A and the first outer surface axis 54B in the central plane CP is approximately 2°. In other embodiments, the angle subtended between the first compression lug outer surface axis and the first outer surface axis may be any appropriate angle, for example, it may be between 1° and about 3° or it may be between about 0.5° and 10°.

[0089]The second outer surface is generally linear along a second outer surface axis 56B. The second compression lug 62 has a generally linear second compression lug outer surface 62a which extends along a second compression outer surface axis 62A. In the central plane CP, which contains the second compression lug outer surface axis 62A, the second outer surface axis 56B and the central axis A, the second compression lug outer surface axis 62A and the second outer surface axis 56B diverge, moving along the central axis A in the first direction D. This divergence is such that the point of intersection I2 of the second compression lug outer surface axis 62A and the second outer surface axis 56B is located in a fourth direction (in this case along the second compression lug outer surface axis 62A) from the second compression lug outer surface 62a, which has a component in the second direction E along the central axis A. For completeness, the fourth direction also has a component in a direction perpendicular to and away from the central axis A (i.e. to the left as shown in FIG. 8).

[0090]In the present example, the angle subtended between the second compression lug outer surface axis 62A and the second outer surface axis 56B in the central plane CP is about 2°. This angle may be any appropriate angle, for example, the angle may be between about 1° and about 3° or between about 0.5° and about 10°.

[0091]It is worth noting that in the present example, given that the angle subtended between the first compression lug outer surface axis and the first outer surface axis; and between the second compression lug outer surface axis and the second outer surface axis is only about 2°, the difference between the profiles of the first compression lug outer surface and relevant portion of the first side flange, and between the profiles of the second compression lug outer surface and relevant portion of the second side flange, is relatively subtle. This is intended and such subtle differences in profile are within the scope of the invention. What is important is not the extent to which the relevant profiles are different, but, rather that the top stop, and in particular the compression lugs of the top stop, have been specifically designed such that the profile of the outer surfaces of the compression lugs differs from that of the portion of the slider side flange which the relevant outer surface of the compression lugs contacts.

[0092]In the presently discussed example, i) the first compression lug outer surface axis and first outer surface axis, and ii) the second compression lug outer surface axis and second outer surface axis, each diverge so that their respective intersection points are located, in relation to the relevant compression lug outer surface, in a direction which has a component in the second direction E along the central axis A. In other embodiments, the divergence of the relevant axes may be such that the relevant points of intersection are such that the third direction from the first compression lug outer surface has a component in the first direction D along the central axis A, and the fourth direction from the second compression lug outer surface has a component in the first direction D along the central axis A.

[0093]Referring to FIG. 8, there is shown a center point 70 of the main body 52 which lies on the central axis A and meets the central space 58. A maximum axial distance (i.e. distance measured along the central axis A) between the center point 70 and a tip 54c of the first leg 54 which is distal from the main body 52 in the present example is approximately 4.5 times an axial length (i.e. length measured along the axis A) of the first compression lug 60. In other embodiments, a maximum axial distance between the center point 70 and the tip 54c of the first leg 54 may be between about 2 and 8 times an axial length of the first compression lug 60. The maximum axial distance between the center point 70 and tip 54c of the first leg 54 is annotated on FIG. 8 as 54L. Likewise the axial length of the first compression lug 60 is annotated on FIG. 9 as 60L. Referring to FIG. 9, the axial length 60L is annotated as being the axial length of the entirety of the first compression lug 60. Alternatively, the axial length of the first compression lug may be measured as the axial length of the linear portion of the compression lug outer surface.

[0094]A maximum axial distance between the center point 70 and a tip 56c of the second leg 56 which is distal from the main body 52 in the present example is approximately 4.5 times an axial length of the second compression lug 62. In other embodiments, a maximum axial distance between the center point 70 and the tip 56c of the second leg 56 may be between 2 and 8 times an axial length of the second compression lug 62. The maximum axial distance between the center point and the tip of the second leg 56 is annotated on FIG. 8 as 56L. It will be appreciated that in the present example, the axial length of the second compression lug 62 is equivalent to the axial length 60L of the first compression lug 60. In fact, the first and second compression lugs are identical mirror images of one another.

[0095]As discussed in relation to the first compression lug, the axial length of the second compression lug may be an axial length of the entirety of the second compression lug which protrudes from the second leg 56 or it may be the axial length of the linear portion of the second compression lug outer surface.

[0096]Referring now to FIG. 5, the first leg 54 of the top stop 50 has a first inner surface 54d. The second leg 56 has a second inner surface 56d. The first and second inner surfaces 54d, 56d generally face the central axis A and define between them an opening 58a to the central space 58. The opening 58a lies on the central axis A and is located in the first direction D along the central axis A from the central space 58. The opening 58a is the portion via which the connection post 59 enters the central space 58 when the slider moves to the fully closed position.

[0097]A portion of the first inner surface 54d which defines the opening 58a and a portion of the second inner surface 56d which defines the opening 58a diverge, relative to the central axis A, moving along the central axis A in the first direction D.

[0098]In more detail, in the central plane CP, which contains the portion of the first inner surface 54d and the portion of the second inner surface 56d and the central axis A, the portion of the first inner surface which diverges and the portion of the second inner surface which diverges are linear and lie along a first inner surface axis 54C and second inner surface axis 56C, respectively. In the present example, the angle subtended between each of the first inner surface axis 54C and the second inner surface axis 56C and the central plane is about 2°. In other embodiments, the angle may be any appropriate angle. For example, it may be between about 1° and about 3° or it might be between about 0.5° and about 10°.

[0099]With continued reference to FIG. 5, the top stop 50 includes first and second outer skirts 80, 82 which protrude from the main body 52 in the first direction D. The first outer skirt 80 and first leg 54 define a first recess 80a therebetween which is configured to receive a first flange 26a of the slider 20 when the slider is in the fully closed position. The second outer skirt 82 and second leg 56 define a second recess 82a therebetween configured to receive a second flange 26a’ of the slider 20 when the slider is in the fully closed position.

[0100]A first end, distal to the main body 52, of each of the first and second outer skirts 80, 82 includes an inward protrusion 80b, 82b which protrudes inwardly, towards the central axis A (and towards the first and second legs 54, 56). The inward protrusions 80b, 82b are configured to engage with respective flanges 26a, 26a’ of the slider 20 when the slider is in the fully closed position.

[0101]As previously discussed, a top stop according to the present invention may be mounted to first and second stringers to form a slide fastener chain according to the present invention. In particular, the top stop 50 may be mounted to the first and second stringers such that the main body 52 of the top stop is mounted to both the first tape of the first stringer and the second tape of the second stringer. This can be seen clearly with reference to FIG. 3.

[0102]With reference to FIG. 6, the first leg 54 of the top stop is mounted to the first tape of the first stringer 112a such that an end of the first leg 54 distal to the main body 52 is adjacent a first coupling element 114a’ of the first stringer 112a. The second leg 56 of the top stop 50 is mounted to second tape of the second stringer 112b such that an end of the second leg 56 distal to the main body 52 is adjacent a second coupling element 114b’ of the second stringer 112b.

[0103]For the avoidance of doubt, when the top stop 50 forms part of a slide fastener or slide fastener chain, the central axis A of the top stop is co-axial with the longitudinal axis of the slide fastener. In the present example, the second leg 56 of the top stop 50 is fused with the second coupling element 114b’. In other embodiments, the first coupling element may be fused with the first leg of the top stop, either in addition to the second leg of the top stop being fused with the second coupling element, or as an alternative.

[0104]With reference to FIG. 4, the function of various aspects of a top stop according to the present invention is now discussed. When a top stop according to the present invention forms part of a fluid-tight (for example, liquid-tight or water-tight) slide fastener, then the top stop will function so as to improve the sealing of the slide fastener. It will be appreciated that it is important for the sealing of a fluid-tight slide fastener to be effective when the slider 20 is in the fully closed position in which the slider fully abuts the top stop 50 and cannot move any further in the closing direction of the slide fastener.

[0105]Within fluid-tight slide fasteners, some form of sealing is provided in order to seal the coupling elements to their respective tape and to seal between the rows of coupling elements when they are coupled to one another. The sealing between coupled coupling elements may come from the interaction between the coupling elements themselves or may take the form of a separate seal portion. However, a potential weakness exists in terms of sealing at the top stop end of the slide fastener. In order to create a fluid-tight seal at the top stop end of the slide fastener, when the slider is in the fully closed position, it is necessary to create a fluid-tight seal between the top stop and the stringer tapes and between the top stop and the slider. Various aspects of the invention as previously discussed enhance such sealing. This is discussed in more detail below.

[0106]Referring to FIG. 4, there are several locations at which effective sealing with the top stop is important in order to ensure that the slide fastener of which the top stop forms part remains fluid-tight.

[0107]The first important sealing location is at the opening 58a to the central space 58 which receives the connection post 59 of the slider when the slider is in the fully closed position. FIG. 5 shows the opening 58a when the slider 20 is located away from the top stop 50, whereas FIG. 4 shows the state of the opening when the slider is in the fully closed position. As can be seen in FIG. 4, when the slider is in the fully closed position, the connection post 59 is received in the central space 58 between the legs 54, 56 which have been closed. In particular, it can be seen that the opening 58a shown in FIG. 5 has been closed such that the first and second inner surfaces 54d, 56d contact one another in a manner by which the interface between them is generally linear and extends along the central axis A. In particular, it can be seen that, with the slider in the fully closed position, the first and second inner surfaces 54d, 56d contact each other along their entire length (i.e. without any form of kinking in the interface between them). The effectiveness of the seal between the first and second inner surfaces 54d, 56d (and hence between the legs 54, 56) is enhanced by the first and second inner surfaces 54d, 56d contacting along their entire length.

[0108]In order to close the opening 58a by bringing the first and second inner surfaces 54d, 56d to sealing contact, when the slider 20 moves into the fully closed position, the side flanges 26a, 26a’ exert a force on the respective legs 54, 56 via their respective compression lugs 60, 62 which urges the legs 54, 56 towards the central axis A and hence towards one another. The use of the compression lugs 60, 62 in order to transmit the compression force from the slider side flanges 26a, 26a’ ensures that the legs 54, 56 are urged inwardly in the appropriate direction so as to bring the inner surfaces 54d, 56d into the previously discussed generally linear interface along their entire length. Furthermore, the use of the compression lugs ensures that once the inner surfaces 54d, 56d are engaged with one another, the compressive force that the surfaces 54d, 56d apply to one another is sufficient to create an effective fluid-tight seal between the first and second legs 54, 56 of the top stop 50.

[0109]In addition, the divergence of the first and second inner surfaces 54d, 56d when the sliders is not in contact with the top stop (as seen in FIG. 5) means that, once the inner surfaces 54d, 56d are brought into contact, they create the previously discussed effective seal in which the surfaces 54d, 56d contact each other along their entire length, without any kinks, in a generally linear manner extending along the central axis A.

[0110]The use of the compression lugs 60, 62 in order to transmit the compression force exerted by the side flanges 26a, 26a’ on the legs 54, 56 and the diverging geometry of the inner surfaces 54d, 56d not only ensure that there is sufficient sealing force between the inner surfaces 54d, 56d to create an effective seal between the legs 54, 56, but also ensures that the sealing force first and second inner surfaces 54d, 56d of the legs 54, 56 is not excessive thereby permitting relatively easy movement of the connection post 59 between the first and second inner surfaces 54d, 56d when a user is trying to open the slide fastener by moving the slider 20 out of engagement with the top stop 50 (i.e. out of the fully closed position). Furthermore, when the slider is in the fully closed position, because the contacting inner surfaces 54d, 56d extend in a generally linear manner extending along the central axis A, this helps to facilitate linear movement of the slider away from the fully closed position (and hence of the connection post 59 between the inner surfaces 54d, 56d). This results in reduced user effort being required to open the slide fastener by moving the slider away from the fully closed position.

[0111]An additional benefit of the first and second inner surfaces 54d, 56d having the diverging geometry previously discussed is that as seen in FIG. 5, as the slider is moved in the second sliding direction E (i.e. towards the top stop 50), the diverging nature of the inner surfaces 54d, 56d helps to guide the connection post 59 of the slider 20 through the opening 58a between the inner surfaces 54d, 56d and into the central space 58. As such, this reduces the effort required by a user in order to move the slider into the fully closed position.

[0112]The use of compression lugs 60, 62 to transmit the compression forces from the side flanges 26a, 26a’ to the legs 54, 56 means that a reduced surface area of the legs (i.e. only the outer surfaces 60a, 62a of the compression lugs, as opposed to the entire side of the legs 54, 56) contacts the side flanges 26a, 26a’ of the slider. Minimizing the surface area of the legs which contacts the side flanges of the slider may help to minimize the frictional engagement between the legs of the top stop and the side flanges of the slider, thereby reducing the force required to move the slider away from the fully closed position and hence facilitating the easy operation of the slider by a user attempting to open the slide fastener by moving the slider away from the fully closed position.

[0113]In addition, it is thought that the geometry of the compression lugs 60, 62 whereby their outer surfaces diverge relative to the outer surfaces of the legs 54, 56 themselves helps to urge/facilitate the separation of the side flanges 26a, 26a’ from the compression lugs 60, 62 when the slider moves away from the fully closed position, thereby facilitating easy operation of the slider being moved away from the fully closed position by a user.

[0114]As can be seen in FIG. 4, when the slider is in the fully closed position, the first and second outer skirts 80, 82 (and in particular the inward protrusions 80b and 82b) contact the outside of the side flanges 26a, 26a’ when the slider is in the fully closed position. It is thought that providing the outer skirts so that they engage with the outside of the side flanges of the slider improves the effectiveness of the seal between the top stop and the slider when the slider is in the fully closed position. Furthermore, the provision of the inward protrusions 80b, 82b on the ends of the outer skirts 80, 82 further increases the sealing effectiveness between the top stop and the side flanges of the slider.

[0115]As an additional benefit provided by the outer skirts 80, 82, it has been found that, in some applications, as the slider is moved into the fully closed position so as to engage with the top stop 50, the outer skirts 80, 82 may interact with the slider such that the slider clicks into place as it enters the fully closed position. The clicking can be audible and/or haptic. The provision of feedback to a user as to the slider entering the fully closed position is of particular use when the top stop forms part of a fluid-tight slide fastener. It is important for a user to be aware that the slider is in the fully closed position such that the slide fastener is fully closed and therefore fluid-tight. It follows that the outer skirts may minimize the occurrence of users failing to move the slider all the way into the fully closed position, thereby failing to make the slide fastener fully fluid-tight and hence presenting a risk that fluid will pass through the slide fastener.

[0116]As previously discussed, in some embodiments, the coupling element 114b’ is fused with the leg 56 of the top stop. Such fusing may occur in any appropriate manner, for example by one of the components being formed against the other component, by using adhesive or a sealant or the like, or by forming the components integrally. Fusing the coupling element with the leg of the top stop ensures that there is no potential leak path created between the top stop and the coupled rows of coupling elements. In particular, fusing the coupling element 114b’ with the leg 56 of the top stop prevents a potential leak path between the coupling element and leg. This helps to create a fluid tight seal when the slider is in the fully closed position. Furthermore, the forces which the coupled coupling elements exert on one another when they are coupled may result in the coupling element which is fused to the leg of the top stop exerting a force on the relevant leg of the top stop which assists in bringing the inner surfaces 54d, 56d into sealing engagement as previously discussed.

[0117]In view of the above, the top stop according to the present application may be suitable for a gas-tight, liquid-tight or watertight slide fastener. The slide fastener chain according to the present application may be configured to form part of a gas-tight, liquid-tight or watertight slide fastener. The slide fastener according to the present application may be a gas-tight, liquid-tight or watertight slide fastener.

[0118]When the slider is engaged with the top stop, the top stop may form a gas-tight, liquid-tight or watertight seal with the slider and the first and second stringers (in particular the portions of the first and second stringers which are not secured together by interdigitated coupling elements).

[0119]It should be understood that the examples provided herein are merely exemplary of the present application and that various modifications may be made thereto without departing from the scope defined by the claims.