BACK SUPPORT ATTACHMENT SYSTEM FOR AN OFFICE CHAIR

BACKGROUND OF THE INVENTION

[0001]The present invention is directed to office chairs, and, more particularly, to an office chair that can be efficiently manufactured, and efficiently shipped and installed.

[0002]In the competitive market for office seating, users demand office seating options that provide comfort, function, and a high degree of adjustability, but these chairs must also be cost effective to purchase, manufacture and ship. As a result, office chair manufacturers are continually searching for improved methods of manufacturing office chairs and office chair components, and improved methods of boxing and shipping these chairs and components.

[0003]Some office chairs have increased efficiency in manufacture by reducing or simplifying components such as the back support or the mechanism. For example, some modern office chairs have moved to a one-piece seat back, often molded unitarily to form a plastic shell, thus reducing the number of seat back components from multiple elements requiring assembly to a single element that can simply be attached to the office chair base. Other office chairs have reduced the size of the chair mechanism, typically a series of controls and springs, and the number of spring elements within the mechanism in order to simplify the assembly process and reduce weight for shipping. Still others are designed with “quick-connect” seat backs, such that the chair can be shipped with the seat back unattached in order to reduce the packing size required for the chair. These seat backs are then attached to the chair base after shipment and removal from the packaging.

[0004]Each of the above noted efforts in efficiency, however, have drawbacks, including aesthetic challenges, the reduction of comfort and adjustment features, and increased work for installers that may need to partially assemble products after they have been shipped. As a result, manufacturers continue to search for efficiencies that may minimize drawbacks.

SUMMARY OF THE INVENTION

[0005]The present invention provides an office chair with a seat back attachment system that provides efficient shipping and ease of installation. The attachment system includes a seat back and a seat that are mounted on a base. The seat back has a support portion and an attachment portion. The support portion has a forward surface for supporting the back of a user. A locking element is connected between the attachment portion and the base, the locking element locking the attachment portion in place with respect to the base, the locking element capable of toolless attachment to the base.

[0006]In one embodiment, prior to the connection of the locking element, the seat back is pivotable with respect to the chair base between a shipping position and an upright position, the connection of the locking element locking the seat back in the upright position. The locking element may be a pin or elongated rod, and the chair base may define a locking element receptacle into which the pin can be inserted. The pin may include a first end, a second end, and a longitudinal length between the ends, and the pin may define a notch along the longitudinal length. The base may include a resilient element that extends into the notch upon insertion of the pin to prevent removal of the pin.

[0007]In one embodiment, the base includes a back support mounting rod, and the attachment portion of the seat back is connected to the back support mounting rod. The back support may be connected to the base via a back support mounting bracket mounted on the mounting rod, with the attachment portion of the back support including a back support bracket, and the attachment portion of the back support including a first portion connected to the back support bracket and a second portion defining an open slot receptacle receiving the mounting rod.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is an exploded view of the office chair with seat back attachment system according to one embodiment of the present invention.

[0017]FIG. 2 is a perspective, partially exploded view of the chair base according to one embodiment.

[0018]FIG. 3 is a perspective view of the office chair in a folded, ship position with locking element removed.

[0019]FIG. 4 is a perspective view of the office chair in an upright position with the locking element removed.

[0020]FIG. 5 is a perspective view of the office chair in an upright position with the locking element inserted.

DESCRIPTION OF THE CURRENT EMBODIMENTS

[0021]An office chair having a seat back attachment system according to the current embodiments of the present invention is shown in FIGS. 1-5 and generally designated 10. In particular, the embodiments of the office chair 10 disclosed in the present application include a back support structure 12 for supporting the back of a user, a seat 14 for supporting a user, and a base 20 supporting the seat 14 and back support 12. As disclosed in more detail below, the present invention includes a system and method for attaching the back support 12 to the base 20 in a manner that provides efficient shipping and easy installation by an installer or end user. The system includes an attachment portion 22 of the seat back 12 that connects to the base 20 in a manner that enables the seat back 12 to be folded down onto the seat 14 for shipment, and then unboxed and pivoted to an upright use position, and held in place in the upright position by a lock element 24 that can be positioned on the base 20 without separate tools (i.e., a toolless insertion), and retained in place on the base 20 by a lock receptacle 26.

[0022]Referring to FIG. 1, the base 20, seat 14 and seat back 12 are shown in an exploded view. A more detailed, exploded view of the base 20 is shown in FIG. 2. The base 20 may be arranged in a variety of ways depending on the features and design of the particular office chair 10. The base 20 generally forms a central hub for the components of the office chair 10, and in one embodiment forms a housing 25 having a pair of sidewalls 28. The sidewalls 28 may be spaced apart from each other, and in one embodiment each include an outer surface 30 and an inner surface 32 that extend in a fore-aft direction that is parallel to a ground surface when the chair 10 is in use, and a vertical direction that is normal to the ground surface. The inner surfaces 32 may face one another. A bottom wall 34 may extend between the inner surfaces 32 of the sidewalls 28, and in the illustrated embodiment, the bottom wall 34 defines a cylindrical opening 36 for receiving a conventional office chair pedestal (not shown) which may extend vertically from a ground engaging unit having a series of legs supported on casters. The base 20 is supported above the ground surface by the pedestal and ground engaging unit.

[0023]Referring again to FIG. 2, the base housing 25 forms a housing and support for various systems of the office chair 10. For example, the base housing 25 includes structure for supporting the seat 14. In the illustrated embodiment, this structure includes a pair of seat support rails 40, each mounted at the top of one of the sidewalls 28. The seat support rails 40 are spaced apart from each other, and each includes an upper surface 42 and an outside edge 44. With reference to FIG. 1, the seat support rails 40 may include structure for slidably connecting with the seat 14, such as tracks (not shown) on the lower surface 47 of the seat 14 that extend around the rails 40 and slidably attach to the rails 40 via a forward edge 48 of the rails 40 or a rearward edge 51. As shown, the rails 40 include tension tabs 52 on the outside edges 44 that may bias against the seat 14 to take up any slack between the seat 14 and the rails 40. The rails 40 may be mounted on a tiltable portion 53 of the housing 25 that pivots about an axis 57 to enable the seat back 12 to recline from the upright position (shown in FIG. 4) to a reclined position. The housing 25 may also contain one or more components of a tilt tension mechanism for controlling the degree of tension experienced by the user as the seat back 12 is reclined. For example, in the illustrated embodiment, the housing 25 contains a tension spring 55 that is connected to the tiltable portion 53 of the housing to bias the seat back 12 in the upright position. In another embodiment, the base housing 25 may include a different structure for mounting the seat 14, such as structure for attaching the seat 14 to the upper surface 42 of the rails, or an alternate structure.

[0024]The seat 14 includes an upper surface 45 and a lower surface 47. As noted, the lower surface 47 may include structure, such as a track or an attachment portion, that enable attachment of the seat 14 to the base 20. The upper surface 45 of the seat 14 forms a user support surface and generally faces away from the ground surface when the chair is in use. The seat 14 may include a cushion or an elastomeric fabric material to provide comfort to a user sitting on the upper surface 45.

[0025]The base housing 25 further includes structure to attach to the back support 12. As illustrated, the base housing 25 includes a seat back support rod 50, formed as a generally cylindrical rod and extending between the sidewalls 28. Although the positioning and shape of the support rod 50 may vary, the support rod 50 of the illustrated embodiment is located adjacent to the upper edge 52 of the sidewalls 28, and the rear edges 54 of the sidewalls 28. With reference to FIGS. 1 and 3, in one embodiment, the seat back attachment system 10 includes a seat back support bracket 56 providing connection between the base 20 and the seat back 12. In one embodiment, the support bracket 56 is a U-shaped bracket having a central web 60, and a pair of side webs 62 extending from the central web 60. As shown, each side web 62 includes a series of mounting holes that align through both of the side webs 62, including a pair of attachment holes 64, a support rod hole 66, and a lock receptacle hole 68. The support bracket 56 may pivotally connect to the base housing 25 with the support rod 50 extending through the support rod holes 66 of the bracket 56 such that the bracket 56 can rotate about the support rod 56 between the folded “ship” position shown in FIG. 3, wherein the seat back 12 is folded down onto the seat 14, and the upright position shown in FIG. 4 wherein the seat back 12 is approximately vertical with respect to the ground surface and forms an angle with respect to the seat 14 that would enable a user to sit on the seat 14.

[0026]Referring to FIG. 1, the seat back 12 includes an upright, or occupant support portion 80 and the attachment portion 22. The upright portion 80 is generally conventional, and may be structured in a variety of constructions. In the illustrated embodiment, the upright portion 80 includes a seat back frame 82 having a pair of uprights 84, an upper member 86 extending between the uprights 84 at an upper end of the uprights 84, and a lower member 88 extending between the uprights 84. The frame 82 this forms a structural ring shape having a forward surface 90 and a rearward surface 92. The forward surface 90 may support a shell 94 that supports the back of an occupant. The shell 94 has a rear surface 96 facing the frame 82, and with reference to FIG. 4, an oppositely facing forward surface 98 that engages the back of a user. In another embodiment, the frame 82 or shell 94 may also support a cushion or upholstery, and in another embodiment the frame may support a load bearing fabric in tension.

[0027]The attachment portion 22 extends from the seat back frame 82 to form a structure for attachment to the chair base 20. More particularly, as shown in FIG. 1, the attachment portion 22 includes a pair of spaced apart walls 100 extending forwardly from the forward surface 90 of the lower member 88 of frame 82. The walls 100 of the attachment portion 22 include a series of holes for attaching the seat back 12 to the base 20 and for interfitting with the lock element 24 as noted in more detail below. As shown in FIG. 1, the walls 100 each define an open receptacle 102 at a leading edge 105 of each wall 100. The open receptacle 102 is sized to receive the support rod 50. The walls 100 each additionally include a lock receptacle hole 106, and a pair of attachment holes 108. The receptacle 102 is positioned to align with the support rod hole 66 when the walls 100 of the seat back 12 are fitted over the side webs 62 of the bracket 56, and the attachment holes 108 and lock receptacle hole 106 are positioned to align with the attachment holes 64, and lock receptacle hole 68 hole of the bracket 56. Fasteners 70 may be inserted through each of the aligned attachment holes 108, 64 to rigidly attach the attachment portion 22 to the bracket 56. In an alternative embodiment, the walls 100 may include one or more of the attachment holes 108 and lock receptacle hole 106, and the positioning of these holes may vary from application to application.

[0028]In one embodiment, the base housing 25 also includes the lock receptacle 26 and lock element 24. The lock receptacle 26 is formed such that the lock element 24 can be inserted into the lock receptacle 26 to prevent further pivoting of the seat back 12 relative to the support rod. With reference to FIGS. 1-5, the lock receptacle 26 is an opening extending though the base housing 25, including receptacle holes 110 extending through both of the sidewalls 28. These receptacle holes 110 are positioned to align with the lock receptacle holes 106 of the attachment portion 22 of the seat back 12 and with the lock receptacle holes 68 of the bracket 56 when the attachment portion 22 is attached to the bracket 56 and the seat back 12 is pivoted to the upright position. The lock element 24 is sized and shaped such that it can be inserted through the lock receptacle 26 with the seat in the upright position. In one embodiment, the lock element 24 is an elongated rod having a first end 112, a second end 114 and defining a longitudinal length therebetween. The ends 112, 114 may be rounded for ease of insertion into the lock receptacle 26. The length of the rod 24 is at least sufficient to extend through a sidewall 28 of the housing 25 and one of the walls 100 of the attachment portion 22 of the seat back 12, and in the illustrated embodiment the length is sufficient to extend through both sidewalls 28 of the base housing 25.

[0029]In one embodiment, the base housing includes a retention element 120 that acts to retain the lock element 24 in the lock receptacle 26 upon insertion of the lock element 24. With reference to FIG. 2, the retention element 120 is a resilient element, such as spring steel, having a first section 122 and a second section 124 extending at an angle from the first section 122. The first section 122 defines an attachment hole 126 for attaching the first section 122 to a screw boss 130 on the bottom wall 32 of the base housing 25. The second section 124 extends at an angle from the first section 122 such that at least a portion of the second section 124 interferes with the lock receptacle 26, for example, by extending at least partially into the path of the lock element 24 when the lock element 24 is inserted into the lock receptacle 26. As illustrated, the lock element 24 defines a circumferential notch 132 along its longitudinal length that aligns with and receives at least a portion of the retention element 120 upon full insertion of the lock element 24 into the lock receptacle 26. As a result of the retention element 120 having a degree of resiliency, the retention element 120 may snap fit into the notch 132 upon insertion of the lock element 24 to prevent removal of the lock element 24 from the lock receptacle 26 without the use of a tool to flex the retention element away from the notch 132.

[0030]In operation, the office chair attachment system 10 may be assembled and shipped by providing the chair base 20 with housing 25. The seat support bracket 56 may be attached to the housing 25 by inserting the seat back support rod 50 through the support rod holes 66 of the bracket 56. This connection enables the seat support bracket 56 to pivot about the support rod 50. The seat 14 may be attached to the base 20 by a conventional method, and in the illustrated embodiment, the seat 14 is attached to the base by sliding tracks on the bottom surface of the seat 14 onto the seat support rails 40 on the base housing 25. The seat back 12 is attached to the base 20 by attaching the attachment portion 22 of the seat back 12 to the bracket 56. In one embodiment, this attachment is made by inserting the support rod 50 into the open receptacle 104 on the attachment portion 22, aligning the attachment holes 108 on the attachment portion 22 with the attachment holes 64 on the bracket 56, and connecting the bracket 56 to the attachment portion 22 by inserting the fasteners 70 through the attachment holes 108, 64. Upon attachment of the seat back 12 to the base 20, the seat back 12 is pivotable about the support rod 50 with the bracket 56 between the folded, ship position shown in FIG. 3—wherein the forward surface 98 of the seat back shell 94 faces the upper surface 45 of the seat 14 and generally faces in the direction of the upper surface 42 of the seat support rails 40. In this folded position of the seat back 12, the seat 14 may be slid forward on the rails 40, exposing a rearward portion of the rails 40 as shown in FIG. 3. In this position, the ground engaging structure, such as a pedestal and ground supports may also be attached to the base housing 25, and the system 10 with folded seat back 12 may be placed in a box or other container, along with a lock element 24.

[0031]Upon unboxing the folded seat system 10, the installer or user may pivot the seat back 12 about the support rod 50 to the upright position shown in FIG. 4, wherein the lock receptacle holes 106 on the attachment portion 22 align with the lock receptacle holes 110, and the lock element 24 may be inserted into the lock receptacle 26. Notably, in the illustrated embodiment, the lock element 24 may be inserted into the lock receptacle 26 without the use of separate tools. As the rounded first end 112 of the lock element 24 is inserted past the resilient retention element 120, the retention element may be pivoted slightly by the force of the lock element 24. As the lock element 24 is then fully inserted into the lock receptacle 26, the retention element 120 may snap fit into the notch 132 on the lock element 24 to retain the lock element 24 in the lock receptacle 26. With the lock element 24 being inserted through the lock element holes 106 of the attachment portion 22 of the seat back 12, the seat back 12 is prevented from further free rotation about the support rod 50. The seat 14 may be slid backward—in the direction of the seat back 12—and into its use position, wherein a user can sit on the seat 14 with their back supported on the seat back 12.

[0032]Alternative embodiments of foldable seat backs, or quick connect seat backs that may be attached to the chair base after shipping are also contemplated. For example, the attachment portion of the seat back may be structured to insert into a receptacle on the chair base, and the receptacle may contain a locking mechanism to retain the attachment portion upon insertion. The locking mechanism may include a portion that moves upon insertion of the attachment portion to lock the attachment portion to the chair base. For example, the attachment portion may include a notch that receives a spring biased pin upon insertion of the attachment portion into the receptacle.

[0033]Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s).

[0034]The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.