Patent Publication Number: US-2004056517-A1

Title: Portable folding chair

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates generally to folding chairs and, more particularly, to a chair that may be folded into a portable configuration that is easily stored and carried.  
       [0002] Foldable chairs for intermittent use in homes and apartments are popular and necessary as they meet the need for adequate comfortable seating when the dwelling is occupied by more than the usual number of people, and are easily stowed away in a closet or other hidden area when not required. Also, individuals engaging in leisure activities, such as concerts festivals, camping, fishing or the like, frequently desire seating in settings remote from localities where traditional chairs are available. Though often sitting on the ground or sidewalk on blankets or pillows, such individuals often desire to sit on chairs for added comfort. As a result, the prior art is filled with folding chairs having a variety of designs.  
       [0003] One of the most common types of folding chairs, often called a “lawn chair” or a “beach chair,” features a framework formed from aluminum tubing that is pivotally connected so as to fold and unfold between transport/storage and use configurations. Rectangular pieces or strips of fabric that form the seat and back of the chair are riveted or otherwise secured to the aluminum tubing framework. Variations where other types of framework members are substituted for the aluminum tubing, such as illustrated in U.S. Pat. No. Des. 417,561 to Liu, also exist. Such chairs often feature armrests which are typically a structural necessity and desired by most people for comfort. Some individuals, particularly those of large girth, however, may find the armrests constraining so that the chair is difficult to sit in and get in or out of.  
       [0004] While designs for folding chairs featuring a fabric and framework construction without armrests do exist, as illustrated in U.S. Pat. No. 6,106,056 to Wegner, such chairs still suffer from other disadvantages due to the inclusion of fabric in their construction. These disadvantages include wear or tearing of the fabric seat and/or back requiring that the chair either be repaired or discarded. In addition, the fabric back and/or seat of the chair may not provide the occupant with sufficient support. As a result, the chair may be uncomfortable.  
       [0005] As an alternative to chairs featuring a fabric and framework construction, several designs exist for folding chairs having a rigid seat and back. Examples of such chairs are illustrated in U.S. Pat. No. 6,099,073 to Bruschi and U.S. Pat. No. Des. 461,968 to Adams et al. As with the chairs described above, such chairs fold and unfold between transport/storage and use configurations.  
       [0006] A problem shared by all the above prior art chairs, however, is the bulk or thickness of the chair in the folded transport or storage position. More specifically, the chairs may have seats which fold adjacent to or abutting the legs and/or have front and back legs which fold against one another such that the thickness of the folded chair equals the combined thickness of both the front and rear legs, and/or the thickness of the legs and the seat. In addition, the lengths or heights of the folded chairs make them unwieldy and limits storage options. Carrying of the chairs is further complicated in that they typically lack a handle for gripping. Furthermore, folding such chairs can be an awkward exercise.  
       [0007] Prior art designs which combine a folding chair with a carry case do exist. An early example may be found in U.S. Pat. No. 1,231,386 to Kuczabowski wherein a rigid seat back is fastened by a hinge to a rigid, box-like seat portion. Legs formed from wire and armrests are attached in a pivoting fashion to the bottom of the seat portion and the sides of the seat back, respectively. The seat back, armrests and legs fold so as to lay against the box-like seat portion. The folded chair may then be carried by a handle secured to the side of the seat portion. While somewhat more compact than the above chairs, the chair of the Kuczabowski &#39;386 patent would still be quite thick and could easily unfold. In addition, the folded chair features a number of protrusions which could catch on clothes or other objects as the chair is carried. This could cause both damage to the chair and clothing or other property damage.  
       [0008] Another early folding chair and carry case design is illustrated in U.S. Pat. No. 1,493,467 to Butt et al. The Butt et al. &#39;467 patent shows a folding chair featuring a rigid seat with legs formed from metallic tubing attached in a hinged-fashion to the bottom. A backrest, having a framework also constructed from metallic tubing, is attached in a hinged fashion to the top of the seat. When the chair is in the unfolded, use configuration, a fabric covering featuring a pocket is positioned over the framework to complete the backrest. The legs of the chair pivot so that they lay against the bottom of the rigid seat and the framework of the seatback folds down to rest on top of the rigid seat. Prior to folding the backrest framework, the fabric covering is removed therefrom and folded to form a fabric carrying bag. The folded chair may then be slid into the fabric carrying bag which features handles for carrying. While this arrangement is compact, the fabric carry bag may suffer from wear rather quickly and require replacement. In addition, it is somewhat difficult to fold the fabric carry bag and insert the folded chair.  
       [0009] U.S. Pat. No. 6,145,716 to Caicedo illustrates a combination backpack and folding chair. The chair features seat and seatback portions, each constructed from an aluminum tubing framework to which fabric is attached. The rear of the seat portion framework is joined to the bottom of the seatback portion framework in a hinged fashion so that the seat portion may be pivoted 270° from a use position to a folded position. A fabric backpack is attached to the back of the seatback portion so that it is sandwiched between the fabric of the seat and seatback portions when the chair is in the folded configuration. The folded chair and backpack may be carried upon the back of an individual. While quite compact and useful for hiking, the chair of the Caicedo does not feature full-sized legs so that the occupant has to sit very close to the ground with his or her legs extended or knees raised. In addition, due to the fabric and framework construction, the chair suffers from the wear considerations described above.  
       [0010] Accordingly, it is an object of the present invention to provide a portable folding chair that is durable, stable and comfortable.  
       [0011] It is another object of the present invention to provide a portable folding chair that is lightweight, compact and easy to store and carry.  
       [0012] It is another object of the present invention to provide a chair that is relatively free of protrusions and attractive when in the folded configuration.  
       [0013] It is still another object of the present invention to provide a portable chair that is easy to fold and unfold.  
       [0014] It is still another object of the present invention to provide a chair that is cost effective to produce.  
       SUMMARY OF THE INVENTION  
       [0015] The present invention is directed to a portable folding chair having a seat and a back that are joined in a pivoting fashion. A pair of front legs are pivotally attached to the bottom of the seat near its front edge and a pair of rear legs are pivotally attached to the seat bottom near its rear edge. The chair may be unfolded into an open configuration so that an individual may sit thereon. The chair may also be folded into a closed configuration where the front and rear legs of the chair are pivoted so as to lay adjacent to the seat bottom and the back is pivoted so as to be positioned adjacent to the legs so that the legs are enclosed between the bottom of the seat and the back. As such, the seat and back of the chair join together to form a clamshell with the legs inside.  
       [0016] A U-shaped front leg brace is pivotally attached between the front legs and a U-shaped rear leg brace is pivotally attached between the rear legs. A track is attached to the bottom of the seat and has a pair of runners with elongated slots formed therein that receive the front and rear leg braces in a sliding fashion. A leaf spring is mounted between the track and the bottom of the seat. A front locking device is positioned adjacent to the front edge of the elongated slot and a rear locking device positioned adjacent to the rear edge of the elongated slot. The locking devices are mounted on opposite ends of the leaf spring and each includes release levers as well as a pair of locking wedges. The spring urges the locking wedges away from the seat bottom so that front and rear leg braces are secured between the locking wedges and the front and rear edges of the elongated slots, respectively. The locking wedges release the leg braces when the release levers of the locking devices are pressed towards the seat bottom.  
       [0017] The chair back includes a tab portion that pivots to a position beneath the seat bottom so that it is engaged by the angle bars when the chair is in the open configuration. As a result, the back of the chair is restrained from rotating towards the seat bottom. The tab portion includes an opening which may be gripped by an individual so that a handle is formed by which the chair may be carried when folded into the closed configuration.  
       [0018] The following detailed description of embodiments of the invention, taken in conjunction with the appended claims and accompanying drawings, provide a more complete understanding of the nature and scope of the invention.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0019]FIG. 1 is a top rear perspective view of an embodiment of the portable folding chair of the present invention in the unfolded or open configuration;  
     [0020]FIG. 2 is a bottom front perspective view of the chair of FIG. 1;  
     [0021]FIG. 3 is an enlarged perspective view of the rear locking device of the chair of FIGS. 1 and 2;  
     [0022]FIG. 4 is an enlarged perspective view of the engaging angle bars and tab portion of the back of the chair of FIGS. 1 and 2;  
     [0023] FIGS.  5 A- 5 C are top plan, side elevation and bottom plan views, respectively, of the chair of FIG. 1 in the folded or closed configuration;  
     [0024] FIGS.  6 A- 6 E are perspective views of the chair of FIGS.  1 - 5 C illustrating the opening or unfolding of the chair.  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0025] An embodiment of the portable folding chair of the present invention is indicated in general at  10  in FIG. 1. The chair features a seat  12  and a back  14 . The seat and back preferably are formed from molded plastic for strength and durability. Alternative materials, such as wood, could be used to form the seat and/or back instead. The seat is supported upon a surface by a pair of front legs  16   a  and  16   b  and a pair of rear legs  18   a  and  18   b . The legs preferably are constructed of metallic tubing such as, for example, steel or aluminum and, as illustrated in FIG. 2, are mounted to the bottom  22  of the seat  12 . The bottom  22  of the seat  12  has a number of ribs  24  formed thereon to improve the strength and rigidity of the seat.  
     [0026] As illustrated in FIG. 2, front legs  16   a  and  16   b  are connected to the bottom of the seat in a hinged fashion. More specifically, legs  16   a  and  16   b  are joined by their proximal portions  26   a  and  26   b , respectively, by a cross member or joining portion (not shown), also preferably constructed of metallic tubing. Indeed, leg  16   a  and  16   b  and the horizontal joining portion may be constructed from a single, continuous piece of metallic tubing featuring the appropriate bends. A cosmetic front panel  28  positioned adjacent to the front edge  32  of the seat cooperates with the bottom  22  of the seat to form a passage through which the horizontal joining portion connected to legs  16   a  and  16   b  passes. The passage is sized so that the joining portion may pivot therein.  
     [0027] The rear legs  18   a  and  18   b  are also joined by a horizontal joining portion or cross member, indicated at  33  in FIG. 2. The horizontal joining portion  33  passes between cosmetic rear panels  35   a  and  35   b  and the bottom of the seat so that, similar to the front legs, the rear legs are secured to the chair in a pivoting fashion. The cosmetic rear panels and rear horizontal joining portion are mounted near the rear edge of the seat, indicated at  37  in FIG. 1.  
     [0028] A track, indicated in general at  40  in FIGS. 2 and 3, has a generally U-shaped cross section and is preferably constructed from metal. The track features a horizontal base  42  from which vertical runners  44   a  and  44   b  extend. As best illustrated in FIG. 3, each runner  44   a  and  44   b  of the track  40  features an elongated slot, illustrated at  45   a  and  45   b.    
     [0029] As illustrated in FIG. 2, the bottom  22  of the seat  12  has a number of bosses  47  molded thereon. The track  40  is secured by its base  42  to the bottom  22  of the seat  12  with a number of screws that engage the bosses, as illustrated with screw  46  and boss  47  in FIG. 2. A leaf spring, indicated at  50  in FIG. 3, extends nearly the entire length of track  40  and is sandwiched between the track  40  and the bosses formed on the bottom  22  of seat  12  so that there is spacing between the leaf spring and the bottom of the seat. As will be explained below, the leaf spring, which is preferably constructed from a strip of metal, is used by the locking mechanisms that secure the chair legs in the open or unfolded configuration.  
     [0030] As illustrated in FIGS. 1 and 2, both the front and rear legs are provided with U-shaped front and rear leg braces indicated at  52  and  54 , respectively. The front leg brace  52  is connected to the front legs near their proximal portions  26   a  and  26   b  in a pivoting fashion by fasteners  56   a  and  56   b , which preferably are rivets. The front leg brace  52  is also received within the elongated slots formed in the runners  44   a  and  44   b  of the track  40 .  
     [0031] Similarly, the rear leg brace  54  is pivotally connected to the proximal portions of the rear legs, indicated at  58   a  and  58   b , respectively, by fasteners  62   a  and  62   b , which also preferably are rivets. Rear leg brace  54  also resides in the elongated slots of the runners  44   a  and  44   b  of track  40 . As illustrated in FIG. 2, when the chair is in the open position, the rear leg brace  54  is positioned at the rear edges  64   a  and  64   b  of the elongated slots  45   a  and  45   b  (FIG. 3) while the front leg brace  52  is positioned at the front edges  66   a  and  66   b  of the elongated slots.  
     [0032] The rear leg brace is secured in the position illustrated in FIGS.  1 - 3 , that is, with the chair in the open or unfolded configuration, by the rear locking device indicated in general at  70  in FIG. 3. The rear locking device  70  is secured by fasteners  71  and  73  to the rear end of the leaf spring  50  that is positioned between the base  42  of track  40  and the bottom of the seat. The fasteners  71  and  73  may be rivets, screws, bolts or some other type of fastener or fastening method including soldering or welding. Alternatively, the leaf spring  50  and rear locking device  70  may be integrally formed from a single piece of material. The rear locking device includes release levers  72   a  and  72   b  and a pair of vertically extending lock wedges  74   a  and  74   b . The leaf spring urges the rear locking device  70  towards the position illustrated in FIG. 3.  
     [0033] When the release levers  72   a  and  72   b  of rear locking device  70  are pushed towards the bottom of the seat, the lock wedges  74   a  and  74   b  retract so that the rear leg brace  54  is free to travel within elongated slots  45   a  and  45   b  of track  40  towards the front of edge of the chair (illustrated at  32  in FIG. 2). As a result, the rear legs may be folded towards the bottom of the chair in the direction indicated by arrow  78  in FIGS. 1 and 2.  
     [0034] A front locking device, indicated at  80  in FIG. 2, is a mirror-image of the rear locking device  70  and is secured to the front end of the leaf spring  50 , that is, the end of the leaf spring opposite the end upon which rear locking device  70  is positioned. Front locking device  80  operates in the same fashion as rear locking device  70  so as to lock the front legs in the open or unfolded configuration illustrated in FIGS. 1 and 2. When the release levers of the front locking device are pressed towards the bottom of the seat, the front leg brace  52  is free to move in the elongated slots of the track towards the rear of the chair ( 37  in FIG. 1). As a result, the front legs fold towards the bottom of the chair in the direction of arrow  82  in FIGS. 1 and 2.  
     [0035] As illustrated in FIGS. 1 and 2, the back  14  of the chair includes a tab portion  84  having an opening  86  so that a handle is formed. As will be explained below, the opening provides a gripping area so that the chair may be easily carried by an individual when the chair is in the folded or closed configuration. As illustrated in FIGS. 1 and 2, the tab portion  84  of the back extends down slightly below the bottom of the seat  12  when the chair is in the open or unfolded configuration. The joining portion  33  of FIG. 2 that joins rear legs  18   a  and  18   b  passes through the tab portion  84  of the back so that the chair back  14  pivots with regard to the chair seat  12  about the rear horizontal joining portion  33 .  
     [0036] As shown in FIG. 2, a pair of L-shaped angle bars  88   a  and  88   b  are secured to the rear leg brace  54 . As best illustrated in FIG. 4, the angle bars  88   a  and  88   b  engage the tab portion  84  of the back of the chair when the chair is in the open or unfolded configuration. As a result, the back is supported/braced when an occupant leans against the chair back. It should be noted that, as opposed to the construction illustrated in the figures, the angle bars  88   a  and  88   b  may instead be integrally or continuously formed with the rear leg brace  54  so as to take on an appearance similar to that of a goal post, that is, the portions of the rear leg brace  54  between the ends of the angle bars  88   a  and  88   b  could be eliminated.  
     [0037] The chair is folded or closed by folding the rear legs in the direction of arrow  78  of FIGS. 1 and 2 after either release lever  72   a  or  72   b  (FIG. 3) of the rear locking device  70  is pressed. Similarly, the front legs are folded in the direction of arrow  82  in FIGS. 1 and 2 after either release lever of front locking device  80  is pressed. As a result, the front and rear legs lay flat against the bottom  22  of the seat  12 , as illustrated in FIG. 6B. With the angle bars  88   a  and  88   b  of FIGS. 2 and 4 moved away from the tab portion  84  of chair back  14 , the back is free to be rotated approximately 265° from the open or unfolded position indicated in FIGS. 1 and 2, in the direction of arrow  92  in FIGS. 1 and 2, to the closed or folded position illustrated in FIG. 5C.  
     [0038] As a result of folding the legs and back of the chair, the chair is in the closed or folded configuration illustrated in FIGS.  5 A- 5 C. The seat  12  and back  14  of the chair thus form a clamshell arrangement with the folding legs, track and locking mechanisms secured inside. The chair may be secured in the closed configuration by a number of latching arrangements including, but not limited to, a magnetic catch, VELCRO or interference fitting components (such as dimples) molded into the chair back and seat.  
     [0039] As is clear from FIGS.  5 A- 5 C, the chair in the folded or closed configuration has a compact size, a smooth and aesthetically pleasing appearance and may be conveniently carried in the same manner as a briefcase or other piece of luggage having a handle. This also permits the chair to be easily stored in small space such as, for example, the trunk of a car or closet. The handle further allows the folded chair to be stored in a hanging fashion. FIG. 5B illustrates the minimal thickness of the closed or folded chair. FIGS. 5A and 5B show the smooth shape of the seat  12 , which makes the chair comfortable to sit in. FIG. 5C illustrates how the cosmetic front panel  28  and the cosmetic rear panels  35   a  and  35   b  enhance the smoothness of the exterior surface of the folded or closed chair and also illustrate how the front and rear legs of the chair are enclosed and protected against damage by the clamshell formed by the chair seat and back.  
     [0040] As illustrated by FIG. 5B, the shape of the folded chair also facilitates stacking of multiple folding chairs when each are placed in a horizontal orientation and piled on top of one another. As a result, multiple chairs may be efficiently stored in a stacked configuration. Various dimples or other engagement features may optionally be molded or otherwise added to the exposed top and bottom surfaces of the folded chair to further facilitate stacking.  
     [0041]FIGS. 6A through 6E illustrate how the chair is opened or unfolded so as to be returned to the configuration illustrated in FIGS. 1 and 2. More specifically, the chair, initially in the position illustrated in FIG. 6A, is flipped or rotated 180° and the chair back  14  is lifted away from the seat  12 . The back is rotated approximately 265° to the position illustrated in FIGS. 6B and 6C. As a result, the bottom of the seat  12  and the folded front and rear legs are exposed.  
     [0042] The rear legs  18   a  and  18   b  are next opened or unfolded until they arrive in the position illustrated in FIG. 6D. Due to the shape of locking wedges  74   a  and  74   b  (FIG. 3) of the locking device, the rear leg brace  54  travels through the elongated slots of track  40  until locking into the position illustrated in FIG. 3. In other words, the rearward traveling leg brace forces the rear locking device  70  (FIG. 3) down as it travels over the locking wedges  74   a  and  74   b . As illustrated in FIG. 6E, the front legs  16   a  and  16   b  are finally opened or unfolded until being locking into such a position by the similar interaction between the front leg brace  52  and the front locking mechanism  80 .  
     [0043] As a result, the chair of the present invention is easily reconfigured between an open or unfolded configuration, where it accommodates an occupant in a stable and comfortable fashion, and a folded or closed configuration where it presents a trim, compact appearance and may be easily carried and stored.  
     [0044] While the preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.