Abstract:
A folding chair has a hinges on the seat and on a back panel and on a brace. The chair further includes side frame elements to which the seat, back panels and brace are all hingeably connected. The chair can be folded into a very compact form.

Description:
TECHNICAL FIELD OF THE INVENTION 
   The present invention relates to the general art of chairs, and to the particular field of chairs. 
   BACKGROUND OF THE INVENTION 
   Throughout history, people have sought more comfortable seating arrangements. Chairs, stools, and the like allow people to relieve stress on the legs and feet, while remaining alert and performing tasks that do not require a great deal of motion. In the twentieth century, folding chairs have made it possible for people to keep a space clear when necessary, and to erect suitable seating for gatherings or special events. However, current folding chairs possess a number of drawbacks. 
   Folding chairs of a variety of configurations are known in the art. Indeed, an intended advantage of folding chairs is that, in a folded state, they may be shipped or stored more conveniently than non-folding or fully assembled chairs. Conventional folding chairs generally include a backrest frame having legs that extend at downward angles to become the front legs of the chair, back legs pivotally mounted to the back rest frame, and a seat frame pivoted to the backrest frame, and the back legs. In addition, the prior art is replete with a wide variety of hinge and joint configurations to support and guide the folding members. 
   While the folding chairs of the prior art fulfill their respective objectives, the folding chair configurations of the prior art often sacrifice stability and durability relative to traditional, non-folding chairs, to achieve their respective functions. Accordingly, a need exists in the art for a folding chair that erects into a stable from approximating traditional, non-folding chairs. Embodiments of the present invention substantially fulfill this need. 
   The inventor has found that folding chairs are often somewhat heavy. The chair must reliably support the weight of even a fairly large person. The bending stress on any member is proportional to the length of the member multiplied by the force acting upon it. Therefore, the length of the seat effectively multiplies the forces tending to bend or break the seat. Typically, seats for folding chairs have been made from stronger (and heavier) materials, such as steel, to overcome the effect of these bending stresses. The resulting chairs are heavier and therefore cost more to ship, and require more effort to move, fold, and unfold. 
   Thus, it is desirable to use lightweight materials such as plastics to reduce the weight of folding chairs. However, many known folding chairs, especially those that incorporate lightweight materials, do not stand up to repetitive use. Groups such as the business and institutional furniture manufacturers&#39; association have set up standards for portable furniture. Such standards typically require that portable chairs be designed to receive a given weight loading to simulate use for a specified number of cycles, often on the order of 100,000. Many known folding chairs bend or break after only a few thousand cycles, and therefore can be expected to have a relatively short useful life. 
   Still further, many known folding chairs are somewhat expensive to produce because the manner in which they are assembled requires the use of a great deal of manual labor. The legs must often be properly aligned with the seat so that mechanical fasteners can be attached to the legs and the seat. If metal supporting parts are to be threaded through the lightweight seat member to connect the legs, the lightweight seat member may have to be aligned with each leg assembly so that the threading operation can be carried out. Often, the various fasteners involved must be installed at locations that are not easily accessible for machinery. Thus, the fasteners must often be installed by hand. 
   Accordingly, a need exists for a portable, folding chair that is lightweight and comfortable, and yet folds to a thin, stackable configuration. Such a chair must safely support the weight of a fairly heavy person. In addition, the chair should be inexpensive to produce in large quantities with a minimum of parts and assembly. 
   SUMMARY OF THE INVENTION 
   The above-discussed disadvantages of the prior art are overcome by a folding chair that has a hinges on the seat and on a back panel and on a brace. The chair further includes side frame elements to which the seat, back panels and brace are all hingeably connected. The chair can be folded into a very compact form. 
   Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 

   
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views. 
       FIG. 1  is a perspective view of a folding chair embodying the present invention. 
       FIG. 2  is a right side elevational view thereof. 
       FIG. 3  is a top view thereof. 
       FIG. 4  is a front side view thereof. 
       FIG. 5  is a bottom view thereof. 
       FIG. 6  is a left side view thereof. 
       FIG. 7  is a back view thereof. 
       FIG. 8  is a top view of a hinge. 
       FIG. 8A  is a side view of a hinge. 
       FIG. 9  is a top view of another hinge. 
       FIG. 9A  is a side view of the hinge shown in  FIG. 9 . 
       FIG. 10  is a side view of another hinge. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the figures, it can be understood that the present invention is embodied in a folding chair  10  which overcomes the drawbacks associated with the prior art. Chair  10  comprises a first left rectangular side frame  12  and a second right rectangular side frame  14 . The side frames are identical to each other. Therefore, only one side frame will be described, it being understood that the following description applies to both side frames. Each side frame includes a first end  20  which is a bottom end when the side frame is set up, with the set up condition being shown in  FIG. 1 . Each side frame further includes a second end  22  which is a top end when the side frame is set up and a longitudinal axis  24  which extends between first end  20  and second end  22  of the side frame. Each side frame further includes a first side  30  which is a front side when the side frame is set up, a second side  32  which is a rear side when the side frame is set up and a width axis  34  which extends between first side  30  and second side  32  of the side frame. A cross bar  40  is attached at end  42  thereof to first side  30  and at end  44  thereof to second side  32  and which extends in the direction of width axis  34  of the side frame. Each side frame is planar and each side frame is contained in a plane. 
   A seat section  50  includes a first portion  52  which has a first end  54  hingeably attached to the cross bar on the first side frame to move between a use orientation extending perpendicular to the plane containing the first side frame toward the second side frame and a stored orientation lying in the plane containing the first side frame. First portion  52  further includes a second end  56  which is sinuous in shape. Seat section  50  further includes a second portion  60  which has a first end  62  hingeably attached to the cross bar on the second side frame to move between a use orientation extending perpendicular to the plane containing the second side frame toward the first side frame and a stored orientation lying in the plane containing the second side frame. Second portion  60  further includes a second end  64  which is sinuous in shape. The second end of the second portion being shaped to snugly and neatly mate with the second end of the first portion when both portions are in the use orientation so the seat section is planar as can be understood from the teaching of  FIG. 1 . 
   The chair further comprises a brace portion  70  which includes a first portion  72  which has a first end  74  hingeably attached to first side  30  of the first side frame and to second side  32  of the first side frame to move between a use orientation extending perpendicular to the plane containing the first side frame toward the second side frame and a stored orientation lying in the plane containing the first side frame. Brace portion  70  further includes a second end  76  which is sinuous in shape. Brace portion  70  further includes a second portion  80  which has a first end  82  hingeably attached to the first side of the second side frame and to the second side of the second side frame to move between a use orientation extending perpendicular to the plane containing the second side frame toward the first side frame and a stored orientation lying in the plane containing the second side frame. Second portion  80  further includes a second end  84  which is sinuous in shape. Second end  84  of second portion  80  of the brace portion is shaped to snugly and neatly mate with second end  76  of first portion  70  of the brace portion when both portions of the brace portion are in the use orientation so the brace portion is planar. 
   Chair  10  further comprises a back panel  90  which includes a first portion  92  which has a first end  94  hingeably attached to the second side of the first side frame to move between a use orientation extending perpendicular to the plane containing the first side frame toward the second side frame and perpendicular to the plane containing the seat portion and a stored orientation lying in the plane containing the first side frame. First portion  92  further includes a second end  96  which is sinuous in shape. Back panel  90  further includes a second portion  100  which has a first end  104  hingeably attached to the second side of the second side frame to move between a use orientation extending perpendicular to the plane containing the second side frame toward the first side frame and perpendicular to the plane containing the seat portion and a stored orientation lying in the plane containing the second side frame. Second portion  100  further includes a second end  106  which is sinuous in shape. Second end  106  of the second portion of the back panel is shaped to snugly and neatly mate with second end  96  of first portion  90  of the back panel when both portions of the back panel are in the use orientation so the back panel is planar. 
   In one form of the chair, the seat section includes a hinge  110  ( FIGS. 9 and 9A ) connecting the second ends of the portions of the seat section together. The hinge includes a hinge pin  112 . Yet another form of the chair includes a similar hinge on the back panel and a similar hinge on the brace portion. The chair can be formed of plastic so it is light weight yet strong and durable. Hinges, such as hinge  120  shown in  FIG. 10  can be used to attach the parts to the side frames. Yet another form of the hinge that can be used on the chair is shown as hinge  130  in  FIGS. 8 and 8A . The hinges can include steel inserts for added strength. 
   Another form of the seat can have the portions  52  and  60  concave. The back panel can also include concave portions. The corners of the seat and back panel can be rounded if desired. A second brace portion can be included near the bottom ends of the side frames for further support if desired. The chair can be folded outwards toward the side frames with the back panel folding towards the rear. The seat folds up as does the brace section. 
   While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.