Abstract:
A collapsible chair constructed of tubing and fabric that is for use at the beach, camping or outdoors where portability is important to the user. The chair included folding support members that allow the chair to fold up into a small package.

Description:
PRIORITY CLAIM 
       [0001]    This invention claims the benefit of U.S. Provisional Application Ser. No. 61/271,194 to inventors William H. Ayre and Timothy J. C. O&#39;Shea, filed Jul. 17, 2009, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Lounge chairs have been in widespread use for many years. Such prior art type lounge chairs come in a variety of shapes and sizes. Some of these lounge chairs may be provided with cushions while other less costly lounge chairs are not. 
         [0003]    It is also well known to carry lounge chairs to sit in while at the beach. These lounge chairs are normally made with an aluminum frame and plastic fabric to reduce the weight. 
         [0004]    However, many of the existing designs are cumbersome, expensive and don&#39;t fold up into small enough of a package. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a collapsible chair constructed of tubing and fabric that is for use at the beach, camping or outdoors where portability is important to the user. The chair is easy to set-up and put-away and can be stored in a sac when not in use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
           [0007]      FIG. 1  is a perspective view of a preferred embodiment of the collapsible chair; 
           [0008]      FIG. 2A  is a perspective view of the embodiment of  FIG. 1  at a first folding position; 
           [0009]      FIG. 2B  is a view of the collapsed frame of the chair of  FIG. 1 ; 
           [0010]      FIG. 3A  is a top view of an embodiment of a folding brace in the open condition; 
           [0011]      FIG. 3B  is a perspective view of the folding brace of  FIG. 3A  in the folded position; and 
           [0012]      FIG. 3C  is a side view of a leg with a retained brace end pivot and limit pin. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0013]      FIG. 1  shows an embodiment of a collapsible chair  10  in the operational and open position. Seat fabric  12  is tensioned taught between two main side seat tubes  14 - 1 ,  14 - 2  which are U-shaped having vertical ends forming legs  16 - 1 ,  16 - 2 . The legs  16 - 1 ,  16 - 2  are terminated at feet  18  to spread the load and limit slippage on hard surfaces. A seat back  20  includes two tubes  22  that pivot at their lower ends on the main side tubes  14 - 1 ,  14 - 2  and that have seat back fabric  24  stretched between them. 
         [0014]    Front and rear folding braces  26  press outward between the front legs  16 - 1  and between the rear legs  16 - 2  and tension the seat fabric  12 . These folding braces  26  pivot at their outer ends around the legs  16 - 1 ,  16 - 2 . In the embodiment shown these folding brace pivot points are formed of vertical tubing or sleeve  31  slightly larger than the leg tubing. A plastic bushing (not shown) may be provided between the legs  16 - 1 ,  16 - 2  and the sleeves  31  to reduce friction. The vertical tubing sleeves  31  transmit forces to the main seat tubes  14 - 1 ,  14 - 2  to maintain position of the seat tubes  14 - 1 ,  14 - 2 . The braces  26  are also constrained in rotation motion around the legs  16 - 1 ,  16 - 2  by limit and retaining pins  28  fixedly attached to the legs  16 - 1 ,  16 - 2 . The limit and retaining pins  28  move in the slots  30  in the sleeves  31 , seen in  FIG. 3C . The arrangement of the limit pins  28  in the slots  30  resist racking of the chair in the open position, helping maintain a rectangular relationship between the braces  26  and main side tubes  14 - 1 ,  14 - 2 . In the closed position this arrangement of the limit pins  28  in the slots  30  assist in maintaining the general alignment of the folded chair tubes,  FIG. 2B . In addition pins  28  retain the braces  26  in a fixed vertical position on the legs  16 - 1 ,  16 - 2 . It is to be appreciated that the pivot ends of folding braces  26  (the sleeves  31 ) may be formed by other readily available means of producing hinges to those skilled in the art. 
         [0015]    The braces  26  may be alternately constructed such that the brace vertical tubing sleeves extend downward from the legs to form feet (not shown) that extend toward central pivots  32 . The vertical tubing sleeves  31  are shown surrounding the leg tubes in  FIGS. 1 ,  2 A,  2 B, and  3 C. However, the brace sleeves may be located inside the leg tubes without departing from the scope of the invention. Also alternately the limit pins  28  and slots  30  may be reversed from those described above with slots  30  in the legs and the limit pins  28  fixedly attached to the brace vertical tubing sleeves. In addition the legs may be terminated in side runners, rather than feet. Such side runners (not shown) may connect the left (front and rear) legs  16 - 1 ,  16 - 2  to each other and the right (front and rear) legs  16 - 1 ,  16 - 2  to each other, and the side runners would substantially parallel the main seat tubes  14 - 1 ,  14 - 2 . 
         [0016]    As seen in  FIG. 3A  each folding brace  26  has a first tube  48  and second tube  44  with the central pivot  32  connecting them near center. The central pivot  32  includes a guide plate  34  fixedly attached to the second tube  44 . A pivot pin  36  attaches through a hole or inline holes in the guide plate  34  to the first tube  48 . The first tube  48  is bent slightly such that in the open position the two tubes  44 ,  48  are substantially in line. The pivot pin  36  is off the center line of the two tubes  44 ,  48 . When the folding braces  26  are in the open position the central pivot  32  is in an over center position such that the central pivot point has passed the central in-line point, depicted by dotted line  38  in  FIG. 3A . In this position the central pivot  32  tends to stay open due to the tension of the seat fabric  12  and any additional forces placed upon the seat fabric  12 . Release of the central pivot  32  requires a force to push it inward past center to fold the chair indicated by arrows in  FIG. 2A  showing the start of folding. The center pivots  32  are also designed such that the left and right brace tubes  44 ,  48  are substantially parallel and side by side when the chair is folded,  FIGS. 2B and 3B .  FIG. 2B  shows the frame of an embodiment of the inventive folding chair in the folded condition. The front and rear folding braces  26  are positioned such that in this folded position one central pivot  32  is higher than the other such that they do not interfere with each other when in the folded position. 
         [0017]    Alternate central pivots having over center latching or other latching may be produced within the scope of the invention, such as incorporating a spring pin in the pivoting tube of the folding brace (not shown). In the open configuration the spring pin would secure central pivot  32  in the open position by extending into a hole in the pivot guide plate  34  thereby fixing the folding brace  26  in the open configuration. Further construction of the folding braces may be of other structure than tubing without departing from the scope of the invention. 
         [0018]    The seat back  20  described above further arises off reinforced seat back pivots  40  on the main side seat tubes with rectangular tubing reinforcement welded around the round side seat tubes  14 - 1 ,  14 - 2 ,  FIG. 1 . The pivots  40  allow the seat back tubes  22  to fold forward over their corresponding seat side tubes  14 - 1 ,  14 - 2  for compact storage,  FIG. 2B . Reinforcement of the pivot points  40  may be achieved in other ways without altering the scope of the invention, such as addition of side plates to the round side seat tubing or a sleeve of tubing over or inside of the round main side seat tubing  14 - 1 ,  14 - 2 , or solid round stock material added inside the seat side tubing  14 - 1 ,  14 - 2  for additional support of the pivot pin, main side seat tubing may be of square construction rather than round, or support material below the pivot point may be added and extended flanges attached to the seat back tube that will brace against the surface of this added material. 
         [0019]    In another embodiment, the folding chair includes an additional folding cross brace (not shown) at the upper rear of the seat back tubes  22  to resist the inward forces induced by the pressure of a person leaning back into the seat back  20 . Such an additional folding cross brace may be similar to any descriptions for the braces  26  above. 
         [0020]    Operation of the chair as shown from the folded condition in  FIG. 2B  to the open condition in  FIG. 1  involves lifting the seat back  20  (either before or after the following steps) and pulling the main seat side tubes  14 - 1 ,  14 - 2  apart which starts to open the folding braces  26 . Opening of braces  26  is completed by pulling forward on the front brace  26  while simultaneously pulling rearward on the rear brace  26  until their respective pivots  32  pass over center and arc held in place by fabric tension, or latching spring pins if provided. 
         [0021]    A carrying bag may be provided for easily carrying the chair in the folded condition. 
         [0022]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, telescoping poles may used for the seat side tubes  14 - 1 ,  14 - 2  for the ability to compact the size of the folded chair even more. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.