Abstract:
A wheelchair including a collapsible frame with rearward and forward portions that can be pivoted towards each other for compact storage. The collapsible frame rides on a pair of casters at its front and a pair of drive wheels at its rear. The positioning of a seat, footrest and a pair of armrests on the collapsible frame may be selectively varied to accommodate any user.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to land vehicles and, more particularly, to wheelchairs.  
         BACKGROUND OF THE INVENTION  
         [0002]    Wheelchairs have long provided a means of locomotion for disabled individuals. Unfortunately, conventional wheelchairs are constructed from a “one size fits most” standpoint, making them uncomfortable for large or small individuals to use. While fully adjustable wheelchair designs have been proposed to accommodate people of varied size, these designs have not seen widespread use and great commercial success. Perhaps the complex and cumbersome nature of the known wheelchair designs incorporating adjustable features has been their principal drawback.  
         SUMMARY OF THE INVENTION  
         [0003]    In light of the problems associated with the known wheelchairs, it is a principal object of the invention to provide a wheelchair of uncomplicated construction that can be adjusted to accommodate any user. In the preferred embodiment, the positioning of the seat, chair arms and footrest can be separately changed. Such changes can be performed intuitively, without specialized instruction and without tools of any sort.  
           [0004]    It is another object of the invention to provide a wheelchair of the type described that is fully collapsible for compact storage. When in a collapsed condition, the wheelchair can be wheeled about in the manner of a dolly to a convenient place of rest. Opening the collapsed wheelchair for subsequent use may be accomplished in a matter of seconds.  
           [0005]    It is a further object of the invention to provide a wheelchair of the type described that can be manually powered or can be adapted, if desired, for locomotion by means of one or more motors.  
           [0006]    It is an object of the invention to provide improved elements and arrangements thereof in a wheelchair for the purposes described that is lightweight in construction, inexpensive to manufacture, and fully dependable in use.  
           [0007]    Briefly, the wheelchair in accordance with this invention achieves the intended objects by featuring a collapsible frame including a forward portion hingedly secured to a rearward portion such that the frame can be opened with the forward portion is oriented substantially at right angles to the rearward portion and collapsed with the forward portion oriented substantially parallel to the rearward portion. The frame rides on a pair of casters secured to the forward portion and a pair of drive wheels secured to the rearward portion. A user is supported by a seat secured to the forward portion and a backrest secured to the rearward portion.  
           [0008]    The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The present invention may be more readily described with reference to the accompanying drawings, in which:  
         [0010]    [0010]FIG. 1 is a side elevational view of a wheelchair in accordance with the present invention.  
         [0011]    [0011]FIG. 2 is a side elevational view of the wheelchair of FIG. 1 in a partially collapsed condition.  
         [0012]    [0012]FIG. 3 is a side elevational view of the wheelchair in a fully collapsed condition.  
         [0013]    [0013]FIG. 4 is a top plan view of the wheelchair.  
         [0014]    [0014]FIG. 5 is a front elevational view of the wheelchair.  
         [0015]    [0015]FIG. 6 is a rear elevational view of the wheelchair.  
         [0016]    [0016]FIG. 7 is a bottom plan view of the wheelchair.  
         [0017]    [0017]FIG. 8 is a perspective view of a portion of the frame of the wheelchair showing details thereof. 
     
    
       [0018]    Similar reference characters denote corresponding features consistently throughout the accompanying drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    Referring now to the FIGS., a wheelchair in accordance with the present invention is shown at  10 . Wheelchair  10  includes a collapsible frame  12  with a forward portion  14  secured by means of a pair of hinges  16  to a rearward portion  18 . A pair of casters  20  is secured to the front of forward portion  14  and a pair of drive wheels  22  is secured to the rear of rearward portion  18  to stably support frame  12  at a fixed height above the ground. A cushioned seat  24  is secured atop forward portion  14  whereas a cushioned backrest  26  is secured to rearward portion  18  to support a user in comfort on frame  12 . A pair of armrests  28  extends upwardly from the opposite sides of forward portion  14  and a footrest  30  extends forwardly from forward portion  14  for added comfort.  
         [0020]    Forward portion  14  has a pair of side rails  32  joined together by a crosspiece  34  so as to form a rigid structure. Secured to the inner surfaces of side rails  32  is a first pair of socket members  36  for receiving a pair of posts  38  at the front of seat  24 . A second pair of socket members  40  is secured to the inner surfaces of side rails  32  rearwardly of socket members  36  for receiving a pair of upwardly extending legs  42  comprising footrest brace  44 .  
         [0021]    Rearward portion  18  includes a pair of side members  46  connected at their tops by an arcuate crossbar  48  that serves as a handle for pushing wheelchair  10  from behind. Beneath crossbar  48 , a pair of crossbars  50  and  52  connects side members  46  at spaced intervals and further reinforce rearward portion  18 . A pair of mounting bosses  54  extends forwardly from the bottoms of side members  46  and abuts side rails  32  of forward portion  14 . Secured to the inner surfaces of bosses  54  is a third pair of socket members  56  for receiving pins  38  at the rear of seat  24 .  
         [0022]    Hinges  16  connect the side rails  32  to mounting bosses  54 . As shown, hinges  16  permit forward portion  14  to pivot upwardly relative to rearward portion  18  so that both may be oriented substantially parallel to one another as illustrated in FIG. 3. Affixed to the fronts of mounting bosses  54  beneath hinges  16  is a pair of locking plates  58 . Locking plates  58  extend forwardly from bosses  54  to which such are rigidly affixed and have transverse apertures  60  that may be brought into registry with transverse apertures  62  in the rears of side rails  32 . Locking pins  64  passed through the registered apertures  60  and  62  maintain wheelchair  10  in an open condition for use as illustrated in FIG. 1.  
         [0023]    Seat  24  is generally rectangular in outline and is provided with a downwardly extending post  38  in each of its four corners. Each post  38  is provided with a plurality of transverse apertures  66 , each being adapted for registry with a transverse aperture  68  in one of the socket members  36  or  56 . Locking pins  70  passed through the registered apertures  66  and  68  maintain seat  24  at a desired height above forward portion  14 . Thus, a user can adjust the height of seat  24  to meet his needs.  
         [0024]    Backrest  26  is shown, for the sake of drawing simplicity, to be permanently attached to rearward portion  18 . It should be appreciated, however, that backrest  26  could be attached to rearward portion  18  in the same manner as seat  24  is attached to forward portion  14 , i.e., with pins passing through posts and socket members. Such an arrangement, of course, would permit the position of backrest  26  to be adjusted forward and back to accommodate the desires of a user.  
         [0025]    An armrest supporting brace  72  is secured to forward portion  14 . Brace  72  has a pair of armrest supporting posts  74  joined at their bottoms by a tie bar  76 . As shown, bar  76  is adapted to engage the bottoms of sides rails  32  whereas posts  74  are adapted to engage the outer surfaces of side rails  32  and to extend upwardly therefrom. The bottom of each post  74  is provided with a transverse aperture  78  adapted for registry with one of a plurality of transverse apertures  80  arrayed along each side rail  32 . Locking pins  82  passed through registered apertures  78  and  80  set the position of posts  74  forward or back relative to rearward portion  18 .  
         [0026]    Each armrest  28  includes a cushioned arm support  84  positioned atop a tubular sleeve  86 . Each sleeve  86  is configured for snug, yet slidable, positioning upon a post  74 . As shown, each sleeve  86  is provided with a plurality of transverse apertures  88 , each adapted for registry with a transverse aperture  90  in a post  74 . A locking pin  92  passed through registered apertures  88  and  90  maintains cushioned support  84  at a desired height above seat  24 . Thus, the construction of wheelchair  10  permits a user to move armrests  28  not only up and down but also forward and back.  
         [0027]    Footrest brace  44  is secured to forward portion  14 . Brace  44  has a pair of legs  42  joined at their bottoms by a tie bar  76 . Tie bar  76  is provided with a longitudinal opening  94  at its center for slidably receiving footrest  30 . Legs  42 , however, are adapted for insertion into socket members  40 . The top of each leg  42  is provided with a plurality of transverse apertures  96  adapted for registry with a transverse aperture  98  penetrating each socket member  40 . Locking pins  100  passed through registered apertures  96  and  98  set the height of tie bar  76  relative to forward portion  14 .  
         [0028]    Footrest  30  includes a spar  102  having a cushioned support  104  secured to its front. Spar  102  is provided with a plurality of transverse apertures  106  adapted for registry with a transverse aperture  108  penetrating tie bar  76  and opening  94 . A locking pin  110  passed through registered apertures  106  and  108  permits the extension of support  104  forward of forward portion  14  to be adjusted by a user.  
         [0029]    From the foregoing, it should be appreciated that use of wheelchair  10  is straightforward. First, the height of seat  24  is adjusted by withdrawing pins  70  (if necessary), repositioning posts  38  in socket members  36  and  56  and reinserting pins  70  in apertures  66  and  68 . Next, similar adjustments are made to the heights armrests  28  and footrest  30 . A person positioned in wheelchair  10  can, now, be moved about in complete comfort.  
         [0030]    When use of wheelchair  10  is no longer required, it may be collapsed in stages as illustrated in FIGS.  1 - 3  for compact storage. First, pins  70  are withdrawn from socket members  36  and  56  and seat  24  is removed from frame  12 . Then, pins  64  are removed from plates  58  thereby permitting forward and rearward portions  14  and  18  to pivot toward one another as illustrated in FIG. 2. Further pivoting results in forward portion  14  pressing against backrest  26 . A strap (not shown) may be wrapped around portions  14  and  18  to retain wheelchair in a collapsed condition as long as is desired. Wheelchair  10  may be moved to a convenient location like a closet for storage simply by grasping crossbar  48  and steering wheelchair  10  in the manner of a dolly.  
         [0031]    While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that modifications may be made thereto. For example, the cushioned support  104  of footrest  30 , shown as being rigidly affixed to spar  102 , can be made to pivot by a variety of conventional means to provide greater comfort to a user. Furthermore, the wheelchair  10 , shown as being manually powered principally to avoid obscuring important details of the construction of frame  12  thereof, can be outfitted with one or more electric motors, batteries and control apparatus to permit wheelchair  10  to move over the ground under its own power. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.