Abstract:
An apparatus for mounting a wheelchair back that provides a high degree of support and adjustability such that it can be used with wheelchairs that originate from a wide variety of different manufacturers. In order to provide this custom fit, the present invention provide for depth adjustability, height adjustability and angle adjustability of a wheelchair back. The present invention also provides the convenience of a quick-release wheelchair back so that the wheelchair occupant can easily remove the back of the wheelchair from the canes so that the wheelchair can be collapsed and stored. The present mounting system also provides a two point mounting system that is reliable yet simple to use.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to wheelchairs and more specifically to adjustable wheelchair backs. In even more detail, the present invention relates to a device and system for mounting a wheelchair back to the upright canes of a wheelchair that provides infinite adjustability in three dimensions. The mounting apparatus and system of the present invention is also adjustable so as to precisely fit a wide variety of existing wheelchairs. 
       BACKGROUND OF THE INVENTION 
       [0002]    People requiring wheelchairs include those affected with cerebral palsy, muscular dystrophy, multiple sclerosis, and head injuries, among other debilitating physical conditions. These individuals often suffer from kyphosis, scoliosis, lordosis and other back ailments. One of the most common complaints of wheelchair occupants is that of pain that is directly related to their use of a wheelchair. Unfortunately, at least some of the problems faced by wheelchair users are further exacerbated by the failure of current designs of wheelchair backs and back systems to properly position a wheelchair occupant. 
         [0003]    One problem with current back wheelchair systems is that they are difficult to install and to remove. Disabled users may need to remove and install the wheelchair back to collapse the wheelchair for storage, such as when the user enters and exits motor vehicle. 
         [0004]    Yet another problem with current wheelchair back systems is the variability between commercially available wheelchairs. In particular, the upright posts of the wheelchair, or canes, often differ in configuration between wheelchairs. Specifically, in the inventor&#39;s experience, the diameter of the canes may vary from between ¾″ to 1¼″. Additionally, the center-to-center distance of the canes may vary ±2″ from the manufacturer&#39;s designation. This may also be referred to as the cane-to-cane distance later in this disclosure. An additional problem is that some canes may not be perfectly vertical. To add to the confusion, some manufacturers use metric designations. 
         [0005]    An additional problem with current wheelchair back systems is that they are not adaptable to all wheelchair backs. For example, some wheelchairs, particularly those designed for more active lifestyles, have short canes. Therefore, there is little area in which to attach a wheelchair back, which may mean that wheelchair occupants who pursue a more active lifestyle may not be able to take advantage of the benefits offered by a wheelchair having an adjustable back. Additionally, wheelchair occupants, needing their hands for mobility, have little capacity for carrying cargo. Therefore, another problem with current wheelchair back designs is that they leave little room for mounting other accessories, such as bags, to them. Many chairs for highly involved users have gas assist cylinders, saliva suction apparatus, chest harnesses and other accessories that further limit cane space. 
         [0006]    Another disadvantage of current wheelchair back systems is that they provide limited adjustability for people of different sizes, shapes and physical needs. For example, a simple sling back wheelchair back provides almost no adjustability. Some wheelchair backs provide limited adjustability, e.g. the wheelchair back can move vertically but has no seat depth adjustability, or the wheelchair back has seat depth adjustability but has no angle adjustability. Often users are put into wheelchairs that are too big or too small. This can cause the patient to be uncomfortable and, in some cases, actually causes skeletal misalignment problems such as scoliosis and/or kyphosis. A properly fitted backrest can improve the interface between the user and the wheelchair. 
         [0007]    Another common problem with wheelchair backrests is excessive weight. Wheelchair users propel themselves using their shoulders and arms. This repetitive motion of the wheelchair user&#39;s arms can deteriorate the user&#39;s arm and shoulder joints over time. Reducing wheelchair weight can help prolong the users&#39; mobility and reduce wear and tear on the user. 
         [0008]    Accordingly, what is required is a backrest mounting apparatus and system that can be fitted to the user while the user is seated in the wheelchair. Such a device will reduce the number of transfers during such a fitting. This reduces the chances of falling, torn skin, bruising, etc. This also expedites the fitting process, which allows the therapist to spend more time fine tuning the fit. 
         [0009]    Safety and user-friendliness are further important requirements to wheelchair users. Specifically, a quick release mechanism is critical to the user in that it allows the user to collapse the wheelchair for storage and transportation. The ability to transport the wheelchair is important as it allows the user to maintain a level of independence. An additional important feature to those who desire mobility is a collapsible wheelchair. Therefore, what is also required is a lower profile design such that the mounting devices on the canes do not interfere with one another when the wheelchair is collapsed. 
         [0010]    An additional requirement is that of easy installation. For example, prior mounting devices required mounting hardware to be clamped onto two tracks, each mounted onto a cane. Commonly, those tracks became misaligned, thereby making the backrest very difficult, if not impossible, to remove and reinstall. 
         [0011]    What is also needed is a safer mounting device. Prior devices achieved depth adjustment and quick release by sliding on a set of horizontal rails, each mounted onto a wheelchair cane. Earlier devices simply clamped onto these horizontal rails. If the clamping force was not applied properly by the user, the backrest could move backwards, possibly falling off the wheelchair while in use. While the prior device provided mechanical stops on the ends of the rails to prevent the backrest from falling off completely, the mechanical stops were frequently not installed correctly by users and healthcare workers. 
         [0012]    Therefore, what is needed is a wheelchair back mounting apparatus and system that is adaptable to wheelchairs having canes, or upright vertical posts, having a wide variety of different widths. There is also a need for a wheelchair back mounting apparatus and system that takes up less space on the wheelchair canes so as to fit onto wheelchairs with limited space and permit the attachment of other items, such as bags. There is also a need to provide a wheelchair back mounting device and system that provides a wide variety of adjustability so that it can fit all shapes and sizes of people. The backrest weight must be minimized to prolong the mobility of the user. Lastly, there is a need to provide a wheelchair back that is quickly and easily removable such that the wheelchair back can be removed, and the wheelchair collapsed and stored. 
       SUMMARY OF THE INVENTION 
       [0013]    The claimed invention provides an apparatus and system for mounting a wheelchair back that provides a high degree of support and adjustability such that it can be used with wheelchairs from a wide variety of different manufacturers. This adjustability is also beneficial to the occupant of the wheelchair, as the adjustability can provide a wide variety of people with a more custom fit. In order to provide this custom fit, the claimed invention provides for depth adjustability, height adjustability and angle adjustability of a wheelchair back. 
         [0014]    The claimed invention also provides the convenience of a quick-release wheelchair back so that the wheelchair occupant can easily remove the back of the wheelchair from the canes so that the wheelchair can be collapsed, stored and transported. 
         [0015]    The claimed mounting device and system also provides for an effective two point mounting system. Therefore, the mounting device of the present invention provides a high degree of adjustability with respect to the angle that it can be inclined or declined with respect to prior systems. Additionally, use of a two-point mounting system is particularly important with wheelchairs having short canes, such as those used by more active individuals, as it leaves room for other wheelchair accessories. 
         [0016]    The depth, height and width adjustability achieved by the claimed invention uses entirely closed—end components, thereby preventing unwanted travel and possible failure. Further, the quick release is achieved in the vertical plane, which is perpendicular to the applied force of the user. In the event the clamping force is not applied properly to the expanding shaft, it will not fail. Rather, it will remain in the aperture and wiggle around. 
         [0017]    The foregoing and other features of the device and system of the present invention will be apparent from the description that follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is an exploded view of a backrest designed for use with a wheelchair together with the mounting device of the claimed invention. 
           [0019]      FIG. 2A  is a side elevational view of the right-side inner wheelchair cane clamp. 
           [0020]      FIG. 2B  is a top plan view of the right-side inner wheelchair cane clamp. 
           [0021]      FIG. 2C  is a top and side perspective view of the right-side inner wheelchair cane clamp. 
           [0022]      FIG. 2D  is an end elevational view of the right-side inner wheelchair cane clamp. 
           [0023]      FIG. 3A  is a top and side perspective view of the left-side inner wheelchair cane clamp. 
           [0024]      FIG. 3B  is a top plan view of the left side inner wheelchair cane clamp. 
           [0025]      FIG. 3C  is a side elevational view of the left side inner wheelchair cane clamp. 
           [0026]      FIG. 3D  is an end elevational view of the left side inner wheelchair cane clamp. 
           [0027]      FIG. 4A  is a side elevational view of the outer wheelchair cane clamp. 
           [0028]      FIG. 4B  is a top or bottom plan view of the outer wheelchair cane clamp. 
           [0029]      FIG. 4C  is a top and side perspective view of the outer wheelchair cane clamp. 
           [0030]      FIG. 5A  is a side elevational view of the expanding post. 
           [0031]      FIG. 5B  is a second side elevational view of the expanding post rotated ninety (90) degrees. 
           [0032]      FIG. 5C  is a bottom plan view of the expanding post. 
           [0033]      FIG. 5D  is a top plan view of the expanding post. 
           [0034]      FIG. 6A  is a side elevational view of the cam lever and expanding post. 
           [0035]      FIG. 6B  is a bottom plan view of the expanding post and the angle adjustment bracket. 
           [0036]      FIG. 7  is an expanded view of the cam lever and expanding post. 
           [0037]      FIG. 8A  is a side elevational view of the left triangle clamp. 
           [0038]      FIG. 8B  is a top elevational view of the left triangle clamp. 
           [0039]      FIG. 8C  is a backside elevational view of the left triangle clamp. 
           [0040]      FIG. 8D  is an additional side elevational view of the left triangle clamp 
           [0041]      FIG. 8E  is a top and side persepective view of the left triangle clamp. 
           [0042]      FIG. 8F  is a bottom view of the left triangle clamp. 
           [0043]      FIG. 9A  is a top and side perspective view of the right triangle clamp. 
           [0044]      FIG. 9B  is backside elevational view of the right triangle clamp. 
           [0045]      FIG. 9C  is a top side elevational view of the right triangle clamp. 
           [0046]      FIG. 9D  is a side elevational view of the right triangle clamp. 
           [0047]      FIG. 9E  is an additional side elevational view of the right triangle clamp. 
           [0048]      FIG. 9F  is a bottom elevational view of the right triangle clamp. 
           [0049]      FIG. 10A  shows a right side view of the backrest and mounting device of the claimed invention reclined at approximately fifteen (15) degrees from vertical. 
           [0050]      FIG. 10B  shows as front view of the backrest and mounting device of the claimed invention reclined at approximately fifteen (15) degrees from vertical. 
           [0051]      FIG. 11A  shows a right side view of the backrest and mounting device of the claimed invention inclined at approximately fifteen (15) degrees from vertical. 
           [0052]      FIG. 11B  shows a front view of the backrest and mounting device of the claimed invention inclined at approximately fifteen (15) degrees from vertical. 
           [0053]      FIG. 12A  is a side elevational view of the depth adjustment mechanism of the claimed invention showing the seatback adjusted 2″ (two inches) back. 
           [0054]      FIG. 12B  is front elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 2″ (two inches) back. 
           [0055]      FIG. 13A  is a side elevational view of the depth adjustment mechanism of the backrest and mounting device of the claimed invention showing the seatback adjusted 0″ (zero inches) back. 
           [0056]      FIG. 13B  is front elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 0″ (zero inches) back. 
           [0057]      FIG. 14A  is a side elevational view of the backrest and mounting device of the claimed invention wherein the mounting device is reversed to provide a shallow wheelchair back. 
           [0058]      FIG. 14B  is a front elevational view of the backrest and mounting device of the claimed invention wherein the mounting device is reversed to provide a shallow wheelchair back. 
           [0059]      FIG. 15A  is a side elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 5″ (five inches) upwardly. 
           [0060]      FIG. 15B  is a front elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 5″ (five inches) upwardly. 
           [0061]      FIG. 16A  is a side elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 5″ (five inches) downwardly. 
           [0062]      FIG. 16B  is a front elevational view of the backrest and mounting device of the claimed invention showing the seatback adjusted 5″ (five inches) downwardly. 
           [0063]      FIG. 17A  is a side elevational view of the backrest and mounting device of the claimed invention showing the seatback in roughly the middle of its vertical adjustment. 
           [0064]      FIG. 17B  is a front elevational view of the backrest and mounting device of the claimed invention showing the seatback in roughly the middle of its vertical adjustment. 
           [0065]      FIG. 18  is a top plan view of the backrest and mounting device of the claimed invention for a wheelchair having a relatively smaller cane to cane distance. 
           [0066]      FIG. 19  is a top plan view of the backrest and mounting device of the claimed invention for a wheelchair having a relatively neutral cane to cane distance. 
           [0067]      FIG. 20  is a top plan view of the backrest and mounting device of the claimed invention for a wheelchair having a larger cane-to-cane distance. 
           [0068]      FIG. 21A  is a top and side perspective view of an alternative embodiment of the triangle clamp of the claimed invention. 
           [0069]      FIG. 21B  is a side elevational view of an alternative embodiment of the triangle clamp of the claimed invention. 
           [0070]      FIG. 21C  is a top elevational view of an alternative embodiment of the triangle clamp of the claimed invention. 
           [0071]      FIG. 21D  is an additional side elevational view of an alternative embodiment of the triangle clamp of the claimed invention. 
           [0072]      FIG. 21E  is a back elevational view of an alternative embodiment of the triangle clamp of the claimed invention. 
           [0073]      FIG. 21F  is a bottom elevational view of an alternative embodiment of the triangle clamp of the claimed invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0074]    Now referring to the drawings in detail, wherein like reference numbers refer to like elements throughout,  FIG. 1  shows an exploded view of the claimed invention. Specifically,  FIG. 1  shows the backrest  1 , the compass mounting hardware of the claimed invention  5  and a portion of the wheelchair cane  11 . More specifically, the  FIG. 1  shows height adjustment bracket  21 , depth adjustment bracket  31 , triangle clamp  41 , angle adjustment bracket  51 , quick release mechanism  60 , expanding post mechanism  71 , inner cane clamp  91  and outer cane clamp  101 , all in an expanded view. 
         [0075]    In more specific detail,  FIGS. 2A-2D  show the right side inner cane clamp  91 .  FIGS. 3A-3D  show the left side inner cane clamp  91 , which is a mirror image of the right side inner cane clamp  91 . Each inner cane clamp  91  contains a passage  93  therethrough to accommodate the expanding post  71 . The inner cane clamps  91  further comprise a curved base  95  opposite the passage  93  and a mid section  87  having apertures  89  therethrough. Opposite the curved base  95  of the inner cane clamp  91  is a hook-shaped extension  92  having an arcuate surface  94 . 
         [0076]    Now referring to  FIGS. 4A-4C , complementary to the inner cane clamp  91  is an outer cane clamp  101  comprising a base  103 , the base  103  having at least two apertures  105  and, at the opposite end of the base  103 , a hook-shaped extension  107  having an arcuate surface  109 . Assembled, via attachment means such as screws through the aperture  89  in the inner cane clamp  91  and the aperture  105  in the outer cane clamp  101 , the inner cane clamp  91  and the outer cane clamp  101  remain mounted to the wheelchair canes  11  if the backrest  1  of the wheelchair is removed, e.g., for storage. Preferably, full size socket head screws should be used as it is difficult to strip the heads of socket head screws and they are easy to work with. 
         [0077]    The arcuate surface  94  of the inner cane clamp  91  and the arcuate surface  109  of the outer cane clamp  101  have a unique design that allows substantial surface area contact when clamped around both ⅞″ and 1″ diameter cane tubes, thereby increasing the flexability of the claimed invention to cover various wheelchairs. Alternatively the arcuate surfaces  94  of the inner cane clamp  91  and the arcuate surface  109  of the outer cane clamp  101  could be of virtually any size to accommodate a wide variety of sizes of wheelchair canes  11 . A benefit of the lower profile design of the inner cane clamp  91  and the outer cane clamp  101  is that they do not interfere with one another when the wheelchair is collapsed. 
         [0078]    Referring now to  FIGS. 5A-5C  and  FIG. 6 , they show the quick-release mechanism  60  employed in the claimed invention, although alternative such structures could be used. More specifically, the quick-release mechanism  60  comprises a cam lever  61  and expanding post  71 . The expanding post  71  is shown in detail in  FIGS. 5A-5C . The expanding post  71  is comprised of an upper tube  73  having a passage  80  therethrough, and angled bottom surface  76  and a groove  74  partially around the angled bottom surface  76 . The lower tube  77  contains a passage  81  therethrough, an angled upper surface  79  and a groove  78  partially around the angled upward surface  79 . The expanding post  71  is further comprised of a gasket  82 , the gasket fitting into the groove  74  in the upper tube  73  and the groove  78  in the lower tube  77  and a post cone  83 , the post cone  83  having a threaded passage  84  therethrough. 
         [0079]    The quick release cam mechanism  60  comprises a cam toggle  61 , a cam roller  63 , a cam washer  64  and a threaded skewer  65 , the skewer  65  being operable to move upwardly relative to the cam washer  64  when the cam toggle  61  is rotated downwardly. 
         [0080]    The upper tube  73  and the lower tube  77  are inserted onto the skewer  65  with the gasket  77  secured thereon. The post cone  83  is then threaded onto the threaded skewer  65  and secured into place using a set screw  85 . 
         [0081]    It is to be understood that a quick release mechanism  60  is critical to the user in that it allows the user to collapse the wheelchair for storage and transportation. Transportation is important as it allows the user to maintain a level of independence. The claimed invention provides a quick release mechanism  60  that is designed to secure the angle adjustment bracket  51  to the passage  93  in the inner cane clamp  91  and is what releasably secures the wheelchair backrest  1  to the wheelchair. 
         [0082]    As shown in detail in  FIG. 6 , when the cam toggle  61  is relaxed, the overall diameter of the upper tube  73  and the lower tube  77  combined is less than the diameter of the passage  93  in the inner cane clamp  91 . To secure the angle adjustment bracket  51  to the inner cane clamp  91 , the cam toggle  61  is actuated thereby causing the upper tube  73  and lower tube  77  to slide along the common surface  76 ,  79  between them, thus causing them to shift outwardly. This shifting movement increases the amount of space consumed by the combination of the upper tube  73  and the lower tube  77  such that the space consumed by upper tube  73  and the lower tube  77  together is greater than the diameter of the passage in the inner cane clamp  91 , which effectively locks the angle adjustment bracket  51  to the inner cane clamp  91 . When the cam toggle  61  is relaxed, the rubber gasket  81  helps the upper tube  73  and the lower tube  77  maintain a smaller diameter such that the quick release mechanism  60  can be easily inserted into the angle adjustment bracket  51  and inner cane clamp  91  and removed therefrom. 
         [0083]    A primary advantage of the claimed invention is that the quick release mechanism  60  moves in the vertical plane, which is perpendicular to the force that is applied to the backrest  1  and toggle  61  by the user. Therefore, in the event the clamping force is not applied properly to the expanding shaft  71 , the backrest  1  will not fall off the wheelchair, or even move. 
         [0084]    The backrest  1  of the claimed invention is generally comprised of a rigid plastic shell that is normally covered with a foam pad having a fabric cover (not shown). The backrest  1  has a pair of 6¾ inch (six and three quarter inch) vertical slots  3 . 
         [0085]    The height adjustment bracket  21  comprises a double nut, that is, it comprises a pair of threaded apertures  22 , and can be conveniently secured to the backrest  1  using just one tool. The height adjustment bracket  21  is attached to the backrest  1  by a pair of socket head cap screws  25  which additionally secure height clamps  23  to the adjustment bracket  21 . Again, see  FIG. 1 . 
         [0086]    Continuing outwardly,  FIGS. 8A through 8E  and  FIGS. 9A through 9D  show the left and right triangle clamps  41 , which are essentially mirror images of one another, and therefore will be discussed together. The triangle clamp  41  comprises a first side  42  having a pair of parallel longitudinally-extending slots  43 , a top side  44  having an longitudinally-extending slot  45 , a bottom side  46  having a longitudinally-extending slot  47  that is parallel to the longitudinally-extending slot  45  in the top side  44 , and at least one additional side  48 . 
         [0087]    The triangle clamp  41  is secured to the wheelchair back  1  by the height clamps  23  at the top and bottom of the triangle clamp  41 . Specifically, the top height clamp  23  has a downwardly-extending protrusion, or catch  24  that slots within the longitudinally-extending slot  45  in the top  44  of the triangle clamp. Similarly, the bottom height clamp  27  has and upwardly-extending catch  28  that fits within the longitudinally-extending slot  47  on the bottom side  46  of the triangle clamp  41 . When the socket head screws  25  are tightened, the upper height clamp and the bottom height clamp  27  secure the triangle clamp  41  in position. 
         [0088]    The height clamps  23 ,  27  also provide up to two (2″) inches of variability such that different types of wheelchairs with different cane-to-cane spacing can be accommodated. Specifically, to accommodate wheelchairs having larger cane-to-cane spacing, the height clamps  23 ,  27  can be moved along the longitudinally extending slot  47  in the top  44  of the triangle clamps  41  and the edge  47  of the bottom  46  of the triangle clamp. Measuring indica are provided on the top  44  of the triangle clamps  41  such that the backrest  1  can be visually centered between the wheelchair canes  11  without other tools. 
         [0089]    The triangle clamp  41  is attached to the angle adjustment bracket  51  via depth adjustment bracket  31 . The depth adjustment bracket  31  contains a pair of tapped apertures  32  such that it effectively serves as a double nut whereby the angle adjustment bracket  51  can be secured to the triangle clamp  41  with just one tool. As shown in  FIGS. 12A and 12B , using the combination of the slots  43  in the triangle bracket and the depth adjustment bracket  31  the backrest  1  is permitted 2″ (two inches) of depth adjustment. An additional 2″ (two inches) of depth adjustment is available if the inner cane clamp  91  and the outer cane clamp  101  are mounted on the front of the wheelchair canes  11  as shown in  FIGS. 14A and 14B . An important advantage of the claimed invention is that the claimed invention has depth adjustment capabilities that are achieved using slots that are closed on their ends, thereby preventing unwanted travel and thus failure. 
         [0090]    An alternative embodiment of the triangle clamp  121  is shown in  FIGS. 21A through 21E . The main distinction between this embodiment and that described above is the addition of flanges  122  on the top  44  and bottom  46  of the triangle clamp  121 . These flanges  122  contain longitudinally extending slots  123 . The slots  123  are designed to replace the height clamps and provide a simpler mechanism that is less expensive to produce but permits the same range of motion as the embodiment described above. 
         [0091]    The angle adjustment bracket  51  is generally comprised of a lower portion  52  and an upper portion  54 . See  FIGS. 6 and 7 . The lower portion  52  comprises a first aperture  53 , and a second arc-shaped angle adjustment aperture  55 . In an embodiment of the claimed invention the angle adjustment aperture  55  permits adjustment of the backrest  1  ±15° from vertical (+/−15 degrees). As shown in  FIG. 1 , the upper portion  54  of the angle adjustment bracket  51  contains a passage  57  therethrough, the passage  57  being slightly larger than the diameter of the upper tube  73  and the lower tube  77  such that the quick release mechanism  60  can be inserted therethrough to releasably secure the angle adjustment bracket  51  to the inner cane clamp  91 . 
         [0092]    Now referring to the exemplary drawings,  FIG. 10A  shows a side view of the backrest of the claimed invention reclined 15° (fifteen degrees) from vertical.  FIG. 10B  shows the complementary front view of the reclined backrest  1 .  FIGS. 11A and 11B  show side and front views of the claimed invention with the backrest  1  rotated forward 15° (fifteen degrees) from vertical.  FIGS. 12A and 12B  show views of the backrest  1  showing the backrest adjusted 2″ (two inches) back.  FIGS. 13A and 13B  show the backrest  1  of the claimed invention in its furthest forward position with the cane clamps  91 , 101  in the standard position. As discussed above and shown in  FIGS. 14A and 14B , the cane clamps  91 , 101  could be reversed for an additional 2″ (two inches) of rearward adjustability. 
         [0093]      FIGS. 15A and 15B  demonstrate the adjustability of the wheelchair back in the vertical direction, specifically in comparison to  FIGS. 16A and 16B . In  FIGS. 15A and 15B , the backrest  1  is adjusted upwardly relative to the claimed invention, while in  FIGS. 16A and 16B , the backrest  1  is adjusted downwardly relative to the claimed invention. 
         [0094]      FIGS. 17 and 18  demonstrate the adaptability of the claimed invention to various types of wheelchairs. The distance between the canes  11  of a wheelchair is variable between wheelchair manufacturers. Therefore, it is useful to have an attachment means which is capable of securing to a wide variety of wheelchairs of different manufacture. The claimed invention permits such variation by providing up to 2″ (two inches) of width accommodation. 
         [0095]    The claimed invention has many advantages over other backrest mounting devices. Specifically, the claimed invention allows for 5″ of height adjustment, 4″ of depth adjustment and 15 degrees of adjustment fore/aft of vertical for a total of 30 degrees. Further, all of this adjustability is accomplished in a compact assembly that is both functional and stylish. 
         [0096]    Importantly, all adjustments can be performed while the user is seated in the wheelchair. This is an important distinction over competitor hardware systems because it reduces the number of transfers during such a fitting. This reduces the chances of falling, torn skin, bruising, etc. This also expedites the fitting process, which allows the therapist to spend more time fine tuning the dimensions. 
         [0097]    Of additional importance to the user is that the present invention is substantially lighter than prior backrest mounting systems. Specifically the present mounting system is 0.5 lbs (½ pound) lighter than prior mounting systems, a 25% (twenty-five percent) reduction. Such a weight reduction is critical in prolonging the users&#39; ability to propel themselves as the repetitive motion of propelling the wheelchair can cause injuries to and general deterioration of the users&#39; body, including injuries to the user&#39;s rotator cuffs, and user&#39;s elbows and wrists. 
         [0098]    Although I have very specifically described the preferred embodiments of the invention herein, it is to be understood that changes can be made to the improvements disclosed without departing from the scope of the invention. Therefore, it is to be understood that the scope of the invention is not to be overly limited by the specification and the drawings, but is to be determined by the broadest possible interpretation of the claims.