Abstract:
The present invention provides 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 for an effective 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 for mounting a wheelchair back to the upright canes of a wheelchair that provides smooth, non-incremental adjustability in three dimensions. The mounting apparatus 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, head injuries, etc.. 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 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 back system designs to properly position a wheelchair occupant.  
         [0003]     One problem with current back 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 a motor vehicle.  
         [0004]     Yet another problem with current back systems is the wide 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 canes may vary in diameter between 0.75″ to 1.125″. Additionally, the center to center distance of the canes may vary ±1″ despite the manufacturer&#39;s designation. Frequently, the canes may not be perfectly vertical.  
         [0005]     An additional problem with current wheelchair back systems is that they are not adaptable to all wheelchairs. For example, some wheelchairs, particularly those for persons having 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 positioning benefits offered by a wheelchair having an adjustable back. For example, wheelchairs for patients with special needs often have pneumatic cylinders and/or brake cables that limit the space required for mounting a back adequate to treat the particular patient. Frequently, therapist are required to mount the back support in the way it will fit, as opposed to the optimum fit for a particular user, potentially causing additional injuries to the patient. 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 carrier accessories such as bags.  
         [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 style wheelchair back provides almost no adjustability. Other wheelchair backs require a four point mounting system, which occupies lots of space along the wheelchair canes as well as limiting the ability of a therapist to position the wheelchair back. Additionally, some wheelchair backs provide limited adjustability, e.g. the wheelchair back can move vertically but has no seat depth adjustment, or the wheelchair back has seat depth adjustment but no angle adjustment.  
         [0007]     Therefore, what is needed is a wheelchair back mounting apparatus that is adaptable to wheelchairs having canes with varying diameters and being a wide variety of widths. There is also a need for a wheelchair back mounting apparatus that takes up less space on the wheelchair canes so as to permit the attachment of other items, such as bags. There is also a need to provide a wheelchair back mounting device that provides a wide variety of adjustability so eliminate comprising the users positioning requirements and that it can position all shapes and sizes of people. 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  
       [0008]     The present invention provides 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. This adjustability is also beneficial to the occupant of the wheelchair, as the adjustability can provide a wide variety of people having different shapes and sizes with a more custom fit. In order to provide this custom fit, the present invention provide for depth adjustability, height adjustability and angle adjustability of a wheelchair back.  
         [0009]     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.  
         [0010]     The present mounting system also provides for an effective two point mounting system that is reliable yet simple to use. The mounting system of the present invention provides a high degree of adjustability with respect to the angle that it can be inclined, particularly with respect to four-point mounting 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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  shows an exploded view of the mounting apparatus disclosed in the present application.  
         [0012]      FIG. 2  shows a close in view of the mounting apparatus disclosed in the present application.  
         [0013]      FIG. 3  shows a side view of the angle adjustment means of the mounting apparatus and the track system for use in depth adjustment of the wheelchair back.  
         [0014]      FIG. 4  shows a front view of the angle adjustment means of the mounting apparatus and the track system for use in depth adjustment of the wheelchair back.  
         [0015]      FIG. 5  is a side elevational view of the angle adjustment bracket.  
         [0016]      FIG. 6  is a top elevational view of the angle adjustment bracket.  
         [0017]      FIG. 7  is a side and bottom perspective view of the angle adjustment bracket.  
         [0018]      FIG. 8  is a top elevational view of the inner cane clamp.  
         [0019]      FIG. 9  is a side elevational view of the inner cane clamp.  
         [0020]      FIG. 10  is a back and side perspective view of the inner cane clamp.  
         [0021]      FIG. 11  is a top elevational view of the outer cane clamp.  
         [0022]      FIG. 12  is a side elevational view of the outer cane clamp.  
         [0023]      FIG. 13  is a top and side perspective view of the outer cane clamp.  
         [0024]      FIG. 14  is a side, front and top perspective view of the safety stop.  
         [0025]      FIG. 15  is a top elevational view of the safety stop.  
         [0026]      FIG. 16  is a side elevational view of the safety stop.  
         [0027]      FIG. 17  shows an exploded view of an embodiment of the present invention that employs a cam-lock quick release mechanism.  
         [0028]      FIG. 18  is a side elevational view of the cam-lock quick release mechanism.  
         [0029]      FIG. 19  is a side front and top perspective view of the dual back clamp.  
         [0030]      FIG. 20  is a front elevational view of the dual back clamp.  
         [0031]      FIG. 21  is a top plan view of the dual back clamp.  
         [0032]      FIG. 22  is a right side elevational view of the dual back clamp. 
     
    
     DETAILED DESCRIPTION  
       [0033]     Now referring to the drawings in detail, wherein like numbered elements correspond to like elements throughout,  FIG. 1  shows an exploded view of the Compass™ mounting system mounting system or apparatus, generally identified  1 , used to secure a wheelchair back  3  to a wheelchair cane  5 . In slightly more detail,  FIG. 1  shows the T-stock height adjustment  11 , the back dual clamper  21 , the cane clamp angle adjustment bracket  31 , the inner cane clamp  41 , the outer cane clamp  51 , the angle adjustment stud  71 , and the safety stop  81 .  FIG. 2  provides a closer view of the mounting system  1  as it would be when assembled and mounted to a wheelchair back  3 .  
         [0034]     Although no particular wheelchair cane  5  is shown in  FIG. 1 , the Compass™ mounting system  1  can be used to secure a wheelchair back to wheelchairs with cane diameters ranging from 0.75″- 1.125″. Additionally, the compass mount system  1  requires only two (2) inches of cane length to be securely mounted to the wheelchair cane  5 . This is especially advantageous in the case of wheelchairs having telescopic wheelchair canes  5 , as the strongest point of the telescoping wheelchair cane  5  is at the base of the cane  5 .  
         [0035]     Now referring to  FIGS. 8, 9  and  10  which show the inner cane clamp  41  in detail, it will be seen that the inner cane clamp  41  can generally be described as having a base  43  having a first set and a second set of tapped apertures  45 ,  46 , respectively, therethrough. The base  43  curves inwardly to form a narrower curved neck section  47  extending from the base  43 . The neck section  47  has an inner radius  49  for contacting a wheelchair cane  5 . The radius  49  is actually a double-hump radius in that it has an outer section accommodating a cane radius of up 1″ and an inner radius accommodating a cane radius of 0.875″. An additional feature of the inner cane clamp  41  is the rounded inset  44  which will be discussed in more detail later in this detailed description.  
         [0036]     Complementary to the inner cane clamp  41  is the outer cane clamp  51  as shown in  FIGS. 11,12  and  13 . The outer cane clamp  51  can generally be described as having a curved base portion  53  which fits around the curved base  43  of the inner cane clamp  41 . The outer cane clamp  51  also has a narrower neck portion  57  having a curved inner radius  59  for contacting a wheelchair cane  5 . The radius  59  is actually a double-hump radius in that it has an outer section accommodating a cane radius of up 1″ and an inner radius accommodating a cane radius of 0.875″. An additional feature of the outer cane clamp  51  is the rounded inset  54  which will be discussed later in this detailed description.  
         [0037]     It is to be understood that a pair of cane clamp screws (not shown) are to be inserted through the first set of apertures  45  in the inner cane clamp  41  and through the set of apertures  55  in the outer cane clamp  51 . The cane clamp screws can be tightened to provide compression to a wheelchair cane  5 . The Compass™ mounting system  1  is thus held in place on the wheelchair cane  5  by pressure exerted by tightening of the screws.  
         [0038]     Now referring to  FIGS. 5, 6  and  7 , which show the cane clamp angle adjustment bracket  31  in detail, the angle adjustment bracket  31  is attached to the inner cane clamp  41  via a pair of adjustment screws (not shown) that are inserted through the passages  33  and are tightened into the second set of tapped apertures  46  of the inner cane clamp  41 . The angle adjustment bracket  31  has an arched inset  34  that is disposed generally opposite to the arched insets  44 ,  54  of the inner cane clamp  41  and the outer cane clamp  51 , respectively.  
         [0039]     Now referring to  FIGS. 3 and 4 , which show the angle adjustment stud  71 , the device used for angle adjustment of the wheelchair back  3 . The angle adjustment stud  71  can generally be considered to be comprised of two parts. First, there is a length of round stock  73 . The length of round stock  73  is attached to a T-stock  77 . The round stock  73  fits into the passage created by the inset archway  34  in the cane clamp angle adjustment bracket  31  and the complementary inset archways  44 ,  54  in the inner and outer cane clamps  41 ,  51 , respectively. Angle adjustment screws (not shown) are inserted through the passages  33  in the angle adjustment bracket  31  and are used to secure the round stock  73  in the passage created by the inset archways,  34 ,  44  in the cane clamp angle adjustment bracket  31  and the inner cane clamp  41 , respectively.  
         [0040]     The round stock  73  provides adjustment means for wheelchairs of differing widths. More specifically, the round stock  73  provides a means for extension in the form of a tapped aperture  75 . The tapped aperture  75  permits the addition of a second length of round stock, thus permitting use of a wider wheelchair back  3 .  
         [0041]     As previously mentioned, the length of round stock  73  is attached to a piece of T-stock  77 . The piece of T-stock  73  includes a track  77  and can be any particular embodiment of sliding rail or track, which is well known in the art. The T-stock track  77  is in physical connection with the first inset track acceptor  23  on the back dual clamper  21 . See  FIGS. 19 through 22 . The back dual camper  21  is so called because it contains a first inset track acceptor  23  and a second inset track acceptor  25 . The first inset track acceptor  23  and the second inset track acceptor  25  are at right angles to one another. The first inset track acceptor  23  mates with the T-stock track  77  on the angle adjustment stud  71 . The second inset track acceptor  25  mates with the T-stock track  11 . Therefore, the back dual clamper  21  provides two directions of adjustment. Although a T-stock track  77  is used, other types of track are also acceptable for use with the invention. The requirements of the track  77  are that it simply include linear motion in one dimension.  
         [0042]     In application, the depth of the wheelchair back  3  in relation to the wheelchair seat is quickly and easily adjustable via a quick-release cam-lock  91  which is inserted through the aperture  29  in the back dual damper  21  and tightened against a nut (not shown) on the other side of the back dual damper  21 . The back dual damper has a relief, or slotted aperture  22  that permits the quick release,  91  to clamp the back dual damper on the T-stock track  77 . See  FIG. 18 . The quick-release cam lock  91  permits a wheelchair occupant or health care provider to quickly release the clamp on the T-stock track  77  in order to adjust the depth of the wheelchair back  3 . Additionally, if the wheelchair needs to be collapsed, the release of the cam lock  91  on each side of the wheelchair permits removal of the wheelchair back  3 .  
         [0043]     The dual back damper  21  is attached to the T-stock height adjustment track  11  on the wheelchair back  3  and slides along the T-stock height adjustment track  11  to allow wheelchair adjustment. To secure the dual back damper  21  to the T-stock height adjustment track  11  on the wheelchair back  3 , the dual back damper  21  provides a pair of passages  27  through which bolts (not shown) are inserted. When the wheelchair back  3  is positioned properly, the bolts are tightened, thus clamping the second inset track  25  to the T-stock height adjustment track  11 . The back dual clamper  21  has a relief or an slotted aperture  22 , which permits the user to clamp the dual back clamper  21  in place on the T-stock height adjustment track  11 . In this way, the wheelchair back height is locked into place. The present invention also provides for a safety stop, such as is shown in  FIGS. 14, 15  and  16 .  
         [0044]      FIGS. 14 and 15  and  16  show the safety stop  81 , which has a T-shaped inset  85  and is inserted over either of the T-stock height adjustment track  11  or the T-stock tracks  77  to prevent movement from a preset position. When the safety stop  81  is properly located, a screw (not shown) is threaded through the aperture  83  and tightened, thus eliminating the potential for motion in that direction. Frequently, the safety stops  81  are located on the T-stock track  77  so that a wheelchair can properly locate the appropriate depth on the T-stock track  77  so as to not repeatedly need to refit the depth of the wheelchair back. Additionally, the wheelchair occupant is not permitted to push on the wheelchair back so hard as to overcome the quick-release mechanism  91 . The safety stops  81  can also be located on the T-stock height adjustment track  11  on the wheelchair back  3 .  
         [0045]     The Compass™ mounting system  1  provides a single mount bracket system used to secure a wheelchair back to a wheelchair cane. This single mount system has many benefits, most important being that it requires only about 2″ of space on each wheelchair cane. This permits ample space along the cane for the use of other wheelchair accessories such as pneumatic cylinders, respiratory aids, positioning equipment and bags. Additionally, in the case of wheelchairs having telescopic canes, use of the Compass™ mounting system permits attachment of the mounts lower on the canes, which is the strongest portion of the telescoping canes.  
         [0046]     The single mount system also provides a large amount of adjustment travel in five degrees of motion. By simply loosening the two bolts (not pictured) in the threaded apertures  27 , a wheelchair back can be adjusted vertically a total of 6.8″ . The Compass™ mounting system  1  provides for quick and easy storage of the present invention in that the wheelchair back can be removed by the operation of two quick-release cam locks.  
         [0047]     Lastly, the present mounting system provides for angle adjustment of ±20° by simply loosening two bolts on each side of the wheelchair back  3 . What is especially important about the Compass™ hardware is that the patient does not need to be transferred during any of these adjustments. Other systems require the back to be unloaded. Each time a patient is transferred they run the risk of injury in the fitting stage for patients about to use a wheelchair as it alleviates the burden of transferring the patient into and out of the wheelchair.  
         [0048]     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.