Abstract:
A propulsion and exercise device for attaching to a conventional wheelchair having: at least one drive wheel operably interposed between the rear set of wheelchair wheels. A telescoping mast may connect the drive wheel axle to pedals to permit the pedals to be selectively moved from a stowed position to an extended position for use. Power is transmitted from the pedals to the drive wheel through a chain drive that passes over idler sprockets that maintain the chain length during adjustment of the telescoping mast.

Description:
[0001]    This application claims benefit to U.S. provisional patent application Ser. No. 60/945,214, filed Jun. 20, 2007, the entirety of which is hereby incorporated by reference, and is a continuation-in-part patent application of U.S. patent application Ser. No. 11/532,791, the entirety of which is hereby incorporated by reference, which claims priority to U.S. provisional patent application Ser. No. 60/722,676, filed Sep. 30, 2005, the entirety of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention known as the “Pedalong” is a foot-powered attachment for propulsion by and therapeutic exercise for the seated user of a wheelchair. 
       BACKGROUND 
       [0003]    Wheelchair mobility improvements and exercising devices have been developed by numerous inventors. Beddome et al. (U.S. Pat. No. 5,242,179) discloses a four limb exercising attachment for wheelchairs which will also propel the wheelchair. In one embodiment, the Beddome device incorporates a fifth wheel connected by chain drive to pedals mounted on a mast which extends forward of the chair seat. Further, one segment of the chain drive telescopes to shorten when the drive is stowed; however, a substantial part of the chain drive extends beyond the wheelchair frame when in the stowed position. 
         [0004]    Berkheimer (U.S. Pat. No. 5,273,304) discloses a leg-powered, lean-steerable attachment for a wheelchair. This device attaches to the underside of the wheelchair with a pole extending forward and carrying a bearing for a vertical axis about which steering of a pedaled front wheel occurs. This new front wheel lifts the wheelchair&#39;s two front wheels so the combination behaves like a tricycle. 
         [0005]    Long et al. (U.S. Pat. No. 6,910,701) discloses a wheelchair propulsion using hand cranks driving sprockets which (through chain connection) drive the large rear wheels of the chair. The cranks reciprocate, rather than rotate through 360 degrees to ease the user&#39;s task. 
         [0006]    McKelvey (U.S. Pat. No. 5,207,286) discloses a bicycle-like front end for a wheelchair with pumping rather than rotating pedals. 
         [0007]    Merlan (U.S. Pat. No. 3,485,510) powers the wheelchair&#39;s forward motion with hand-cranked pedals above a chain-driven front wheel. This assembly is on a pivotable support for steering. 
         [0008]    Adams (U.S. Pat. No. 6,409,195) discloses a “sport-type” wheelchair which is tricycle-form with the pedals driving the rear wheels through a chain and sprockets. 
         [0009]    Benz (U.S. Pat. No. 3,912,032) discloses a gasoline engine powered front end for a wheelchair. This front-end device attaches and lifts the front two wheels of the wheelchair converting it into a tricycle. 
         [0010]    Salmon (U.S. Pat. No. 6,092,822) discloses a wheelchair having a pedal operated transmission to drive a pair of rear wheels. 
         [0011]    Van Vooren (U.S. Pat. No. 5,066,032) merges a hand-driven bicycle at the front end of a wheelchair and lifts the forward wheels of the wheelchair with attachment of the bicycle. The apparatus may be adjusted in height or width during the initial assembly only, but it does not permit the adjustment of the position of the pedal assembly forward or backward (e.g., to be able to position the pedal assembly substantially under the seat). 
         [0012]    Young (U.S. Pat. No. 4,471,972) discloses a hand-driven front end to the wheelchair which lifts the front wheels of the wheelchair. 
         [0013]    Durham et al. (U.S. Pat. No. 4,572,501) disclose an exercise attachment which fits under and lifts the wheelchair&#39;s front wheels from the ground. The device is claimed to also have a propulsion mode. The attachment has four wheels which are in front of the wheelchair when attached. 
         [0014]    Moore (U.S. Pat. No. 4,824,132) discloses an arm exercise device connecting to the front of the wheelchair. Moore&#39;s device also has a propulsion mode in which a forward wheel is lowered to the ground raising the wheelchair&#39;s front two wheels. 
         [0015]    A published Japanese patent application (Publication No. 2003-339779; published Dec. 2, 2003) owned by Honda Seiki KK, discloses a pedal drive type wheelchair. In the Honda device, the front wheels function as drive wheels and the rear wheels function as steering wheels. The seat is movable longitudinally to adjust for the size of the user as well as rotationally, to ease entry and exit from the device. Steering is provided by way of a steering shaft connected to gearing serving to turn the rear wheels. 
         [0016]    Finally, Honda Rikio describes a foot-operated wheelchair driving mechanism in Japan Patent Abstract 2004-065887 published on 3 Apr. of 2004. His device incorporates a driving pedal system in front and a driving fifth wheel in the rear both mounted on a connecting gear case which pivots at a shaft fixed to the frame of the wheelchair and penetrating across at the front of the gear case. The rear part of the gear case is pushed down by a spring fixed to the frame of the wheelchair rearward of the pivot, thus supplying grounding pressure. 
         [0017]    The present invention differs from and provides improvements over this Honda design in its elimination of the forward pivot and hold-down spring and in its connection of the rear wheel axle rigidly to the wheelchair frame. This rigid connection eliminates the tendency of the hold-down spring to pitch the wheelchair forward. Also, pivoting about the rear wheel axle permits the raising and lowering, and telescoping, of the system for greatly improved user access and adjustability to user size. 
       SUMMARY OF THE INVENTION 
       [0018]    The invention (generally referred to as the “Pedalong”) disclosed herein is for both exercise and propulsion of wheelchair-bound individuals. These decreased mobility individuals include the very elderly, recovering accident, stroke, and heart attack victims, and chronic disease victims like those with cerebral palsy, MS, obesity and diabetes. 
         [0019]    In a first embodiment of the device, the Pedalong contains a “fifth wheel” located between the rear wheels and rotating on its own horizontal axle below this fixed rear wheel axis. This fifth wheel&#39;s lower edge is adjusted relative to the lower edge of the two rear wheels so that most of the user&#39;s weight is divided between the fifth wheel and one or the other of the rear wheels. Of course, part of the user&#39;s weight is carried on the two front wheels. On this fifth wheel axle, a telescoping tube is mounted to support the pedals. From the pedals, power is transmitted to the fifth wheel by a chain drive. The telescoping tubes permit the length, and an adjustable front support permits the height of the pedals, to be adjusted by the therapist or the user. The placement of the telescoping tubes above the rear axle also enables retraction of the pedal mechanism under the chair for stowage. 
         [0020]    A collet-like clamp or other fastening mechanism secures the forward, inner tube within the rear, outer tube at the properly adjusted length. A set of idler sprockets adjusts the total chain path length to retain chain tension during extension of the system. The pedal/front axle assembly is releasably connected to the drive sprocket so that the wheelchair can be pushed without the pedals rotating while they are retracted. 
         [0021]    Steering can be accomplished by turning one of the front wheels with a handle or steering arm mounted at the armrest level, or by the user&#39;s leaning in the direction of the desired turn and continuing to pedal the fifth wheel while retarding the rear wheel now on the ground. The front wheels are on castors and follow the steering movement for either method of steering by the occupant of the wheelchair. It is also possible for the therapist or attendant to completely control direction of movement by simply pushing the wheelchair in the desired direction. 
         [0022]    An electric motor and controller may be added to assist the pedaled drive. Also, motors may be provided for electrically lifting and/or telescoping the adjustment for user size and for ease of access for the user. Alternatively, a multi-speed capability may be added by, for example, incorporating a conventional three-speed bicycle rear axle in the chain drive. 
         [0023]    A brake may be provided for slowing, stopping or parking the wheelchair, as well as a “deadman switch” that releases the propulsion system to allow motion only when activated by the user. 
         [0024]    In a second embodiment of the present invention, the rear axle carries two wheels and the attachment brackets for the rear axle are easily adjusted for height. This permits either or both of the large wheels to be lifted from the ground as selected by the user. In this configuration, the entire rear axle rotates. To allow cornering, either one of the wheels may be loose on the axle or a conventional differential may be used. 
         [0025]    In a third embodiment of the present invention, the rear axle carries two wheels, the attachment brackets for this rear axle are locked, the rear axle is driven by the driven sprocket, one or both wheels are driven, and the original wheelchair rear wheels may be eliminated. 
         [0026]    Any of these embodiments can be supplied in small, medium and large main frame lengths to accommodate different users, and with other combinations of the features described. To motivate the user and assist the therapist, an odometer may be mounted on the front end of the device. 
         [0027]    The invention likewise comprises: a wheelchair device having any of the propulsion and exercise systems described above attached. 
         [0028]    The present invention is also directed to a method for converting a conventional wheelchair, having a frame with at least two structural rails, pivoting front wheels, a rear set of laterally spaced wheels and a surface for supporting the user, to a propulsion and exercise device. The method comprises the step of operably attaching any of the propulsion and exercise systems described above to the wheelchair using brackets at both ends of both the rear axle and the front crossbar. It is important that the Pedalong attaches to most conventional wheelchairs because individual comfort and operability is possible only with proper fitting of the wheelchair to the individual. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is a side perspective view of the Pedalong&#39;s first embodiment attached to a conventional wheelchair. 
           [0030]      FIG. 2  is a rear view of  FIG. 1 . 
           [0031]      FIG. 3  is a side view of the wheelchair and Pedalong shown in  FIG. 1  with the right side of the wheelchair removed. 
           [0032]      FIG. 4  is a side view of the wheelchair and Pedalong shown in  FIG. 3  showing the Pedalong in a retracted position. 
           [0033]      FIG. 5  is a top perspective view showing one embodiment of the Pedalong. 
           [0034]      FIG. 6  is a top perspective view showing the Pedalong of  FIG. 5  with its front and rear supports removed. 
           [0035]      FIG. 7  is a side view showing the Pedalong of  FIG. 6  with the drive wheel removed. 
           [0036]      FIG. 8  is a partial perspective view showing the collet and front support of one embodiment of the Pedalong installed on a wheelchair. 
           [0037]      FIG. 9  is a partial perspective view showing the connection between the pedal assembly and front sprocket for the Pedalong shown in  FIG. 6 . 
           [0038]      FIG. 10  is a rear view of an embodiment of the Pedalong with the drive wheels locked down and the original wheelchair rear wheels eliminated. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]    While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will herein be described in detail, several specific embodiments, with the understanding that the present disclosure is to be considered merely an exemplification of the principles of the invention and the application is limited only to the appended claims. 
         [0040]      FIG. 1  shows a conventional wheelchair  10  with its structural rails  11  providing connection for its four wheels and with the chain-driven first embodiment of the Pedalong  12  located between and supported between these rails. Front cross rod or support assembly  14  connects to the rails, and provides a rigid connection for the mast  13 . A drive chain  18  connects the drive sprocket  15  and wheel or driven sprocket  16  (shown on  FIG. 7 ). Steering arm  20  connects through a vertical shaft  28  to the front wheel  21 . 
         [0041]      FIG. 2  is a rear view of the wheelchair and attached Pedalong. The drive wheel  17  and wheel sprocket  16  are interconnected. While one drive wheel is shown, it is appreciated that multiple drive wheels may be used and not depart from the scope of the present invention. This assembly is then supported by a wheel or rear axle  19  which connects to the structural rails  11  through a pair of adjustable brackets  22 . U-bolts  23  or other fasteners may be used to secure the brackets  22  to the structural rails. Eyebolts  24  then connect to the wheel axle  19 . It is appreciated that in the case of multiple drive wheels, the height of the wheels may be adjusted using the adjustable brackets or other known means to permit a user to selectively engage the drive wheels and lift of one or both of the wheelchair&#39;s rear wheels off the ground. 
         [0042]    As shown on  FIG. 3 , the front drive assembly, or pedal and driving sprocket assembly, contains pedal arms  25 , pedals  26 , the drive axle  27 , and drive sprocket  15 . The chain path passes over drive sprocket  15 , idler sprockets  30 ,  31 ,  32  (partially hidden by the rear wheel  17 ), wheel sprocket  16  (completely hidden by the rear wheel  17 , but shown in  FIG. 7 ), and then idler sprockets  33  and  34 . The length of the mast  13  is telescopically adjustable and the idler sprockets maintain chain length when the mast telescopes. 
         [0043]    In  FIG. 4 , the pedals are shown retracted under the seat of the wheelchair. Use of the idler sprockets  30  and  31  spreads the chain so that idler sprocket  34  can move rearward above the wheel axle  19 . Plate  62  carries a sleeve which, during mast angle adjustment, rotates on the fixed wheel axle  19 . The outer tube  60  is fixed to plate  62  as are the idler sprockets  30 ,  31 , and  32  (partially hidden by the rear wheel  17 ). Idler sprocket  33  is supported from front plate  61  attached to the right end of the outer tube  60 . 
         [0044]      FIG. 5  shows the Pedalong without the wheelchair. The adjustable brackets  22  and the front support brackets  40 , the outer tube  60  and the inner tube  70  of the telescoping mast extend forward from the wheel axle  19  to the drive axle  27 , which carries the drive sprocket  15 . 
         [0045]    Drive chain  18  transfers the drive axle  27  rotation to the wheel sprocket  16  (completely hidden by the drive wheel  17 ) which is connected to drive wheel(s)  17 . The chain is serpentinely looped around a set of idler sprockets to provide length adjustability as set forth in more detail below. Chain guard  50  may be used to provide safety and/or improve the appearance. A handle  51  or other object to permit a user to firmly grasp may be used to pull the inner tube forward to the desired extension. It is also appreciated that an electrically powered extension-retraction screw may be operably attached to the mast to facilitate adjustment and movement of the mast. 
         [0046]    In  FIG. 6 , the Pedalong is shown in an extended position, illustrating the forward movement of sprocket  34  toward sprocket  33  (as compared to the retracted Pedalong in  FIG. 4 ). This movement occurs because sprocket  34  is mounted on a shaft which extends from its mounting on the inner tube  70  through the slot  64  on the outer tube  60 . 
         [0047]      FIG. 7  has the wheel and axle removed revealing wheel sprocket  16  and idler sprocket  32  which increases the wrap of chain  63  on wheel sprocket  16 . When a user (e.g., the therapist) releases collet (as shown in  FIG. 8 ) and pushes leftward on handle  51  to shorten the mast  13 , the inner tube  70  slides leftward in outer tube  60  carrying sprocket  34  to the left. With this motion, the upper chain strand  65  shortens, and the lower strand  66  lengthens by equal amounts. This action preserves the chain tension which had been earlier adjusted with screw  67  pushing on the mounting of sprocket  30 . 
         [0048]    To permit reduction of the overall height of the Pedalong, sprocket  16  can be moved to the opposite side of plate  62  and beyond tube  60  so that rear axle  19  can be moved up to nearly touch chain  66 . A new sprocket may be placed on the shaft with sprocket  31  to carry a new, short chain to the relocated drive sprocket  16 . 
         [0049]    Further, sprocket  32  is eliminated and sprocket  31  raised so that chain  63  goes straight from sprocket  31  to sprocket  33 . The effect of these changes is an approximately 20% height reduction that allows the pedals to be raised to an improved operating position when Pedalong is mounted on a conventional wheelchair. 
         [0050]      FIG. 8  shows one embodiment of the collet mechanism and front support of the outer tube in detail. When the therapist tightens the threaded handle  53  onto the front block  54  which is welded on to the outer tube  60 , the split  52  (running through both the outer tube and the block) closes down and holds the inner tube  70  at the desired extension length by friction. The threaded handle  53  passes through one of the holes on the vertical guide  55 , which is attached to the front cross rod  14 , to permit the user to change the height of the pedals relative to the ground and to provide a rigid front support for the Pedalong. While a collet-type fastener is shown and disclosed, it is appreciated that other known locking devices or means to selectively position the tubes relative to one another may be used and not depart from the use of the present invention. 
         [0051]      FIG. 9  shows details of one embodiment of the front drive assembly engagement. Blind hole  56  in the drive sprocket  15  hub accepts pin  58  which is retained by holder  57 . Pin  58  has a small side pin (not shown) which slides into either of the slots  59  in holder  57  to engage or disengage the drive. 
         [0052]      FIG. 10  shows an embodiment of the Pedalong with the drive wheels  17  locked down and the original wheelchair rear wheels eliminated such that the wheelchair rests on the drive wheels  17 . In operation, the drive wheels  17  are spaced apart on the rear axle  19 , which rotates upon use of the propulsion and exercise system to drive the wheels  17 . It is appreciated that only one of the wheels  17  on the rear axis may be driven (i.e., act as a drive wheel) and not depart from the scope of the present invention. 
         [0053]    It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is limited only by the scope of the appended claims. In particular, all references to chain and sprockets apply equally to belt and pulley arrangements.