Abstract:
A wheelchair propulsion and contamination reduction arrangement permits the user to drive the chair on the main ground-engaging rear wheels with a compressible wheel cover that is grasped and squeezed against the wheel to provide propulsion and mounted with elastic tension devices on opposite ends that return the drive grip to a neutral position when the user relaxes the compression. The compressible device is a polymeric foam which can also be adapted to carry one or more of a lubricant, cleaner and biostatic treatment.

Description:
BACKGROUND 
     The present invention relates to an apparatus for facilitating operator use of a wheelchair in a sanitary manner that inhibits the transfer of contaminants from the wheel to the user and also prevents the buildup of such contaminants on the wheel surface. 
     Certain governmental agencies, such as the Occupational Safety and Health Administration (OSHA), the Center for Disease Control and Prevention (CDC) and similar state agencies and authorities issue and enforce standards for minimizing contamination of appliances, articles and various other devices that are touched and used by residents and/or patients in hospitals, assisted living facilities, and nursing homes. Responsible agencies, authorities and administrations promulgate, monitor and enforce regulations to inhibit the propagation of contaminants on appliances that may carry bacteria, viruses and other disease carrying contaminants. Rules and regulations to minimize the transfer of such diseases address all types of apparatus and appliances that are routinely touched by patients, residents, healthcare providers and other workers. 
     One device that is particularly problematic and well known to be the source of many kinds of contaminants is the ubiquitous wheelchair found and used in all the aforementioned facilities. A conventional wheelchair has two main large diameter rear wheels to which are attached concentric smaller diameter push or drive wheels. The user grasps the smaller diameter concentric wheel to drive the wheelchair and to avoid user contact with the large diameter floor-engaging rear wheels. Regulations typically require periodic cleaning of the main rear wheels, but, as is apparent, freshly cleaned rear wheels will quickly become contaminated. A user utilizing the push ring oftentimes contacts the large diameter wheel with the user&#39;s wrists as the push wheel is propelled by the user. 
     SUMMARY 
     The present invention provides a sanitary wheel cover and a drive grip that permits the user to drive the wheelchair by the large floor-engaging rear wheel without direct contact therewith. The drive grip can be grasped by the user and flexed to compress a compressible portion against a portion of the outer rim of the main wheel to alternately propel the wheelchair in a forward direction (or similarly the rear direction) and then release the grip for return to a neutral position under the influence of an elastic strap that connects each end of the drive grip for the respective front and rear of the wheelchair frame. The apparatus of the present invention may be used without the need for a conventional push rim because the user&#39;s hands grasp the drive grip and large wheel to provide propulsion. 
     The sanitary wheelchair cover and drive grip of the present invention is intended primarily for use on a wheelchair of the type that has a user supporting frame, a pair of large diameter rear wheels carried on the frame and engageable by the user to propel the chair. The apparatus of the present invention facilitates user propulsion without contamination of the user&#39;s hands from material picked up in use and carried on the outer surface of the rear wheels. 
     A semi-circumferential drive grip  19  is demountably attached to a tire on the large outer rim of each rear wheel. The drive grip includes a manually compressible portion that is in direct contact with the outer rim and a flexible grip cover that overlies the compressible portion of the grip. An elastic strip connects each end of the drive grip to the respective front and rear of the wheelchair frame to hold the grip in a neutral position. The user is able to grasp the grip and compress the compressible portion against the tire on the outer rim and push the main drive wheel forwardly. This movement increases the length of and tension in the rear strap and provides rolling movement of the wheel. Releasing the grip by the user reduces the compression to permit higher tension in the rear strap to return the grip to the neutral position. Rearward movement of the wheelchair is accomplished in a similar manner. 
     The manually compressible portion of the drive grip preferably comprises a tubular piece of polymeric foam that is curved to adapt the tubular piece to the curvature of the wheel. The flexible grip cover preferably comprises a U-shaped plastic piece that overlies the tubular foam piece. In one embodiment, the U-shaped plastic piece is fastened to the tubular foam piece. The plastic piece may be fastened to the tubular piece with an adhesive, a hook-and-loop fastener, or some other suitable connecting device. 
     The radially outer surface of the flexible plastic piece preferably has an outer grip-enhancing texture or similar surface treatment. The elastic strip extends through slots in the respective front and rear ends of the grip cover. The elastic straps may comprise separate straps, but, preferably, the elastic straps are one-piece. Each elastic strip is demountably attached at opposite strap ends to the wheelchair frame. 
     The interior surface of the tubular foam piece may be provided with one or more layers or coating of a material that is selected from the group consisting of a lubricant, a cleaner and a biocide. The lubricant coating facilitates sliding movement of the tubular piece relative to the wheel rim when not being compressed and propelled. The coating of a cleaner and/or a biostatic provides protection against contamination of the user&#39;s hands and anyone or anything else that might come into contact with a user. The tubular foam piece may be detachable from the grip cover for disposal and replacement. Preferably, the tubular foam piece is cut from a spirally wound supply to more easily adapt to the curvature of the wheelchair drive wheels. Further, the tubular foam piece is preferably formed with a slit along its length providing a C-shaped tubular piece having oppositely facing lengthwise edges. If the foam piece is not pre-formed with a curvature, the lengthwise edges of the C-shaped tubular piece can be provided with V-shaped slots to accommodate bending of a straight tubular piece to the desired curved shape. 
     In a related method for facilitating sanitary use and propulsion of a wheelchair by a user, the wheelchair having a frame and a pair of large diameter rear wheels carried on the frame and engageable for propulsion by the user, the method comprises the steps of (1) mounting a semi-circumferential drive grip to an outer portion of a tire on the rim of each rear wheel, (2) providing the drive grip with a tubular piece of polymeric foam in contact with the tire on the wheel outer rim, (3) providing the drive grip with a flexible grip cover that overlies the compressible tubular foam piece, (4) attaching the grip cover to the tubular foam piece, and (5) connecting the opposite circumferential ends of the drive grip to the front and rear of the wheelchair frame with respective front and rear elastic members, whereby the drive grip is initially held in a static neutral position by the elastic members. Manual engagement of the drive grip with squeezing and pushing action by the user causes the compressible tubular foam piece to clamp the wheel, and causes the wheel and chair to move forwardly without direct contacting touch of the wheel by the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a prior art wheelchair to which is attached the sanitary wheel cover and drive grip of the present invention. 
         FIG. 2  is an enlarged side elevation view of the sanitary wheel cover and drive grip of the present invention. 
         FIG. 3  is a bottom plan view of the cover and drive grip shown in  FIG. 2 . 
         FIG. 4  is an isometric sectional view taken on line  4 - 4  of  FIG. 3 . 
         FIG. 5  is an enlarged detail taken on line  5 - 5  of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , there is shown a conventional wheelchair  10  having a general construction well known in the art. A frame  11  provides support for the seated user and includes front and rear frame members  12  and  13  that are interconnected with side frame members  14  and  15 . The front frame member includes a connection at the lower end to a pair of castered support wheels  16 . A pair of large diameter drive wheels  17  and  18  are carried by the side frame members  14  and  15 . To support the user, flexible cloth or cloth-like panels are attached to the frame  11  and include a seat panel  21 , a pair of side panels  22 , and a pair of generally vertically aligned back panels  23 , all in a manner well known in the art. The upper ends of the rear frame member  13  includes push arms  24  to provide assistance to the user and a pair of front foot supports  25  that are typically pivotable to swing away or are completely detachable. 
     In  FIG. 1 , the sanitary wheel cover and grip  19  of the present invention is shown attached to the wheelchair W and, in  FIGS. 2 and 3 , the sanitary wheel cover and grip  19  is shown enlarged and detached from the wheelchair W. The cover and grip  19  includes a tubular semi-circumferential piece of polymeric foam  26  that, in use, is attached to a tire  29  on the rim  27  of the drive wheel  17 ,  18 . The tubular foam piece  26  has a longitudinal slit  28  that defines oppositely facing lengthwise edges  30 . The slit  28  facilitates attachment of the cover and grip  19  to the rims and tires  29  of the drive wheels  17 ,  18 , and also adapts the device to varying rim sizes. 
     The polymeric foam from which the tubular piece is made may vary considerably, but a closed cell polyurethane foam has been found to be suitable. Other foam materials of both open and closed cell construction may also be used. 
     A flexible grip cover  31  overlies and partially covers the tubular foam piece  26 . The grip cover may be formed to the curvature of the drive wheels  17  and  18  or may be sufficiently flexible to bend to the desired curvature. Any relatively hard, but flexible plastic may be used. However, if the tubular foam piece is cut from straight tubular stock, the tubular pieces may be formed with V-shaped slots  32  spaced along the edges  30  of the longitudinal slit  28 . The flexible grip cover  31  is preferably of a generally U-shape and has an outer grip-enhancing texture  33  or similar surface treatment to minimize slippage of the user&#39;s hands on the cover. 
     Although the grip cover  31  may be adhesively attached to the tubular foam piece to provide a desired permanent connection, allowing the integral cover  31  and foam piece  26  to be disposable, the foam piece  26  may be removable or demountable for replacement. If the foam piece is intended to be removable from the grip cover  31 , the pieces may be fastened together with an easily removable adhesive, a hook-and-loop fastener, or some other suitable connecting device. 
     An elastic strip  34  connects each end of the grip cover  31  to a front frame member  12  and a rear frame member  13 . The elastic strip  34  may comprise a single piece of elastic or two separate strip pieces. In the embodiment shown, the elastic strip  34  is unitary. The strip is attached to the grip cover  31  by running opposite ends of the strip through front and rear strip slits  35  in the cover where the center of the elastic strip may be held in place with the same adhesive used to attach the grip cover  31  to the tubular foam piece  26 . The opposite front and rear free ends of the elastic strip  34  may be conveniently wrapped around any suitable portion of the side frame members  14  and  15 , stretched to provide tension in the strip, and brought back on itself and fixed in position with a hook-and-loop fastener  36 . With both ends of the elastic strip  34  attached and tensioned as indicated, the drive grip  19  is held in a neutral position as shown in  FIG. 1 . 
     When a user seated on the wheelchair  10  grasps the grip cover  31  of the drive grip  19 , the grip is easily slid along the tire  29  and rim  27  of the drive wheel  17 , but if the user squeezes the drive grip, a gripping force is applied to the tire and rim to cause the wheelchair to be propelled forwardly. The forward movement of the drive grip simultaneously causes the front end of the elastic strip  34  to contract and to decrease the tension therein. At the end of forward movement of the drive grip, the user releases the compression and the rear end of the elastic strip  34 , having been lengthened and further tensioned by the drive grip, will cause the drive grip to slide rearwardly to the neutral position of the grip. 
     If necessary, the ID of the tubular foam piece  26  may be lubricated by applying a thin coating of a suitable lubricant thereto. In addition, the ID of the foam piece  26  may also be provided with a biostatic coating and/or a suitable cleaner. In this manner, the sanitary wheel cover and drive grip  19  of the present invention minimizes user contact with the tires  29  and rims  27 , helps keep the device clean and may provide a suitable decontaminant. The conventional wheelchair push wheels or rims may be eliminated.