Abstract:
A removable cover for a wheelchair tire. The cover is used to protect against the spread of contamination by the wheelchair tire. The cover may be formed of an elastic material or may have bands of elastic material attached along opposed edges to facilitate the installation of the cover over the tire and to hold the cover against the tire. The cover may be stored on the wheelchair during periods of movement over a contaminated surface, and then installed over the tire prior to moving onto a clean surface. The cover may be periodically washed to maintain its cleanliness or may be made from a disposable material.

Description:
This application claims the benefit of the Oct. 29, 1999, filing date of U.S. Provisional patent application Ser. No. 60/162,731. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of wheelchairs, and more specifically to a protective cover for the wheelchair tires to protect the user and his environment from hazardous contaminates. 
     Wheelchairs are well known in the art, being the subject of well over a thousand United States patents. Motive power for a wheelchair may be provided by an electric motor, or more commonly, by the hands and arms of the wheelchair user. By pushing or pulling on one or both of the main wheels of a wheelchair, a user is able to propel a wheelchair either forward, backward, or through a turn. Manually powered wheelchairs are equipped with push rings attached to each of the main wheels. The push rings provide a clean, smooth surface for the user to grip in order to propel, steer and stop the wheelchair. Because the tires of a wheelchair must necessarily roll over and through any variety of surfaces, they typically become contaminated with foreign matter and often become contaminated with substances that are hazardous to the health of the wheelchair user. The push rings generally provide the user with an alternative to touching the contaminated tire surface. However, because the push rings generally have a smaller diameter than the tires, and because they are typically made with a smooth metal surface having a lower coefficient of friction than the tires, it is at times not possi the required driving force through the push rings as may otherwise be exerted by gripping the tires. Push rings are sometimes wrapped with a cloth or leather wrap to improve the user&#39;s grip, however, wheelchair users often find themselves using the tires to propel the wheelchair in spite of the contaminated surface of the tire. 
     It should be appreciated that the tire surface and any associated crevices, such as the inside of the tire tread, are prone to accumulate foreign substances that are not only unpleasant to touch but may also present a critical health hazard to the wheelchair user. It is generally thought that various viruses and bacteria survive for an extended period of time within the crevices of a wheelchair tire. Such hazardous contaminations may be transferred to the wheelchair user&#39;s hands, and from the hands to the user&#39;s eyes, nose, mouth and any cut or abrasion in the skin. Such hazardous contaminates can also be transferred to any companion of the wheelchair user coming in contact with the contaminated tire or wheelchair user. In order to provide a degree of protection from such health hazardous contamination, wheelchair users often utilize gloves to isolate their hands from contamination present on the wheelchair tires. Gloves provide only a limited protection from a direct contamination of the hands because wheelchair gloves are designed without finger coverage. Therefore, the user is still at a health risk if he/she touches the contaminated tire with his/her fingers or touches any other part of the body with the contaminated glove or fingers. 
     In addition to protecting the user and immediate companions, there is also the need to protect against the spread of contamination onto non-contaminated flooring surfaces. In particular, after moving a wheelchair over a surface contaminated with a foreign substance, the user may desire to move the wheelchair onto a clean surface, such as the carpet in his/her home. Simply rolling the wheelchair over a clean surface may remove the bulk of foreign matter on the tires, thus making the tires appear clean. However, invisible contaminants may remain, as well as bulk contamination within the tire treads. Once inside the home, this contamination will spread, particularly onto carpets, thereby turning what is normally a safe home environment into a health hazardous space. 
     Various devices have been developed to clean the tires of a wheelchair prior to rolling onto a clean surface. One such device is the cleaning apparatus described in U.S. Pat. No. 5,860,180 issued on Jan. 19, 1999 to Heise. However, known cleaning devices are inconvenient to store and to use and they are costly. Furthermore, even after a wheelchair tire is cleaned with one of the prior art cleaning devices, it may still leave marks on a light colored rug or floor, such as when a black tire is turned sharply on a white tile floor, thereby leaving a skid mark. Tire designs having a desirable aggressive tread pattern are more prone to leaving skid marks on a light colored surface. More advantaged wheelchair users will often have one set of gray tires for indoor use and a separate set of standard, deep tread, black rubber bicycle tires for outdoor use. 
     BRIEF SUMMARY OF THE INVENTION 
     Thus there is a particular need for an apparatus and method for protecting against the spread of hazardous contamination by wheelchair tires. Such a device and method should desirably be inexpensive and simple for a wheelchair user to operate. Advantageously, such device and method may also protect against the accidental marking of a light colored floor or rug. 
     Accordingly, a wheelchair is described herein comprising a chair portion; a wheel rotatingly attached to the chair portion; a tire attached around a rim of the wheel; and a cover removably attached around the tire. Also disclosed herein, is a method for protecting against the spread of contamination by a wheelchair tire, the method comprising the steps of: providing a cover adapted to be removably installed over a wheelchair tire; and covering a contaminated wheelchair tire with the cover prior to rolling the tire onto a surface to be protected from contamination. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the present invention will become apparent from the following detailed description of the invention when read with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a wheelchair having a protective cover wrapped around the wheelchair tires. 
     FIG. 2 is a bottom view of a section of the protective cover of FIG.  1 . 
     FIG. 3 is a sectional view of a protective cover disposed over a wheelchair tire and push ring. 
     FIG. 4 is a sectional view of a protective cover disposed over a wheelchair tire and a second protective cover disposed over the push ring of the wheelchair. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a perspective view of a wheelchair  10  including a chair portion  12  and a wheel  14  rotatingly attached to the chair portion  12 . A pair of such rear wheels  14  provides the primary support for the wheelchair  12 . A smaller, secondary set of wheels  16  are attached near the front of the chair portion  12  to provide stability for the wheelchair  10 . Wheel  14  includes a hub  18 , spokes  20 , and a rim  22 . A tire  24  is attached around rim  22 , and may be any known solid, tube or tubeless design having any variety of tread patterns formed thereon. A protective cover  26  is removably attached around the tire  24 . 
     Cover  26  provides a flexibility of operation for the wheelchair  10  which addresses many of the problems of the prior art. Wheelchair  10  may be operated with covers  26  temporarily removed from the tire  24  and stored on the wheelchair  10 , such as inside pouch  28 . When the wheelchair  10  is moved over a surface contaminated with a foreign substance, tires  24  will become contaminated with the foreign substance. Prior to moving wheelchair  10  onto a clean surface not contaminated with the foreign substance, the covers  26  may be installed over the tires  24 . In this manner, a surface which is not contaminated will remain protected from the harmful residual amounts of the contaminating foreign substance remaining on the tires. This method of operating a wheelchair may be used, for example, when moving the wheelchair  10  onto a surface in the wheelchair user&#39;s home or office. By installing the cover  26  over the tires  24  of the wheelchair  10  upon entering a home or office, the user not only protects the flooring and people within the space from potentially hazardous contamination remaining on the tires and within the tire treads, but also protects the flooring from skid marks that may otherwise be left on the floor by the tires. Upon exiting the home or office and rolling the wheelchair tires off of the surface to be protected from contamination, the covers  26  may be removed from the tires  24  in order to avoid contaminating the outside surface of the cover  26 . The covers  26  may be conveniently stored in pouch  28  or other location on the wheelchair  10  before being reinstalled over the tires  24  prior to again moving the wheelchair  10  into a space where the flooring is maintained as a clean surface. 
     The front wheels  16  of wheelchair  10  are generally treadless and made from a plastic or polyethylene material which tends not to accumulate contamination and not to leave marks on light colored flooring. In the event that they become contaminated with a hazardous material, they can be easily cleaned because of their smooth surface. Therefore, it is less beneficial to install a removable cover on wheels  16 . However, it may be appreciated that additional covers for wheels  16  may be utilized in certain applications. 
     Cover  26  can be sized to extend over push ring  40  which is attached to wheel rim  22  by bracket  42 , as illustrated in FIG.  3 . For this embodiment, the bands of elastic material  34  are operative to urge the cover  26  against both the tread portion  38  and the push ring  40 . 
     Cover  26  may be formed from a ring of material having a generally circular perimeter as can be seen on FIG.  1 . FIG. 2 illustrates a partial bottom view of cover  26  of FIG. 1. A strip of material  29  has a center portion  30  adapted to fit over the tread surface of tire  24 . Attached to and preferably formed to be integral with the center portion  30  are opposed side portions  32  having inside diameter edges  36  disposed toward each other to form a generally tubular volume  27  as may be seen in FIG.  3 . The side portions  32  are adapted to fit over the side walls  25  of the tire  24  so that the tire  24  is disposed within the generally tubular volume  27 . A band of elastic material  34  is attached to the edge  36  of each of the respective side portions  32 . The elastic material  34  may be attached by any known means in the art, such as by sewing or by an adhesive. The bands of elastic material  34  are operative to urge the center portion  30  against the tread portion  38  of tire  24 . 
     Cover  26  may be conveniently manufactured by joining opposed short ends  44  of a generally rectangular strip of material  29  to form a ring shape. The respective ends  44  may be joined by sewing, gluing or other known joining process. The materials of construction of cover  26  must be flexible and are preferably washable or otherwise cleanable. Alternatively, cover  26  may be made from a paper or other inexpensive material and may be designed to be disposable after a limited duration of use. In one embodiment the strip of material  29  is a single generally rectangular shaped strip of a sueded polyester fabric material such as is sold under the trademark Conlure. This material has an inside surface  46  in contact with tire  24  which has a rough texture in order to promote friction between the cover  26  and the tire  24 . The outside surface  48  of the sueded material has a soft texture in order to protect the hands of the wheelchair user. The strip of material  29  may alternatively be an elastic material, in which case the separate bands of elastic material  34  may optionally be deleted. 
     Cover  26  may be made entirely without elastic properties, however such an embodiment would be operative for only a single sized tire. By providing either an elastic band  24  and/or elastic material for the ring of material  29  used to form cover  26 , a single cover  26  may be useable on more than one size tire. It may also be appreciated that by providing cover  26  with an elastic property, the installation of To the cover onto the tire  24  is made much easier for the wheelchair user to accomplish from within the wheelchair  10 . To install the cover  26 , a portion of the cover may be placed over the conveniently reachable portions of tire  24 , whereupon the wheelchair is rolled forward or backward to bring the uninstalled portion of cover  26  within easy reach of the user. 
     FIG. 4 illustrates an alternative embodiment of the invention wherein there is a first cover  26  disposed over tire  38  and a second cover  50  disposed over push ring  40 . Second cover  50  may have elastic bands  52  and/or may have ties  54  operable to be fastened to the brackets  42  used to support the push ring  40 . The selection of material for the cover  50  may be the same as cover  26  or may be a rubber or other material providing improved friction against push ring  40 , which is typically a stainless steel or chrome material. Cover  50  may remain installed over push ring  40  while cover  26  may alternately be installed and removed at will as the wheelchair  10  is moved between contaminated and noncontaminated surfaces.