Patent ID: 6203041
Filing Date: 2001-03-20
Classification: A61G

Abstract:
A wheelchair employing an incline anti-rollback device associated with each of two main wheels of the wheelchair for enabling a user to selectively and independently prevent forward or reverse rotation of either of two main wheels and to alternatively selectively and independently permit free-wheeling rotation of either of those two main wheels, each of the anti-rollback devices comprising:a hollow cylindrical axle fixedly mounted to a frame of the wheelchair proximate one of the main wheels, the axle having two diametrically opposed slots longitudinally positioned in a central area of the axle;a wheel hub coaxially positioned over the central area of the axle and supporting one of the main wheels for rotation;a pair of sprag assemblies mounted over the axle within the wheel hub in opposing rotational relationship to each other such that an outer cylindrical surface of each of said sprag assemblies reacts against an adjacent inner surface of said wheel hub;a pair of hub supports fixedly mounted on inner and outer flanges of said wheel hub to coaxially support said wheel hub over the axle;a shift lug diametrically positioned for longitudinal motion within the two slots in the axle;a shift cable, one end of which is positioned within said axle and fixedly attached to said shift lug; anda shift lever fixedly mounted to a frame member of said wheelchair within reach of the user, the other end of said shift cable being attached to said shift lever, the shift lever being actuable by the user for moving the shift lug to a neutral position between said pair of sprag assemblies to permit the associated main wheel to rotate freely in either direction, for moving the shift lug to a position of engagement with one of said sprag assemblies to permit said main wheel to rotate freely in a first direction but to prevent rotation thereof in a second opposite direction, and for moving the shift lug to a position of engagement with the other one of said sprag assemblies assembly to permit said main wheel to rotate freely in said second direction but to prevent rotation thereof in said first direction.