Patent ID: 7665754

Claim:
A propulsion unit for a wheelchair wherein the wheelchair has a frame with a pair of large diameter wheels of the type having a track having an outer surface and an inner surface, the propulsion unit comprising: a body having a front portion, a rear portion and a handle; at least three rollers pivotally mounted to said body, two of said at least three rollers being spring biased and adapted to be mounted in contact with one of the inner and outer surfaces of the track, the remaining of said at least three rollers adapted to be mounted in contact with the other of the inner and outer surfaces of the track; front and rear friction elements positioned in said front and rear portions of said body respectively, said front friction element adapted to engage the track when a forward pressure is applied to said handle rocking said body forward, said rear friction element adapted to engage the track when a rearward pressure is applied to said handle rocking said body rearward; and wherein when the handle is pressed forward the wheel is propelled forward and when the handle is pressed rearward the wheel is propelled rearward.