Patent ID: 6047980
Filing Date: 2000-04-11
Classification: A61G

Abstract:
A manual two-speed wheelchair comprising:a frame;a chair supported by the frame;a pair of oppositely situated wheel axles, each said wheel axle being fixedly connected to the frame and extending outwardly from the frame;a pair of wheel assemblies, each said wheel assembly including a wheel, a centrally positioned hub, and at least one torque transferring support interconnecting the hub to the wheel; said hub defining an opening of a size and shape to receive one of said wheel axles, wherein each said wheel assembly can freely rotate about its corresponding wheel axle, and wherein the wheel assemblies are spaced apart with the frame and chair positioned between the two spaced apart wheel assemblies, and wherein each wheel assembly is confined to rotate about its corresponding wheel axle such that when a user applies a propulsion force onto the wheel assembly, the wheelchair is propelled in the direction of the applied force in a direct drive mode;a pair of secondary input rim assemblies, each secondary rim assembly to correspond with one said wheel axle, wherein each secondary input rim assembly is external and adjacent its corresponding wheel assembly; andeach said secondary input rim assembly including a secondary input rim and a centrally located input hub, such that an input axle shaft extends essentially perpendicularly from the input hub and offset from the wheel axle;said secondary input rim assembly further including a gear reducing assembly having a toothed driven gear connected to the hub, and a toothed belt, wherein the driver gear is offset from the driven gear such that when a propulsion force is applied to one of the secondary input rims, the corresponding input axle shaft drives its corresponding driver gear, which, in turn, drives the corresponding toothed belt, which, in turn, drives the corresponding driven gear, and which, in turn, drives the corresponding wheel assembly in a reduced gear mode; anda rigid offset arm to offset the driver gear from the driven gear;wherein the offset arm further includes an elongated slot of a size to receive the input axle shaft, wherein the distance between the driver gear and driven gear is adjustable along the longitudinal length of the elongated slot, said offset arm also further includes another opening offset from the elongated slot, wherein the other opening is of a size to receive the wheel axle; andwherein the secondary input rim assembly further includes a belt tension adjuster plate positioned externally of the offset arm and adjacent said elongated slot of the offset arm, said belt tension adjuster plate defining an opening through which the input axle shaft may be received and includes peripheral notches, each said notch being of a size to mate with a pin connected to the offset arm, wherein the pin and belt tension adjuster plate maintain the tension of the toothed belt in relation to the driven gear and driver gear and the location of the input axle shaft in relation to the wheel axle.