Abstract: A propulsion means for wheelchairs includes two drive assemblies, one mounted at each side of a wheelchair. Each drive assembly includes an axle which is rotationally oscillated by pumping a drive lever pivotally mounted on and engaged with said axle. Two overrunning clutches are also mounted on said axle: one clutch disposed to engage when the axle is rotated in a clockwise direction, and the other disposed to engage when the axle is rotated counterclockwise. A chain, connected to a ground wheel, is connected to one clutch and then the other through a reverse bend in said chain, so that the oscillatory motion of said axle is transmitted through said chain to cause unidirectional rotational motion in said ground wheel.