Bicycle drive without dead centres - has internally toothed plate engaged by eccentric two-lobed cam

摘要

The drive has no dead centre position either at top or bottom, and reduces static resistance, while simultaneously accelerating the return of the non-driving pedal. It comprises an internally toothed plate (2) and an eccentric two-lobed cam (3). This engages each lobe alternately in the teeth, while the other one comes free of them. Then the lobe is connected by a pin and a slide to a semicircular lever fixed to a crank, a lug is provided on the outside of the plate so that each pawl on the levers provides the drive between the lever and the plate in the same vertical plane. Each pawl is controlled by a sliding eccentric section in its lever, moved by the relative positions of the levers.