Automatic transmission for multi-speed bicycle

摘要

An automatic transmission for a linked chain driven wheel includes a plurality of chain-engaging sprockets disposed coaxially with and spaced apart along the axis of rotation of the wheel. Each of the sprockets has a predetermined diameter which differs from that of the other sprockets. The sprockets are drivingly connected to the wheel. A chain guide, which is axially movable relative to the sprockets, is provided. The chain guide, when aligned with a given sprocket, will guide the drive chain into engagement with that given sprocket. A chain guide actuator is operatively connected to the chain guide for varying the axial position of the chain guide automatically in response to the angular speed of the wheel.