DRIVE APPARATUS FOR A CYCLE

摘要

Drive apparatus (2) for a cycle (4), comprising an electric motor (6), a first pulley (8) driven by the electric motor (6), a second pulley (10), an endless belt (12) which passes around the two pulleys (8, 10) and is driven by the first pulley (8), and a swinging link mounting means (14). During use the endless belt (12) is in driving engagement with a tyre (16) of a wheel (18). The mounting means (14) enables the distance between centres of the first and the second pulleys (8, 10) and the tyre (16) to vary during use of the drive apparatus (2), which enables the drive apparatus (2) to exert on the tyre (16) a varying contact pressure which increases as transmitted torque increases. The mounting means (14) comprises attachment means for attaching the drive apparatus (2) to the cycle (4) and pivot means (24) about which the electric motor (6), the first and second pullies (8, 10) and the endless belt (12) pivot. The drive apparatus (2) is characterised in that the electric motor (6), the first pulley and second pullies (8, 10) and the endless belt (12) form transmission means which is counter-balanced about the pivot means (24) such that in an equilibrium position the endless belt (12) is not in contact with the tyre (16) when the drive apparatus (2) is not in use.