Multi-stage transmission

Abstract

Disclosed is a multi-stage transmission which ensures that gear shifts are efficiently performed with a small number of component parts, smooth operations are performed with small forces, there are no loss of changeover time during gear shifts and no loss of the driving force, and the shift shock is small. The transmission has a driven gear shaft, in which are provided a first swing pawl memberengageable in a rotational direction with a first gear n, a second swing pawl memberengageable in the rotational direction with a second gear nwhich is one step lower in reduction ratio, a third swing pawl memberengageable in the opposite rotational direction with the first gear n, and a fourth swing pawl memberengageable in the opposite rotational direction with the second gear n. A first cam rodand a second cam rodare provided which are slidable axially on and along the surface of an internal hole of the driven gear shaft. The first cam rodis formed with a plurality of cam surfaces, which operate by movement thereof the second swing pawl memberand the third swing pawl member, while the second cam rodis formed with a plurality of cam surfaces, which operate by movement thereof the first swing pawl memberand the fourth swing pawl member. Gear shift is carried out by moving the first and second cam rods