Unidirectional spring-loaded ratchet drive mechanism - has pawls fitted with counter weights to assist return spring mounted in extension

摘要

The drive mechanism is fitted to the starter motor of an internal combustion engine and consists of a drive pinion (4) driven by a ratchet (2) attached to the electric starter motor. The drive pinion carries the ratchet pawls (6) which are enclosed in a cage (10). The pawls are maintained in mesh with the ratchet cy the springs. When the starter motor is operated the ratched drives the pinion via the pawls. Once the engine has started and attained sufficient speed, the pawls disengage due to the centrifugal force of rotation. The return springs are housed in extensions of the paws. These extensions act as counterweights to assist the springs.