What is a rachet pawl?

Answer 1

A Pawl can be considered as a pointy thing that sits between the teeth of a gear (cog) wheel to either prevent it turning in one or both directions or to push on a tooth to make it turn. This could, for example, be used to lock an automatic transmission into Park position. With a Ratchet Pawl, the ratchet part assumes the gear wheel has teeth shaped like the teeth of a circular saw and therefore not designed to mesh with another gear. Now the Pawl is angled to fit into the angled teeth and can be used either to a) push on a tooth to turn it as before (but this time only in one direction, as it would slip out going the other way) or b) as a one-way lock so that the wheel can turn freely one way (with the Pawl slipping out one tooth at a time) but preventing it turning the other way as the pawl engages. Example a is typical of the mechanism on a revolver handgun that turns the cylinder as the hammer is cocked. Example b is typical of a safety mechanism on a cable winch so that the load cannot drop in the event of failure of the hauling force. Tommikat.