Pawl



A pawl is a movable lever that engages a fixed component to either prevent movement in one direction or restrain it altogether. As such, it is a type of latch and can also be considered a type of dog. It typically consists of a spring-loaded lever that engages a mating component at a steep enough angle to restrain it. Pawls are often tapered, being widened at their pivot for anchoring and narrow at their tip.

Applications

 * Anchor windlass: A pawl is used in an anchor windlass to prevent a free-spooling chain by grabbing and snubbing an individual link. Similar mechanisms include a Devil's claw, or a claw and dog.
 * Ratchet: A pawl is used in combination with a ratchet gear in socket wrenches, bicycle freehubs, winches, ratchet reels for diving, fishing, and many other applications.
 * Ladder: Dogs (in the form of pawls) are used on extension ladders to temporarily anchor their sections to one-another.
 * Table saw: Pawls are used on table saws to prevent a workpiece being sawn from kicking back.
 * Transmission: A parking pawl is a device in an automobile automatic transmission which prevents it from moving when the vehicle is parked.
 * Revolvers: The hand (pawl) indexes the cylinder.