Pawl

For other uses, see Pawl (disambiguation).

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.

A ratchet and pawl mechanism

A parking pawl in an automatic transmission

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.^[1][2]

Ladder

Dogs (in the form of pawls) are used on extension ladders to temporarily anchor their sections to one-another.^[3]

Table saw

Pawls are used on table saws to prevent a workpiece being sawn from kicking back.^[4]

Transmission

A parking pawl is a device in an automobile automatic transmission which prevents it from moving when the vehicle is parked .^[5]

Revolvers

The hand (pawl) indexes the cylinder.