Crossword Dictionary

What's The Definition Of Ratchet?

\Ratch"et\, n. [Properly a diminutive from the same word as rack: cf. F. rochet. See 2d {Ratch}, {Rack} the instrument.] 1. A pawl, click, or detent, for holding or propelling a ratchet wheel, or ratch, etc. 2. A mechanism composed of a ratchet wheel, or ratch, and pawl. See {Ratchet wheel}, below, and 2d {Ratch}. {Ratchet brace} (Mech.), a boring brace, having a ratchet wheel and pawl for rotating the tool by back and forth movements of the brace handle. {Ratchet drill}, a portable machine for working a drill by hand, consisting of a hand lever carrying at one end a drill holder which is revolved by means of a ratchet wheel and pawl, by swinging the lever back and forth. {Ratchet wheel} (Mach.), a circular wheel having teeth, usually angular, with which a reciprocating pawl engages to turn the wheel forward, or a stationary pawl to hold it from turning backward. Note: In the cut, the moving pawl c slides over the teeth in one direction, but in returning, draws the wheel with it, while the pawl d prevents it from turning in the contrary direction.