Escapement

Es*cape"ment (?), n. [Cf. F. échappement. See Escape.] 1. The act of escaping; escape. [R.]

2. Way of escape; vent. [R.]

An escapement for youthful high spirits.
G. Eliot.

3. The contrivance in a timepiece which connects the train of wheel work with the pendulum or balance, giving to the latter the impulse by which it is kept in vibration; -- so called because it allows a tooth to escape from a pallet at each vibration.

Escapements are of several kinds, as the vertical, or verge, or crown, escapement, formerly used in watches, in which two pallets on the balance arbor engage with a crown wheel; the anchor escapement, in which an anchor-shaped piece carries the pallets; -- used in common clocks (both are called recoil escapements, from the recoil of the escape wheel at each vibration); the cylinder escapement, having an open-sided hollow cylinder on the balance arbor to control the escape wheel; the duplex escapement, having two sets of teeth on the wheel; the lever escapement, which is a kind of detached escapement, because the pallets are on a lever so arranged that the balance which vibrates it is detached during the greater part of its vibration and thus swings more freely; the detent escapement, used in chronometers; the remontoir escapement, in which the escape wheel is driven by an independent spring or weight wound up at intervals by the clock train, -- sometimes used in astronomical clocks. When the shape of an escape- wheel tooth is such that it falls dead on the pallet without recoil, it forms a deadbeat escapement.