escapement

escapement
/i skayp"meuhnt/, n.
1. Horol. the portion of a watch or clock that measures beats and controls the speed of the going train. Cf. anchor escapement, deadbeat (def. 1), lever escapement.
2. a mechanism for regulating the motion of a typewriter carriage, consisting of pawls and a toothed wheel or rack.
3. a mechanism in a piano that causes a hammer to fall back into rest position immediately after striking a string.
4. an act of escaping.
5. Archaic. a way of escape; outlet.
[1730-40; ESCAPE + -MENT (calque of F échappement]

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      in mechanics, a device that permits controlled motion, usually in steps. In a watch or clock, it is the mechanism that controls the transfer of energy from the power source to the counting mechanism. The classic form for a timepiece, which made the mechanical clock possible, was the verge escapement, probably invented in 13th-century Europe. This consists of a crown wheel (i.e., a gearwheel shaped like a crown) driven by a weight and repeatedly checked by the action of a pair of metal pallets that alternately stop successive teeth. The pallets are mounted on a vertical shaft (the verge), and their speed of oscillating back and forth is controlled by a crossbar at the top (the foliot) with two small weights; moving the weights outward from the shaft slows the oscillations. The anchor escapement, an improvement invented in England in the 17th century, works with a pendulum and allows much smaller arcs of swing than the verge escapement with a pendulum. In the anchor escapement the pallets are in the shape of an inverted anchor, lying in the same plane as the wheel. Many improvements have since been made in escapements, most significantly the concept of detachment, where the escapement, while providing energy for the oscillator, is as detached from it as possible to allow the oscillator to swing as freely as possible.

Jonathan D. Betts
 

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Universalium. 2010.

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  • Escapement — Es*cape ment, n. [Cf. F. [ e]chappement. See {Escape}.] 1. The act of escaping; escape. [R.] [1913 Webster] 2. Way of escape; vent. [R.] [1913 Webster] An escapement for youthful high spirits. G. Eliot. [1913 Webster] 3. The contrivance in a… …   The Collaborative International Dictionary of English

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  • escapement — [e skāp′mənt, iskāp′mənt] n. [ ESCAPE + MENT, after Fr échappement] 1. Rare the action of escaping or a means of escape 2. the part in a mechanical clock or watch that controls the speed and regularity of the balance wheel or pendulum, and… …   English World dictionary

  • escapement error — Horol. loss of isochronism in the movement of a pendulum as a result of its relation to the escapement. * * * …   Universalium

  • escapement error — Horol. loss of isochronism in the movement of a pendulum as a result of its relation to the escapement …   Useful english dictionary

  • escapement — noun Date: 1779 1. a. a device in a timepiece which controls the motion of the train of wheelwork and through which the energy of the power source is delivered to the pendulum or balance by means of impulses that permit a tooth to escape from a… …   New Collegiate Dictionary

  • escapement — number of migratory fish that reach a favourable spawning area annually. Refers to the fish that pass through a fishing area unscathed and reach the spawning grounds; usually said of anadromous fish …   Dictionary of ichthyology

  • escapement — noun a) The contrivance in a timepiece (winding wrist watch) 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… …   Wiktionary

  • Escapement — Матрицевыпускающий механизм (строкоотливной наборной машины); Смещение на ширину знака, отработка ширины знака …   Краткий толковый словарь по полиграфии

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