escapement
/ɪˈskeɪpm(ə)nt
/ /ɛˈskeɪpm(ə)nt/noun
1A mechanism in a clock or watch that alternately checks and releases the train by a fixed amount and transmits a periodic impulse from the spring or weight to the balance wheel or pendulum: a lever escapement...
- In 1730 Harrison visited London, taking with him his gridiron pendulum and the grasshopper escapement which he had developed, and there he learnt exactly what was required to win the longitude prize.
- In general, any lantern clock with a balance wheel has had its escapement restored.
- Because they have no gears or escapements to disturb their regular frequency, quartz clocks are extremely accurate and have become the dominant timekeeping technology.
2A mechanism in a typewriter that shifts the carriage a small fixed amount to the left after a key is pressed and released.The five key subassemblies of the standard typewriter (the carriage, paper handling system, escapement, typebasket, and keyboard) are put on trucks and moved to the main assembly line where they are added to the typewriter frame....
- In 1945 the Rochester Museum of Arts and Sciences awarded him a fellowship for the invention of an escapement for spacing typewriter characters variably according to their widths.
- One of the motors drives the escapement while another is used to select the character for printing.
3The part of the mechanism in a piano that enables the hammer to fall back as soon as it has struck the string.Although the escapement enables the hammer to fall away from the string, the damper is not allowed to fall back and damp the string until the key is released.
Origin
Late 18th century: from French échappement, from échapper 'to escape'.