| 释义 |
▪ I. detent, n.1|dɪˈtɛnt|
(Also 7 detton.)
[a. F. détente, OF. destente (Froissart, 14th c.), deriv. of détendre ‘to slacken, unstretch, undo’, in OF. destendre, f. des-, L. dis- privative (cf. de- 6) + tendre to stretch. (In L. distendĕre the prefix had a different force: see distend.)
The earliest application of the word in French was to the destente of the arbalest or cross-bow, whereby the strained string was released and the bolt discharged; hence it was transferred to the analogous part in fire-arms. In English, the word seems to have been viewed as connected with L. dētinēre, dētent-, and so with detain, detention, and to have been modified in meaning accordingly. The fact that the same part which allows of the escape of that which is detained or held tense, is also often the means of detention, favoured this misconception of the word.]
1. gen. A stop or catch in a machine which checks or prevents motion, and the removal of which brings some motor at once into action.
1831Brewster Nat. Magic xi. (1833) 283, When a spring was touched, so as to release a detent, the figure immediately began to draw. 1832Babbage Econ. Manuf. viii. (ed. 3) 59 Leaves a small dot of ink on the dial-plate whenever a certain stop or detent is pushed in. 1860Proc. Amer. Philol. Soc. VII. 339 A detent shoots the slate back and a new record begins. 1869Daily News 16 Mar., The handle, on being pulled, releases a detent in the guard's van, which allows a weighted lever to drop and pull up the slack of a chain which communicates with the engine whistle. 1869Athenæum 25 Dec. 874 A Christmas recollection..more than fifty years old..These boxes..had each a little slit, into which, a halfpenny being dropped, a detent was let go, the box would open, and the pipe might be filled. 1871Tyndall Fragm. Sc. (1879) I. xx. 488 An engineer..loosing a detent, can liberate an amount of mechanical motion [etc.]. Ibid. II. vii. 97 When these crystals are warmed, the detent is lifted, and an outflow of light immediately begins.
2. spec.
a. In a gun-lock: see detant.
b. In clocks and watches: The catch which regulates the striking.
1688R. Holme Armoury iii. 374/1 In the Clock..the two Dettons with their Notches, that strike into two Wheel Detton Latches. 1704J. Harris Lex. Techn., Detents, in a Clock, are those stops, which by being lifted up, or let fall down, do lock and unlock the Clock in striking. 1825J. Nicholson Operat. Mechanic 509 When the oil thickens, the spring of the pivot-detents become so affected by it, as to prevent the detent from falling into the wheel quick enough, which causes irregular time, and ultimately a stoppage of the watch. 1884F. J. Britten Watch & Clockm. 85 The detent of a chronometer escapement is the piece of steel carrying the stone which detains or locks the escape wheel.
c. In locks.
1850Chubb Locks & Keys 28 If any one of the tumblers was lifted too high, it overset the detector detent, which by a spring action fastened the bolt.
3. attrib. and Comb., as detent-wheel, detent-catch, detent-work; detent-joint, the ‘trigger-joint’ by which the pectoral spine of a siluroid fish is kept erect.
1704J. Harris Lex. Techn., s.v. Watch-work, The Detent-wheel moves round every Stroke the Clock striketh or sometimes but once in two Strokes. 1822J. Imison Sc. & Art I. 93 Regard need only be had to the count-wheel, striking-wheel, and detent-wheel. 1874Knight Dict. Mech. I. 690/2 A detent-catch falls into the striking-wheel of a clock, and stops it from striking more than the right number of times. 1881Greener Gun 244 The furniture filer also fits the detent work for the hair-triggers.
▪ II. detent, n.2|dɪˈtɛnt|
[? f. L. dētent- ppl. stem of dētinēre to detain.]
? Restraint; holding back or inhibition.
c1465Pol. Rel. & L. Poems (1866) 10 Gabull of the chancery begynyth ‘heu mihi!’ that is his preve bande, and detent of treson. 1907W. James Mem. & Studies (1911) 256 They are forces of detent in situations in which no other force produces equivalent effects, and each is a force of detent only in a specific group of men. 1929R. Bridges Test. Beauty iv. 150 A pinprick or a momentary whiff or hairbreadth motion freëth the detent of force.
▪ III. † deˈtent, ppl. a. Obs.
[ad. L. dētent-us, pa. pple. of dētinēre to detain.]
detained; kept back; ‘holden’ (with infirmity, etc.).
(In quot. 1494 perhaps past tense.)
1432–50tr. Higden (Rolls) I. 361 After that thei be detente with longe infirmite thei be brouȝhte to another yle. 1494Fabyan Chron. vii. 591 And yet for that his mynde nothynge detent All goostly helthe for his soule to prouyde. |