| 释义 |
ˈpick-off
Also pickoff, pick off.
[f. vbl. phr. to pick off s.v. pick v.1 18.]
1. Chiefly Aeronaut. In an automatic control or guidance system, any device which produces or alters a pneumatic or an electrical output in response to a change in motion.
1938P. V. H. Weems Air Navigation (ed. 2) xiv. 243 If the aircraft changes attitude laterally, one of the ports..of the air pick off is opened fully and the other closed. 1938A. Jordanoff Through Overcast xiv. 180 Whenever you wish to fly in a certain direction under automatic control, you must be sure to set the air pick-offs at neutral at the same time your plane points in the direction which gives the desired reading on the directional gyro. 1940E. Molloy Aeroplane Maintenance & Operation II. i. 12 In actual practice the air pick-off consists of a disc attached to the gyro element, with knife edges which intercept the air flow at two nozzles on the supporting frame. 1958J. G. Truxal Control Engineers' Handbk. xvii. 49 The displacement gyro is continually being torqued by the coupling of the motion of the base through the gimbal gearing friction and pickoff loading to the wheel. 1962F. I. Ordway et al. Basic Astronautics ix. 377 The precession..is sensed by a pickoff that sends a signal to the servo amplifier.
2. In baseball: the act of catching a runner off base by means of the pitcher or catcher suddenly throwing the ball at that base. Freq. attrib.
1939G. S. Cochrane Baseball iv. 76 The danger of a throw to first for the pickoff is that the runner has over⁓run first not only too far to get back but far enough to make a break for second. 1948Sun (Baltimore) 19 July 12 (caption) Bill Martin gets back in time as Eddie Shokes..tries to complete pickoff attempt in opener. 1968Washington Post 4 July c 2/4 Wills moved to second when Ryan's attempted pickoff throw went wide. 1968Globe & Mail (Toronto) 10 July 26/6 Killebrew..said Tiant's pickoff throw on Mays, which opened the gates for the winning run, was behind the runner. 1974Spartanburg (S. Carolina) Herald 23 Apr. a6/4 Bill Dancy of Spartanburg singled with one out in the fourth, moved to second on an errant pickoff attempt and went to third on Mark Ammons' infield hit. 1976Washington Post 19 April d2/2 Manning scored the only run Cleveland needed in the first inning when he..came home when Busby threw away a pickoff throw.
3. Used attrib. to designate auxiliary parts of a machine positioned so as to be easily selected or brought into use when required.
1949Tool Engineers Handbk. (Amer. Soc. Tool Engineers) xxxv. 602 A secondary operation may be eliminated by the use of a pick-off attachment, which is an independently driven spindle and collet arrangement mounted in the cutoff position. 1950J. A. Oates in A. W. Judge Machine Tools & Operations III. i. 30 These ‘pick-off’ gears are arranged under a cover..in some easily accessible position, and it is only a matter of two or three minutes to change over to a new speed or feed. |