| 摘要 |
1,016,458. Retractive switches; retarding action of switches. ELASTIC STOP NUT CORPORATION OF AMERICA. Aug. 23, 1963 [Sept. 13, 1962], No. 33553/63. Heading H2B. A time-delay switch is provided with an operating mechanism which prevents interference with the operation of the switch, once initiated, until the preset delay interval has expired. The actuating member 16 of the switch unit (Fig. 1, not shown), when moved to the left initiates a timed interval during which it progressively returns to the position shown. When plunger 22 is pushed it engages and rotates a lever 34 pivoted on shaft 41 between two discs 40 (only one shown) which are mechanically connected together and also pivoted on shaft 41. Lever 34 is rotated against the action of a " rat-trap" spring 74 and tensions another " rat-trap spring 64 anchored on a drive-pin 52 secured between discs 40. Due to a latch-bar 86 engaging notches 107, discs 40 cannot rotate until surface 108 on lever 34 cams the latch 86 out of engagement, whereupon discs 40 quickly rotate and a cam 50 thereon urges follower 116 to the left in passing to the operated position (Fig. 13, not shown). Follower 116 is integral with collar member 30 which thus moves rod 16 to operate the switch unit (not shown) and initiate delayed retraction. The movement of shoulder 114 on member 30 allows a blade spring 104 to lift a latch 94 behind the face 79 of lever 34, thereby maintaining lever 34 and discs 40 in the operated position (Fig. 13, not shown) against the restoring force of spring 74. In this condition movement of plunger 22 is ineffective and can have no effect on the preset time delay. When member 30 is returned to its Fig. 6 position the shoulder 114 pivots latch 94 out of engagement with lever 34 which springs back, taking discs 40 with it by virtue of a pin 78 thereon. The cam 50 has no effect during this return rotation since it pivots - on pin 52 against a light spring 54, which then returns it to abut a pin 58 in readiness to initiate a new timing cycle. |
