GB987762A - Improvements relating to self-disengaging rotary drive mechanisms and devices incorporating the same - Google Patents

Abstract

987,762. Clutch control. AUTOMATIC TIMING & CONTROLS Inc. Feb. 13, 1962 [Feb. 13, 1961], No. 5462/62. Heading F2L. [Also in Division H2] Depression of a button closes switches and initiates a drive to rotate a preset pointer back to zero, whereupon the drive is uncoupled and the switches opened. Knob 13 is turned to set a flange 15a to a desired time interval which is indicated on a scale on face-plate 11 by a pointer 25 held in contact with flange 15a by spring 40 secured to the freely rotatable shaft 26. The button 20 is then depressed and moves shaft 26 axially thereby pivoting an actuator plate 50 about pin 51 against the action of spring 55. Arms 63, 64 on plate 50 depress the operating members of switches 70 and 71 respectively, and the plate 50 is locked in this operated condition by a notch in a latch 80 which pivots about pin 78 under action of spring 79. Actuator 50 thereby holds shaft 26 in its operated axial position by virtue of a spring-urged collar thereon (Fig. 6, not shown) behind the collar 44 and in this position of shaft 26 flanges on pointer 25 are held in frictional engagement with a rubber ring 32 mounted on gear-wheel 36. One switch energizes a synchronous motor 60 which drives shaft 61 to rotate gear-wheel 36 clockwise and thereby slowly returns pointer 25 to the zero position. As pointer 25 approaches the zero position it engages the end of a trip arm 91 and turns a block 89 about fixed pivot 90, causing a depending pin 88 to move latch 80 to the left. This releases actuator 50 which restores shaft 26, freeing pointer 25 from the clutch ring 32, and also restores switches 70 and 71, one of which switches off the motor 60. Specification 920,703 is referred to.