GB878444A - Improvements relating to lever units for time controlled apparatus - Google Patents

Abstract

878,444. Time switches. VENNER Ltd., and HORGAN, W. F. Sept. 26, 1957 [Sept. 27, 1956], No. 29604/56. Class 38 (5). [Also in Group XXIV] A lever unit 17, especially for co-operation with the hands 5b to 5f of a timer dial 4 of a time switch, comprises a pair of plates 22, 23 on a pivot 19 and carrying a pin 24 which serves as the pivot for a lever 29. The pin 24 and a pin 30 on lever 29 extend through a slot 34 in a second lever 32 which has a slot 33 through which passes pivot 19. Lever 32 has a pin 36 passing through a slot 37 in plate 23 and connected by a spring 39 to the lever 29 to urge the lever 32 to the right (Fig. 3). When the lever 32 is in this right-hand position, the pin 30 engages the end 48 of slot 34 so that if a pin 31 on lever 29 is engaged by a hand of the dial 4, the unit is rocked clockwise to the dotted position in Fig. 2. Thus a pawl 27 carried by the pin 24 moves a ratchet-wheel 28 on a camshaft 21a one step. The lever unit is returned by a spring 25a to the full line position (Fig. 2). If the lever 32 is in its extended left-hand position, Fig. 3, the pin 30 is opposite a lateral arcuate part 47 of slot 34 so that movement of lever 29 by a hand is not communicated to lever 32 and the cam-shaft 21a is not stepped on. As shown, two lever units 17, 18 are arranged one above the other, and the inner and outer location of levers 32 is determined by a selector member 11 similar to that of Specification 838,218. The cams 16 of member 11 bears on levers 57, 58 in turn acting on levers 51, 54 respectively engageable with the ends 35 of the levers 32 to project them to the left (Fig. 3) on desired days. A similar member 10 acts through levers 71, 78 to move fixed contact springs 68 away from a stop 70 and out of reach of contacts 66 which are controlled by cams 20 on shaft 21a. Members 10, 11 are driven by a gear-wheel 8 stepped round by a hand 5a on dial 4.