GB1375311A - - Google Patents

Abstract

1375311 Time switches GULF & WESTERN INDUSTRIES Inc 17 Feb 1972 [22 July 1971] 7393/72 Heading H1N [Also in Division F2] A time delay switch comprises a first clutch member angularly fast with but axially movable along a drive shaft between a first non-engaging position and a second engaging position with a second clutch member which is rotatably mounted on said drive shaft; means for selectively shifting said first clutch member; a switch; a cam member movable by said second clutch member between first and second positions to actuate said switch; drive means for said shaft; and means biasing the cam member in the opposite direction to the drive by the clutch member, whereby when the first clutch member is in said second engaging position the cam member is driven to its second position and when the first clutch member is in said first non-engaging position the cam member is moved by said biasing means back to its first position. As shown, a first clutch member 62 is axially movable but angularly coupled to a drive shaft 22 by mating hexagonal surfaces (Fig. 5, not shown). The shaft 22 is coaxially journalled in, but angularly independent of, a shaft 30 of a time-interval setting knob 24, and is driven by a synchronous motor (20, Fig. 1, not shown). A coil spring (88, Fig. 6, not shown), around shaft 22 urges member 62 to the right, but a spring 118 acting on the armature lever 112 of a solenoid 68 is effectively stronger and by means of a forked lever 64 normally holds member 62 to the left, as shown. On energization of electromagnet 68 the clutch member 62 is allowed to move to the right and a serrated surface engages a similar surface 46 of a rotary cam member 42 freely journalled on shaft 22. A return spring 50, which normally holds an arm 44 carried on cam member 42 against an adjustable bracket 34, is thus stressed by rotation of cam member 42 until two adjustable screws 60 on arm 44 actuate respective switches (130, 132, Figs. 2, 4 and 5, not shown), whereupon one of the switches de-energizes electromagnet 68, the clutch is released and spring 50 restores cam 42 to its initial position determined by bracket 34. Bracket 34 is settable by knob 24 which thus determines the time interval before actuation of the switches. A knob 26 serves to lock knob 24 in its preset position. It is stated that by simple alteration of the linkage between levers 112 and 64 the clutch may be normally engaged and energization of electromagnet 68 then disengages it. Figs. 9, 10 and 11, disclose a slightly simplified embodiment without the external setting control knob.