GB922899A - Improvements in or relating to time controlled actuating mechanisms - Google Patents

Abstract

922,899. Time-switches. S. SMITH & SONS (ENGLAND) Ltd. July 24, 1959 [Aug. 7, 1958], No. 25419/58. Class 38 (5). [Also in Group XXIX] The start and finish times of, e.g. a cooking operation are controlled respectively by relatively adjustable cams 25, 24 which are engaged by a follower 23 moved along the cams by a timeactuated member 31. The follower 23 is fixed to a rack 12 movable in a guide 13 in an angularly-movable support 10, the follower being urged into engagement with the cam faces by springs 14. The rack has one set of teeth engaging a pinion 16 and a set 33 engaging a pinion 17 on a spindle 18 carrying a contact-actuating cam 19. The switch is set as follows: (a) knob 28 is turned anti-clockwise to rotate a setting arm 29 which engages a projection 26 on cam 25 which is then rotated until faces 2, 5 in the cams coincide. In this position, the follower 23 moves outwardly to engage these faces and move the switch on. At the same time, pinion 16 is moved counter-clockwise by rack 12 to bring, a projection 22 close behind arm 29; (b) further anti-clockwise movement of arm 29 continues, resulting in rotation of both cams and the follower, until the finish time is set; (c) the arm 29 is then turned clockwise and by engaging projection 22 turns pinion 16 clockwise and retracts the rack 12 and follower 23. This opens the switch. Continued rotation of arm 29 moves the follower 23 against face 4a of cam 25 and turns this clockwise to the start position, leaving cam 24 stationary. When knob 28 is released, springs 14 push follower 23 against face 4 of cam 25 and the timeoperated arm 31 eventually picks up the follower and rotates it anti-clockwise. When the follower slides down face 6a on to face 1, the switch is closed, being re-opened when the follower reaches face 3a and engages face 6.