GB1412138A - Timing system - Google Patents

Abstract

1412138 Time switches MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 2 Nov 1972 [5 Nov 1971 20 June 1972] 50560/72 Heading H1N A timing system, for an automatic washing machine, for example, comprises cam means 71 for actuating a plurality of contact sets T1 to T10 to control a fundamental programme, a synchronous motor 58, a high speed gear train and a low speed gear train to impart respective drives from said motor to said cam means, means to prevent interference between the two drives, an electromagnetic clutch 69, 67 for releasably engaging the high speed gear train, a selector (54, Fig. 1, not shown) for selecting different combinations of said contact sets T1 to T10 to provide respective programmes, and a circuit (Fig. 14, not shown) including means for isolating one or more of said contact sets to omit a respective part or parts of the fundamental programme and for simultaneously energizing the electromagnetic clutch to impart high speed drive to the cam means 71, the circuit including self-holding relay means 167 responsive to operation of said selector to maintain energization of said electromagnetic clutch during high speed rotation of said cam means. As shown the high speed gear train includes a gear 66 having a ratchet type one-way clutch (Figs. 6a and 6b, not shown) and the low, or normal advance, gear train includes a gear 63 with a ratchet type one-way clutch 62. The electromagnet 69 moves a gear 67 axially (Fig. 5, not shown) to couple a gear 61 to a gear 68 when high speed drive is required, and also forms the winding of relay 167 having contact sets R 1 to R 3 , one of which is used to hold the winding (103, Figs. 5 and 14, not shown) of electromagnet 69 energized during high speed advance. Changeover timer contacts T11 are also steadily driven by a conventional "reversing" cam 73. The cam means 71 comprices a bank of ten axially spaced cams associated with respective contact sets T1 to T10. There is some lost motion between the cam bank 71 and drive shaft 82 such that the reaction of spring-urged lever 98 on a locating cam 81 provides simultaneous snap action of the contact sets Tl to T10.