Patent GB-1493278-A (GB)
Title: Programmer
IPC: H01H43/12
Filed: 1975-07-25
Abstract: 1493278 Time switches ETABS CARPANO & PONS 25 July 1975 [2 Aug 1974] 31203/75 Heading H1N A programmer wherein a cam unit is held stationary for a period of time dependent upon the profile of a single selection cam, and which is suitable for use in washing machines where it is necessary to be able to choose one of several rates of operation of the programme cams while maintaining great precision of timing, comprises at least one rotatable programme cam 1 integral with a selection cam 72, a rotatable first member 7 for continuous rotation by a first motor (not shown), a rotatable second member 23/55, means for rotating the second member from a rest position by one step per rotation of the first member 7, means 90 biasing the second member to the rest position, a mechanical slector lever 84 following the selection cam 72 and co-operating with the second member 55 to selectively hold it for a selected number of steps as determined by the selection cam 72, a driving means (for example, a second motor or an electromagnetic clutch, not shown, for a drive from the first motor) for said programme cam(s), a contact device 17, 107 controlling the driving means of the programme cam(s), a third member 11 operable by the rotatable first member 7 once per rotation thereof to actuate the contact device 17, 107 to start said driving means, a fourth member 45 acted upon by the second member 23 to disable the third member 11 to prevent actuation of the contact device 17, 107 during a given number of revolutions of the first member 7, a stop cam 94 rotatably driven with the programme cam(s), a fifth member 101 following cam 94 and co-operating with the contact device 17, 107 to maintain rotation of the programme cam(s) when initiated by the third member 11 until a given angular step has been completed, and means 110, 113 for freeing the mechanical selector lever 84 from the second member 55 to allow the second member 23/55 to return to its initial position upon stopping of the programme cam(s). As shown, the fifth member 101 is a lever pivoted at 102 and having a nose 103 which causes end 106 to lift contacts 107, 17 into engagement until nose 103 drops into a recess 100 on stop cam 94, which is driven in synchronism with the programme cams 1 by gears 96 and 97 from gear teeth 98 (Figs. 1 and 2). Lever 84 is urged by spring 88 such that a nose 86 (sensing selection cam 72) positions a nose 87 to co-operate with ratchet teeth 55 integral with member 23 to determine how many steps of member 23 are made before the contacts 17, 107 are closed to initiate drive to the programme cams 1. The means for stepping the second member 23 comprises an eccentric 20 on continuously driven first member 7 which oscillates a member 21 such that three teeth thereon (Fig. 3, not shown) engage an internal toothing 22 of member 23 to rotate it against the action of coil spring 90, through a fraction of a revolution for each complete revolution of first member 7. The fourth member 45 is pivoted at 46 and follows a cam track on second member 23 which positions member 45 under a projection (49, Figs. 5 to 8, not shown) on lever 11 when it is required to prevent lever 11 actuating contacts 17, 107. On completion of a programme step cam 110, which is geared to rotate with programme cams 1, acts on a lever 113 to lift the nose 87 of lever 84 clear of ratchet 55, thus allowing spring 90 to restore member 23/55 in readiness for control of another step of programme cams 1. A modified arrangement of notches 55 is disclosed in Fig. 9 (not shown).