| 摘要 |
<p>1,166,541. Valves. ROBERTSHAW CONTROLS CO. 26 Jan., 1967 [16 Feb., 1966], No. 3979/67. Heading F2V. [Also in Divisions D1 and G3] A control system for operating actuators in a predetermined pattern to complete a cycle of operation of a dishwasher, washing machine, or other domestic appliance comprises a programme member movable by driving means at a predetermined rate, an overriding means movable in two directions in one direction only of which the overriding means moves the programme member at a faster rate than the driving means, to and fro movement of the overriding means being maintained by a device separate from the programme member and operated by movement of the overriding means. A programme member 28 comprising a flexible sheet having a pattern of indentations 33 and apertures 34 is rotatable by a timer motor 44 relatively to a reading head 21 for connecting pneumatically operated actuators 37 for electric contacts 46, 47, 48 in a required sequence either to a vacuum source 26 or to atmosphere. In order to obtain a rapid advancement of the programme member 28 at a desired instant in the operational cycle the shaft 79 of a selector device 78 is rotated so that when an indentation 33 interconnects ports 72, 73 at the desired instant an actuator 55 is connected to the vacuum source 26 which moves a lever 62 to rotate a pinion 42 to advance the programme member 42. During this movement the lever 62 actuates a valve 89 (Figs. 5 to 7, not shown) to interrupt the connections between ports 84, 86 and disconnect the actuator 55 from the vacuum source 26. The lever 62 is then returned to its original position by a spring 60 (Fig. 1, not shown) and in so doing reconnects the ports 84, 86 so that the actuator 55 is operated repeatedly to advance the programme member 28 in rapid steps for as long as the indentation 33 interconnects the ports 72, 73.</p> |
