| 摘要 |
1,134,524. Valves. ROBERTSHAW CONTROLS CO. 28 Feb., 1966 [4 March, 1965], No. 8732/66. Heading F2V. [Also in Division A4] A programmed pneumatic control system, particularly for a dish-washing machine, comprises a timer motor for moving a programme member at a constant rate to effect a timed sequence of operations, and a pair of over-riding actuators for moving the programme member at a rate faster than said constant rate to eliminate certain operations of the sequence, the actuators acting upon the programme member in alternation. In the illustrated system the programme member comprises a flexible sheet 119, Fig. 4, provided with recesses 125 and apertures 126 and secured to a rotary member 117 having a ring gear 121 by which it is rotatable by a pinion 122 on a shaft 123 connected by a one-way clutch to the output shaft of a timer motor 112. The sheet 119 is mounted adjacent a plate 35 provided with apertures 19 to 34 shown diagrammatically in Fig. 1, and various combinations of which are interconnected by the recesses 125 as the sheet 119 rotates to control the dishwashing programme. The plate 35 is also provided with apertures 47 to 54, pairs of which may be interconnected by recesses 133 in a member 127 which is rotatable to various positions D, N, H, S, P, and C, to select the programme steps to be performed. In the H position of the selector member 127 none of the apertures 47 to 54 are interconnected and a heavy washing programme is performed. The programme is started by closing a switch to energize a vacuum pump 43 and the timer motor 112. The programme sheet 119 thus rotates so that in sequence (a) the parts 28, 30 are interconnected to apply suction to an actuator 88 to open the water inlet valve 92 for an interval terminated when the port 30 is connected to atmosphere through an aperture 126, (b) the ports 32, 34 are interconnected whereby an actuator 101 closes a switch 13, 14, 15 to energize the dishwasher impeller motor 11 for a first rinsing period, (c) the ports 26, 28 are interconnected so that an actuator 16 operates a switch 12 to cause the motor 11 to operate a drain pump, and (d) by further interconnections of selected ports effecting washing with detergent, draining, and rinsing a plurality of times, followed by draining and drying steps. If, however, the selector 127 is set in the N or D position to effect normal washing (when parts of the washing periods of the heavy washing programme are omitted), or drying, vacuum is applied to ports 24 or 23. The rotating programme sheet 119 then alternately interconnects the ports 23, 24 to ports 20, 21 while alternately interconnecting the ports 20, 21 to atmosphere to operate actuators 62, 63 alternately to rapidly advance the programme member 116 by pawl-and-pinion devices 140, 124 (Fig. 5, not shown). |
