GB889373A - Dishwashers - Google Patents

Abstract

889,373. Dish-washing machines. GENERAL MOTORS CORPORATION. May 18, 1960 [May 25, 1959], No. 17524/60. Class 138 (1). A dish-washing machine comprises an automatic control means which may be operated either to provide a dish-washing cycle comprising washing, rinsing, and drying the dishes, or a dish-soaking cycle excluding a drying operation. To operate the machine in the dish-washing cycle a selector switch 54, Fig. 2, is left open and a push-button switch 52 is closed to energize a timer motor 50 which first, briefly closes a switch 76 to energize a solenoid 32 to open a drain valve for the washing chamber 12, Fig. 1, and simultaneously engages contacts 78, 80 to energize a solenoid 26 to open a valve in the inlet pipe 24 to admit hot water to the washing chamber from a water heater. After an interval sufficient for flushing any cold water from the supply system the solenoid 32 is de-energized to close the drain valve. When the switch 76 opens a switch 82 closes to energize a motor 22 driving a pump 20 so that the latter pumps the washing liquid from the sump 18 through a pipe 30 for discharge through a rotating spray tube 28 on to the dishes contained in baskets 36, 38. A switch 84 is next closed to energize a solenoid 43 to actuate a dispenser 42 to admit a change of washing agent into the chamber 12. After the predetermined washing period the switch 76 is again closed to open the drain valve to discharge the soiled water from the chamber 12. After the draining period the solenoid 26 is again energized to admit clean rinsing water into the chamber 12 to be circulated through the spraying system. The timing switches may be so arranged and constructed that one or more wash cycles and one or more rinse cycles are performed. At the conclusion of the rinsing the switch 76 is closed to drain the rinse water and the contacts 78, 88 engaged to energize an electric heater 19 in the sump for a period sufficient to dry the dishes in the baskets 36, 38. Additionally the heater 19 may be energized intermittently throughout the dish-washing cycle to boost the temperature of the washing or rinsing liquid. To operate the dish-soaking cycle a switch 54 is closed to energize a timer motor 50, to operate switches 94, 96, 98 and 100 controlling the solenoids 32, the pump motor 22, and the solenoids 43, 26, respectively, to perform washing and rinsing operations but no drying operation. In a modification the timer cams are such that a number of soaking cycles are performed in sequence. In a further modification a single timer device only is provided, having a manually operated selector switch whereby it may be actuated to initiate either a dish-washing cycle or a dishsoaking cycle.