GB900599A - Improvements in dishwashers - Google Patents

Abstract

900,599. Dish-washing machines. GENERAL MOTORS CORPORATION. Nov: 27, 1959 [Feb. 9, 1959], No. 40375/59. Class 138 (1). A dish-washing machine has a single-reversible pump impeller which when rotated in one direction pumps liquid from a sump of a wash,- ing chamber on to dishes in the chamber, and when rotated in the opposite direction pumps liquid from the sump through a drain outlet to a drain: 'The impeller 64, Fig. 1, is driven by a reversible electric motor 44, and when driven in one direction draws liquid from a sump at the bottom of the washing chamber 18, and pumps it through a conduit 50 to a rotary perforated spraying tube 32. The connection between the conduit 50 and the tube 32 is such that the liquid is swirled to rotate the tube 32. The impeller 64, Fig. 5, comprises a disc 124 having vanes 128 inclined over apertures 136 in the disc, so that on clockwise rotation the vanes 128 raise the liquid into the conduit 50, and on counterclockwise rotation the vanes direct the liquid through apertures 136 into the drain. The machine is controlled by an electric timing device which on being energized by manual closing of a switch, opens a solenoid valve to admit liquid to the chamber 18, and closes a motor switch to rotate the impeller for pumping liquid to the sprayer 32. At the end of the washing period the timing device reverses the motor to drain the chamber 18. A drying period is then initiated by the timing device which energizes an electric heater 76 whilst the impeller 64 continues to rotate to draw air through an opening 200 in the bottom of the chamber door 20, and through louvres 198 and over the dishes in baskets 80, 82, and to discharge it through the lower compartment 24. In a modified construction the impeller is provided with teeth for comminuting the solid material passing to the drain, a strainer arranged above the impeller being raised to an inoperative position by a spring when the impeller is rotated in the draining direction.