Patent GB-792566-A (GB)
Title: Electric dishwashing apparatus
IPC: A47L15/06
Filed: 1955-02-01
Abstract: 792,566. Dishwashing machines. GENERAL ELECTRIC CO. Feb. 1, 1955 [Feb. 1, 1954], No. 2993/55. Class 138(1). An electric dishwasher comprising a wash tub having a rotatable liquid circulating means, (e.g., impeller) in the bottom thereof and drainage means is characterized in the circulating means is rotatable in either direction, so that in one direction of rotation liquid is maintained in the tub and in the other direction of rotation, the tub is drained. The dishwashing machine is of the general type disclosed in Specification 663,586 and the liquid and air circulating impeller 30, Fig. 3, preferably of the type disclosed in Specification 557,034, is mounted in the sump 5 of the wash tub 2 for rotation in either direction by an electric motor 15. Mounted below the impeller 30 is a pump. impeller 38 rotatable conjointly with the impeller 30 through the agency of a yoke 42 secured to the motor shaft and exten-' sion 16. The pump impeller is housed within a pump chamber 7 formed by a side wall 6 and bottom wall 8, both integral with the sump 5, and a top plate 17 having a flange 18 fitted securely within the wall 6, with the interpositioning of a resilient gasket 19. The plate 17, Figs. 2 and 4 has a plurality of radial slits cut therein and the material on either side of each slit is pressed upwardly and downwardly to form dome-like baffles 37 and depressions 45 and, incidently, vertically disposed radial openings 36, Fig. 4. Centrally the plate 17 has a flanged opening 20 to permit passage of the yoke 42, the motor shaft and extension 16 and the usual liquid guard tube 11 secured, with the interpositioning of a gasket 10, to a depression 9 in the bottom wall 8. As shown in Fig. 2, the pump chamber 7 has a tangential drain pipe 26 and a lip 26.2 thereof projects into the chamber. Liquid which passes through the pipe 26 may pass to waste under gravity or be pumped to waste at a higher point, by the impeller 38, past a non-return valve (not shown). When the impeller 30 is rotating in a counterclockwise direction in Fig. 2, which is the case when a washing operation takes place, a body of liquid in the sump around the impeller will be likewise rotated. This liquid which is moving from the left to the right in Fig. 4 is diverted by the baffles 37 past the openings 36 and thus prevented from entering the chamber 7. The pump impeller blades 39 are each connected to the impeller top plate 40 by arcuate portions 41. Should any liquid leak through the openings 36 it engages the portions 41 which are also rotating in a counterclockwise direction, i.e., to the right in Fig. 4, and is deflected back into the depressions 45 to the tub. Liquid not deflected back into the tub flows radially outward of the pump plate 40 to form a rotating annulus around the outer wall of the chamber 7. This liquid is diverted from the drain pipe 26 by the lip 26.2. When the impellers are stopped from rotating, liquid may drain by gravity through the openings 36 into the chamber 7. When the rotation of the impellers is reversed the baffles 37 serve to direct liquid into the pump chamber and the blades 39 cause an annulus of liquid to. rotate therein in a clockwise direction as viewed in Fig. 2 and to be expelled through the drain pipe 26, the lip 26.2 assisting in this discharge of liquid. In the embodiment just described, the openings 36 are within the confines of a screen 35 surrounding the impeller 30. According to another embodiment the openings 36 may be provided in the pump chamber top plate outside the confines of the screen and the depressions 45, on the underside of the plate eliminated. The machine is provided with the usual solenoid operated liquid inlet valve and electric heating element and performs a cycle of spraying, washing, rinsing and drying operations under the control of a timer motor and cams which operate, in sequence, switches for the motor 15, the timer motor energizing circuit, the heater, and the inlet valve solenoid which latter is also controlled by a " marginal " relay in the motor circuit, in known manner. The motor 15 is controlled by a triple pole, double throw switch to allow of its rotation in either direction as described with reference to Fig. 8 (not shown).