Patent GB-776138-A (GB)
Title: Improvements in dishwashing apparatus
IPC: A47L15/44
Filed: 1955-12-20
Abstract: 776,138. Dishwashing machines. GENERAL ELECTRIC CO. Dec. 20, 1955 [Dec. 29, 1954], No. 36479/55. Class 138(1) In a dishwashing apparatus having a vat, means for circulating water throughout the vat during each of two periods separated by a quiescent period, there is provided means for introducing detergent into the vat during the second period. which means comprise a detergent compartment openly facing the vat to expose the contents thereof to water action during the second period, a shutter closing the compartment during the first period, latch means for releasably holding the shutter closed and a cup operatively connected to the latch means and arranged to accumulate water during the first period and drain during the quiescent period, to cause the latch-to release the shutter. The dishwasher is of the type comprising a vat with a front opening closable by a door hinged about its lowerhorizontal edge, an electric motor driven impeller in the sump of the vat, solenoid operated inlet and drain valves, a dish rack provided with rollers engaging guide rails in the vat sides and which is movable over the door when in its horizontal open position, and an electric motor driven cam type sequence timer for controlling a cycle of washing, rinsing and drying operations, in known manner. Referring to Figs. 2 and 3, two compartments 22; 23 for powdered or granulated detergent are provided in a container 20 having a flange 21 whereby the container may be secured within an aperture in the inner liner 4.1 of the vat door 4. The compartment 23 is separated from the compartment 22 by the shutter 24 pivoted on a pin 25 adjacent a step 27 in the floor of the container 20. A spring 26 and gravity, bias the shutter in a clockwise direction to the position shown in Fig. 5. A hook 28, Fig. 2, on the shutter, engages in a slot 35 and over a flange 36 both formed. in a central support arm 32 of the cup 30. Two further support arms 31, 33 are provided on the cup and the three arms 31, 32 and 33 pivoted on a pin 34. The cup 30 and its support arms are urged upwardly by a spring 37, Fig. 3, adjustably secured at one end, at 39, to the liner 4.1 and connected at its other end to a pin 38 on the cup 30. As will be seen in Fig. 3, the shutter is latched by the flange 36 engaging the hook 28 under the urge of the spring 37. When the door 4 is open the mouth of the compartment 22 faces upwardly and the compartment 23 may be filled with powdered detergent and the shutter 24 latched in place whereafter the compartment 22 may also be filled with detergent. After closing the door the dishwashing cycle is commenced by operating a manual knob on the timer in known manner, whereafter the timer motor controls the cycle. During the first washing cycle when the drain valve is closed and the impeller hurls water throughout the vat, the detergent in the compartment 22 is washed out and the cup 30 is filled with liquid. Although the liquid can escape from the cup through holes 30.1 in its bottom wall, the rate of escape is less than the rate of inflow. The cup and arm 32 are therefore caused to move downwardly as shown in Fig. 4 against the action of the spring 37 so that the hook 28 is released from the flange 36. However the opposite side of the hook then abuts the edge of the slot 35 in the arm 32 and thus the shutter is cocked in readiness for release. During the next quiescent, portion of the cycle the cup empties and thereafter the spring 37 raises the empty cup 30 and the arm 32 to the position shown in Fig. 5, whereby the shutter is released and lies adjacent the floor of the detergent container. The detergent in the compartment 23 is washed out during the next washing cycle during which the drain valve is closed and the impeller is operating. Specification 725,913 is referred to.