Patent GB-505817-A (GB)
Title: Improvements in and relating to dish-washing machines
IPC: A47L15/06
Filed: 1938-08-23
Abstract: 505,817. Washing dishes. BRITISH THOMSON-HOUSTON CO., Ltd: Aug. 23, 1938, No. 24789. Convention date, Aug. 27, 1937. [Class 138 (i)] Relates to dish-washing machines of the general character described in Specification 482,089, comprising a vat, a water supply thereto controlled by a spring-closed valve, an impeller driven by an electric motor, and an electromagnetic device arranged to allow the valve to close when the vat is full, and consists in control means for opening the valve and for rendering the motor and electromagnetic device operative, together with manual means for allowing the valve to close irrespective of operation of the electromagnetic device. The machine comprises a vat 15, dish racks 14, drain valve 33 controlled by a knob 34, water-supply valve 22 biassed to closing position by a spring and controlled by a knob 24, and impeller 17 driven by an electric motor 18 controlled by a switch knob 46. The control devices are shown in operative position in Fig. 4. The knob 46 operates the switch 43 of the motor 18 through a plate 44 The knob 24 is fast on a shaft 25 on which is freely mounted a lever 28 connected to the valve 22 by a link 29. The lever 28 is moved by a plate 31 fast on the shaft 25 and provided with lugs 32 on each side of the lever, the lugs being spaced apart sufficiently to allow some lost motion between the lever and plate. When the valve 22 is open, the lever 28 is locked by a catch 51 biassed by a spring 54, and a link 56 connected to the lever has rocked a switch 48 to connect the electromagnetic device, not shown, in the armature circuit of the motor. In this condition of the apparatus, the switch 43 having first been closed, the impeller is driven, and the vat fills with water until the increasing load on the motor causes the armature 58 of the electromagnet to release the catch 51. The valve 22 then closes, and the switch 48 opens. If it is desi red, with the parts in the position of Fig. 4, to close the valve 22 manually, the knob 24 is turned counterclockwise. A cam surface 59 on the plate 31 then raises the catch 51 to release the lever 28. Interlocking means are provided for preventing opening of the valve 22 until the knob 46 has been turned to start the motor, and stopping of the motor before the valve has been closed. In a modification, the lever 28 is not freely mounted on the shaft 25, but is mounted with limited freedom of movement thereon. Specification 505,816 also is referred to. The Specification as open to inspection under Sect. 91 describes an arrangement, Fig. 15 (Cancelled), in which a single shaft 72 carries a cam plate, not shown, for controlling the motor and electromagnet circuits, and a plate 78 adapted to open the valve 22 through a push rod 77 and links 76, 75. The plate is locked in position, with the valve open, by the electromagnet catch 83. The plate is freely mounted on the shaft and has an enlarged keyway 79 engaged by a key 80 on the shaft. A member 84 adapted for the manual release of the catch 83 is fast on the shaft and is connected to the plate by a spring 85. This subject-matter does not appear in the Specification as accepted.