Patent GB-775975-A (GB)
Title: Improvements relating to dish-washing apparatus
Inventor: PANISSET DENIS SYDNEY
IPC: A47L15/46
Filed: 1952-10-02
Abstract: 775,975. Dishwashing apparatus. SIMPLEX ELECTRIC CO., Ltd. Oct. 2, 1953 [Oct. 2, 1952], No. 24660/52. Class 138(1) [Also in Group XXIX] ' A dishwashing apparatus comprises a' washing container 14, Fig. 1, provided with nozzles 16 connected with a boiler 15 for projecting jets of steam or hot water on to dishes in racks 18, 19, and a receptacle 27 for an auxiliary cleansing liquid communicating with one or more of the nozzles so that constituent is entrained by the jets issuing from the nozzles, the receptacle 27 being so arranged that the constituent is not diluted or contaminated by matter removed from the dishes or liquid already delivered to the container 14..The apparatus in Fig. 1 comprises a cylindrical vessel 12 surrounded by lagging 44 in a housing 10. The vessel 12 is divided by a partition 13 into the boiler 15 and the container 14 and is provided with a hinged lid 33. Communication between the boiler and container 14 is obtained through venturi nozzles 16 mounted in the partition 13. Detergent may be supplied to the throats of the nozzles 16 from the container 27 and pipe 28 through branch pipes 29. Water in the boiler 15 is boiled by an electric element 40 or by a gas or liquid fuel. Steam passes through the nozzles and entrains detergent which is directed on to the dishes in the container. After the detergent is exhausted the steam continues to flow to finally rinse and sterilize the dishes. The lid is locked at 35 by an electric solenoid actuated by a pressure switch 36 when the steam pressure rises above a certain value. This locking device could be alternatively operated by mechanical means such as a piston or diaphragm operated by the steam pressure. Another pressure switch is actuated to open the heater circuit when the pressure reaches a predetermined value. A safety switch is also provided to open when the water level falls below that of the heater 40. In the embodiment of Fig. 4, the boiler 53 and washing container 45 are completely separate and lagged within an outer container 46 by material 47. The container 45 is provided with a side door hinged either on one of its vertical sides or on its bottom side. Nozzles 57 are provided in pipes 54 in.the tub which pipes extend into the boiler and below the water level therein. In this case water is first forced through the nozzles and when the water level falls below the ends 55 of the pipes 54 steam is ejected. Detergent may be entrained in the jets as described with reference to Fig. 1. A steam pressure actuated electric switch 58 controls a door locking device (not shown). This switch may also contain contacts to cut out the heater 59 on attainment of a predetermined steam pressure. To economize in the use of steam, flow regulated means are provided to cut off communication between the boiler and to establish communication when the pressure rises to a predetermined value. As shown in Fig. 5, the end of the pipe 54 is provided with a fixed barrier plate 70 having an aperture 74. A plate valve 71 having an aperture 73 is movable by a pivoted lever 78 and piston 76 against the action of a spring 75. When the valve 71 is lowered as shown steam passes in a tortuous path through the aperture 73, between the plates 71. 70 and through the aperture 74. A pressure gradient is thereby set up through the control valve the pressure between the plates being intermediate of that in the boiler and that in the pipe 54 above the plate 70. For example a pressure of 10 lbs. per square inch may be reouired to open the valve when the plate 71 is pressed against the plate 70 and there is no intermediate pressure zone, whereas once the valve is opened it may be so retained due to the existence of the intermediate pressure zone until the boiler pressure falls to say 5 lbs. per square inch. If desired a distributing device may be provided to connect the boiler successively with different groups of nozzles. In another alternative, a. flash type boiler may be provided to produce pulsating jets of washing fluid in the tub. According to the Provisional Specification a device may be provided to prevent the generation of steam until the lid of the tub is closed. Also the dish rack may be arranged to rotate under the action of the jets.