Patent GB-790204-A (GB)
Title: Improvements in or relating to dish washing machines
Inventor: MARSHALL FREDERICK GEORGE
IPC: A47L15/23
Filed: 1953-04-15
Abstract: 790,204. Dishwashing machines. C.S.A. INDUSTRIES, Ltd. April 15, 1954 [April 15, 1953; April 15, 1953], Nos. 10252/53 and 10253/53. Class 138(1). A dishwashing machine comprises a dish-carrying container 10, Fig. 1, a washing liquid heating chamber 11 having an inlet 34 supplied with liquid by gravity from a lower part of the container 10 and an outlet 24 for the delivery of liquid boiled in the chamber 11 to the upper part of the container 10, and a valve 31 adopted to close the inlet 34 after a predetermined volume of liquid has been supplied thereto, the arrangement being such that, on closure of the valve 31, the total pressure in the chamber 11 due to boiling the liquid is available as head for discharging the liquid through the outlet 24. The heating chamber 11 is secured, coaxially, to the bottom 15 of the dish carrying container 10 and is in communication with the inlet opening 34 in a trough 12 also coaxially secured to the bottom 15 above the chamber 11. A bell-shaped vessel 18 mounted in the chamber 11 is connected to a vertical delivery tube 27 having at its upper end a turbine sprayer 36. A float element 28 is arranged around the vessel 18 and a covering plate therefor constitutes the valve 31 for closing the opening 34 as later described. The vessel 18 is guidable vertically by a guide bush 21, in a bridge piece 20 in the vessel, engaging a fixed guide pin 22. Water is supplied from a water main at 49 to a separate control vessel 48 provided with an overflow 50 communicating with the machine drain 51, from which vessel 48 it passes through a pipe 52 to the trough 12. The trough comprises an annular portion 45 supported by a partition 44 from a central portion 46. The water in the portion 45 enters the portion 46, through weirs 47 in the partition 44, and can flow into the chamber 11 through the opening 34. When a predetermined amount of water has passed to the chamber 11 the valve plate 31 rises to close the opening 34. On boiling the liquid in the chamber 11 by means of an electric element 35 it is caused to rise up the tube 27 to the turbine 36 from whence it is sprayed over dishes held in a rack (not shown) in the container 10. The float valve 31 falls when the chamber is emptied and the chamber 11 is then recharged with liquid from the trough 12 so that the action of the machine is repeated intermittently. In the initial operation detergent contained by a small receptacle carried by a partition plate 38 in the container 10 mixes with the water in the trough 12. The washing solution ejected from the turbine 36 returns to the trough through strainers 53 in the plate 38 and the solution gradually dilutes by the addition of more water from the pipe 52 and by overflow to an opening 56 connected with the drain 51, until finally clean water is ejected over the dishes. A bush 41 in the plate 38 facilitates the guiding of the assembly 18, 27, 36 in its vertical movement, the bush 41 engaging a shroud 42 fixed relative to the tube 27. In another embodiment three separate heating chambers each provided with a separate float valve are mounted celow the container 10 and are equiangularly spread around the axis of the delivery tube which in this case is restrained from movement. Each heating chamber communicates with the base of the delivery tube through one of the hollow arms of a three-armed spider secured to the bottom of the container 10. Each heating chamber also communicates through its float valve with an annular trough coaxial with the delivery tube and the level of the liquid in the trough is controlled by an overflow pipe open at both ends and secured to the bottom of the trough. The heating chambers in this case may be of different capacities, their heating elements may be of different capacities and they may operate alternately or may be arranged to deliver liquid simultaneously to the delivery tube. In a further embodiment one heating chamber is provided below the container 10 and has three float valves spread equiangularly from the delivery tube, each float valve communicating with the base of the container 10. In this case the base of the container 10 serves as the feeding trough and is provided with an overflow to limit its content. The base of the container 10 is fed from an annular vessel surrounding the container 10. The supply of water to the annular vessel is controlled by a tap and a single control member operates the tap and a switch for the heating element. Heating of the heating chambers may be effected by gas or liquid fuel in lieu of electricity.