Patent GB-698936-A (GB)
Title: Improvements in and relating to dishwashing machines
IPC: A47L15/42
Filed: 1952-05-26
Abstract: 698,936. Dishwashing machines. BRITISH THOMSON-HOUSTON CO., Ltd. May 26, 1952 [May 26, 1951], No. 13275/52. Class 138 (i). A dishwashing machine comprises a stationary cabinet with a substantially horizontal counter surface thereon, an open top tub carrying washing mechanism and slidably mounted under the counter surface for movement between a position under the counter and a position withdrawn from the counter, a cover for the open top of the tub carried by the cabinet under the counter surface and means for moving the cover towards and away from sealing relation with the tub top when the tub is under the counter. The tub 7, Figs. 3 and 5, has slides 9 co-operating with interconnecting slides 10 having rollers 12, 13 and side tracks 8 having rollers 11 carried by the cabinet, in known manner and the cabinet is comprised of angle pieces 5, side and back panels 6 and a top constituted by the counter surface 1. The counter 1 is provided at one end with a sink (not shown) the cover 42 and a pressure plate 53 thereon has four upright pins 52 passing through side angles 49 fixed to a channel member 44 carried by the cabinet, see Fig. 6. The cover is normally urged upwardly by springs 50 acting between the angles 49 and washers 51 connected to the pins 52. The member 44 serves as a bearing for a shaft 41 connected at its outer end outside the cabinet to a handle 40. Within the channel 44, the shaft 41 carries a cam 55 which can coact with a roller carried by an arm 57 pivoted within the 'channel. By rotating the handle 40 the cam 55 causes the roller and thus the cover 42 to be urged downwardly so that when the tub is within the cabinet the cover will be sealably engaged with a gasket 48 around the open top of the tub, against the action of the springs 50. The cover has two vent openings which, when the cover is urged onto the tub, are sealably engaged with vent openings 79, Fig. 3, in the cabinet through the agency of flexible vent ducts 78. Springs 81, Fig. 6, in the ducts 78 hold them fixed in the vent openings in the cover and also serve to condense moisture as it passes through the duets. The springs 81 will also prevent suds from passing through the ducts 78 by breaking- up such suds. The tub 7, Fig. 3, is provided with an impeller 17 driven from a motor 18, and an electric heater 23. The motor 18 also drives a drain pump 68, an air blower fan 24 and a control mechanism 27 which controls an automatic washing, rinsing and drying cycle. The control mechanism 27 is similar to that described in Specification 638,075. The air blower 24 supplies air through a pipe 25 to an opening 26 in the tub above the impeller 17 which opening is covered by a screen 76. In a similar manner to that described in Specification 696,278 air is only supplied to the tub when the screen 76 is drained dry. The inlet to the drain pump 68 comprises a hole or holes 69 in the bottom of the tub while its outlet 70 connects with a chamber just above a drain valve 22 in its closed position. When the valve 22 is closed the pump 68 will merely circulate water back into the tub. However when the valve 22 is opened by a rod 31 under the control the mechanism 27 the water will pass through a pipe 71 having a downwardly directed terminal portion 72. This water will pass an air gap 73 and enter a funnel 74 of a drain pipe 75 fixed within the cabinet. Water is supplied to the tub from a pipe 63, solenoid operated valve 64 and pipe 65 having a downwardly directed end 66 which valve and pipe system are carried by the cabinet. This water passes an air gap 67 into a funnel 21 of a pipe 19 carried by the tub and thus into the tub at 20. The control mechanism 27 operates in conjunction with a control panel 32 secured between the front of the tub and the front panel 14. This panel carries a pivot 34 on which are separately mounted a vertical arm 33 having a slot connection 39 with the pivot, and a horizontal arm 35. However the arms are operable together as by an ear 36 on the arm 33 engaging under the arm 35 to limit the movement of the arms away from one another, and by a compression spring 37 extending between another ear 38 on arm 33 and an ear 39 on arm 35. A control wire 28 connects the arm 35 to the mechanism 27 and the arm 35 is also connected by tie bar 61 to a resetting rocker 59, pivoted on the panel 32 at 60 and having a roller 62. Moreover the arm 33 has a pair of projecting pins 46, 47. The mechanism 27 also connects by a cable 29 to a pivoted detergent dispenser lever 30 of the same character as that disclosed in Specification 638,075. When it is desired to operate the machine, the tub is loaded with dishes and slid into the cabinet and the handle 40 is then turned to the vertical position to lower the cover on to the tub. At the same time an arm 45, Fig. 4, on the shaft 41 in line with the handle also moves into a vertical position and in so doing causes, through the pins 46, 47, slot 39 and spring 37, the arms 33, 35 to assume the positions shown in Fig. 4 and the cable 28 to be pulled upwardly to start the control mechanism 27. When a washing and rinsing cycle have geen completed the control mechanism 27 causes the cable 28 to be pulled downwardly and cause the arms 33, 35 and the rocker 59 with roller 62 to assume the positions shown in Fig. 3 the pin 47 having been urged downwardly under the tip of the arm 45. After this the drying cycle will be effected until the entire operating cycle is complete. During this time the tub has been interlocked with the cabinet by the arm 45 engaging between the front panel and the tub and also by the handle 40 itself. In order to reset the actuating arms to a starting position intermediate of the positions shown in Figs. 3 and 4, the arm 45 on being returned to its horizontal position passes over both pins 46, 47 and engages the roller 62 to rotate the rocker 59 clockwise and thus lift the arm 33. When the arms 33, 35 are in the intermediate position the circuits to the motor, heater, and supply valve will all be open. Since the cover 42 has now been raised the tub may be withdrawn from the cabinet, unloaded and then reloaded in readiness for the next operation of the machine.