Patent GB-602733-A (GB)
Title: Improvements in or relating to thermally controlled valves
IPC: G05D23/13
Filed: 1944-11-16
Abstract: 602,733. Washing machines. DOLE VALVE CO. Nov. 16, 1944, No. 22716. Convention date, March 20. [Class 138(ii)] [Also in Group XXIX] A temperaturecontrolled mixing valve for a washing machine is provided with an adjusting member for setting the temperature level at which the valve will operate and with means for changing the setting of the temperature adjusting member at predetermined times in a cycle of operations. The invention is shown applied to a washing machine comprising a rotary drum 29, Fig. 2, driven by an electric motor 31, the hot and cold water supplies 51, 52 passing to an inlet pipe 53 leading to an aperture in the front of the drum through the mixing valve 50 which is controlled by a timing device 32. Water is discharged from the drum through a sump 56, pipe 57, drain valve 58, and a pump 55 driven by the motor 31. The mixing valve comprises a sliding spindle 82, Fig. 6, with valve closure members 81, 83, 84 controlling the flow of hot and cold water from the inlet pipes into a mixing chamber in which a coiled bi-metallic element 87 is located, the latter being anchored at one end to a pin 88 and having its free end connected to the spindle 82. The mixed fluid passes into the inlet pipe 53 past a diaphragm stop valve 130, Fig. 5. Apertures 133 in the diaphragm allow the water to pass to the upper side of the diaphragm so that the latter is normally balanced and the diaphragm will be pressed on to its seating by a plunger 139 which closes a passage 127 passing through the diaphragm. The plunger constitutes the armature of a solenoid 136, and when the latter is energised by the timer, the plunger is lifted and the passage 127 opened to allow the water above the diaphragm to flow away with the result that the diaphragm will be lifted by the pressure on its undersurface and water will be able to flow into the drum. The datum of the bi-metallic spiral is set by rotating the anchoring pin 88, this being effected from a shaft 94 which. carries a pin 92 engaging in a slot in an arm 90 carried by the pin 88. Shaft 94 can be rotated manually by means of a knob on the end of a shaft 107, Fig. 7, the latter being formed with a square shank which engages in a slot 110 in a disk formed with stepped edges 102, 103 and engaging in an oval aperture 100 on the end of an arm 97 carried by the shaft 94. Arm 97 is loaded by a spring 111 tending to press the edge 102 and a finger 104 carried by the edge 103 into engagement with cams 106 and 105 respectively, these cams being carried on a timing shaft 38 driven by a separate electric motor. Timing shaft 38 also carries cams to actuate switches controlling (i) the starting and stopping of the timing motor, (ii) the energisation of solenoid 136 controlling valve 139, (iii) the energisation of a solenoid controlling drain valve 58 and pump 55, and (iv) the energisation of a solenoid controlling a clutch for changing the speed of rotation of the drum. Included in the circuit of the solenoid 136 is a switch controlled by a float 60 in a stand-pipe in communication with sump 56. Thus, when the drum has been filled with water, the float will close the switch and allow valve 139 to operate. In a modification, the flow to the inlet side of the cut-off valve 130 is regulated by an apertured disc of resilient material and the valve 139. is actuated mechanically. The valve is attached to one end of a pivoted bell crank 208, Fig. 20, the other end of which constitutes a follower to a cup-shaped cam 203 rotated by a shaft 200. The cam is disconnected from the follower to allow valve 139 to close by sliding the shaft 200 to the right, a key-and-slot connection 201 between this shaft and the driving shaft 202 allowing this movement to be made, and a detent 229 engages one of two grooves 227, 228 in the shaft 200 and keeps the shaft in one or the other of its two positions. A bucket 212 carried on a bell crank 216, 217 is in connection through a pipe 220 with the drum, and when the latter is nearly full, the bucket begins to fill and finally drops so that the arm 216 will move shaft 200 to disconnect cam 203 from its follower, and valve 139 will close and the supply to the drum will be shut off.