GB1002755A - Water mixing valve assembly - Google Patents

Abstract

1,002,755. Valves. ROBERTSHAW CONTROLS CO. Oct. 3, 1962 [Oct. 5, 1961; June 12, 1962], No. 37478/62. Heading F2V. [Also in Division G3] A water mixing valve has identical hot and cold water inlet valves 22, 22a, Fig. 1, each loaded to the closed position, shown, by a spring and the supply pressure; each valve communicates on its downstream side with a mixing chamber 26 leading to an outlet 28 via a restriction in a washer 30. A control chamber is associated with each inlet valve and is divided by a diaphragm 46 into upper and lower chambers 42, 44, the former being permanently open to atmosphere through an orifice 48 whilst the latter is connectible to a vacuum source 54 or atmosphere under the control of a valve 56 which may be manually or automatically actuated; the diaphragm 46 is connected to its associated inlet valve by a rocker 60. Thus, depending upon whether either one or both inlet valves are opened, water is supplied to the outlet 28 at any one of three different temperatures. The upper wall of the diaphragm chamber may be dispensed with. In a modification, the inlet valves are each actuated by a pair of diaphragms 124, 126 Fig. 3, interconnected by a lost-motion means 154, 156 whereby any one of five different temperatures of the outlet water may be obtained. The upper chamber 118 is open to atmosphere whilst the intermediate and lower chambers are connected to a vacuum source 136 or atmosphere by valves 134, 142. By reducing the amount of lost-motion to less than one-half of the complete range of movement of the upper diaphragm 124, as well as providing a stop 200 for the lower diaphragm 126, each valve has two further intermediate positions whereby a range of nine outlet water temperatures is available. The diaphragm or diaphragms may be replaced by bellows of polypropylene plastic. The filter and a flow limiter 48a are provided upstream of each inlet valve. The housing may be formed from a thermoplastic material and the diaphragm means may be secured thereto by spring clips; the lower fixed wall of the diaphragm chamber may be formed by moulding polycarbonate acetal resin, acrylonitrile butadiene styrene, polyvinyl chloride, or cellulose acetate butyrate. A flow-limiting means may be provided in the outlet, the means comprising a flexible member 138, Fig. 16, supported above the outlet pipe 132<SP>1</SP> by a transverse element 134<SP>1</SP> having two pins 136<SP>1</SP> that co-operate with slots 137<SP>1</SP> in the member 138<SP>1</SP>; the latter is held on the element 134<SP>1</SP> by a rod 139<SP>1</SP>. As the flow of water increases the member 138<SP>1</SP> flexes downwardly to progressively restrict the amount of water passing to the outlet. The valves may control the programmed cyclic operation of a washing machine.