GB547220A - Improvements in or relating to thermostatic valve mechanism - Google Patents

Abstract

547,220. Fluid-pressure servomotor-control systems. BRITISH THERMOSTAT CO., Ltd., and SHERLOCK, J. E. Dec. 16, 1940, No. 17730. [Class 135] A device for controlling the flow of heating or cooling medium particularly applicable to the cooling system of an internal combustion engine comprises a main valve element adapted to be operated by the pressure of the fluid circulating in the system under the control of thermallyactuated auxiliary valve device. In the arrangement shown in Fig. 1 a main valve casing a is connected at g to the outlet from the cooling jacket h of an engine and at band d to the inlet and outlet respectively of a radiator c. A pump e draws liquid from the radiator and returns it to the cooling jacket and also supplies pressure fluid through a pipe z to a nozzle t. Fluid from the nozzle t passes into a nozzle u unless interrupted by a baffle v and builds up a pressure beneath an actuating piston working in cylinder supported from the casing a by radial arms or a ported web q. The piston k is coupled to a lift valve i and a tubular lift valve o adapted to co-operate with seats m, n on opposite sides of partition m<SP>1</SP>. When the pressure in the cylinder is low the radiator c is short circuited through the port. As the pressure rises the valve i opens and the valve o closes to prevent more and more of the liquid to circulate through the radiator. In a modification the valve i is replaced by a double beat valve and the valve o by a simple lift valve. In the first form the valve acts to maintain the pressure at the radiator inlet at a valve corresponding to the controlling temperature while in the second form the pressure at the radiator outlet is maintained at the required value. Any alternative form of auxiliary valve may replace the baffle and nozzles and a light spring may load the valve i towards its seat.