GB534978A - Improvements in or relating to thermostatic regulating valves - Google Patents

Abstract

534,978. Valves: fluid-pressure servomotors. SHERLOCK, J. E.. and BRITISH THERMOSTAT CO., Ltd. Sept. 21, 1939, No. 26351. [Class 135] A thermostatic regulating valve for controlling heating or cooling systems of the kind in which a regulating valve is operated by the thermal expansion of a fluid contained in a flexible metal bellows, or similar expansible chamber, is constructed so that in the event of a leakage in the bellows the valve is moved to cause a cooling system to operate at the full, or to cut off the source of heat in the case of a heating system. As applied to a cooling system for an internal combustion chamber in which when the engine is cold the cooling liquid flows from a pipe 5 to a pipe 7 which byepasses the radiator, the control valve 15' throttles the flow of fluid in a circuit containing a reservoir 1, pump 2, and a bellows 3. The pressure in the bellows 3 thus acts against a spring 8 to maintain a valve 4 in a position which directs the cooling fluid to the pipe 7. When a phial 13, filled with liquid is heated by the engine. a bellows 12 raises the valve 15, and liquid flows through the valve via pipe 17 and port 15a, thus relieving pressure in bellows 3 and permitting spring 8 to cause the valve 4 to direct the cooling liquid through the radiator. In the event of leakage in the bellows 12, a spring 14 depresses the valve 15 to such a position that the throttle valve is moved downwards past its closed position to a position in which the opening 15a registers with pipe 18 thus causing the valve 4 to move to the position in which the passage to the radiator is open fully. In a modification Fig. 2, the phial 27 connects by pipes 26, 28 to two bellows 25, 29 acted upon by springs 30, 31, of which the spring 30 has a stronger action than the spring 31. Valves 24, 23 are operated by the bellows, and the valve 24 normally opens, when the fluid in the phial 27 attains a given temperature, to permit the supply of cooling fluid from a pipe 20 to a pipe 21 leading to the radiator, or the like. Or the valve may control the supply of fluid to a throttle device as in Fig. 1. If either of the chambers 25, 29 leaks the valve 24 closes but the valve 23 opens and maintains the supply of cooling fluid. In a further modification involving the use of two metal bellows, the movements of these control a lever member which operates a lift valve controlling the flow of a cooling fluid. The action of this modification is somewhat similar to that of Fig. 2 in that springs of unequal. strength determine the actions of the bellows on the lever, and also in that the cooling action is caused to operate at full efficiency in the event of a leakage in either of the bellows.