GB417464A - New or improved temperature control means for ventilator installations - Google Patents

Abstract

417,464. Thermostats. STONE & CO., Ltd., J., Deptford, London, and VIDAL, J. F. B., 48, Woodcrest Road, Purley, Surrey. April 5, 1933, No. 10211. [Class 64 (ii).] Ventilating installations comprise two temperature sensitive devices responsive respectively to external and internal temperature of a ventilated space, such as a railway vehicle, a proportioning mechanism through which the devices additively control means regulating the temperature of the ventilating air, and means for readily adjusting the mechanism to vary the proportion in which the temperature sensitive devices partake in the control. A fluid bulb a within a duct d supplying warm air, or within the ventilated space, is connected to a bellows chamber c, and a fluid bulb b, external to said duct or space, is connected to a bellows chamber c<1>. The chambers c, cl operate, through rods f, f<1> respectively, a beam h, a rod and a two-armed lever k, k<1> actuating a switch contact o. To vary the proportionate effect of the bulbs a, b upon this switch the rod j is connected adjustably to the beam h and a screw s adjusts the point of connection. In the application described (Fig. 2, not shown), the contact o co-operates with fixed contacts q, r to control a reversible motor which drives through reduction gearing a rod actuating coupled valves variably byepassing the air supply in relation to heating apparatus. The lever mechanism may be adapted to cut in or out electric, hot water, or other heaters instead of controlling a byepass device. Magnetic or spring click means for preventing fluttering of the contact o may be provided.