Patent GB-427840-A (GB)
Title: Improvements for the regulation of temperature
IPC: G05D23/275
Filed: 1934-03-03
Abstract: 427,840. Thermostats. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Vapor Car HeatingCo. ; 80, East Jackson Boulevard, Chicago, U.S.A.) March 3, 1934, No. 6866. [Class 64 (ii)] An automatically operating thermostatically controlled temperature regulating system for an enclosed space comprises heating means and refrigerating means and maintains selected temperatures. A railway car which may have separate compartments has an air circulating passage wherein air is withdrawn from the car at 1 and forced out at selected places 2 by a blower F. A valved inlet 3 is provided for outside air. In the air passage are heating means G<11> and refrigerating means J ; separate heating means G, G<1> in the compartments independently regulate the temperature therein. Separate thermostatic electric controls are provided for each of those means. Outside the car is a thermostat 7 which operates through a selector relay X to determine whether heating or refrigerating means shall be operative. A selector switch Z operated by the pressure in some pipe line on the car when in service acts through the selector relay to prevent the heating meansmaintaining more than a certain low temperature. The selector relay renders the refrigerating means effective when it is closed and limits the temperature produced by the heating means to this low degree ; when open the relay renders the refrigerating means ineffective. Steam or other heating fluid is admitted to the radiators G ... G<11> through electrically operated valves H .. H<11> each controlled by a relay N ... N<11>. These relays are respectively associated with a group of thermostats L .. L<11> each with a switch 72 by which the controlled temperature is determined. The switches 72 in compartments B and C are adapted for shutting off the heat entirely. Refrigerant is supplied to the coil J from mechanism K driven by a motor 5 under the control of relays P and a group of thermostats O with a switch 72 which has a contact causing continuous operation independent of the thermostats. Should one of the valve mechanisms H stick or an excessive or prolonged current occur the supply link 103 is interrupted by a circuit breaker W which at the same time operates an indicator 123 and is preferably automatically reclosing, as shown and with a time delay. Test switches 107 are provided to locate the faulty apparatus. The refrigerator motor is rendered inoperative when the main switch U of the lighting system is open. The selector relay X completes the heating control circuits when energized and when de-energized closes the refrigerator control circuit and also auxiliary control circuits through the low temperature thermostats of compartments A and B so that when the car is out of service and coupled to an extraneous source of heat a minimum temperature is maintained in such compartments ; the radiator G<11> is completely cut off at such times. To permit the raising of the minimum temperature a cam lever 198 may be used to cause the selector switch Z to open whereupon the control devices L become operative in the normal manner. The refrigerator and heating mechanisms are inoperative until the switch 45 has closed the circuit of the blower motor 4. A test switch 196 is provided for the refrigerating mechanism and control connections.