GB637699A - Improvements relating to ventilating arrangements for vehicles - Google Patents

Abstract

637,699. Ventilating vehicles. CHILTON. A. H., and STONE & CO., Ltd., J. Feb. 5, 1948, No. 3401. [Class 137] [Also in Group XXXV] A heating and ventilating apparatus for a vehicle especially a railway coach, is such that the proportions of fresh air drawn through intake 14 and return air through intake 9 are varied by thermostatically controlled adjustments of the pivoted damper 12. The position of the damper when 100 per cent fresh air or 100 per cent return air is being circulated and the train is stationary, is determined by the limit switches 341, 343. Fresh air is drawn in by fan 3 over heater 2, supported by a frame-work 1 in a housing 4, the air being distributed by duct 11 to various compartments and returned through the intake 9. Alternative damper devices may comprise a single flap or two flaps coupled by a link. The damper 12, air and floor heaters 2, 18 are controlled by thermostats 47, 48, 49 through cooling, air-heat and floor-heat relay windings 31-33, these being energized by an axle driven generator 16 through on-contacts 17 of a cut-in switch while the vehicle is in motion, and by batteries 25 while stationary. At or above 75‹ F, when the vehicle is at rest, the thermostat 47, which may be provided with a heater 50 giving a 3‹ F bias, completes the circuit of the cooling relay winding 31, thus closing the contacts 29 to energize the field windings 26 of the motor 28, causing clockwise rotation of the damper. In this temperature range, the windings 32, 33 of air heat, floor heat relays will be short circuited by thermostats 48, 49 respectively. Below 70‹ F, the windings 32 are no longer short circuited and become energized, closing contacts 30 to excite motor field windings 27 and cause anti-clockwise rotation of the damper. The solenoid 36 is energized through contacts 37 of the cut-in switch when the switch is open, and renders the limit switch 342, which is adjustable relative to the switches 34<SP>1</SP>, 34<SP>3</SP>, ineffective when vehicle is stationary. When the vehicle is in motion and contacts 17 closed, heaters 2, 18 are switched on by respective relays when temperature is below 68‹ F. The damper being closed, temperature will rise and the heaters will be switched off at 68‹ F, 70‹ F respectively. If temperature rises above 75‹ F the damper will be turned in clockwise direction, coming to rest when temperature falls below 75‹ F. If temperature falls below 70‹ F, heater 2 is switched on and the damper turned in anticlockwise direction towards switch 342, the winding 36 being open circuited at the contacts 37. The damper will thus oscillate between limit switches 34<SP>2</SP>, 34<SP>1</SP>. The fan 3 is driven by motor 40. Air disturbing fans 42 will be switched on only when the cooling relay is in action and the contacts 46 are closed.