GB140103A - Improvements in apparatus for regulating the temperature of a room or the like - Google Patents

Abstract

140,103. Crida, G. March 11, 1919, [Convention date]. Thermostats.-In apparatus for automatically maintaining the temperature of a room between predetermined limits, the valve or the like controlling the supply of steam or other heating agent is controlled by a reversible electric motor 7, operated by two circuits opened or closed by contacts in the wall of a mercury thermometer 1. A fixed terminal 2, and alternative minimum temperature contacts 3, 3<1>, and alternative maximum contacts 12, 12<1> with plug switches, are in the circuit of the low-tension coil of a transformer 4, the circuit including also a spiral switch 13 on the shaft of the motor 7, so arranged that the appropriate motor circuit is broken when the valve is fully closed. In operation, when the temperature of the room is below the desired minimum. the electro-magnet 5 is inactive and the circuit from the high-tension coil of the transformer 4 is closed through the special switch 8 on the motor shaft and the coil of the motor 7 for opening the control valve, the circuit being broken automatically by the spiral switch 8 when the valve is fully open. On the mercury reaching the minimum contrast, the circuit is broken by the electro-magnet 5. The further ascent of the column to a maximum contact energizes an electro-magnet 17 and closes the switch 19 in circuit with the coil of the motor 7 for closing the control valve.