Patent GB-774899-A (GB)
Title: Improvements in or relating to gas heating equipment
Inventor: EADON-CLARKE CHRISTOPHER ERSKI
IPC: F23N1/00
Filed: 1953-12-21
Abstract: 774,899. Controlling gas burners. STANDARD TELEPHONES & CABLES, Ltd. Dec. 17, 1954 [Dec. 21, 1953], No. 35544/53. Addition to 716,111. Class 75(1) Gas heating equipment includes at least one burner for burning a gas mixture at each of a plurality of work stations, a plurality of electrically operable timing means, a selector for selecting one or more work stations and one timing means, and a common push button control, the arrangement being that the supply of gas mixture to the selected stations as initiated by the common control and terminated by the selected timing means. The burners at each station are supplied with a gas/air mixture from two injectors supplied with gas and air through electro-magnetically operated gas and air valves, there being one electro-magnet gas and one electromagnetic air valve for each station. In Fig. 2, which shows a control circuit for two work stations, the electro-magnetic gas valves 4, 5 and the electro-magnetic air valves 15, 16 are selectively controlled by switches 28, 29, one bank S1 of a selector switch S and a push button control switch S30. A second bank S2 of the selector switch selectively energizes two timing motors 21, 22 which at the end of a heating period open contacts 211 or 221 selectively included by a third bank S3 of the selector switch in the circuit of a contactor 27 adapted to close contacts RS1 shunting the push button S30. In operation with the switches 28, 29 in their upper positions a heating operation is carried out at work station No. 1 by setting the selector switch to position No. 1. On depressing the push button S30 air valve 15 and gas valve 4 supplying the burners of work station No. 1 only are energized through switch bank S1, timing motor 21 is energized through switch bank S2 and contactor 27 is energized through switch bank S3 and contacts 211 to close contacts RS1 so that the push button S30 can be released. At the end of the heating period timing motor 21 opens contacts 211 to de-energize the contactor 27 and hence the gas and air valves 4, 15. In position No. 2 of the selector switch the other gas and air-valves 5, 16 are energized to supply the burners of work station No. 2 and the heating operation is terminated by the other timing motor 22. Position No. 3 of the selector switch allows heating operations to be carried out simultaneously at both work stations, both operations being terminated by timing motor 22. With switch 28 in its lower position the air valves 15, 16 are not controlled by the banks S1 of the selector switch but are both energized when the push button is depressed or shunted by the contacts RS1 whereby air only for cooling is supplied to the burners of one work station whilst a heating operation is being carried out at the other work station. Switch 29 en ables both gas valves 4, 5 to be closed without closing one or both air valves 15, 16. The timing motors 21, 22 can be disconnected by means of the switches 25, 26, the heating process then being terminated by manual operation of a push of switch S40. Bank S4 of selector switch S energizes indicator lamps 23, 24.