GB422944A - Thermostatic regulator - Google Patents

Abstract

422,944. Valves; thermostats. FAIRWEATHER, H. G. C., 65, Chancery Lane, London.-(Wilcolator Co. ; 17, Nevada Street, Newark, New Jersey, U.S.A.) March 2, 1934, No. 6781. [Class 135] [See also Group XIII] in the thermostatic control of an oven, a second thermostat is arranged so as to compensate for the effects of outside temperatures (due for instance to other burners) on the main thermostat. The second thermostat may be arranged to over-compensate in order to account also for the pressure drop in the gas supply to the oven when exterior burners are lit. In Fig. 2, the main thermostat comprises a copper bulb 16, a flexible capillary copper tube 17, and a metal bellows 49, which are filled with fluid through a tube 56, and controls through a spring-urged rod 44 connected to the bellows-end 48, the valve 30 between the gas-inlet 18 and the outlet 21 to the oven-burner. The second thermostat, consisting of a U-shaped bimetallic strip 43, is interposed between the rod 44 and the valve 30, being connected to a disc 41 which disc is pivoted on a screw 39 and between which disc and the valve 30 a spring 42 is placed. The valve 30 slides on a nut 38 on the screw 39 and is adjusted by turning a knob 33 until keys 40 on the nut engage the valve member. A byepass 57, also connected at 23 to the pilot burner, prevents extinguishing of the oven burner when the valve 30 is nearly closed. In Fig. 3, the main thermostat comprises bulb 16<1>, flexible tube 17<1>, and internal bellows 72, and controls the valve 63 between the inlet 18 and outlet 21 through the compensating thermostat consisting of bimetallic strip 77 fulcrumed at 78. Adjustment is effected from the knob 68 which rotates nut 69.