GB732180A - Control device for gas burners - Google Patents

Abstract

732,180. Thermally-actuated valves. STIERLIN, H. April 29, 1953, No. 11851/53. Class 135. A combined temperature regulator and safety cut-off device for gas burners comprises a rotatable and axially displaceable plunger 5 one end of which forms a valve closure member 5<SP>1</SP> for cutting off the gas supply on retraction of a transverse pin 19 operatively connected to' a member which is influenced by the heat of the burner flame and normally engaging a cam 15 carried by the plunger, the plunger also being arranged to carry the seat 14 of a second valve 12 controlled by an expansible member responsive to the temperature to be regulated. The arrangement is particularly suitable for controlling the gas supply to absorption refrigerating apparatus, but may be used for other temperature control purposes. The plunger 5 has a sleeve-like extension 5<SP>11</SP> slidable in the bore of a casing 1 having a gas inlet and outlet connections 10, 25. The closure member 5<SP>1</SP> seats on the end of a sleeve 3 mounted in the bottom of the casing 1 and when open allows gas to pass from the inlet connection through passages 9, 7 into the sleeve 5<SP>11</SP>. The cam is formed on the lower edge of a ring 15 pinned to the plunger 5. The pin 19 is operated against a spring 20 by a thermal capsule 18 mounted in a housing 16 screwed into the casing 1. The fixed end of the capsule is connected to a capillary tube 22, the remote end of which has coils 22<SP>1</SP> in heat conducting relation with the burner tube 23 and coils 22<SP>11</SP> exposed to the radiation of but not actually in the burner flame. The gas regulating valve comprises a ball 12 adapted to be moved away from its seat 14 against a spring 13 by a push-rod 27 influenced by a fluid-filled thermal capsule 29 connected to a capillary tube 31, the remote end of which is exposed to the refrigerating space. The plunger 5 is initially raised against the action of a spring 28 by a rod 8 operated from outside the casing. This opens the valve 5<SP>1</SP> and pushes the seat 14 away from the ball 12 so that the burner may be lighted. On expansion of the capsule 18, the pin 19 maintains the valves open so long as the burner flame remains alight, the degree of opening of the valve 12 and therefore the temperature to be maintained being adjusted by turning the cam ring 15 by the rod 8. The cam surface has notches at each end whereby the valve 12 may be kept permanently open or the valve 5 may close down completely.