Patent GB-843491-A (GB)
Abstract: 843,491. Thermally-actuated valves. SWISS GAS STOVE CO. SOLOTHURN. July 6, 1956 [July 14, 1955; Aug. 15, 1955; Jan. 24, 1956], No. 20957/56. Class 135. A thermally responsive device controls the flow of fuel to a burner in such a way that fuel flow to any part of the burner is prevented unless the thermally responsive device has been heated to a predetermined temperature, e.g. by a match. In one form, the burner 2, Fig. 1, is fed with gas through an inlet 28 and a regulating needle valve 18. The needle valve is mounted on a lever 15 pivoting on a pin 14 and carrying a solenoid 22 energized by a thermocouple 4 to hold an armature disc 24 against the bias of a spring 30. If the burner is extinguished, the thermocouple 4 cools down and, the solenoid 22 being no longer energized, the spring 30 forces the armature disc 24 away from the solenoid against the bias of a weak spring- 29 to close the inlet orifice 28 and thus shut off the supply of gas. To re-ignite the burner, a match or the like is held against the thermocouple 4 which accordingly warms up and supplies current to the solenoid 22. The lever 15 is then turnedanti-clockwise of Fig. 1 until the solenoid 22 contacts the armature disc 24. On turning the lever 15 &c. clockwise, the magnetic field of the solenoid 22 holds the armature disc 24 in position against the bias of the spring 30, so that it is withdrawn from the inlet orifice 28. The lever 15 is turned about the pin 14 on rotation of a screw 11. In one modification, the cock 34 and shaft 52, Figs. 2, 3, of a valve can turn relatively to a control shaft 45. Fast with the control shaft 45 is the solenoid 37 and the core 36 of an electromagnet co-operating with an armature 35 fast on the cock shaft 52. A hoop 38 mounted on the burner casing 32 guides the movement of the electromagnet 36, 37 and of the armature 35. A strong spring 39 biases the armature 35 away from the electromagnet 36, 37. The solenoid 37 is energized by a thermocouple 4 in the flame of the burner, as described above. If the burner is extinguished the solenoid 37 is no longer able to hold the armature 35 in place against the bias of the spring 39. The armature 35 is then turned clockwise to lie against a stop 41 by the spring 39 and shut off the supply of gas to the burner, while the electromagnet 36, 37 is simultaneously turned anti-clockwise to lie against a stop 40. To re-ignite the burner, a match is held against the thermocouple 4 which, when it heats up, energizes the solenoid 37, so that on turning the control shaft 45 clockwise of Fig. 2 until the core 36 &c. occupies the position shown in dotted lines, the spring 39 is compressed and the magnetic force is sufficient to hold the armature 35 in contact with the electromagnet. The control shaft 45 can then be turned anticlockwise of Fig. 2, taking the electromagnet 36, 37 and the armature 35 with it, to open the valve and start the flow of gas. In another form, a cock shaft 52, Fig. 4, carries a transverse armature pin 35 engaging at its ends with two poles at the ends of a U-shape core and solenoid 36, 37. The core 36 is mounted in a sleeve 51 which can be turned by a control shaft 45 movable axially to disengage a catch mechanism 50. The solenoid 37 is energized by a thermocouple 4. A torsion spring 53 biases the cock shaft 52 and armature pin 35 to turn away from the ends of the core 36 against the magnetic force. If the burner is extinguished, the solenoid 37 is de-energized, so that the torsion spring 53 turns the cock shaft 52 &c., and shuts the valve. The amount through which the cock shaft 52 can turn is limited by a stop-pin 55. To re-ignite the burner, the thermocouple 4 is heated by a match to energize the solenoid 37, and the control shaft 45 is pushed axially inwards and turned to re-engage the armature pin 35 with the ends of the arms of the core 36. The shaft 45 can then be turned together with the shaft 52 against the bias of the torsion spring 53 to re-open the valve. As a modification the thermocouple 4 may be replaced by a bimetallic strip or the like.