GB1246172A - Improvements in gas valves - Google Patents

Abstract

1,246,172. Burner controls. JUNKERS & CO. G.m.b.H. 7 Feb., 1969 [9 Feb., 1968], No. 6627/69. Heading F4T. [Also in Division F2] A gas ignition safety device has an off key 31 for controlling a gas inlet valve 13, an adjacent operating key 32 for controlling an ignition safety valve 17 and a main valve 20, both keys being displaceable along parallel axes, and a member 40, slidable against a spring transversely of the parallel axes, having a cam 42 co-operating with a projection 321 on key 32 and a latch 41 engageable with an abutment 311 on key 31 to hold the key when it is depressed against a spring 35, so that depression of key 32 causes the member to slide and release key 31 and is characterized in that a flat spring 50 placed between valves 17 and 20 has arms 511, 521 which prevent depression of a rod 34 secured to key 32 unless the valve 17 is shut, when a conical extension 562 of the valve stem 56 forces the arms apart and may co-operate with a conical depression in the end of rod 34 when it is desired to open the valve 17. Starting from the off position, Fig. 1, key 32 is depressed against a spring 36 to close valve 20 and open valve 17, simultaneously allowing key 31 to move outwards and open valve 13, so that gas can flow from an inlet 11, via chambers 14, 16 interconnected by a passage 15, to an aperture 19 in a chamber 18 leading to a pilot burner, Fig. 5 (not shown). The pilot burner is ignited and a thermocouple thereat supplies current to an electromagnet 60 to hold valve 17 open. Releasing key 32 lifts valve 20 to supply gas to a main burner through an outlet 22. To switch the gas supply off, key 31 is depressed and latched, closing valve 13 with a snap action, and it cannot be released to open valve 13 again until the ignition safety valve 17 closes to permit depression of key 32. The closure member 23 of the inlet valve 13 is slidably mounted on the rod 33 secured to the key 31, and has a locking disc 44 connected thereto which engages with an abutment 48 on each of at least three levers secured to the housing, arranged about and parallel to the rod 33, when the valve is open. The levers also possess cam faces 47 so that depression of rod 33 causes the edge 450 of a releasing disc 45, in the form of a truncated cone, secured on the rod, to move the levers outwards until disc 44 is released and the valve closes with a snap action due to a spring 43 between the discs 44 and 45.