GB853319A - Improvements in or relating to safety valve devices for gas-heated or gas burning appliances - Google Patents

Abstract

853,319. Valves. JUNKERS & CO. G.m.b.H. July 8, 1957 [July 14, 1956], No. 21484/57. Class 135. A safety device for gas-heated appliances has a main valve 34 upstream of an auxiliary valve 49 axially displaceable on a control stem 40, 42 which is longitudinally displaceable and carries a stop 47 against which the auxiliary valve is held by a spring 48, depression of the stem into the valve casing causing the auxiliary valve to close, the main valve to open and an armature 33 on the main valve to contact an electromagnet 26 which retains the main valve open when a thermal element 29 is heated by the main burner 24 or pilot burner 18 and energizes the magnet, the valve closing should the burner go out, and the stem is mounted in the valve casing for both axial and rotatable displacement and is guided along a helical path 45 by a transverse pin 41 carried by the stem. A control stem actuating knob 40 has the transverse pin 41 engaging a cam surface 45 in a sleeve 37 and screwed in a casing cap 36 and also engaging in an annular recess in the control stem whereby, when the main valve is held open, the knob is released to allow the auxiliary valve to open for gas to flow to the main burner and then rotated so that the cam axially adjusts the control stem and adjusts the opening of the auxiliary valve. The cam may have a notch and a flat for engaging the transverse pin and holding the valve 49 respectively in a position allowing just sufficient gas to ignite the main burner or closed. In this position or when closed, the control stem may hold the main valve just open and the cam surface is of such a slope that the impact of the main valve closing, on flame extinction, allows the spring 43 to raise the valve 49 fully from its seat 13. Specification 474,271 is referred to.