GB1499075A - Thermoelectric ignition safety device - Google Patents

Abstract

1499075 Burner controls JOH VAILLANT KG 9 March 1976 [26 March 1975] 09379/76 Addition to 1317535 Heading F4T In the device of Specification 1,317,535 the lever 8 carries, mounted for pivoting about an axis 27 perpendicular to the axis 9 of the lever 8, a lever 29 which is arranged to be rotated by an OFF push-button 30 against the force of a spring 35 which has a projection (37), Figs. 3, 4, 11, 12 (not shown) engaging a lever 38 and preventing it from returning to its initial position in which it causes microswitches 16 to be open. To switch on the device the ON pushbutton 4 is depressed, turning lever 7 and (by engagement of projections 22, 46) lever 38 anticlockwise and moving armature 3 and rod 12 to the left so that the armature abuts electromagnet 2. The movement of the rod 12 causes the lever 8 to turn anti-clockwise, carrying the lever 29 so that it depresses stem 6 of pilot gas valve 5; however cam 19a on the lever 7 retains lever 14 and hence the microswitches are held open. Upon heating of a detector (not shown) by the pilot flame the magnet 2 is energized and retains the armature 3 and the rod 12; on release of the button 4 the lever 14 is released and the switches 16 close, operating the main gas valve, and a pump if provided. To switch off, the button 30 is depressed, engaging a cam surface 32 on the lever 29 and pivoting it, allowing the valve stem 6 to enter an aperture (52), Fig. 10 (not shown) in the lever 29 and bending the spring 35, thus releasing the lever 38 which moves the lever 14 to open the switches 6. The valve stem 6 remains engaged in the aperture (51) until the magnet is de-energized, releasing the armature and allowing the. lever 8 to pivot clockwise, carrying the lever 29; thus the burner cannot be reignited until the pilot flame detector has cooled sufficiently to de-energize the magnet.