Patent GB-946266-A (GB)
Title: Flame protection device for burners
IPC: F16K17/38
Filed: 1962-04-09
Abstract: 946,266. Controlling burners. G. KROMSCHRODER A.G. April 9, 1962 [April 8, 1961; Feb. 28, 1962], No. 13553/62. Heading F4T. A flame protection device for controlling a plurality of pilot burners (not shown) associated with a plurality of main burners (not shown) comprises a plurality of electromagnets 16, 17, 18 arranged end-to-end and each energized by a thermocouple heated by a pilot burner, and a valve 11 held open, when all the thermocouples are heated, to supply gas to the pilot burners. If any one pilot burner should fail the associated thermocouple is de-energized and causes the valve 11 to close. The valve 11 also controls the supply of gas to the main burners. The two lower electromagnets 16, 17 are slidably mounted on a guide rod 60 of non- magnetic material and the uppermost electromagnet 18 is attached to a mounting 20 secured to a tubular casing enclosing the electromagnets. The valve 11 is urged to seat on a gasway 7 by a spring 13 and its stem is secured to an armature 15 adapted to be attracted by the lower electromagnet 16. In operation a push-rod 10 is pressed in against a spring 8 so that it lifts the valve 11 from its seating and lifts the armature 15 and the two lower electromagnets 16, 17 into contact with the uppermost electromagnet 18. Gas therefore passes through an outlet connection 3 to the pilot burners but gas is prevented from passing through a further outlet connection 3a to the main burners by a spring-urged valve 50 slidable on the push-rod 10 and seating on the lower end of the gasway 7. The pilot burners are lighted by hand and the thermocouples energize the electromagnets. On release of the push-rod 10 the valve 11 is held open by the electromagnets and the valve 50 is opened by the spring 8 to allow gas to pass to the main burners. If a pilot burner fails its electromagnet becomes de-energized and the electromagnet below it or the armature 15 drops to allow the spring 13 to close the valve 11 and all the pilot and main burners go out. In the construction shown in Fig. 3 the gas supply to the main burners is controlled by an electromagnetic valve (not shown) energized by contacts 24 actuated by a setting member 22 attached to an armature 21 slidably journalled in the fixed mounting 20. The lower electromagnet 16 has two windings, each connected to a separate thermocouple. In operation the push-rod 10 is pushed in to open the pilot valve 11 and to raise the uppermost electromagnet into contact with the armature 21. The pilot burners are then ignited by hand and the electromagnets are consequently energized. When the push-rod is released the electromagnets then move down, carrying the armature 21 with them, until the setting member 22 fully compresses a spring 23 or abuts a stop 20<SP>1</SP>. In this position the pilot valve 11 is still open and the contacts 24 are closed to open the main valve. If a pilot burner fails the pilot valve closes and the reduction in weight on the armature 21 allows the spring 23 to lift the setting member 22 to open the contacts 24 and close the main valve. The electric circuit to the main valve also includes a room thermostat which shuts the main valve when a certain temperature has been reached. In a modification, Fig. 5 (not shown), the main valve is on the push-rod 10 as in Fig. 1, the contacts 24 energize an indicating lamp and the pilot burners are ignited by spark igniters or hot wire coils energized by a transformer energized by contacts operated by the push-rod 10.