GB948655A - Improvements in or relating to lighting devices for gas stoves, cookers, boilers, and the like - Google Patents

Abstract

948,655. Piezo-electric generators. WOLF SAFETY LAMP CO. Aug. 14, 1962 [May 27, 1961], No. 19210/61. Heading H2A. [Also in Divisions F4 and H1] A lighting device comprises a manuallyoperated piezo-electric spark generator connected to a spark gap between the end of a high voltage lead 3 and a conductive tube 15. The spark generator is housed in a two-part handle 7 made of insulating material and comprises two piezo-electric crystals 1 separated by a conductor 2 and electrically conducting load-spreading pads 4, 5. Electrically conductive rubber pads 10 are interposed between the crystals 1, the pads 4, 5 and the conductor 2. A lever 8 with a fulcrum 9 is actuated by a cam 22 on an insulated lever 21, to compress the crystal assembly. The fulcrum is adjustable by means of a screw 23. The high voltage lead 3 extends from the conductor 2 through an insulating sleeve 12 within the tube 15 which is connected by a branch level 17 to the pads 4, 5. A gas torch shown in Fig. 2 is removably mounted in a claw 32 integral with a tapered plug 31 of a rotary gas valve 30. A compression spring 35 encircles a stem 33 of the plug 31 between a cam 34 secured to the stem 33 and the valve body 30 to urge the plug into sealing engagement in the tapered bore. A gas inlet 36 communicates through the plug valve with a flexible pipe 28 connected to a tube 27 leading through the torch handle 26 to a nozzle 25 having a collar 41 resting on a shelf 42 in the inoperative position. A piezoelectric generator of the type described is mounted in a housing 37 integral with the value body 30. A screwed cap 45 protects the crystal pre-loading screw. In operation the handle 26 is rotated to open the gas valve and to bring the tip of the nozzle 25 opposite an arcuate electrode 40 connected to the high voltage lead. Simultaneously the generator is activated by the cam 34. In a further embodiment, Fig. 6 (not shown), the piezo-electric generator is mounted in a housing secured to a gas appliance. A manually-operated selfreturning lever is integral with the generator activating cam. The high voltage lead forms a spark gap with a main burner but may be replaced by a plurality of leads extending to a corresponding number of burners and separate earth leads may be used for each burner. In a final embodiment, Fig. 7 (not shown), the generator is mounted in a housing integral with a rotary plug valve attached to a gas stove. A cam integral with the valve, activates the generator.