Method and apparatus for electrically heating dielectrics

Claim 1

HIGH FREQUENCY HEATING APPARATUS FOR BAKING COLORS AND FUSING VITRIFIABLE ENAMELS ON GLASS WARE, COMPRISING A HIGH FREQUENCY ELECTRIC ENERGY GENERATOR; A RESONATOR CAVITY IN WHICH AN ARTICLE TO BE HEATED IS PLACED; PLUNGER MEANS FOR VARYING THE CAPACITY OF THE CAVITY TO TUNE THE SAME INTO RESONANCE WITH THE GENERATOR FREQUENCY; ENERGY TRANSMISSION MEANS FOR TRANSMITTING THE EXACT PORTION OF THE ENERGY OF SAID GENERATOR REQUIRED TO HEAT THE GLASSWARE ARTICLE TO THE REQUIRED HEAT; SAID TRANSMISSION MEANS FORMED OF HOLLOW WAVE GUIDES COMPRISING TWO PARALLEL BRANCHES, AN INPUT T COUPLING AT THE INPUT ENDS OF SAID BRANCHES, AN OUTPUT T COUPLING AT THE OUTPUT END OF SAID BRANCHES, EACH OF SAID T COUPLINGS BEING FORMED WITH AN ARM TRANSVERSE TO THE PLANE OF SAID PARALLEL BRANCHES; DUMMY ENERGY ABSORBING LOAD ELEMENTS DISPOSED IN SAID ARMS; PHASE VARYING MEANS IN ONE OF SAID PARALLEL BRANCHES FOR ADJUSTING THE EFFECTIVE LENGTH OF ONE OF SAID BRANCHES TO DETERMINE THE DESIRED COMPONENT OF ENERGY WHICH SHALL BE TRANSMITTED TO SAID CAVITY TO SECURE THE REQUIRED HEATING OF THE ARTICLE; AN INDUCTIVE IRIS COUPLING SAID WAVE GUIDE MEANS WITH SAID RESONATOR CAVITY; THERMOCOUPLE TEMPERATURE INDICATING MEANS COMMUNICATING WITH SAID RESONATOR CAVITY TO INDICATE THE TEMPERATURE TO WHICH SAID PHASE VARYING MEANS MAY BE ADJUSTED; MEANS FOR DETERMINING WHEN THE CAVITY IS TUNED TO RESONANCE WITH THE FREQUENCY OF THE RESONATOR AFTER THE ARTICLE HAS BEEN PLACED IN HEATING POSITION, INCLUDING A PROBE ELEMENT EXTENDING INTO SAID CAVITY, MEANS FOR INDICATING THE AMOUNT OF ENERGY DELIVERED TO SAID PROBE ELEMENT COMPRISING A WATTMETER AND ATTENUATOR MEANS CONNECTING THE PROBE ELEMENT WITH SAID WATTMETER; AND CONVEYOR MEANS OF DIELECTRIC MATERIAL FOR CARRYING THE ARTICLES INTO AND OUT OF SAID CAVITY THROUGH INLET AND EXIT OPENINGS IN THE SIDE WALLS THEREOF, THERE BEING DIELECTRIC MATERIAL ATTACHED TO THE INTERIOR OF THE TOP WALL OF SAID CAVITY AND ADAPTED TO CONTACT THE TOP OF THE ARTICLES AND TO SPACE THE SAME FROM THE TOP CONDUCTING SURFACE OF THE CAVITY.