Radio frequency apparatus

Claim 1

RADIO FREQUENCY HEATING APPARATUS COMPRISING A GENERALLY TUBULAR CONDUCTIVE ENCLOSURE HAVING OPPOSITE, SPACED, PARALLEL, CONNECTED, SHEET METAL WALL MEMBERS PROVIDING AN AXIALLY EXTENDED CONDUCTIVE LOOP HAVING A PAIR OF OPPOSITE ENDS SPACED A SUBSTANTIAL DISTANCE FROM ONE ANOTHER A LUMPED CONSTANT RESONANT CIRCUIT COMPONENT COMPRISING A PLURALITY OF ELECTRICALLY CONDUCTIVE PLATES GENERALLY PARALLEL TO ONE ANOTHER AND PERPENDICULAR TO SAID WALL MEMBERS, SAID PLATES BEING SPACED FROM ONE ANOTHER IN A DIRECTION PERPENDICULAR TO THE PLANE OF SAID PLATES AND BEING MOUNTED ALONG A COMMON LINE WITHIN AND GENERALLY ALONG SAID WALL MEMBERS THROUGHOUT A SUBSTANTIAL PORTION OF THE LENGTH THEREOF BETWEEN SAID OPPOSITE ENDS CLOSELY SPACED TO ONE OF SAID WALL MEMBERS, SAID PLATES FORMING TWO SERIES OF PLATES ARRANGED ALTERNATELY WITH ONE ANOTHER, DEFINING A RADIO FREQUENCY CURRENT PATH IN ONE SERIES OF PLATES OF OPPOSITE DIRECTION FROM THAT IN THE OTHER SERIES OF PLATES FOR MUTUAL COUPLING THEREBETWEEN, AND RADIO FREQUENCY GENERATOR MEANS CONNECTED TO SAID COMMON LINE AND TO CONNECTING POINTS ON AT LEAST ONE OF SAID SERIES OF PLATES, SAID TWO SERIES OF PLATES BEING THE MAJOR RESONANT CIRCUIT COMPONENT OF THE OUTPUT OF SAID GENERATOR MEANS, PROVIDING A RADIO FREQUENCY POWER SOURCE WITHIN SAID ENCLOSURE ENERGIZING SAID ENCLOSURE TO HEAT MATERIAL.