Tube-firing gas burner assembly

Claim 1

IN A GAS BURNER ASSEMBLY, IN COMBINATION, A MAIN BURNER CASTING IN THE FORM OF A GENERALLY CYLINDRICAL CUPSHAPED BODY HAVING A REAR WALL, A CYLINDRICAL SIDE WALL DEFINING A FORWARD OPEN CIRCULAR RIM DESIGNED FOR ATTACHMENT TO THE MATING CIRCULAR RIM OF A TUBE TO BE INTERNALLY FIRED, AND MEANS CASTING AND TERMINATING IN A CENTRALLY DISTHROAD IN SAID CASTING AND TERMINATING IN A CENTRALLY DISPOSED CYLINDRICAL WALL FORMING A MAIN GAS CHAMBER, SAID LAST NAMED CYLINDRICAL WALL BEING SPACED FROM SAID SIDE WALL AND DEFINING A FORWARD OPEN CIRCULAR RIM COAXIAL WITH AND SPACED REARWARDLY FROM THE CIRCULAR RIM OF THE SIDE WALL OF THE MAIN BURNER CASTING, THE ANNULAR SPACE WITHIN SAID CUP-SHAPED BODY BETWEEN SAID CYLINDRICAL WALLS DEFINING A MAIN ANNULAR AIR CHAMBER SURROUNDING THE MAIN GAS CHAMBER, A TRANSVERSELY EXTENDING FIXED REAR CIRCULAR PROPORTIONING PLATE FIXEDLY SECURED TO SAID MAIN BURNER CASTING AND EXTENDING ACROSS THE OPEN ENDS OF THE MAIN GAS AND AIR CHAMBERS, A COOPERATING MOVABLE FRONT CIRCULAR PROPORTIONING PLATE COAXIALLY DISPOSED IN FACE-TOFACE SLIDING CONTACT WITH SAID FIXED PROPORTIONING PLATE AND CAPABLE OF ANGULAR TURNING MOVEMENT ABOUT THE COMMON AXIS OF SAID PLATES, THE FORWARD SIDE OF SAID FRONT PROPORTIONING PLATE BEING PROVIDED WITH A FORWARDLY EXTENDING CYLINDRICAL WALL DEFINING A CIRCULAR FORWARD RIM, SAID LATTER WALL IN COMBINATION WITH THE CENTRAL REGION OF SAID FRONT PROPORTIONING PLATE DEFINING A SECONDARY GAS CHAMBER FORWARDLY OF AND COAXIAL WITH SAID MAIN GAS CHAMBER, A CUP-SHAPED NOZZLE MEMBER HAVING A FRONT WALL DISPOSED ADJACENT TO SAID LATTER CIRCULAR FORWARD RIM AND A CYLINDRICAL SIDE WALL DEFINING A REAR OPRN RIM IN SEATING CONTACT WITH THE FORWARD SIDE OF THE FRONT PROPORTIONING PLATE AND SPACED FROM AND SURROUNDING THE CYLINDRICAL WALL WHICH IN PART DEFINES THE SECONDARY GAS CHAMBER, SAID CYLINDRICAL WALL OF THE NOZZLE MEMBER AND SAID CY-