Closed heat treating chamber having a seal roll oscillating mechanism

Claim 1

IN AN APPARATUS FOR THE CONTINUOUS APPLICATION OF HEAT TO A WEB, SAID APPARATUS COMPRISING A CLOSED VESSEL FORMING A HEAT-TREATING CHAMBER AND HAVING ENTRANCE AND EXIT OPENINGS FOR THE WEB, A PAIR OF SEAL ROLLS AT THE ENTRANCE OPENING ADAPTED TO ENGAGE OPPOSITE SIDES OF THE WEB, A SECOND PAIR OF SEAL ROLLS AT THE EXIT OPENING ADAPTED TO ENGAGE OPPOSITE SIDES OF THE WEB, AND INTERNAL ROLLS MOUNTED IN THE CHAMBER FOR PASSING THE WEB IN LOOPS THROUGH THE CHAMBER FROM ONE PAIR OF SEAL ROLLS TO THE OTHER PAIR, THE IMPROVEMENT WHICH COMPRISES REVERSIBLE DRIVING MEANS CONNECTED TO SAID SEAL ROLLS FOR ROTATING THEM AND INCLUDING A REVERSING ELEMENT OPERABLE IN A FIRST POSITION TO DRIVE THE SEAL ROLLS IN THE DIRECTION TO DRAW THE WEB FROM SAID ENTRANCE TO SAID EXIT OPENING, SAID ELEMENT BEING OPERABLE IN A SECOND POSITION TO DRIVE THE SEAL ROLLS IN THE OPPOSITE DIRECTION, START-UP MEANS OPERATIVELY CONNECTED TO SAID ELEMENT FOR MOVING IT ALTERNATELY FROM ONE OF SAID POSITIONS TO THE OTHER TO OSCILLATE THE SEAL ROLLS AND WEB, AND MEANS FOR RENDERING SAID STARTUP MEANS INOPERATIVE.