Heat treating furnace with circulated gas quench

Claim 1

IN A FURNACE FOR FIRST HEATING AND THEN COOLING A WORK LOAD, THE COMBINATION OF, A HOLLOW VESSEL, A WALLED ENCLOSURE WITHIN SAID VESSEL DEFINING A WORK CHAMBER WITHIN SAID ENCLOSURE AND A COOLING CHAMBER WITHIN THE VESSEL OUTSIDE THE ENCLOSURE, A SELECTIVELY OPERABLE RADIANT HEATER IN SAID WORK CHAMBER FOR HEATING A WORK LOAD THEREIN, INLET AND OUTLET PORTS IN THE ENCLOSURE WALLS SPACED APART ACROSS SAID WORK CHAMBER AND COMMUNICATING WITH SAID COOLING CHAMBER, FIRST AND SECOND MEMBERS HAVING REFLECTING SURFACES OVERLYING SAID PORTS CLOSELY ADJACENT SAID ENCLOSURE WALLS AND SUBSTANTIALLY CLOSING THE PORTS TO BLOCK HEAT RADIATION THROUGH THE PORTS AND CONFINE HEAT WITHIN SAID WORK CHAMBER DURING HEATING OF THE WORK LOAD THEREIN, AND MEANS SUPPORTING SAID MEMBERS FOR MOVEMENT OUT OF THE OVERLYING POSITIONS INTO OUT-OFTHE-WAY POSITIONS SPACED FROM SAID PORTS FOR A FULL AND UNOBSTRUCTED FLOW OF GAS THROUGH THE PORTS DURING COOLING OF THE WORK LOAD.