Apparatus for viewing the interior of furnaces

Claim 1

IN COMBINATION WITH A VACUUM ARC FURNACE, INCLUDING A FRAME SUPPORTED ON A FLOOR, A VERTICAL FURNACE HOUSING OF A HEIGHT SUBSTANTIALLY IN EXCESS OF THAT OF A MAN CARRIED BY SAID FRAME INCLUDING A TOP WALL HAVING A CENTRAL OPENING AND A LATERALLY OFFSET OPENING THEREIN, AN UPWARDLY OPENING CRUCIBLE IN THE BASE OF SAID HOUSING, AN ELONGATED CONSUMABLE ELECTRODE DISPOSED OVER SAID CRUCIBLE WITH THE LONGITUDINAL AXIS PASSING THROUGH THE CENTER OF THE CRUCIBLE OPENING, MEANS EXTENDING THROUGH SAID CENTRAL OPENING IN THE TOP WALL FOR LOWERING THE ELECTRODE AXIALLY DURING THE MELTING THEREOF, MEANS FORMING AN ARC BETWEEN SAID ELECTRODE AND METAL IN THE CRUCIBLE, A PROTECTIVE WALL SURROUNDING SAID FRAME, AND A FURNACE CONTROL PANEL OUTSIDE SAID WALL, AN OPTICAL VIEWING SYSTEM COMPRISED OF A VERTICAL CYLINDRICAL HOUSING EXTENDING THROUGH SAID LATERALLY OFFSET OPENING AND VACUUM SEALED THERETO, A LIGHT TRANSPARENT WINDOW CLOSING THE END OF SAID CYLINDRICAL HOUSING WITHIN SAID FURNACE HOUSING, A HORIZONTAL CYLINDRICAL HOUSING EXTENDING FROM THE TOP OF SAID VERTICAL CYLINDRICAL HOUSING THROUGH SAID PROTECTIVE WALL, A SECOND VERTICAL CYLINDRICAL HOUSING DEPENDING FROM THE END OF SAID HORIZONTAL CYLINDRICAL HOUSING EXTERIORLY OF SAID PROTECTIVE WALL TO A POINT SUBSTANTIALLY AT THE EYE LEVEL OF A MAN STANDING ON SAID FLOOR, A HORIZONTALLY OFFSET VIEWING TUBE EXTENDING OUTWARDLY FROM THE LOWER END OF SAID LAST MENTIONED VERTICAL CYLINDRICAL HOUSING ADJACENT SAID CONTROL PANEL, AN IMAGE RECEIVING SCREEN CLOSING THE OUTER END OF SAID VIEWING TUBE, AND AN OPTICAL SYSTEM IN SAID CYLINDRICAL HOUSINGS AND VIEWING TUBE COMPRISING LENSES AND MIRRORS PROJECTING AN IMAGE OF THE INTERIOR OF THE CRUCIBLE AND THE MELT AS IT FORMS AS SEEN FROM A DIRECTION PARALLEL TO THE AXIS OF THE ELECTRODE ON THE IMAGE RECEIVING SCREEN AT EYE LEVEL ADJACENT SAID CONTROL PANEL, WHEREBY AN OPERATOR MAY VIEW THE MELT AND ARC AND CONTROL THE FURNACE ACCORDINGLY.