Tubular electric furnace of the resistance type

Claim 1

IN A TUBULAR ELECTRIC FURNACE OF THE RESISTANCE TYPE, AN OPEN ENDED FURNACE TUBE ADAPTED TO BE HEATED BY THE PASSAGE OF ELECTRIC CURRENT THERETHROUGH, A HOUSING STRUCTURE ENCIRCLING SAID TUBE IN SPACED RELATIONSHIP THERETO, MEANS FOR SUPPORTING SAID TUBE WITHIN SAID HOUSING STRUCTURE AND COMPRISING A TUBULAR CONTACT PIECE, CLAMPING MEANS FOR DETACHABLY CONNECTING SAID TUBE IN PRESSURE CONTACT ENGAGEMENT WITH SAID CONTACT PIECE, SAID CONTACT PIECE EXTENDING THROUGH THE WALL PORTION OF SAID HOUSING STRUCTURE, AN ELECTRICALLY INSULATING SLEEVE FOR SEPARATING SAID CONTACT PIECE FROM SAID HOUSING STRUCTURE, SAID SLEEVE ENGAGING ONE OF THE PARTS SEPARATED THEREBY AND BEING IN SLIDING ENGAGEMENT WITH THE OTHER OF SAID PARTS FOR PERMITTING AXIAL MOVEMENT OF THE ASSEMBLY OF SAID TUBE AND SAID CONTACT PIECE RELATIVE TO SAID HOUSING STRUCTURE TO COMPENSATE FOR THERMAL EXPANSION AND CONTRACTION OF SAID TUBE, AND MEANS FOR SUPPLYING ELECTRIC CURRENT TO SAID CONTACT PIECE EXTERNALLY OF SAID HOUSING STRUCTURE, SAID CLAMPING MEANS INCLUDING AN INTERNAL CONICAL SEATING SURFACE WITHIN SAID TUBULAR CONTACT PIECE AND A TUBULAR PRESSURE CONTACT ELEMENT AROUND AN END PORTION OF SAID FURNACE TUBE AND HAVING A CONICAL END SURFACE MATING WITH SAID INTERNAL CONICAL SEATING SURFACE AND A NUT AROUND SAID FURNACE TUBE IN THREADED ENGAGEMENT WITH SAID CONTACT PIECE FOR FORCING SAID CONTACT PIECE AND SAID PRESSURE CONTACT ELEMENT AND SAID FURNACE TUBE INTO PRESSURE ENGAGEMENT WITH EACH OTHER.