Electric furnaces

Claim 1

AN ELECTRIC FURNACE COMPRISING A TUBULAR RESISTANCE ELEMENT SUBDIVIDED TO PROVIDE A PATH FOR THE PASSAGE OF HEATING CURRENT IN EXCESS OF THE LENGTH OF THE ELEMENT, SAID ELEMENT HAVING AT ONE END A PLURALITY OF ANGULARLY SPACED AXIALLY EXTENDED APERTURED ARCUATE PORTIONS CONSTITUTING SUPPORTING LEGS FOR THE ELEMENT, A TUBULAR WATER JACKET, A PLURALITY OF CURRENT FEEDERS OF ARCUATE CROSS SECTION, EACH LYING LONGITUDINALLY OF THE JACKET BETWEEN THE JACKET AND ONE OF SAID LEG PORTIONS CLOSELY ADJACENT THERETO, INSULATION MEANS INTERPOSED BETWEEN AN INNER SURFACE PORTION OF THE WATER JACKET AND THE CURRENT FEEDERS, WHEREBY THE CURRENT FEEDERS ARE IN HEAT-CONDUCTING RELATIONSHIP WITH SAID JACKET BUT ELECTRICALLY INSULATED THEREFROM, AND IN ELECTRICALLY CONDUCTING RELATIONSHIP WITH THE OUTER SURFACE OF SAID ONE LEG PORTION OF THE HEATING ELEMENT, AND RELEASABLE CLAMPING MEANS OPERABLE TO PRESS SAID LEG PORTIONS AGAINST THE CURRENT FEEDERS AND THE CURRENT FEEDERS AGAINST THE JACKET IN A MANNER SUCH THAT A SUBSTANTIALLY UNIFORM PRESSURE IS EXERTED OVER THE RESPECTIVE SURFACES THROUGH WHICH HEAT TRANSFER AND THE FLOW OF CURRENT OCCUR.