Heated roll assembly and method of construction

Claim 1

AN ELECTRICALLY HEATED ROLL ASSEMBLY COMPRISING A HOLLOW, CYLINDRICAL ROLL MEMBER ENCLOSING AN ELECTRICAL RESISTANCE HEATER, SAID HEATER COMPRISING A NON-ROTATABLY MOUNTED, SPOOL-SHAPED CORE ASSEMBLY OF A DIAMETER SLIGHTLY LESS THAN THE TERMINAL DIAMETER OF SAID ROLL MEMBER TO THEREBY DEFINE A SMALL AIR GAP BETWEEN THE SURFACE OF SAID CORE ASSEMBLY AND THE INTERIOR WALL OF SAID ROLL MEMBER, AN ELECTRICAL RESISTANCE HEATER ELEMENT WOUND IN A SUBSTANTIALLY HELICAL FASHION ABOUT SAID CORE ASSEMBLY, FASTENING MEANS OPERATIVE TO MAINTAIN SPACED POINTS ALONG SAID ELEMENT FIXED RELATIVE TO SAID CORE ASSEMBLY, SAID FASTENING MEANS COMPRISING PAIRS OF SUPERPOSED ELECTRICAL INSULATING STRIPS SPACED CIRCUMFERENTIALLY ABOUT SAID CORE ASSEMBLY AND EXTENDING AXIALLY THEREOF, SAID HEATER ELEMENT EXTENDING BETWEEN THE MEMBER STRIPS OF EACH OF SAID PAIRS, MEANS TO CLAMP SAID STRIPS TO SAID CORE ASSEMBLY, A ROTATABLY MOUNTED DRIVE SHAFT EXTENDING COAXIALLY THROUGH SAID HEATER, SAID ROLL MEMBER BEING SUPPORTED AND DRIVEN BY THE FREE END OF SAID DRIVE SHAFT, WHEREBY THERMAL EXPANSION OF SAID HEATER ELEMENT IS EFFECTIVELY SEGMENTED AND CAUSED TO BE UNIFORMLY DISTRIBUTED ABOUT THE ENTIRE CIRCUMFERENCE OF SAID CORE ASSEMBLY TO THEREBY PREVENT EXCESSIVE BUCKLING AND CONSEQUENT GROUNDING OF SAID HEATER ELEMENT AGAINST THE INTERIOR SURFACE OF SAID ROLL MEMBER.