Heat-exchange jacket attachment to extrusion cylinder

Claim 1

IN AN EXTRUDER, THE COMBINATION WITH A STEEL CYLINDER HAVING AN AXIS AND AN OUTER PERIPHERY CONCENTRIC WITH SAID AXIS, OF HEAT-EXCHANGE JACKETS ON SAID CYLINDER SUBSTANTIALLY THROUGHOUT ITS LENGTH, EACH JACKET HAVING TWO CAST COMPLEMENTAL SECTIONS OF A METAL OF BETTER HEAT CONDUCTIVITY AND OF A LARGER COEFFICIENT OF EXPANSION THAN THE STEEL OF THE CYLINDER, WITH EACH SECTION HAVING A SUBSTANTIALLY SEMI-CIRCULAR WALL WITH AN INNER SURFACE AND HEATING MEANS WITHIN AN INTERNAL ZONE OF SAID WALL OVER THE GREATER PART OF ITS SEMI-CIRCULAR EXTENT, AND SAID COMPLEMENTAL SECTIONS FITTING WITH THE INNER SURFACES OF THEIR WALLS SAID CYLINDER PERIPHERY AND HAVING NARROWLY SPACED CONFRONTING PARTING SURFACES; AND STRAIGHT ROD-TYPE METAL BRACES EACH ANCHORED WITH ITS OPPOSITE ENDS TO THE COMPLEMENTAL SECTIONS, RESPECTIVELY, OF A JACKET AND EXTENDING ACROSS SAID CONFRONTING PARTING SURFACES OF THEIR WALLS AT A GREATER DISTANCE THEREAT FROM THE CYLINDER AXIS THAN SAID INNER ZONES OF SAID SECTIONS, AND FURTHER EXTENDING BEYOND EACH OF SAID PARTING SURFACES FOR A DISTANCE OF OVER HALF THE RADIUS OF SAID CYLINDER PERIPHERY, SAID METAL BRACES SOLELY SECURING SAID COMPLEMENTAL JACKET SECTIONS TO THE CYLINDER AND HAVING A SMALLER COEFFICIENT OF EXPANSION THAN THE METAL OF SAID JACKET SECTIONS, AND SAID METAL BRACES BEING LONGITUDINALLY EXPANDED WITHIN THEIR ELASTIC LIMIT WHEN THE CYLINDER IS NON-HEATED, WHEREBY SAID SECTION WALLS ARE FORCED TO BEND IN PERIPHERAL EXPANSION INTO SUBSTANTIALLY UNIFORM FORM-FIT WITH SAID CYLINDER PERIPHERY AT ALL OPERATIONAL CYLINDER TEMPERATURES.