Calender heating roll

A heating calender roll, comprising;

• a hollow cylindrical shell comprising a chill casting large enough to calender thereon a rubber-asbestos sheet having a length of several meters on each side thereof, the shell being of cast iron and having a plurality of parallel tubular bores extending through the cast iron of the hollow shell parallel to the axis of the shell at locations regularly distributed circumferentially of the shell;
• first and second end structures comprising chill castings of cast iron, having similar coefficients of thermal expansion as the shell, and provided respectively at first and second ends of the hollow cylindrical shell, each end structure extending inwardly from the respective end of the shell, and having (a) a plurality of radial passages, all extending through the end structure radially of the shell at locations regularly angularly spaced from one another to match the locations of some of the parallel tubular bores extending through the shell, and all connected to such parallel tubular bores;
• and (b) means for maintaining a meandering flow of heating medium through said parallel tubular bores to keep heating of the chill casting of said shell uniform at and between both ends thereof, said means comprising two sets of segmental grooves, one set for each end structure and disposed therein, angularly between said radial passages, to interconnect two of said parallel tubular bores of the chill casting of said shell;
• means for fastening and sealing each end structure to the respective end of the shell;
• and
• hollow shaft means centrally secured to the end structures for rotating them to rotate the shell, for passing the heating medium into the radial passages of one end structure and thereby, with assistance of the segmental grooves, into the meandering flow through the parallel tubular bores of the shell, and for receiving the heating medium from the parallel tubular bores of the shell through the other end structure,
• to heat the large chill casting of the shell by said medium, to similarly heat the chill castings of both end structures, and thereby to enable the shell to calender the rubber asbestos sheets.