Ceramic core laminating roll

Claim 2

A heating roll for laminating or the like, said roll comprising: an extruded fired ceramic cylindrical core having a plurality of equally spaced holes extending longitudinally through said core, adjacent the outer periphery of said core; a helically wound electrical resistance heating coil stretched from one end of said core successively back and forth through the successive holes to the other end of said core, said heating coil being stretched from about 1.5 to about 4.0 times its closed length; and a highly heat-conductive metal tubing surrounding and contacting said core.

Claim 3

A roll according to claim 1, wherein said holes are partially open along their sides to the outer periphery of said core and wherein the electrical resistance element is larger than the said partial opening whereby it is positively retained in the holes.

Claim 4

A roll according to claim 2, wherein said heating coil comprises a helical coil of uninsulated resistance wire.

Claim 5

A roll according to claim 1, wherein said ceramic core is extruded or pressed fired steatite.

Claim 6

A roll according to claim 1, wherein external surfaces of the tubing is coated with a molded resilient material.

Claim 7

A roll according to claim 1, wherein said tubing is coated with a thin inert layer of plastic.

Claim 8

A roll according to claim 3 wherein the helical wire is wound with adjacent turns more closely spaced at the ends of the roll than at the center thereof.

Claim 9

A heating roll for laminating and the like, said roll comprising: an extruded or pressed fired ceramic cylindrical core; a series of holes extending longitudinally through said core and equally spaced near the outer periphery of said core, said holes being partially open along their sides to the outer periphery of said core and being accessible at their ends; a helically wound electrical resistance heating coil stretched from one end of said core successively through each of said holes to the other end of said core, said heating coil being stretched from about 1.5 to about 4.0 times its closed length, said holes being arranged so that said heating coil can be inserted in said holes only at their ends; dielectric end caps closing said holes and covering said heating coil at the ends of the core, separate commutator means connected to each end of said coil for energizing said coil; and a highly heat-conductive metal tubing surrounding and contacting said core and end caps and providing an exterior roll surface.

Claim 10

A heating roll for laminating and the like, said roll comprising: an extruded or pressed fired ceramic cylindrical core; a series of holes extending longitudinally through said core and equally spaced near the outer periphery of said core, said holes being partially open along their sides to the outer periphery of said core and being accessible at their ends; a helically wound electrical resistance heating coil stretched from one end of said core successively through each of said holes to the other end of said core, said heating coil being stretched from about 1.5 to about 4.0 times its closed length, said holes being arranged so that said heating coil can be inserted in said holes only at their ends; dielectric end caps closing said holes and covering said heating coil at the ends of the core, separate commutator means connected to each end of said coil for energizing said coil; and a highly heat-conductive metal tubing surrounding and contacting said core and end caps and providing an exterior roll surface.

Claim 11

A roll according to claim 8, wherein said ceramic core and end caps are fired steatite, and the tubing is a metal selected from the group consisting of aluminum and copper.

Claim 12

A roll according to claim 9, wherein the metal tubing is coated with TEFLON.