Patent ID: 8022339

Claim:
An electric cartridge type heater, comprising: an inner metal jacket defining a continuous central fitting hole for receiving a cylindrical body in a gap-free manner; an outer metal jacket surrounding said inner metal jacket, said inner metal jacket and said outer metal jacket defining an annular chamber such that said annular chamber is located between said inner metal jacket and said outer metal jacket, said annular chamber being closed on a front side; a hollow cylindrical coil form having a cylinder wall with a circumferential surface, said cylinder wall defining a plurality of axially parallel holes; a heating conductor in the form of a first heating wire winding and a second heating wire winding, said first heating wire winding and said second heating wire winding being wound about said circumferential surface of said hollow cylindrical coil form, said hollow cylindrical coil form with said first heating wire winding and said second heating wire winding being located within said annular chamber, each hole of said cylinder wall receiving one end of said first heating wire winding or one end of said second heating wire winding; electric connecting conductors, each electric connecting conductor receiving another end of said first heating wire winding or another end of said second heating wire winding, said outer metal jacket having an outer metal jacket surface defining a wire opening located at a spaced location from each axial end of said annular chamber and between said first heating wire winding and said second heating wire winding, said electric connecting conductors radially extending through said wire opening to a position located outside of said outer metal jacket; and an insulating compound consisting essentially of a ceramic mass or a metal oxide, said insulating compound filling said annular chamber and surrounding said hollow cylindrical coil form such that said hollow cylindrical coil form, said first heating wire winding, said second heating wire winding and said inner metal jacket are radially compacted via said insulating compound.