Patent ID: 8039765

Claim:
A leadthrough for an electrical high voltage conductor through a wall which separates a process area from an ambient area, comprising: a body of a dielectric high voltage and leak current resistant material including a cylinder ( 1 ) having an ambient area end face and a truncated cone ( 2 ) having a small diameter end disposed adjacent the cylinder ( 1 ) opposite the ambient area end face thereof and a large diameter end face remote from the cylinder ( 1 ) with a guide bore ( 3 ) extending centrally through the body for accommodating a high voltage conductor, said small diameter end of the truncated cone ( 2 ) having a diameter smaller than the cylinder ( 1 ) so that the cylinder ( 1 ) has a radial annular face area adjacent the truncated cone ( 2 ) which, together with the truncated cone ( 2 ) is exposed to the process area, said cylinder including axially extending gas supply bores ( 4 ) arranged uniformly distributed over the circumference in an annular array and having exit openings ( 4 ′) in the radial annular open face area of the cylinder ( 1 ) directed toward the truncated cone ( 2 ) whereby gas supplied to the gas supply bores ( 4 ) at the ambient area end face of the cylinder ( 1 ) is discharged from the gas supply bores ( 4 ) onto the outer surface of the truncated cone ( 2 ) to form a gas envelope around the truncated cone ( 2 ).