Patent ID: 7137822

Claim:
High voltage swivel ( 1 ), comprising an annular outer element ( 2 ) defining a cylindrical chamber around a longitudinal axis ( 27 ) and an inner cylindrical element ( 3 ) coaxial with the outer element ( 2 ) and rotatable relative to said outer element around said longitudinal axis ( 27 ), the inner and outer elements each comprising at least two axially spaced electrical conductors ( 15 , 16 , 17 , 18 ; 28 , 29 , 30 , 31 ) which conductors are rotatable with the inner and outer elements ( 2 , 3 ), the conductors forming at least two pairs ( 15 , 28 ; 16 , 29 ; 17 , 30 ; 18 , 31 ) placed with contact surfaces in mutual electrical contact, one conductor in each pair ( 15 , 16 , 17 , 18 ) being provided at the inner element ( 3 ), the other ( 28 , 29 , 30 , 31 ) at the outer element ( 2 ) and being connected to a respective voltage line ( 32 , 33 )) which extends to an input terminal ( 6 ) and to an output terminal ( 7 ) respectively, the conductors ( 15 – 18 , 28 – 31 ) being surrounded by an insulating material, characterised in that, the electrical conductors ( 28 – 31 ) of the outer element ( 2 ) are provided in a recess in an annular solid outer insulating ring ( 8 , 9 , 10 , 11 , 12 ), the electrical conductors ( 15 – 18 ) of the inner element ( 3 ) are provided in a recess in an annular solid inner insulating ring ( 21 , 22 , 23 , 24 ), coaxial with the outer ring, the inner and outer insulating rings ( 8 – 12 , 21 – 24 ) each defining a boundary surface ( 20 , 20 ′) extending in an axial direction, the boundary surfaces of the rings being placed in close proximity, the electrical conductors being placed with their contact surfaces at or near the boundary surface ( 20 , 20 ′).