Patent ID: 8839931

Claim:
An electromagnetic friction clutch having two clutch plates ( 2 , 8 ) having a plurality of concentrically circular, magnetically soft ring areas ( 3 a - 3 c , 9 a - 9 d ) which are at least partially magnetically insulated from one another, wherein a first clutch plate of the two clutch plates comprises an axially movable armature plate ( 2 ) which has at least one magnetically conductive ring area ( 3 a - 3 c ) which magnetically connects two magnetically insulated ring areas ( 9 a - 9 d ) of the second clutch plate ( 8 ), wherein, the clutch plates ( 2 , 8 ,) have, when viewed in a radial cross section, oscillating pole faces ( 4 a - 4 f , 10 a - 10 f ) which are uniformly smooth in the circumferential direction, at the magnetically soft ring areas ( 3 a - 3 c , 9 a - 9 d , 19 ), via which attraction occurs during shifting of the clutch, wherein radial cross-sectional profiles of the two clutch plates ( 2 , 8 ) are matched in an accurately fitting fashion to one another at least in the region of the pole faces ( 4 a - 4 f , 10 a - 10 f ).