Patent ID: 7176597

Claim:
A focal electromagnetic retarder ( 1 ) for a vehicle, the retarder comprising: at least one inductor ( 2 ) being a stator and adapted to carry at least one electromagnetic winding ( 3 ), a first rotor ( 5 ) being an armature, and a second rotor ( 6 ) being an armature, the first rotor and the second rotor being coupled together by means of a central fastening ring ( 19 ), each rotor being situated on either side of a plane defined by the stator ( 2 ), and a single disc ( 20 ) separate from the central fastening ring ( 19 ) and adapted to connect the first rotor and the second rotor to a transmission shaft of the vehicle, wherein the disc is fixed to only one of the two rotors in such a way that it is positioned in longitudinal offset relationship with respect to an axis ( 21 ) of the retarder towards that rotor.