Slip ring unit for fitting to an alternator, especially for a motor vehicle

A slip ring unit arranged to be force-fitted on to an alternator shaft, especially a motor vehicle alternator shaft, is made by moulding insulating material over electrically conductive elements so as to encapsulate the latter. It has a generally cylindrical body which includes two slip rings at its outer surface, the slip rings being connected to two electrical connecting elements for connecting the slip ring unit to the ends of winding wires of the alternator. The body of the unit has a bore for accommodating the alternator shaft. The insulating material is extended beyond one of the two slip rings, to define a collar at that end of the unit on which the fitting force is to be applied. At least one notch is formed in the extension constituted by the collar, these notches extending through the whole axial thickness of the latter so as to leave one side of the adjacent slip ring exposed. The applied fitting force can then be exerted directly on the slip ring, through the notch.