Motor vehicle screen wiper having means for orientation of the drive head

A motor vehicle screen wiper assembly comprising a screen wiper drive unit having a rotatable motor shaft defining an end portion and an axis of rotation thereof, a drive head of a screen wiper arm, and fastening means securing the drive head on the said end portion of the motor shaft, the said end portion comprising a conical portion and a terminal threaded shank projecting from the conical portion, the drive head having a conical through hole complementary to the conical portion of the motor shaft for cooperation therewith, the fastening means including the said conical portion and shank of the motor shaft and a nut having a radial thrust face, the nut being screwed on to the threaded shank of the motor shaft, the drive head having an upper face with which the said thrust face of the nut cooperates, wherein the drive head includes an orientation ring in which the said conical hole is formed and which has a first arcuate face defining a first set of elongated ridges thereon, the drive head further including a drive head body having a second arcuate face formed with a second set of elongated ridges cooperating with the first set of ridges, the drive head body having an oblong through hole, with the said motor shaft end portion extending through both said conical and oblong holes, wherein said oblong hole allows lateral movement of the drive head body with respect to the axis of rotation and the orientation ring.