Rotation sensing assembly

Claim 1

A rotation sensing assembly for transducing the rotational movement of an axle shaft enclosed within an axle housing of a vehicle into an electric signal where the driven end of the axle shaft is splined to a differential side gear of the vehicle and the opposite end is drivingly connected to a road wheel of the vehicle, comprising: a. a magnetic sensor head having pole pieces defining a magnetic gap and for producing a change in an electric output signal when patterns of ferromagnetic material are moved past the gap; b. a support member for the sensor head adapted to be mounted within an aperture in the axle housing so that the magnetic gap of the sensor head is disposed inside the axle housing and having a ring-shaped extension which encircles the axle shaft when the support member is mounted in the aperture; c. a tubular element, bearing means rotatably supporting the tubular element on the ring-shaped extension so as to encircle the axle shaft in proper alignment with the magnetic sensor head, coupling means for rotatably driving said element synchronously with the axle shaft through a loose coupling with the side gear; d. a tone wheel having a crown of ferromagnetic teeth, said tone wheel being rigidly supported upon said tubular element for rotation therewith, whereby the ferromagnetic teeth move past the magnetic gap during rotation of the tone wheel.