Trw Limited

James L Graves

Emil M Shtarkman

Thomas Joseph Wand

Philip A Gaubis

Philip Q Guest, Jr

Michael E Behr

Kenneth P Wozniak

An apparatus for damping movement includes a housing and a blade which are movable relative to each other. The blade is cantilevered to an axis and has segments formed of magnetizable material which are separated by segments formed of nonmagnetizable material. Electromagnetic coils are connected with the housing and apply a magnetic field to a magnetic field responsive fluid through which the blade is movable. The blade has recesses which are formed in the segments of magnetizable material and hold magnetic field responsive fluid. A plurality of ribs separate the recesses and are at least partially formed of the nonmagnetizable material. In one embodiment of the invention, ribs and recesses are provided on opposite sides of the blade. In another embodiment of the invention, the ribs and recesses are provided on one side of the blade and the opposite side of the blade is flat. A side surface which is connected with the housing may have ribs and recesses which are aligned with the ribs and recesses in the blade.

Apparatus for damping movement

An electronic control system for a steering system having an electric motor coupled to the steering system for providing power assist. The steering system is of the rack and pinion type having an input gear coupled to the steering wheel and a pinion gear in meshing engagement with the rack. Two torsion sensors are coupled across the input and pinion gears and generate analog output signals. When no input torque is applied to the steering wheel, the output signals from the two torsion sensors are equal. When input torque is applied to the steering wheel, the signals from the torsion sensors vary substantially linearly in opposite directions. An electronic control unit controls operation of the electric power assist motor in accordance with the output signal from one of the torsion sensors. Failsafe circuitry is provided for monitoring the outputs of the redundant torsion sensors to insure proper control of the electric power assist motor. The failsafe circuitry provides (i) a sensor-to-sensor check to insure the output voltage of one sensor is consistent with the output voltage of the other sensor, (ii) a sensor limit check to insure that the output voltage from each sensor does not exceed a predetermined limit, (iii) a sensor direction check to insure that the signal being used to drive the electric power assist motor, as derived from one sensor, will drive the motor in the same direction sensed by the other sensor, and (iv) an excess assist check to insure that the signal used to drive the electric assist motor, as derived from one sensor, will not cause the motor to provide a greater amount of assist than an amount requested, as detected by the other sensor.

Electric steering gear

Growing community of inventors

Royal Oak, MI, United States of America

James L Graves