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US 4,726,437 AGranted
Servo steering system
OwnerPeter Nortoninventor
Life of this patent
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OwnerPeter Nortoninventor
Estimating the term…
An electrically energized power steering system for vehicles is disclosed using a clutch that disengages the servomotor at times of near zero driver input torque. The servomotor is energized for power assist in executing turns and for synchronizing servomotor speed with the steering mechanism during the return of the dirigible wheels to the straight ahead position and at other times when the clutch is disengaging the servomotor thereby eliminating clashing upon clutch reengagement. A torque transducer operatively coupled with the steering wheel shaft and the steering gear generates a torque signal corresponding to the torque applied by the driver to the steering wheel. Two tachometers are provided, one on the servomotor and one on the steering wheel shaft and the outputs are combined to develop a signal corresponding to differential speed. The torque signal and the differential speed signal are added and the resultant signal is applied to the servo amplifier which energizes the servomotor. When the driver turns the steering wheel the clutch engages the servomotor, the torque signal predominates and the servomotor is energized to provide power assist. When the driver releases the steering wheel, the torque signal drops to approximately zero and the differential speed signal controls the energization of the servomotor to maintain its speed in near synchronization with the return of the dirigible wheels to the straight ahead position.
In a vehicle power steering system of the type comprising a manual input means, a steering gear, an electric servomotor having an output shaft, a clutch operatively disposed between said output shaft and said steering gear and adapted to be engaged or disengaged, means for generating a torque signal corresponding to the torque transmitted by said manual input means, and control means adapted to control the energization of said servomotor in accordance with said torque signal, the improvement comprising:
In a vehicle power steering system of the type comprising a manual input means, a steering gear, an electric servomotor having an output shaft, a clutch operatively disposed between said output shaft and said steering gear and adapted to be engaged or disengaged, means for generating a torque signal corresponding to the torque transmitted by said manual input means, and control means adapted to control the energization of said servomotor in accordance with said torque signal, the improvement comprising:
Dependencies are inferred from the claim text.