Steering apparatus for a steered vehicle

Abstract

A steering apparatus comprises a rotatable steering shaft and a sensor which senses angular movement of the steering shaft. An electromagnetic actuator actuates a stop mechanism to releasable engage the steering shaft. There is a microcontroller which causes the electromagnetic actuator to actuate the stop mechanism to fully engage the steering shaft and prevent rotation of the steering shaft in a first rotational direction, which corresponds to movement towards the hardstop position, while allowing rotational play between the steering shaft and the stop mechanism in a second direction, which corresponds to rotational movement away from the hardstop position, when the sensor senses that the steering shaft has reached a hardstop position. A driver applies a reverse polarity pulse to the electromagnetic actuator when the stop mechanism is fully engaged and the steering shaft is rotated, as permitted by the rotational play, in the second rotational direction.

1 . A steering apparatus for a steered vehicle, the steering apparatus comprising:
 a rotatable steering shaft;   a sensor which senses angular movement of the steering shaft as the vehicle is being steered;   a stop mechanism which releasably engages the steering shaft to prevent rotation of the steering shaft;   an electromagnetic actuator which actuates the stop mechanism to engage or release the steering shaft;   a microcontroller which causes the electromagnetic actuator to actuate the stop mechanism to fully engage the steering shaft when the sensor senses that the steering shaft has reached a hard stop position to prevent rotation of the steering shaft in a first rotational direction, which corresponds to movement towards the hard stop position, while allowing rotational play between the steering shaft and the stop mechanism in a second direction, which corresponds to rotational movement away from the hard stop position;   a driver which applies a reserve polarity pulse to the electromagnetic actuator when the stop mechanism is fully engaged with the steering shaft and the steering shaft is rotated, as permitted by the rotational play, in the second rotational direction.   
     
     
         2 - 15 . (canceled)