Patent ID: 8616826

Claim:
A method of operating a vehicle restraint disposed adjacent to a loading dock face, wherein the vehicle restraint includes a movable barrier adapted to prevent movement of a RIG (rear impact guard) of a vehicle in a direction opposite the loading dock face, wherein the RIG includes a front surface and a rear surface opposite the front surface, the rear surface facing the loading dock face and the front surface facing away from the loading dock face, the method comprising: moving the barrier toward the front surface of the RIG to a first operative position such that the barrier engages the front surface of the RIG; holding the barrier in the first operative position; sensing a position of the front surface relative to the barrier when the barrier is in the first operative position; and sensing a separation between the front surface of the RIG and the barrier as the front surface of the RIG moves away from the barrier in a horizontal direction toward the loading dock face and responsively initiating a signal; moving the barrier toward the dock face to a second operative position such that the barrier engages the front surface of the RIG in response to sensing the separation.