Patent ID: 8532816

Claim:
A device for restraining a horizontal bar at the rear of a vehicle to a stationary support adjacent a loading dock, the device comprising: a frame having a vertical track and a mounting bracket for securing the frame to the stationary support; a suspended carriage mounted to the track for vertical movement relative to the track, the suspended carriage having a forwardly and upwardly extending member; a vertical motion actuator mounted to the frame and having: a master carriage slidably mounted to the suspended carriage, the master carriage engaging the suspended carriage for moving the suspended carriage between a lower retracted position and an upper engaged position wherein the member engages a forward surface of the horizontal bar; and a resilient suspension member disposed between the master carriage and the suspended carriage and having a resilient range of travel, whereby the suspended carriage is capable of vertically floating relative to the master carriage within the range of travel; a control system including: a suspended carriage position sensor on at least one of: the master carriage; and the suspended carriage for determining the position of the suspended carriage relative to the master carriage; and a processor in communication with the position sensor and the vertical motion actuator that: determines when the suspended carriage has engaged the horizontal bar by measuring the relative distance between the suspended carriage and the master carriage; and produces a signal command to the vertical motion actuator to move the master carriage relative to the suspended carriage by a predetermined distance.