Automatic control system for a releasable vehicle locking device

Claim 1

An automatic control system for a releasable locking device which secures a parked vehicle to an adjacent structure including i. a hook for engaging a coupling on the vehicle; ii. means for actuating said hook into a locked position where said hook engages said coupling or into an unlocked position where said hook clears said coupling; and iii. hook position sensor means for sensing whether said hook is in the locked, the unlocked or an unsafe position between the locked and unlocked positions; wherein said automatic control system comprises: a. hook position selector means for generating lock or unlock signals in response to a hook position command selected by an operator and for storing the selected hook position command; b. first actuator control means for energizing said hook actuator means for a predetermined time interval to reposition said hook into the locked position in response to the lock signal; c. second actuator control means for energizing said hook actuator means to reposition said hook into the unlocked position in response to the unlock signal; d. hook position correction means coupled to said hook position sensor means and to said hook position selector means for comparing actual hook position with the selected hook position and for switching into a hook sag correction mode to generate a hook lock signal when the lock position has been selected and the hook is displaced into the unsafe position to automatically energize said hook actuator means for repositioning said hook from the unsafe position back into the selected, locked position; and e. control means for sensing the stored hook position command and the output of said hook position sensor means, for comparing the stored hook position command with the hook position at the end of the predetermined time interval, and for disabling said hook position correction means if the hook position at the end of the predetermined time interval is either unlocked or unsafe.