Patent ID: 8596949

Claim:
A constant torque vehicle restraint for securing a trailer to a loading dock during loading/unloading of the trailer, the loading dock having a face wall and the trailer having an ICC bar, said constant torque vehicle restraint comprising: a track anchored proximal the face wall of the dock; a carriage movably joined to said track and adapted to allow engagement with the ICC bar, said carriage having a hooking mechanism selectively movable between retracted and extended positions and adapted to capture the ICC bar when in said extended position; a multi-mode electric motor operable at one of either a higher power level and a lower power level, said motor being adapted for continuous operation at said lower power level, said motor having a drive shaft drivingly connected to said hooking mechanism, and said motor being adapted to apply torque to said drive shaft in one of either a first rotational direction and a second opposite rotational direction; a control unit with a lock switch, a release switch and a processor to cycle said motor and hooking mechanism through an operating cycle including a hook extending phase, a continuous torque phase and a hook retracting phase; and, wherein said lock switch is operable to activate said motor to apply torque to said drive shaft in said first rotational direction at said higher power level to move said hooking mechanism from said retracted position to said extended position during said extending phase to capture the ICC bar prior to loading/unloading of the trailer, said processor is programmed to operably switch said motor to said lower power level after a time period sufficient for said hooking mechanism to capture the ICC bar, said motor continuously operating in said lower power level during said continuous torque phase to continuously apply torque to said drive shaft and maintain said hooking mechanism in forced engagement with the ICC bar during loading/unloading of the trailer, and said release switch is operable to switch said motor to apply torque to said drive shaft in said second opposite rotational direction at said higher power level during said hook retracting phase to move said hooking mechanism from said extended position to said retracted position after loading/unloading of the trailer.