Rite-Hite's Dok-Lok RHR-4000 Rotating Hook Restraint protects against trailer separation accidents
Rite-Hite's Dok-Lok RHR-4000 Rotating Hook Restraint incorporates a shadow hook, which adds another layer of protection against trailer separation accidents. The Dok-Lok RHR-4000 secures intermodal containers with rear-impact guard obstructions. The Dok-Lok RHR-4000 secures a semi-trailer or intermodal chassis to a loading dock by engaging the rear-impact guard (RIG) with a shadow hook.
When the Dok-Lok is activated, the hook attempts to wrap around the RIG. With an engagement range that extends from 9 inches to 30 inches above the ground, the hook reaches over 6 inches to help maintain engagement in below dock endload situations. The extension springs provide upward force against the RIG to keep the trailer secure during loading, even with air-ride trailers.
If the hook comes in contact with a plate obstruction on an intermodal container, the shadow hook pivots to secure the trailer in place. If the trailer moves, the shadow hook locks in the safety stop, which prevents trailer separation accidents.
The Dok-Lok RHR-4000 is positioned automatically by a backing trailer and adjusts to varying RIG heights. As the trailer backs into position, the RIG contacts the spring-loaded structural steel housing. The housing rides down in its track, allowing the RIG to move over the top of the housing. The restraint maintains constant contact with the RIG and adjusts automatically with trailer float motion to ensure proper hooking at all times during loading/unloading operations. The dock attendant then pushes the lock button which activates the hook to secure the trailer to the dock, providing a holding force in excess of 32,000 lbs. (14,500 kg).
The hook mechanism is controlled from a control panel mounted inside the building. After servicing is completed, the dock attendant pushes the unlock button at the control panel. In the event a trailer is missing, or has a damaged RIG, the Dok-Lok restraint will communicate a fault condition. An audible alarm alerts the operator that the trailer has not been properly secured. At this time, the operator may override the fault condition and secure the trailer by other means.