Abstract: An embodiment of the present invention is a king pin lock device that prevents theft of trailers and other objects equipped with a king pin trailer hitch. The lock device has a lock body with a first end and a second end. The second end has a moveable lock bar to engage and disengage the king pin sitting in the first end, and an internal aperture to receive a conventional round puck lock or other suitable lock or locking mechanism. The puck lock is locked onto an immobile retaining bar on the lock body and secures the lock body onto the king pin, preventing any attempt to access the king pin trailer hitch. The puck lock is protected by a perimeter wall surrounding it in the second end of the lock body. The perimeter wall has a key insert window for user access to the keyhole of the puck lock.

Abstract: A lunette trailer hitch lock prevents theft of trailers and other objects equipped with a lunette-style trailer coupler hitch having a lunette eye. The lock device has a top member and a bottom member which are engageable with each other. A conventional step in lock can be used to lock the top member and the bottom member together while sandwiching and plugging the lunette eye, thereby preventing any attempt to access the lunette trailer hitch.