Abstract: An anti-theft coupler device obstructs a trailer hitch coupler to prevent undesired coupling to the tow ball of a towing vehicle. The device comprises a lock body cooperating with and obstructing front and rear facing portions of a trailer hitch coupler, a ball coupler having a resilient, smooth circular face for receipt by the trailer hitch coupler, a locking pin that locks the coupler device to the trailer hitch coupler, and a lock device for preventing access to the locking pin and the ball coupler. The lock body has upright sides with one upright side having an aperture aligned with the trailer hitch coupler for receiving the locking pin, such that the coupler device cooperates with the trailer hitch coupler to prevent undesired coupling. The lock device comprises a padlock that prevents access to the lock pin and undesired removal of the lock body from the trailer hitch coupler.

Abstract: An improved gooseneck trailer hitch locking device for obstructing a gooseneck coupler to prevent undesired coupling by a towing vehicle, the locking device comprising lock bodies cooperating with and obstructing the front and rear facing portions of a gooseneck coupler, a lock pin securing the lock bodies to each other and having a lock device for preventing access to the lock pin and undesired removal of the lock bodies from the coupler. The lock bodies include apertures which can be aligned with each other and with a bore centrally disposed in a downward projection extending from one of the lock bodies. The lock pin is received by the bore and can be extended into the aligned apertures in the lock bodies when aligned to secure the lock bodies to each other.

Abstract: A gooseneck trailer hitch locking device for obstructing a gooseneck coupler to prevent undesired coupling by a towing vehicle, the locking device comprising lock bodies cooperating with and obstructing the front and rear facing portions of a gooseneck coupler, a lock pin securing the lock bodies to each other, and a lock device for preventing access to the lock pin and undesired removal of the lock bodies from the coupler. The lock bodies include apertures which can be aligned with each other and with a threaded bore centrally disposed in a downward projection extending from one of the lock bodies. The lock pin is threadably received by the bore and can be extended into the aligned apertures in the lock bodies when aligned to secure the lock bodies to each other. The downward projection includes aligned openings having central axes generally perpendicular to the longitudinal axis of the threaded bore, which openings are adapted to receive the shackle of a padlock.