Abstract: A system is described for detachably securing a housing to a ball hitch (e.g. of the type used in trucks for towing). The system includes a tubular housing for fitting over the ball, and attachment means for detachably securing the housing to the ball. A workpiece can then be secured to the housing, as desired. A preferred attachment means is a pair of opposing lock pins which are movable between retracted and extended positions. When the pins are in the extended position, they secure the housing to the ball hitch. The type of workpieces may vary. For example, the workpiece may be a work table, a vise, a fifth-wheel hitch system, a winch, or an arm for a lift bucket.

Abstract: A conversion system for enabling a camper trailer with a king pin to be towed by a vehicle having a ball-type hitch. The system includes a clamp comprising two U-shaped members adapted to be fitted around the king pin of the trailer, a plate which is connected to the U-shaped members, a neck which is connected to the plate, and a socket at the lower end of the neck for connection to a conventional ball-type hitch. The conversion system can be attached to any conventional gooseneck camper trailer without modifying or damaging the trailer or the hitch. Then the camper trailer can be towed by a truck with a conventional ball-type hitch.

Abstract: A hitch system is described for a towing vehicle (e.g. a pickup truck) to enable the vehicle to tow a gooseneck trailer. The hitch system includes a mounting bracket to be attached to the frame of the vehicle, a sleeve secured to the mounting bracket and including a vertical slot in the wall and a second slot communicating with the vertical slot, a ball hitch which slides into the sleeve and including a pin which projects outwardly to be received in the vertical slot (after which the pin moves into the second slot when the ball is rotated), and a lock for preventing rotation of the ball when the pin is in the second slot. After the ball has been inserted into the sleeve and rotated, it is locked in position and will not come out during normal use of the hitch system.