Abstract: A trailer of the container roll-on, roll-off type having a self contained power plant thereby being capable of full operation for loading and unloading regardless of the type of towing vehicle or in the absence thereof. The device is multifarious in uses, in that amoung other capabilities, it may be used as an ordinary flat bed trailer when not in use as a tilting roll-on, roll-off trailer. The device is capable of production in a multitude of sizes making it adaptable to a wide range of needs and uses within the financial means of many who previously have been excluded from ownership of such a vehicle.

Abstract: A coupling for attaching one mechanical device, such as a truck, to another mechanical device, such as a trailer, by the use of a rotatable sleeve located around a coupling arm on which is positioned a socket member with one or more free floating cam which are allowed to move in and out of cam openings by rotating the rotatable sleeve, thereby locking or releasing a ball, or other type, of hitching member in the socket area. The coupling arm and rotatable sleeve can be fashioned in varying lengths so that the hitching ball, or other type of hitching member, can be located in recessed or otherwise remote and inaccessible areas and still be utilized for towing.