A load-bearing trailer dolly which connects a tongue-type boat, utility or other trailer to a towing tandem trailer and bears weight from the trailer during towing. In a preferred embodiment, the trailer dolly is characterized by an axle mounted on a pair of wheels. A dolly frame height-adjustable trailer hitch centered coaxial above the axle axis and midway point framed dolly plate mount by operation of an adjustable sleeve reducer fastened by pinning and lock. Includes dual connecting adjustable height tongues for attachment to rear end trailer hitches on the tandem towing trailer at which a pair of hitch fasteners for engaging the trailer dolly tongues are attached to the rear of the tandem trailer. The adjustable tongue hitches on trailer dolly will give ability to horizontal level tandem dolly. A shock-absorbing spring is fitted between the axle mount and the dolly frame for cushioning the dolly frame on the axle mount as the trailer is towed behind the towing tandem trailer. In the industry of dollies, the car dolly has no shock-absorbing function, just square axle with hubs for wheels, axle is attached to car dolly frame. There is an option with shock-absorbing mechanism or s non shock-absorbing option.

A modular slave vehicle articulatable at one end thereof to another slave vehicle and at another end thereof to an independently driven master vehicle, simultaneously. The slave vehicle comprising a body including a driving system; a structural frame supporting said body; a master coupling system in the form of a mechanical stress absorbing coupling mechanism; at least one first slave coupling device; at least one second slave coupling device; said first and second coupling devices, when mounted to two adjacent slave vehicles intended to be articulated to each other, are detachably connectable to each other to form a tandem coupling configured to constrain all DOF therebetween.

Methods and apparatus are disclosed for a three-point attachment trailer hitch. An example hitch includes a crossbar including a first end and a second end, the first end or the second end including at least one tab protruding from an edge of the first end or the second end, and a first endplate positioned on the first end or the second end of the crossbar using the at least one tab, the endplate including a first threaded hole and a second threaded hole, a diameter of the second threaded hole larger than a diameter of the first threaded hole.

An articulated coupler permits vertical displacement of a towed vehicle relative to a towing vehicle while preventing lateral or horizontal displacement of the towed vehicle relative to the towing vehicle. Multiple linkage arms provide coupling for special configuration towed vehicles such as short wheel-mounted lifts that experience torsional forces due to the presence and absence of loads on the lift.

An articulated coupler permits vertical displacement of a towed vehicle relative to a towing vehicle while preventing lateral or horizontal displacement of the towed vehicle relative to the towing vehicle. Multiple linkage arms provide coupling for special configuration towed vehicles such as short wheel-mounted lifts that experience torsional forces due to the presence and absence of loads on the lift.

An offset hitch bale accumulator hitch for connecting a hay baler to a bale accumulator including a pitch axle based pitch movement assembly, a roll movement assembly using a long channel twisting joint, a yaw limiting movement assembly use double arm connections and an offset movement assembly including a beam in tube linear joint controlled by an extension actuator perpendicular the forward and backward towing forces.

An offset hitch bale accumulator hitch for connecting a hay baler to a bale accumulator including a pitch axle based pitch movement assembly, a roll movement assembly using a long channel twisting joint, a yaw limiting movement assembly use double arm connections and an offset movement assembly including a beam in tube linear joint controlled by an extension actuator perpendicular the forward and backward towing forces.

A load-bearing trailer dolly which connects a tongue-type boat, utility or other trailer to a towing tandem trailer and bears weight from the trailer during towing. The trailer dolly is characterized by an axle mounted on a pair of wheels. A dolly frame height-adjustable trailer hitch that receives a primary or a secondary trailer. The adjustable hitch on the trailer dolly allows horizontal leveling. A shock-absorbing spring is fitted between the axle mount and the dolly frame for cushioning the dolly frame on the axle mount as the trailer is towed behind the towing tandem trailer.

An articulated vehicle assembly comprising a master vehicle having a master steering system and an onboard sensor arrangement configured to monitor at least said master steering system; a slave vehicle having a slave steering system and an onboard actuator arrangement configured to manipulate at least said slave steering system; an articulation system for articulating in a queue the master and the slave vehicles along a common longitudinal axis; and a processing unit configured to receive input signals from the onboard sensor arrangement and produce corresponding output signals to the onboard actuator arrangement to manipulate said slave steering system so as to maintain the master vehicle and the slave vehicle aligned along the common longitudinal axis, at least when the master vehicle performs a turn on a horizontal plane.

The present invention comprises a weight distribution tag trailer, having at least some of the following features: (a) a frame assembly, including beams and cross beams and side axle beams, (b) an axle coupled to the frame assembly, (c) shims for optional position between an axle assembly and the side axle beams to allow adjustment of load and balance (d) at least two wheels rotatably mounted to the axle, wherein at least one beam includes an end complementarily sized to be received by a vehicle receiver hitch assembly, and at least one other beam includes a clamp for coupling the beam to a cross frame of the vehicle receiver hitch.