Abstract: The invention provides a new automotive tractor unit for use with a new semi-trailer unit to form a rigidly-coupled tractor/semi-trailer combination. The tractor has a long wheel base and has its fifth wheel assembly mounted for extended longitudinal movement between a receiving position at its rear end and a mounting position close to the driver's cab. The tractor and semi-trailer chassis frames cooperate with one another to permit pitching between them while preventing yaw between them. The semi-trailer has a retractable landing gear movable beneath the chassis between a forward position close to the king pin to support the semi-trailer front end in the absence of the tractor, and a rear position close to the running wheels so that the semi-trailer can rest on the tractor and be rigidly coupled thereto. Preferably the tractor wheel base is of length from 6.8 meters (22 feet) to 8.5 meters (28 feet), while the fifth wheel assembly is mounted for a longitudinal movement of from 4.8 meters (16 feet) to 6.

Abstract: A operating system for slider locking pins includes an air compressor connected to an air supply tank. An air pressure protection valve is connected to the air tank to protect the brake system of the trailer. A flipper valve is connected to the air pressure protection valve and provides selective fluid communication between the air tank and a plurality of locking pin driver assemblies. Each locking pin driver assembly is adapted to move a locking pin to a disengaged position when in fluid communication with the air tank while being adapted to move the locking pin to the engaged position when not in fluid communication with the air tank. Each driver assembly is configured to substantially provide protection to each of its elements from adverse weather conditions and articles thrown up from the road. In one embodiment, the driver assembly includes a fixed bracket attached to the frame of the sliding undercarriage. A traveling bracket is connected to a locking pin.

Abstract: A control system and method provides automatic adjustments in a heavy duty vehicle that effectively redistributes the weight among the various wheel axles. A plurality of sensors are associated with the plurality of wheel axles on the vehicle. An electronic controller gathers information from the sensors and determines the weight at each wheel axle. The electronic controller then automatically determines adjustments that can be made to effectively redistribute the weight among the wheel axles in the event that the weight at any one axle is outside of a preselected range. The adjustments preferably are made by automatically moving the position of an adjustable “fifth wheel” relative to the cab portion. Additionally, this invention provides the capability of automatically adjusting the position of at least one trailer wheel axle. The adjustments can be made dynamically even while the vehicle is in motion.