Abstract: A road paver-finisher having a tractor unit and a screed unit mounted for vertical movement on and relative to the tractor unit. The tractor unit has a hopper for road material, and conveyors unload the road material from the hopper in front of the screed to be leveled by the screed. Crawler belts mounted on the tractor unit are disposed forwardly of the screed for advancing the tractor unit, and ground engaging steering wheels are mounted on the tractor unit forwardly of the crawler belts. Power devices are provided for moving the steering wheels and crawler belts vertically relative to each other thereby to control tilting of the tractor unit and hence of the screed. These power devices can move the steering wheels vertically relative to the crawler belts, or vice versa.

Abstract: A device for controlling the pressure of the extensible screed of a road paver on the material to be laid down, comprising hydraulic actuators capable of lifting the screed unit and structure for regulating the pressure of the hydraulic fluid without varying the vertical position of said screed, including distributors, non-return valves, maximum pressure valves and, at least one accumulating chamber, wherein an electric circuit for transmitting signals acts upon the hydraulic circuit to adjust the pressure of the fluid in the actuators.

Abstract: A pneumatic suspension device, suitable for transmitting torque, is composed of a single toroid-shaped vibration-damping pneumatic ring. The inner surface of the ring rests on a rim connected to the part of the machine which must be free from vibration (for example, a hydraulic engine). The machine is directly flanged on a reduction unit, and both the machine and device are made integral with a bracket and frame. The outer surface of the pneumatic ring is gripped by a series of S-shaped jaw elements, bolted onto a support ring welded to the inner cylindrical wall of a vibrating drum. The S-shaped jaw elements have a profile such that each pair of jaws, once fixed in position on the outer band of the toroidal pneumatic ring, forms therewith a single body damping the vibration of the drum.