Patent ID: 9267248
Filing Date: 2016-02-23
CPC Classification: E01C

Claim Text:
1. A road finisher comprising a hydraulic control arrangement for activating a double-acting actuating cylinder which is connected on a piston side to the road finisher and on a piston rod side to a screed of the road finisher, comprising: a supply connection, two tank connections and two consumer connections, a loading pressure or a relief pressure being applied to a piston of the actuating cylinder via the consumer connections, wherein the loading pressure and the relief pressure are controlled as a function of a defined operating state, the hydraulic control arrangement being embodied in such a way that, in a controlling the screed load operating state, the relief pressure supplied to the actuating cylinder on the piston rod side is controlled via a proportional pressure control valve, wherein a control valve is in serial connection with said proportional pressure control valve in a conduit to said piston side consumer connection of said double-acting actuating cylinder and wherein said control valve is implemented to generate in addition to the dead weight of the screed an additional force on said screed, the hydraulic control arrangement further being connected to a control pump via the supply connection, the control pump enabling the supply of controlled volumetric flow or pressure according to actual requirements resulting from a speed of travel of the road finisher so that the volumetric flow of hydraulic oil which is conducted to the hydraulic control arrangement via the supply connection of the supply pressure being present at the supply connection is controllable via the control pump.