Sauer Danfoss Aps

Sauer-danfoss (nordborg) A/s

Martin Raadkjaer Joergensen

Carsten Christensen

Rudi Thomsen

Ken Petersen

The invention concerns a method for controlling a raising drive, the raising process occurring by means of pressure activation of at least one lift cylinder and the lowering process occurring by means of relieving, and a control of the lowering speed occurring by means of a variable flow resistance. In order to achieve a load-independent lowering speed, the flow resistance is determined in dependence of at least one load signal.

Raising drive and method for controlling a raising drive

The invention concerns a hydraulic valve arrangement () having at least two working connections (A, B), a check valve () being allocated to each working connection (A, B), and a pressure relief valve () being allocated to each check valve (), each pressure relief valve () being connected to a control pressure passage (). The valve arrangement shall ensure a reliable, pressure-less lowering, also in connection with single-actuated consumers, and further enable a pressure-less float position. For this purpose, the check valves () can be opened by means of tappets (), whose sides facing away from the check valves () are ending in a pressure chamber (), which is connected to the control pressure passage () of one of the pressure relief valves ().

Hydraulic valve arrangement

The invention concerns a brake valve arrangement of a vehicle having a trailer coupling and at least one controllable hydraulic consumer, with a brake valve (). It is endeavored to provide a similar embodiment of a vehicle with such a brake valve arrangement. For this purpose, the brake valve () is combined with at least one control valve () controlling the hydraulic consumer into forming a valve block () having several valve modules.

Brake valve arrangement

The invention concerns a driving device, particularly a lifting device for a working vehicle, with a hydraulic drive, in the form of a motor with a first connection and a second connection, a pump, a control valve arrangement between the pump and the drive, and an operating device with at least one operating element with a setting area, with which at least one parameter of the drive can be set. It is endeavoured to provide a simple manner of extending the functionality of the lifting device. For this purpose, it is ensured that the control valve arrangement is optionally controlling the drive to be single-acting or double-acting and the setting area has a first section, in which the drive is controlled to be single-acting and a second section, in which the drive is controlled to be double-acting.

Driving device, particularly a lifting device for a working vehicle

The invention concerns a driving device, particularly a lifting device for a working vehicle, with a drive in the form of a hydraulic motor, the drive having a first connection and a second connection, a pump and a control valve arrangement between the drive and the pump. It is endeavoured to provide a simple way of extending the functionality of such lifting devices. For this purpose, the control valve arrangement can be switched from a first operating state, in which the motor is driven in a single-acting manner, to a second operating state, in which the motor is driven in a double-acting manner.

Driving device, particularly lifting device for a working vehicle

A hydraulic valve system () has a supply connection arrangement, having a high-pressure connection (P) and a low-pressure connection, with a working connection arrangement, having two working connections (A, B), with a control valve (), which is arranged between the supply connection arrangement and the working connection arrangement, and with a non-return valve () for each working connection (A, B). The valve being arranged between the control valve () and the working connection arrangement. A tappet () mechanically opening the valve element () of said non-return valve.

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Soenderborg, Denmark

Martin Raadkjaer Joergensen