Mannesmann Rexroth Corporation

Gunther Muschong

Reinhard Amrhein

Walter Heid

Manfred Hartwig

The present invention relates to the use of two different sealing means in a directional spool valve. On the one hand side, a pressure guide element is provided at the spool so as to make sure that the pressure medium can only flow in radial direction against a seal located in the housing. The second sealing means may be of different design. It is possible that a spool seat surface provided on the spool and moveable against the force of a spring is used, said spool seat surface being adapted to cooperate with a stationary seat surface provided at the housing; alternatively a plurality of control bores is provided in the housing in the area of a port, said bores having a relatively small diameter d, and wherein a seal located the spool is used for opening and closing said bores so that no damage of the seal can occur. It is also possible to make use of the last mentioned sealing principle by itself.

Directional control device

Control valve

A 3/2 directional poppet valve is provided having a pilot poppet valve and a main valve. Said main valve comprises a housing having a longitudinal bore within which two 2/2 cartridge or logic valves are arranged in an axially opposite manner. A spool is provided in each of said logic valves. The diameters of said spools being different and the front ends of said spools facing towards each other can be mechanically coupled such that the movement of the one or the other spool into the closing position causes a movement of the other spool out of its closing position.

Growing community of inventors

Wuerzburg, Germany

Gunther Muschong