Hydraulic control device and pressure switch

Abstract

In a hydraulic control device H comprising a pressure source P which can be switched on and switched off, a reservoir R and a pressure switch W located in a discharge pathfrom a valve assembly V to the reservoir R, which pressure switch W either connects the valve assembly V with the reservoir R or blocks the valve assembly V versus the reservoir R, the pressure switch W contains a displaceable control memberwhich is actuated in a first switching direction by a springand a pilot pressure originating from the pressure Pacting at the valve assembly V and in a second switching direction to a control position blocking the discharge pathby a pilot pressure originating from the supply pressure of the pressure source, the pressure switch W is designed as a-multi-way seat valveoperating with a blocking position without leakage. A valve memberforms the control memberand co-operates with a valve seatarranged in the discharge path. The pressure source P and the valve assembly V are permanently connected via a main channelcontaining a restrictor D. The discharge pathbranches off from the main channelbetween the valve assembly V and the restrictor D. The pilot pressure actuating the valve memberin the switching direction towards the valve seatoriginates from the supply pressure taken between the pressure source P and the restrictor D.