Hydraulic control device and pressure switch

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 path 13 from 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 member 16 which is actuated in a first switching direction by a spring 17 and a pilot pressure originating from the pressure P1 acting at the valve assembly V and in a second switching direction to a control position blocking the discharge path 13 by a pilot pressure originating from the supply pressure of the pressure source, the pressure switch W is designed as a 2/2-multi-way seat valve 16 operating with a blocking position without leakage. A valve member 24 forms the control member 16 and co-operates with a valve seat 25 arranged in the discharge path 13. The pressure source P and the valve assembly V are permanently connected via a main channel 10, 11 containing a restrictor D. The discharge path 13 branches off from the main channel 10, 11, 12 between the valve assembly V and the restrictor D. The pilot pressure actuating the valve member 26 in the switching direction towards the valve seat 25 originates from the supply pressure taken between the pressure source P and the restrictor D.