Patent ID: 6609539
Filing Date: 2003-08-26
Classification: F15B,F16K,Y10T

Abstract:
A hydraulically operated directional control valve for support mechanisms in underground mining, with a valve piston guided sliding in a boring of a valve seat carrier with a valve cone to abut in a sealing manner a sealing ring arranged in the valve seat carrier and with a control piston for the actuation of the valve piston accommodated so as to slide in a control piston guide, with a high pressure connection, a load connection, a return flow connection and a control pressure connection for hydraulic fluid, whereby on actuation of the valve piston by the control piston the return flow connection is closed by a closing element of the control piston and following the lifting of the valve cone from the sealing ring a fluid connection is set up from the high pressure connection to the load connection, in which the valve piston is guided without sealing between th high pressure connection and the sealing ring in the valve seat carrier allowing at least partial pressure equalization and in which the closing element of the control piston closes the return fib connection, before the valve piston releases the high pressure connection in full cross-section for the establishment of the fluid connection with the load connection.