Valve units for use in hydraulic control systems of mining equipment
AssigneeGewerkschaft Eisenhutte Westfalia
InventorsMichael Dettmers, Bernd Peters
Life of this patent
Estimating the term…
Abstract
A valve block in a mine hydraulic system contains a non-return valve which is opened when a hydraulic control signal occurs to connect a pressure fluid feed or return line to a working chamber of an appliance such as a prop. A auxiliary valve is mounted in the block and is operated manually to relieve the working chamber even if the non-return valve remains closed.
Claims14
In or for an hydraulic system for a mine working comprising an hydraulic appliance with a working chamber and pressure fluid feed and return lines connectible to the chamber;
- a valve unit comprising a non-return valve with an inlet connectible to the pressure fluid feed or return lines, an outlet connectible to the working chamber, hydraulic means for opening the non-return valve to establish connection between the inlet and the outlet, an auxiliary relief valve connectible to the outlet of the non-return valve and manual means for operating the auxiliary valve to relieve the pressure in the working chamber even when the non-return valve is closed;
- wherein the non-return valve and the auxiliary relief valve have housings which are detachably mounted into bores in a common block;
- and
- the housing of the relief valve has a plurality of drainage bores which open from a region of the housing leading to the outside of the block to allow the escape of relieved pressure fluid.
In or for an hydraulic system for a mine working comprising an hydraulic appliance with a working chamber and pressure fluid feed and return lines connectible to the chamber;
- a valve unit comprising a non-return valve with an inlet connectible to the pressure fluid feed or return lines, an outlet connectible to the working chamber, hydraulic means for opening the non-return valve to establish connection between the inlet and the outlet, an auxiliary relief valve connectible to the outlet of the non-return valve and manual means for operating the auxiliary valve to relieve the pressure in the working chamber even when the non-return valve is closed, wherein the non-return valve and the auxiliary relief valve have housings which are detachably mounted into bores in a common block, wherein the housing of the auxiliary valve has a continuous central axial stepped bore containing a valve seat, a valve closure member, a spring for urging the closure member against the seat and a tappet forming part of the manual means, and wherein the stepped bore also contains a sleeve which secures the seat in the bore and the closure member and the spring are located in the sleeve.
Dependencies are inferred from the claim text.