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Title: Hydraulic control systems for mining apparatus

Abstract: A hydraulic control system, particularly for controlling the operation of roof support props of a mine working, employs control devices operated manually to feed pressure fluid to the working chambers of the props to effect extension or retraction thereof. A two-state valve device is operated when the props are extended to ensure that the correct setting pressure is established. This valve device has a control piston which is actuated to cause the device to establish independent connection between the main fluid pressure line and the associated working chambers of the props charged with fluid by the initial operation of the control devices. The connection established by the valve device is maintained even if the control devices break connection between the chambers and the pressure line. When the correct setting pressure is reached, a further control piston of the valve device is actuated to break the connection established by the valve device ready for the next operative cycle.


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Inventors: Weirich, Walter (Dortmund, DE)
Dettmers, Michael (Kamen, DE)
Becker, Kunibert (Werl, DE)
Rosenberg, Harry (Ludinghausen, DE)

Application Number: 06/207507
Filing Date: 1980-11-17
Publication_date: 1983-07-05
Assignee: Gewerk, Eisenhuette Westfalia (DE)

Primary Class(es): 91/29 91/518, 251/31
Other Classes: E21D23/16; E21D23/26; E21D23/00; F15B13/04
US Patent Ref:
3635020January, 1972Mahlmann91/6DRIVING SYSTEM FOR MOVING RAILS OF TEXTILE MACHINES
3638531February, 1972Rieschel911/70MPMINING PIT PROP ADJUSTING DEVICE
3776098December, 1973Behrens91/29CONTROL ARRANGEMENTS FOR MINE ROOF SUPPORT PROPS
3814375June, 1974Grottoh251/31SHUT-OFF VALVE AND CONTROL SYSTEM THEREFOR
4276810July, 1981Zeuner91/461Programmed valve system used for positioning control

Other Refs: GB1095112
December, 1967911/70MP

Primary Examiner: Hershkovitz, Abraham
Assistant Examiner:
Attorney: Sughrue, Mion, Zinn, Macpeak & Seas
Parent Case Data:

This is a continuation of application Ser. No. 948,458, filed Oct. 4, 1978, now aban