EP 0114639 A3 19861203 - CONTROL FOR A HYDRAULIC PROP OF ADVANCING MINE ROOF SUPPORTS
Title (en)
CONTROL FOR A HYDRAULIC PROP OF ADVANCING MINE ROOF SUPPORTS
Publication
Application
Priority
DE 3301674 A 19830120
Abstract (en)
[origin: EP0114639A2] The prop (1) is controlled by a resetting device (10) which is inserted in parallel connection with the setting and withdrawal valves (4, 8) into the resetting line (11) leading to the pressure space (2) of the prop (1). The resetting operation is activated by the actuation of a control plunger (14) at the resetting device (10) which connects a 3/2-way directional control valve (13) to the high-pressure line P. The inflowing pressure fluid acts upon the control piston (16) from a further 3/2-way directional control valve (15) which directs pressure fluid to the pressure space (2) of the prop (1) and to a control piston (17). The latter acts on a bar (18) which engages in a recess (19) of the control plunger (14) against the force of a retaining spring (20) if the pressure in the resetting line (11) exceeds a predetermined minimum setting pressure. The bar (18) is disengaged by loading a control piston (23) with the withdrawal valve (8).
IPC 1-7
IPC 8 full level
E21D 23/16 (2006.01)
CPC (source: EP)
E21D 23/16 (2013.01)
Citation (search report)
- [A] DE 3123278 C1 19821216 - HEMSCHEIDT MASCHF HERMANN
- [AD] DE 3012299 A1 19811008 - HEMSCHEIDT MASCHF HERMANN [DE]
- [A] GB 2047316 A 19801126 - GEWERK EISENHUETTE WESTFALIA
- [A] DE 3015411 A1 19811105 - HEMSCHEIDT MASCHF HERMANN [DE]
- [A] FR 2408031 A1 19790601 - GEWERK EISENHUETTE WESTFALIA [DE]
- [A] DE 2942463 A1 19810430 - KLOECKNER WERKE AG [DE]
Designated contracting state (EPC)
AT FR GB
DOCDB simple family (publication)
DE 3301674 C1 19840105; EP 0114639 A2 19840801; EP 0114639 A3 19861203
DOCDB simple family (application)
DE 3301674 A 19830120; EP 84100425 A 19840117