US2641906A - Mine roof support - Google Patents

Mine roof support Download PDF

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Publication number
US2641906A
US2641906A US113454A US11345449A US2641906A US 2641906 A US2641906 A US 2641906A US 113454 A US113454 A US 113454A US 11345449 A US11345449 A US 11345449A US 2641906 A US2641906 A US 2641906A
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United States
Prior art keywords
props
valve
pressure
roof
jack
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Expired - Lifetime
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US113454A
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English (en)
Inventor
Richard N Knights
Colin M Frye
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Dowty Equipment Ltd
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Dowty Equipment Ltd
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Publication date
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Publication of US2641906A publication Critical patent/US2641906A/en
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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
    • E21D23/006—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor provided with essential hydraulic devices
    • E21D23/0073—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor provided with essential hydraulic devices with advancing shifting devices connected therewith
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
    • E21D15/14—Telescopic props
    • E21D15/44—Hydraulic, pneumatic, or hydraulic-pneumatic props
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
    • E21D23/006—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor provided with essential hydraulic devices
    • E21D23/0065—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor provided with essential hydraulic devices driven, or automatically, e.g. electrically-hydraulically controlled

Definitions

  • the present invention consists in a mine roof support comprising two sets of at least two rigidly interconnected props arranged one behind the other in parallel spaced relationship, and means in the nature of parallel links connecting the two sets together side by side into a parallelogram, whereby when the props of either set are loosened whilst thoseof the other remain held, the set of loosened props can be advanced by being moved relatively to the other set under the influence of a force acting diagonally of the parallelogram.
  • By thus linking the two sets together advancement can take place by the one held set swinging with the parallel links about the other loosened set, and so on alternately in a walking movement.
  • the support will generally be used with one end of each set being nearer the coal face.
  • the props of one set will be loosened and moved forwardly nearer to the coal face.
  • the props of this set will be extended to givethe additional support required.
  • the other set of props will be loosened and similarly advanced to a new position of support.
  • hydraulically actuated props which may embody the usual relief valves for permitting the props to shorten under increasing roof pressure. If the props are of the hydraulic type, the pressure spaces of all the props of a set may intercommunicate so that the pressure can be developed from a single pump.
  • a further feature of the invention consists in providing between the two sets of props power driven mechanism for advancing the support set by set.
  • a double-acting fluid-pressure operated jack may conveniently be used as an extensible and contractible link extending diagonally between linked sets of props. When the jack is extended, the set at one side of the support will be advanced, and when the jack is contracted the other set will advance, provided. of course that the stationary set is clamped between the roof and floor.
  • the invention further consists in a mine roof support comprising at least two hydraulically actuated roof supporting units, means interconnecting, the units so that when one is held and the other is loosened, the loosened unit can be advanced by being moved relatively to the held a 12 Claims; (01. 6185) one, and valvemechanism preventing either unit from being loosened unless the other is taking a predetermined roof loading.
  • the hydraulic system associated with the support may include primary valve mechanism permitting supply flow to the props of one set or unit whilst permitting return flow from the other, and vice versa, and secondary valve mechanism moveable in response to a predetermined pressure in the supply flow to move from a position preventing such return flow to a position permitting such flow.
  • the primary valve mechanism may serve also to permit pressure fluid to reach an appropriate end of an advancement jack while supplying the props of one set and permitting return flow from the other end of the jack, and vice versa, means being provided for reversing the action of the primary valve mechanism upon the attainment of a predetere mined pressure in the system being supplied.
  • the props are of the hydraulic type, and if the hydraulic system supplying them is controlled by valve mechanism in accordance with the invention, the supply of pressure fluid along a single line will serve to bring about automatically a sequence of operations which causes the mine roof support to be advanced step by step.
  • the coal-getting installation includes a conveyer extending along the coal face.
  • the conveyer may, as the working face recedes, be advanced as a whole by means of a number of hydraulic roof supporting units having a single valve mechanism in accordance with the invention, said supports thus being controlled from a single control point.
  • Figures 1 and 2 illustrate the roof supporting structure, Figure 1 being a side elevation partly in section and Figure 2 being a plan view partly in section; and Figure 3 is a diagrammatic representation of the hydraulic system associated with the structure of Figures 1 and 2.
  • the roof supporting structure shown in Figures 1 and 2 incorporates at least four upright hydraulic props, arranged in two sets, one set at the left and the other set at the right.
  • One prop in each set, II and I2, respectively, may be considered the forward prop and the other prop in each set, Ila and I2a, respectively, will be the rear prop of its set.
  • the props ll, Ha ,of one set are pin jointed to a roof bar It and to a floor bar 20, and the props [2, 12a of the other set are similarly pin jointed to the roof bar I9 and the floor bar 2
  • the props I and i id of the right hand set are supported in and con nected by a rigid side frame consisting of cross tubes l3 joining sleeves l4 and Ma that surround and mount the respective props H and Ha.
  • the props l2 and i202 of the left hand set are connected and mounted in the respective sleeves of a second such side frame made up of sleeves i5 and iGa joined rigidly by cross tubes l5.
  • the right hand side frame and the left hand side frame are linked together by parallel linkage such as the four transverse links Ii, two connecting the top and bottom of the sleeves l4 and I6, and the other two connecting the top and bottom of the sleeves I ia and Mia.
  • the links and the two rigid side frames relative to which the ends of the links may swing constitute thus an articulated upright structure which can be deformed by effecting alternately approach of its diagonally opposite sleeves 14a and I5, and their separation, always maintaining their side frames in parallelism.
  • Each prop it will be observed from Figure 1, is permitted limited axial freedom with respect to the sleeve of the rigid side frame wherein it is mounted, and this is required in order to accommodate irregularities in the level of the mine roof and floor, through the pin joints already mentioned which connect the props to the roof bars i3 and the floor bars 25, while avoiding the imposition of any undesirable stresses on the rigid side frames and the links H which connect them.
  • the four props are structurally substantially identical with one another, and referring to the prop l2 in Figure 1 it will be seen that there is a lower outer tubular member 22 within which there is slidable telescopically an upper inner tubular member 23.
  • the tube 22 is closed at its lower end by a closure piece 24 and the tube 23 is closed at its upper end by a head piece 25.
  • the tube 23 is glanded at 25 to the tube 22. troduction of pressure fluid into the space within the tubes will cause the prop to extend, and that contraction is permitted when the pressure fluid is allowed to leave the space.
  • Deformation of the upright articulated structure can be accomplished by a double-acting hydraulic advancement jack 23, 29 which is pin jointed at its respective ends to lugs 2'! fitted upon diagonally opposite sleeves such as and Ida. If, say, the props ll, Ha mounted in the right hand side frame M, Ma, iii are extended between the roof and the floor to hold that side frame fixedly in position, and the props l2,
  • the support may with advantage be fitted with a valve box indicated generally at 33 by which the sequence of operations necessary to effect a number of advancing movements or steps may occur automatically upon the continued supply of pressure fluid along a single feed pipe 3
  • This valve mechanism will now be described in detail with reference to Figure 3 of the drawings.
  • Liquid from a reservoir 38 is fed by a pump 39 to a manually operable control valve 48 from which the liquid flows either through a return line 4! back to the reservoir or through a single supply line 3
  • opens into a chamber 42 from which the liquid reaches the primary valve 43 of the system.
  • the primary valve 43 is a piston valve which opens either one of the passages M and 45 to the source of supply while placing the other of the passages "34 and 45 in communication with a return line at leading back to the reservoir 38, In the position shown, liquid from the chamber 42 can reach the passage 15 through the port 47 and passage it, and the passage 44 communicates with the return line 43 by way of the annular space 53 around the valve 43.
  • the passage 44 communicates directly with the pipe line 36 leading to one end of the jack cylinder 28, and leads through a spring loaded non-return valve 50 to the pipe line of the props I2 and I211.
  • the passage similarly leads directly to the pipe 37 'connected with the opposite end of the jack, and through a spring loaded non-return valve 5
  • are adapted to be unseated by projections 52 and 53 respectively formed on the opposite ends of a piston 54 and thus constitute a coordinated control valve means operatively interposed between the primary control valve and the props of the respective frames.
  • the piston 54 is shown in a mid-position at which neither projection engages its valve, and it may be assumed that the roof support has been standing for a time and that the piston 54 has assumed this mid-position due to leakage in the valve 33. All the props are reacting against the roof, and if necessary could support a maximum roof loading of say tons for each pair of props which is the limit imposed by relief valves 55 and 5B controlling flow from the pipe lines 33 and 35 to the return line 46. By arranging the two relief valves 55 and 55 with a common spring 5?
  • each set of props will be capable of supporting 50 tons loading so that the support as a Whole will withstand a loading of tons.
  • each prop of the set shall be supporting a roof loading of 1 ton which is overcome by the jack when the latter is effecting an advancing movement.
  • pipe lines 33 and 35 each include in parallel a non-return valve 58' preventing flow away from the props and a relief valve 59 permitting return flowonly when pressure in the line'is above a pressure atwhich each prop supports the roof loading of 1 ton.
  • Thevalve43 has a stem 50 extending into the chamber 42, said stem having a longitudinal slot 6
  • the other end of the link 63 is pivoted at 64 to a rocking plate 65 which rocks about a pivot 66 on a'bracket 61.
  • the plate 65 can swing down against the resistance-of apair of snap-over springs one of which is shown at 68 extending between abutments on the rocking plate and on a further fixed bracket 69.
  • the rocking plate 65 has a slot 10 through which extends a pin H on a link 12 connected at the upper end of a plunger I3 which extends through a gland 14 into a chamber 15 where the plunger carries a head it which is spring biassed by a spring 11 so that the plunger i3 tends to project a maximum amount into the chamber 42.
  • the slot '10 in the plate 65 isdisposed in relation to the axis of the plunger 13 so that it forms in effect one side of a V with the pin H at the upper end of the slot.
  • the fluid pressure in the chamber 42 acts upon the end of the plunger 13 and when the pressure has reached a predetermined pressure, the plunger will be moved against its springs 11 to cause the pin H to rock the plate 65 in a clockwise direction thus causing the spring 68 to compress through the dead centre position already mentioned.
  • the pressure in the chamber 42 at which the trip mechanism changes over the po sition of the primary valve 43 in this way will correspond to a pressure somewhat above that at which the props obtain their setting pressure of 5 tons roof support.
  • valve 43 will be moved automatically into its lower position at which the passage 44 is in communication with the chamber 42, and the passage 45 is in communication with the return line 46 by way of the annular space 49 around the valve 43.
  • the changeover of the valve will also place the line 31 from the lower end of the jack in communication with the return line 45, and place the line 36 at the upper end of the jack in communication with the pressure fluid supply in the chamber 42.
  • the valve 43 has moved to its lower position pressure fluid will be applied to the upper end of the jack which will move the relieved props l2 and lZa into the dotted line position.
  • the pressure seouence may be summarised as follows: The jack moves relieved props when the relieved props are taking a l ton-roof loading and while the other props are taking at least 5 tons. The props moved by the jack are then raised to a '5 ton loading and the other props are relieved by the corresponding non-return valve 50 or 5
  • the valve mechanism above described for a single roof supporting unit may serve to control the advancing movements of a number of such units, and these units may be placed at intervals along the length of a conveyor in order to shift the conveyer as a whole as a consequence of shifting the several roof supporting units.
  • the props of one set are said to be loosened while still supporting a roof loading of 1 ton, they may be entirely freed from the roof before the jack causes them to advance.
  • the secondary valve mechanism comprising the piston 54 and the non-return valves 56 and 51 prevent either set of props from being loosened until the other set is taking a predetermined roof loading.
  • manually operable means may be provided whereby the props of a support may be relieved at will.
  • the pipe lines 53 and 35, between their respective props and nonreturn and relief valves 58 and 59, may be fitted with cocks operable separately 01' together to place said lines in connection with the reservoir.
  • a mine roof support comprising at least four constrictable and expansible upright hydraulic props disposed in two sets at right and left, respectively, and one prop ahead and one prop behind in each set, said props being of a length, when extended, to rest upon the floor and to support the roof, a rigid frame connecting and supporting the forward and the rear props, respectively, in the set at the right, and a like rigid frame connecting and supporting the forward and the rear props in the set at the left, parallel linkage means connecting the forward ends and the rear ends of the two frames, to constitute with the frames a deformable parallelogram, extensible and contractable power means extending diagonally of such parallelogram between and connected to the forward end of one frame and the rear end of the other frame, and operable upon contraction to shorten the distance between its two points of connection, and upon extension to length such distance, hydraulic control means shiftable between two limit portions, and operable when in one such position to extend the two props at one side to hold fast these props and their frame between the floor and the roof, and operable when in its other limit position
  • a mine roof support comprising four constrictable and expansible upright hydraulic props disposed in two sets at right and left, respectively, and one ahead and one behind in each set, said props being of a length, when extended, to rest upon the floor and to support the roof, a rigid frame including two spaced parallel upright sleeves connecting and supporting the two props at the right, and a like rigid frame including two spaced parallel upright sleeves connecting and supporting the two props at the left, each prop being mounted by its sleeve with a limited freedom of independent axial movement therein, a
  • a mine roof support as in claim 1, wherein the parallel linkage means interconnecting the two frames comprise an upper and a lower transverse links connecting the forward portion of each frame and two like links connecting the rearward portions of each frame in the parallelogram arrangement, to maintain each frame upright by support from the other frame when the props of either frame are loosened whilst those of the other frame are held fast, and the loosened props and their frame is advanced by being swung uprightly about its connections to the held-fast set.
  • a mine roof support as in claim 2 including a single pressure source, conduit means connecting said source, by way of the control means for the advancement jack and thence to the further control means for the props, and for relief from the same, and a selector device incorporated in said further control means to regulate access of pressure fluid to one or the other set of props, and relief from the other set, in accordance with the setting of the first control means for extension or for retraction of the advancement jack.
  • a mine roof support as in claim 2 including a primary control valve governing thedirection of supply of pressure fluid to one or the other end of the advancement jack, and a coordinated secondary control valve means operatively interposed between the primary control valve and the props of the respective frames, and automatically shiftable by pressure fluid, according to whichever end of the double-acting jack is supplied with pressure fluid, to deliver the pressure fluid likewise to the forward props for their holding fast, and to relieve the rearward props for their loosening.
  • a mine roof support as in claim 6, including means sensitive to back pressure from a held-fast set of props, automatically operable to reverse the primary valve, to reverse thereby the direction of actuation of the double-acting jack, for advance of the loosened set of props.
  • a mine roof support as in claim 1 including a single pressure fluid source operatively connected to the props of both frames, means oprable to connect said source alternatively to the props of one frame or the other, and valve means automatically operable toblock connection of the fluid supply source to loosen the props of one frame unless those of the other frame are loaded to a predetermined value.
  • a mine roof support asin claim 2 including a single fluid pressure source operatively con- I nected to the props of both frames and to the opposite ends of said advancement jack, a reversible primary valve constituting the first-mentionedcontrol means, and governing delivery of pressure fluid to the respective ends of said 1 jack, and tosecondary valve means constitutingv the further control means, said secondaryvalve means including two spaced-apart non-return' valves in separate conduits to the props of the respective frames, and a double-acting differential area piston interposed between said non-return valves, movable under the influence of predetermined pressure in the conduit not being supplied.

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Press Drives And Press Lines (AREA)
US113454A 1948-09-01 1949-08-31 Mine roof support Expired - Lifetime US2641906A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB23081/48A GB658998A (en) 1948-09-01 1948-09-01 Improvements in mine roof supports

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US2641906A true US2641906A (en) 1953-06-16

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US113454A Expired - Lifetime US2641906A (en) 1948-09-01 1949-08-31 Mine roof support

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US (1) US2641906A (de)
BE (1) BE490921A (de)
DE (1) DE974199C (de)
FR (1) FR994590A (de)
GB (1) GB658998A (de)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2694293A (en) * 1953-05-08 1954-11-16 Hydrauliques Pour L Ind Minier Propping device for roofs of mine levels
US2756034A (en) * 1952-10-29 1956-07-24 Joy Mfg Co Roof supporting jacks on a continuous miner
US2795934A (en) * 1952-09-30 1957-06-18 Joy Mfg Co Rotating hydraulic roof supporting jacks
US2795935A (en) * 1952-09-30 1957-06-18 Joy Mfg Co Walking roof support
US2857125A (en) * 1953-02-25 1958-10-21 Dowty Hydraulic Units Ltd Mine roof supports
DE1078514B (de) * 1954-10-01 1960-03-31 Kloeckner Bergbau Victor Icker Wandernder Strebausbau, vorzugsweise fuer den Abbau in steil gelagerten Floezen
DE1088904B (de) * 1957-08-10 1960-09-15 Gewerk Eisenhuette Westfalia Hydraulischer Ausbau fuer bergmaennische Gewinnungsbetriebe
DE1112030B (de) * 1955-09-17 1961-08-03 Rheinstahl Gmbh Wanheim Vorpfaendvorrichtung fuer einen Stempelausbau
DE1151235B (de) * 1958-09-10 1963-07-11 Glueckauf Guenther Klerner Mas Verteiler fuer hydraulisch beaufschlagbare, doppelt wirkende Vordrueckzylinder zum Verlegen von Strebfoerderern od. dgl.
US3115754A (en) * 1959-01-23 1963-12-31 Dowty Mining Equipment Ltd Mining shield
US3143862A (en) * 1958-08-11 1964-08-11 Dobson Ltd W E & F Support of roofs in mines
DE1182614B (de) * 1956-05-17 1964-12-03 Gewerk Eisenhuette Westfalia Rueckvorrichtung fuer eine Hobelfuehrung in steil gelagerten Floezen
US3174289A (en) * 1960-02-08 1965-03-23 Gewerk Eisenhuette Westfalia Travelling hydraulic development frame for mining operations
US20060201322A1 (en) * 2005-03-10 2006-09-14 Kroeger E B Support column installation assembly
WO2025160869A1 (zh) * 2024-02-01 2025-08-07 山东科技大学 一种截割过程非等强支护控制方法

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB658998A (en) * 1948-09-01 1951-10-17 Dowty Equipment Ltd Improvements in mine roof supports
DE977365C (de) * 1950-06-18 1966-03-24 Konrad Grebe Wandernder Strebausbau
US2757515A (en) * 1952-08-04 1956-08-07 Noble Co Tunnel breasting jumbo
US2795936A (en) * 1952-09-30 1957-06-18 Joy Mfg Co Walking roof support
DE1169399B (de) * 1956-06-18 1964-05-06 Gewerk Eisenhuette Westfalia Rueckbarer Ausbau fuer bergmaennische Gewinnungsbetriebe
DE1168372B (de) * 1957-06-28 1964-04-23 Gutehoffnungshuette Sterkrade Mechanisierter Strebausbau
DE1217907B (de) * 1958-12-20 1966-06-02 Bosch Gmbh Robert Anwendung einer Schalteinrichtung mit mehreren Armaturen
DE1155077B (de) * 1960-12-24 1963-10-03 Rheinstahl Gmbh Wanheim Sohlstueck fuer wandernde Ausbauelemente

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US1473157A (en) * 1923-11-06 morgan
US1870088A (en) * 1931-06-12 1932-08-02 Louis I Beckwith Refrigerating apparatus
US2152654A (en) * 1937-11-22 1939-04-04 Jr Glenway Maxon Traction mechanism
US2163959A (en) * 1937-03-18 1939-06-27 John A Edeby Lifting jack
US2420755A (en) * 1942-12-04 1947-05-20 Joy Mfg Co Apparatus for mining
US2452632A (en) * 1944-04-13 1948-11-02 Ransomes & Rapier Ltd Excavating machine

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BE457387A (de) *
BE456556A (de) *
US1450329A (en) * 1916-01-05 1923-04-03 Edmund C Morgan Mine-roof-supporting method and apparatus
US1473498A (en) * 1917-10-06 1923-11-06 Morgan Olive Eugenie Tunneling machine
US1710887A (en) * 1921-11-15 1929-04-30 Morgan Olive Eugenie Mining machine
DE510708C (de) * 1929-02-05 1930-10-22 Albert Hamel Abbaukammer mit in der Hoehe einstellbarem Dach
DE667538C (de) * 1935-05-23 1938-11-14 Ernst Hoffmann Streckenvortriebsmaschine
GB453560A (en) * 1935-05-27 1936-09-14 Wilhelm Fehlemann Yieldable prop for mines
US2202584A (en) * 1935-06-18 1940-05-28 Sullivan Machinery Co Mining apparatus
DE714182C (de) * 1940-02-24 1941-12-02 Konrad Frielinghaus Wanderpfeiler
DE733743C (de) * 1940-02-24 1943-04-01 Bergtechnik G M B H Einrichtung zum seitlichen Verruecken von Foerdermitteln
DE919165C (de) * 1943-03-23 1954-10-14 Gerhard Werner Rueckmaschine fuer Ausbauelemente fuer den Strebausbau
BE456862A (de) * 1943-06-28 1944-08-31
FR905292A (fr) * 1943-07-31 1945-11-29 Poteau de mine
GB658998A (en) * 1948-09-01 1951-10-17 Dowty Equipment Ltd Improvements in mine roof supports

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1473157A (en) * 1923-11-06 morgan
US1870088A (en) * 1931-06-12 1932-08-02 Louis I Beckwith Refrigerating apparatus
US2163959A (en) * 1937-03-18 1939-06-27 John A Edeby Lifting jack
US2152654A (en) * 1937-11-22 1939-04-04 Jr Glenway Maxon Traction mechanism
US2420755A (en) * 1942-12-04 1947-05-20 Joy Mfg Co Apparatus for mining
US2452632A (en) * 1944-04-13 1948-11-02 Ransomes & Rapier Ltd Excavating machine

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2795934A (en) * 1952-09-30 1957-06-18 Joy Mfg Co Rotating hydraulic roof supporting jacks
US2795935A (en) * 1952-09-30 1957-06-18 Joy Mfg Co Walking roof support
US2756034A (en) * 1952-10-29 1956-07-24 Joy Mfg Co Roof supporting jacks on a continuous miner
US2857125A (en) * 1953-02-25 1958-10-21 Dowty Hydraulic Units Ltd Mine roof supports
US2694293A (en) * 1953-05-08 1954-11-16 Hydrauliques Pour L Ind Minier Propping device for roofs of mine levels
DE1078514B (de) * 1954-10-01 1960-03-31 Kloeckner Bergbau Victor Icker Wandernder Strebausbau, vorzugsweise fuer den Abbau in steil gelagerten Floezen
DE1112030B (de) * 1955-09-17 1961-08-03 Rheinstahl Gmbh Wanheim Vorpfaendvorrichtung fuer einen Stempelausbau
DE1182614B (de) * 1956-05-17 1964-12-03 Gewerk Eisenhuette Westfalia Rueckvorrichtung fuer eine Hobelfuehrung in steil gelagerten Floezen
DE1088904B (de) * 1957-08-10 1960-09-15 Gewerk Eisenhuette Westfalia Hydraulischer Ausbau fuer bergmaennische Gewinnungsbetriebe
US3143862A (en) * 1958-08-11 1964-08-11 Dobson Ltd W E & F Support of roofs in mines
DE1151235B (de) * 1958-09-10 1963-07-11 Glueckauf Guenther Klerner Mas Verteiler fuer hydraulisch beaufschlagbare, doppelt wirkende Vordrueckzylinder zum Verlegen von Strebfoerderern od. dgl.
US3115754A (en) * 1959-01-23 1963-12-31 Dowty Mining Equipment Ltd Mining shield
US3174289A (en) * 1960-02-08 1965-03-23 Gewerk Eisenhuette Westfalia Travelling hydraulic development frame for mining operations
US20060201322A1 (en) * 2005-03-10 2006-09-14 Kroeger E B Support column installation assembly
WO2025160869A1 (zh) * 2024-02-01 2025-08-07 山东科技大学 一种截割过程非等强支护控制方法

Also Published As

Publication number Publication date
GB658998A (en) 1951-10-17
FR994590A (fr) 1951-11-19
DE974199C (de) 1960-10-13
BE490921A (fr) 1949-09-15

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