US3908389A - Mine roof support - Google Patents
Mine roof support Download PDFInfo
- Publication number
- US3908389A US3908389A US441485*A US44148574A US3908389A US 3908389 A US3908389 A US 3908389A US 44148574 A US44148574 A US 44148574A US 3908389 A US3908389 A US 3908389A
- Authority
- US
- United States
- Prior art keywords
- support
- shield
- roof
- hinge
- face
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH 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
- E21D23/0004—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor along the working face
- E21D23/0034—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor along the working face comprising a goaf shield articulated to a base member
- E21D23/0043—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor along the working face comprising a goaf shield articulated to a base member and supported by two or more rows of struts parallel to the working face
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH 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
- E21D23/03—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor having protective means, e.g. shields, for preventing or impeding entry of loose material into the working space or support
Definitions
- ABSTRACT Av mine roof support for use at a mineral face has a flushing screening shield arranged on its goaf side.
- the screening shield is in at least two parts one being an upper part and another a lower part, the parts being hingedly Connected together by a hinge means having its axis lying in the longitudinal direction of the mineral face.
- the upper shield part is hingedly connected to the upper or roof-engaging structure of the support. preferably by a universal joint
- the lower shield part is hingedly connected to the base or lower part of the support by a hinge having its axis transverse to the longitudinal direction of the face.
- the screening shield is additionally pivotally movable laterally relatively to the support.
- the axis of the hinge, connecting the lower screen part to the base or lower part of the screen lies parallel tothe floor of the mine and, whenviewed from the longituidinal direction of the mineral face, is disposed approximately centr-ally of the support.
- the invention is concerned with a mine'roof support a support frame and more particularly but notessentially to a mine roof support with a multi-part flushing screening shield, the parts of which are mutually'con-' nected throughhinges with hingeaxes'lying inthe'lon gitudinal direction ofth'c face ana the upper and'lower parts of which are connected "with a roof bar'c'ohstruc tion and a'base late cfmdsupwd; wherein'the connectionwith the roof bar ctins'tiuctionat-least i's 'forrned hingedly about a 'hinge axis' lying transversely to the longitiidin aldirection of the face.
- a mine roof support for use at a mineral face comprising a base member, extensible prop means mounted on '16'we parts of the support, said connecting means providingforadditiona] 'moveme'nt' laterally of the screening shield relatively to the support.
- a mine :roof support as described in' the preceding paragraph having a multi-part flushing screen shield arranged on the goaf si deof the sup'porhhinge means mutually connecting the parts" of said screening" shield and having their'axes lying in the'lon'gitudinal direction of the face,- -hinge means connecting the upper part of the shield to the 'robf engagingstructure and having its hinge axis lying transversely tothe longitudinal direction of the mineral face, and hinge means connecting the'low'er part ofthe shield with the base member and having a hinge axis which 'he-sipar allel to the floor of the mine and transversely to'the longitudinal direction of the face and w hichg viewed from the longitudinal direction of the face is disposed approximately centrally of the'support, whereby the screening shield is pivotally movable not only in'the directionof length of the support but additi onally laterally relatively thereto.
- aligning devices are arranged between the props of the support on the one hand and thelbase plate or parts associated with the baseplate on the other hand ,yvhich ,serve for, swivelling of the flushing screen about the hinge between the base plate. and the underpart of the flushing screen.
- aligning devices suitably have. resilient restoring elements.
- the aligning devices can also have pressure-medium cylinders which serve for application of the aligning forces.
- the support illustrated in the drawing has a base plate which is indicated by reference numeral 1. On this base plate 1 are arranged several props 2 which mutually support a roof bar construction 3. The displacement of the props 2 on the base plate 1 and on the roof bar construction 3 is flexible all round.
- aligning devices 4 are arranged on the base plate 1, which devices serve for alignment of the props 2 relative to the base plate 1. Furthermore the base plate 1 is provided with a ram 5 the reciprocatable piston rod of which acts on a face conveyor 6.
- the flushing screen 7 consists of two box elements 70 and 7b which are open towards the coal face and embrace with their side walls the rearward propsv 2 of the support on the flanks.
- the lower box element 70 is connected through hinge pins 8 with the base plate 1.
- the hinge pins 8 lie on a joint axis which lies parallel to the floor and transversely to the longitudinal direction of the face and seen from the longitudinal direction of the face, is disposed approximately centrally in the support.
- the upper box element 7b is hingedly connected, universally movable, to the roof bar construction 3 by means of a chain 9 or like connecting means.
- box elements 7a and 7b are mutually connected by guide rods 10 which hingedly engage on the side wall of the lower box element 7a and in the region of the rear wall of the upper box element 7b.
- the hinge axes extending through the engagement points of the guide rods 10 lie in the longi tudinal direction of the face.
- the flushing screen shield is movable towards the support in a plane perpendicular to the floor and in the longitudinal direction of the face. Because of this the flushing screen 7 with its hinges lying in the longitudinal direction of the face no longer prevents inclination of the base plate in the longitudinal direction of the face. Also in movements parallel to the stratification between roof and floor in the longitudinal direction of the face the flushing screen can tilt correspondingly without its hinges being overloaded or that impact of the props on the side walls of the screen elements 7a and 7b needs to be feared.
- connecting means quadrilateral links or the like, the hinge axes which lie parallel to the floor and transversely to the longitudinal direction of the face. Similar connecting means can also be arranged between the upper screen element 7b and the roof bar construction 3.
- a mine roof support for use at a mineral face, comprising a base member, extensible prop means mounted on said base member, a roof-engaging structure mounted on said prop means for application thereby to a roof to be supported, a multi-part flushing screen shield including upper and lower parts arranged on the goaf side of the support, first hinge means mutually connecting the parts of said screening shield and having their axes lying in the longitudinal direction of the mineral face, a flexible member connecting the upper part of the shield and the roof-engaging structure and which permits movements of the upper part of the shield about an axis lying transversely to the longitudinal direction of the mineral face, and second hinge means connecting the lower part of the shield with the base member and having a hinge axis which lies transversely to the longitudinal direction of the mineral face, whereby the screening shield is pivotally movable with respect to the support not only toward and away from the mineral face but also parallel thereto.
Abstract
A mine roof support for use at a mineral face has a flushing screening shield arranged on its goaf side. The screening shield is in at least two parts one being an upper part and another a lower part, the parts being hingedly connected together by a hinge means having its axis lying in the longitudinal direction of the mineral face. The upper shield part is hingedly connected to the upper or roof-engaging structure of the support, preferably by a universal joint, and the lower shield part is hingedly connected to the base or lower part of the support by a hinge having its axis transverse to the longitudinal direction of the face. Thus, the screening shield is additionally pivotally movable laterally relatively to the support. In one preferred embodiment the axis of the hinge, connecting the lower screen part to the base or lower part of the screen, lies parallel to the floor of the mine and, when viewed from the longituidinal direction of the mineral face, is disposed approximately centrally of the support.
Description
United States Patent 1 Lubojatsky et al.
1451 Sept. 30, 1975 MINE ROOF SUPPORT [75] Inventors: Walter Lubojatsky, Recklinghauscn;
Wilhelm Wertelewski, Datteln, both of Germany [73] Assignee: Becorit Grubenausbau Gmbl-l,
Recklinghausen, Germany [22] Filed: Jan. 11, I974 [21] Appl. No.: 441,485
[30] Foreign Application Priority Data Feb. 27. 1973 Germany 2509670 [52] US. Cl 61/45 D [51] Int. Cl. E21D 15/44 [58} Field of Search 61/45 D; 299/31, 33; 248/357; 91/170 MP [56] References Cited UNITED STATES PATENTS 3.324 664 6/1967 Allen 61/45 D 3,483.705 l2/l969 Roberts .5. 61/45 D 3 83(),070 8/1974 Rosenberg et al. 61/45 D Primal E.\'zmiiner-Dennis L. Taylor Attorney, Agent, or Firm-Berman, Bishoff & Platt [57] ABSTRACT Av mine roof support for use at a mineral face has a flushing screening shield arranged on its goaf side. The screening shield is in at least two parts one being an upper part and another a lower part, the parts being hingedly Connected together by a hinge means having its axis lying in the longitudinal direction of the mineral face. The upper shield part is hingedly connected to the upper or roof-engaging structure of the support. preferably by a universal joint, and the lower shield part is hingedly connected to the base or lower part of the support by a hinge having its axis transverse to the longitudinal direction of the face. Thus the screening shield is additionally pivotally movable laterally relatively to the support. In one preferred embodiment the axis of the hinge, connecting the lower screen part to the base or lower part of the screen, lies parallel tothe floor of the mine and, whenviewed from the longituidinal direction of the mineral face, is disposed approximately centr-ally of the support.
5 Claims, 1 DrawingFigure US. Patent Sept. 30,1975 3,908,389
The invention is concerned with a mine'roof support a support frame and more particularly but notessentially to a mine roof support with a multi-part flushing screening shield, the parts of which are mutually'con-' nected throughhinges with hingeaxes'lying inthe'lon gitudinal direction ofth'c face ana the upper and'lower parts of which are connected "with a roof bar'c'ohstruc tion and a'base late cfmdsupwd; wherein'the connectionwith the roof bar ctins'tiuctionat-least i's 'forrned hingedly about a 'hinge axis' lying transversely to the longitiidin aldirection of the face.
A sup'por'fof'theabove-mentioned kin'd'is described while is'hindere'd fromcertainadaptation movements.
It isa'que'stion herein particularly of adaptation movements which are requisite in-the movements parallel to the stratification between roof and'floor in the longitudinal direction of the face, in which the roof bar construction moves outward laterally from the position normal to the stratification over the base plate. The same difficulticsz'arise when the base plate inclines laterally because of the irregularities of the floor. Because of this"deficiency 'in' adaptability large loading peaks occur inthe hinges of the flushing screen whichcan 40 damage these hinges. Deformations also occur in the flushing screen itself. In addition on inclination of the props in the longitudinal direction of the face, the props of the support can impinge on the solid parts of the flushing screen so that there can also result jamming or deformations of these parts.
It is therefore an object of the invention to improve a mine roof support in such a way that the parts of the flushing screen shield and especially the hinge axes lying in the longitudinal direction of the face are protected from overloading and deformations, which can occur when the base plate is inclined laterally because of irregularities of the floor or when movements parallel to the stratification between roof and floor occur in the longitudinal direction of the face.
SUMMARY OF THE INVENTION.
According to the present invention there is provided a mine roof support, for use at a mineral face comprising a base member, extensible prop means mounted on '16'we parts of the support, said connecting means providingforadditiona] 'moveme'nt' laterally of the screening shield relatively to the support.
More specifically there is provided a mine :roof support as described in' the preceding paragraph having a multi-part flushing screen shield arranged on the goaf si deof the sup'porhhinge means mutually connecting the parts" of said screening" shield and having their'axes lying in the'lon'gitudinal direction of the face,- -hinge means connecting the upper part of the shield to the 'robf engagingstructure and having its hinge axis lying transversely tothe longitudinal direction of the mineral face, and hinge means connecting the'low'er part ofthe shield with the base member and having a hinge axis which 'he-sipar allel to the floor of the mine and transversely to'the longitudinal direction of the face and w hichg viewed from the longitudinal direction of the face is disposed approximately centrally of the'support, whereby the screening shield is pivotally movable not only in'the directionof length of the support but additi onally laterally relatively thereto.
, As a result of the hinged connection in these supports betweenthe flushing screen and the base plate of the support no transverse forces can be induced in' the hinge mechanism of the flushing screen in the tilt positionof the base plate or in moveirients parallel to the stratification between roof and floor in the longitudinal direction of the face, 'so that, deformations or damages effected through these forces ar'eavoidedi Since the flushing screen can tilt with the props in movements parallel to the stratification in the longitudinal section .of the face impact of the props on the side part of the flushing screenis no longer possible. i
- In order, afterinclination of the flushing screerfto gether with the support, to be able to alig n it again" into the normal position relative to the underpa rt of the port,, aligning devices are arranged between the props of the support on the one hand and thelbase plate or parts associated with the baseplate on the other hand ,yvhich ,serve for, swivelling of the flushing screen about the hinge between the base plate. and the underpart of the flushing screen. These aligning devices suitably have. resilient restoring elements. Alternatively the aligning devices can also have pressure-medium cylinders which serve for application of the aligning forces.
BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention by way of example is described below with reference to the drawing in which is illustrated a support frame according to the invention in side view and partial section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The support illustrated in the drawing has a base plate which is indicated by reference numeral 1. On this base plate 1 are arranged several props 2 which mutually support a roof bar construction 3. The displacement of the props 2 on the base plate 1 and on the roof bar construction 3 is flexible all round. For alignment of the props 2 aligning devices 4 are arranged on the base plate 1, which devices serve for alignment of the props 2 relative to the base plate 1. Furthermore the base plate 1 is provided with a ram 5 the reciprocatable piston rod of which acts on a face conveyor 6.
On the goaf side of the support there is provided a flushing screen which is indicated generally by reference numeral 7. The flushing screen 7 consists of two box elements 70 and 7b which are open towards the coal face and embrace with their side walls the rearward propsv 2 of the support on the flanks. The lower box element 70 is connected through hinge pins 8 with the base plate 1. The hinge pins 8 lie on a joint axis which lies parallel to the floor and transversely to the longitudinal direction of the face and seen from the longitudinal direction of the face, is disposed approximately centrally in the support. The upper box element 7b is hingedly connected, universally movable, to the roof bar construction 3 by means of a chain 9 or like connecting means. Furthermore the box elements 7a and 7b are mutually connected by guide rods 10 which hingedly engage on the side wall of the lower box element 7a and in the region of the rear wall of the upper box element 7b. The hinge axes extending through the engagement points of the guide rods 10 lie in the longi tudinal direction of the face.
As can be seen from the drawing the flushing screen shield is movable towards the support in a plane perpendicular to the floor and in the longitudinal direction of the face. Because of this the flushing screen 7 with its hinges lying in the longitudinal direction of the face no longer prevents inclination of the base plate in the longitudinal direction of the face. Also in movements parallel to the stratification between roof and floor in the longitudinal direction of the face the flushing screen can tilt correspondingly without its hinges being overloaded or that impact of the props on the side walls of the screen elements 7a and 7b needs to be feared.
In place of the hinge pins 8, used in the example, obviously other connecting means between the lower screen element and the base plate 1 can be arranged, which permit movement of the flushing screen shield 7 relative to the base plate 1 in the plane lying in the longitudinal direction of the face and vertically to the floor. For this purpose mortise-and-tenon joints with longitudinal holes can be used, which are arranged, for
example on both sides of the base plate. Likewise there can also be used as connecting means quadrilateral links or the like, the hinge axes which lie parallel to the floor and transversely to the longitudinal direction of the face. Similar connecting means can also be arranged between the upper screen element 7b and the roof bar construction 3.
We claim:
1. A mine roof support, for use at a mineral face, comprising a base member, extensible prop means mounted on said base member, a roof-engaging structure mounted on said prop means for application thereby to a roof to be supported, a multi-part flushing screen shield including upper and lower parts arranged on the goaf side of the support, first hinge means mutually connecting the parts of said screening shield and having their axes lying in the longitudinal direction of the mineral face, a flexible member connecting the upper part of the shield and the roof-engaging structure and which permits movements of the upper part of the shield about an axis lying transversely to the longitudinal direction of the mineral face, and second hinge means connecting the lower part of the shield with the base member and having a hinge axis which lies transversely to the longitudinal direction of the mineral face, whereby the screening shield is pivotally movable with respect to the support not only toward and away from the mineral face but also parallel thereto.
2. A support accordingto claim 1 wherein aligning devices are arranged between props of the support on the one hand and the base member or the parts connected with the base member on the other hand.
3. A roof support as claimed in claim 1, wherein said flexible member connecting the upper part of the shield and the roof-engaging structure is a universal hinge or joint.
4. A roof support as claimed in claim 1, wherein the hinge axis of said second hinge means when viewed from the mineral face is disposed approximately centrally of the support.
5. A roof support as claimed in claim 4 wherein the hinge axis of said second hinge means is parallel to the floor of the mine.
Claims (5)
1. A mine roof support, for use at a mineral face, comprising a base member, extensible prop means mounted on said base member, a roof-engaging structure mounted on said prop means for application thereby to a roof to be supported, a multi-part flushing screen shield including upper and lower parts arranged on the goaf side of the support, first hinge means mutually connecting the parts of said screening shield and having their axes lying in the longitudinal direction of the mineral face, a flexible member connecting the upper part of the shield and the roof-engaging structure and which permits movements of the upper part of the shield about an axis lying transversely to the longitudinal direction of the mineral face, and second hinge means connecting the lower part of the shield with the base member and having a hinge axis which lies transversely to the longitudinal direction of the mineral face, whereby the screening shield is pivotally movable with respect to the support not only toward and away from the mineral face but also parallel thereto.
2. A support according to claim 1 wherein aligning devices are arranged between pRops of the support on the one hand and the base member or the parts connected with the base member on the other hand.
3. A roof support as claimed in claim 1, wherein said flexible member connecting the upper part of the shield and the roof-engaging structure is a universal hinge or joint.
4. A roof support as claimed in claim 1, wherein the hinge axis of said second hinge means when viewed from the mineral face is disposed approximately centrally of the support.
5. A roof support as claimed in claim 4 wherein the hinge axis of said second hinge means is parallel to the floor of the mine.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US05/596,161 US3996753A (en) | 1973-02-27 | 1975-07-15 | Mine roof support |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2309670A DE2309670C2 (en) | 1973-02-27 | 1973-02-27 | Support frame with offset shielding for longwall mining in underground mining operations |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US05/596,161 Continuation-In-Part US3996753A (en) | 1973-02-27 | 1975-07-15 | Mine roof support |
Publications (1)
Publication Number | Publication Date |
---|---|
US3908389A true US3908389A (en) | 1975-09-30 |
Family
ID=5873203
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US441485*A Expired - Lifetime US3908389A (en) | 1973-02-27 | 1974-01-11 | Mine roof support |
Country Status (7)
Country | Link |
---|---|
US (1) | US3908389A (en) |
JP (1) | JPS547487B2 (en) |
CS (1) | CS202030B2 (en) |
DE (1) | DE2309670C2 (en) |
GB (1) | GB1418432A (en) |
PL (1) | PL90941B1 (en) |
ZA (1) | ZA74423B (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4041714A (en) * | 1974-11-23 | 1977-08-16 | Gullick Dobson Limited | Mine roof supports |
CN104213929A (en) * | 2014-08-21 | 2014-12-17 | 四川省华蓥山煤业股份有限公司李子垭南煤矿 | Large-inclination-angle coal bed fully-mechanized mining bracket and support method |
CN105065046A (en) * | 2015-07-13 | 2015-11-18 | 辽宁工程技术大学 | Flexible protection device between adjacent hydraulic support frames |
CN106499425A (en) * | 2016-11-19 | 2017-03-15 | 无锡市洗选设备厂 | The hydraulic prop component of sand washer |
CN106761870A (en) * | 2016-11-19 | 2017-05-31 | 无锡市洗选设备厂 | Sand washer bracket component |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2850073A1 (en) * | 1978-11-18 | 1980-05-29 | Fletcher Sutcliffe Wild Ltd | Roof support for longwall mining - has permanently loaded force applicator acting on roof beams and restoring displaced chock legs after predetermined pressure drop |
GB2136040B (en) * | 1983-03-08 | 1986-06-11 | Dobson Park Ind | Pivotal linkage of a mine roof support |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3324664A (en) * | 1964-04-03 | 1967-06-13 | Gullick Ltd | Resilient biasing device for mine roof support props |
US3483705A (en) * | 1966-04-29 | 1969-12-16 | Gullick Ltd | Mine roof supports |
US3830070A (en) * | 1971-10-02 | 1974-08-20 | Gewerk Eisenhuette Westfalia | Mine roof support assemblies |
-
1973
- 1973-02-27 DE DE2309670A patent/DE2309670C2/en not_active Expired
-
1974
- 1974-01-11 US US441485*A patent/US3908389A/en not_active Expired - Lifetime
- 1974-01-21 ZA ZA740423A patent/ZA74423B/en unknown
- 1974-01-30 GB GB423374A patent/GB1418432A/en not_active Expired
- 1974-02-05 CS CS74790A patent/CS202030B2/en unknown
- 1974-02-22 JP JP2130174A patent/JPS547487B2/ja not_active Expired
- 1974-02-25 PL PL1974169066A patent/PL90941B1/pl unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3324664A (en) * | 1964-04-03 | 1967-06-13 | Gullick Ltd | Resilient biasing device for mine roof support props |
US3483705A (en) * | 1966-04-29 | 1969-12-16 | Gullick Ltd | Mine roof supports |
US3830070A (en) * | 1971-10-02 | 1974-08-20 | Gewerk Eisenhuette Westfalia | Mine roof support assemblies |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4041714A (en) * | 1974-11-23 | 1977-08-16 | Gullick Dobson Limited | Mine roof supports |
CN104213929A (en) * | 2014-08-21 | 2014-12-17 | 四川省华蓥山煤业股份有限公司李子垭南煤矿 | Large-inclination-angle coal bed fully-mechanized mining bracket and support method |
CN105065046A (en) * | 2015-07-13 | 2015-11-18 | 辽宁工程技术大学 | Flexible protection device between adjacent hydraulic support frames |
CN105065046B (en) * | 2015-07-13 | 2017-07-18 | 辽宁工程技术大学 | Flexible protective device between a kind of adjacent frame of hydraulic support |
CN106499425A (en) * | 2016-11-19 | 2017-03-15 | 无锡市洗选设备厂 | The hydraulic prop component of sand washer |
CN106761870A (en) * | 2016-11-19 | 2017-05-31 | 无锡市洗选设备厂 | Sand washer bracket component |
Also Published As
Publication number | Publication date |
---|---|
PL90941B1 (en) | 1977-02-28 |
ZA74423B (en) | 1974-11-27 |
DE2309670B1 (en) | 1974-02-14 |
CS202030B2 (en) | 1980-12-31 |
JPS547487B2 (en) | 1979-04-07 |
JPS49117302A (en) | 1974-11-09 |
DE2309670A1 (en) | 1974-02-14 |
GB1418432A (en) | 1975-12-17 |
DE2309670C2 (en) | 1974-09-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4010618A (en) | Mine roof support | |
US3324664A (en) | Resilient biasing device for mine roof support props | |
US3908389A (en) | Mine roof support | |
US4313698A (en) | Hydraulic shield-type support | |
US3830070A (en) | Mine roof support assemblies | |
US4227833A (en) | Mineral mining installation | |
US3439508A (en) | Mine roof support means | |
US4027489A (en) | Mine roof support | |
US4132081A (en) | Mine roof support | |
US3996753A (en) | Mine roof support | |
US5238330A (en) | Displaceable mine roof support assemblies | |
US3448584A (en) | Hydraulic casing units for mine workings | |
US5178494A (en) | Roof support for underground excavations such as coal mines | |
US3932998A (en) | Mine roof support | |
US4186969A (en) | Apparatus for controlling the position of a mining machine | |
US3375668A (en) | Mine roof supports | |
US4121426A (en) | Mine roof support unit and assembly | |
US3732699A (en) | Mine roof supports | |
GB2031981A (en) | Shield-type mine roof support | |
US4492495A (en) | Roof support for use in mines | |
US4607986A (en) | Shield supports suitable for use in mines | |
US4191497A (en) | Mine roof supports | |
US4075857A (en) | Shield-type support assemblies for mine workings | |
US4231685A (en) | Roof support unit | |
US4402634A (en) | Mineral mining installation |