EP0130770A2 - Etançon télescopique de mine - Google Patents

Etançon télescopique de mine Download PDF

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Publication number
EP0130770A2
EP0130770A2 EP84304291A EP84304291A EP0130770A2 EP 0130770 A2 EP0130770 A2 EP 0130770A2 EP 84304291 A EP84304291 A EP 84304291A EP 84304291 A EP84304291 A EP 84304291A EP 0130770 A2 EP0130770 A2 EP 0130770A2
Authority
EP
European Patent Office
Prior art keywords
mine support
planar surfaces
timber
sleeve
support
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.)
Withdrawn
Application number
EP84304291A
Other languages
German (de)
English (en)
Other versions
EP0130770A3 (fr
Inventor
Dirk Cornelius Stephanus Venter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BESTOBELL SOUTH AFRICA Ltd
Original Assignee
BESTOBELL SOUTH AFRICA Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by BESTOBELL SOUTH AFRICA Ltd filed Critical BESTOBELL SOUTH AFRICA Ltd
Publication of EP0130770A2 publication Critical patent/EP0130770A2/fr
Publication of EP0130770A3 publication Critical patent/EP0130770A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • 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

Definitions

  • THIS INVENTION relates to an elongate mine support used for supporting mine hanging walls relative to their footwalls.
  • a great variety of such mine supports are known, and more particularly this invention relates to a mine support which is constituted primarily of timber and has a yieldable characteristic when placed under axial load.
  • ThQ pattorn of removal of wood is subject to great variations, with equal variety in effectivity.
  • One mine support which is widely used comprises a length of timber with a relatively heavy gauge metal sleeve therearound with timber protruding from both ends of the sioeve.
  • This subbert. commoulyknown as a "pipe stick” has no wood removed for collapsibility, and relies on the axial deformation of the sleeve to provide control of the collapsing wood fibres whilst maintaining axial rigidity.
  • a mine support comprising a timber load supporting element having approximately planar longitudinally extending surfaces spaced circumferentially therearound, there being circumferential reinforcing means around the element adapted for restraining, when the element is under axial load, timber expansion transverse to the element length, the reinforcing means being received against the timber between the adjacent planar surfaces substantially without being in contact with the surfaces themselves.
  • a feature of the invention provides for the planar surfaces to taper from a shallowest portion where they meet the circumferential surface of the element, to a deepest portion at one element end. Preferably the location of the shallowest portion is removed from one element end and at the deepest portion the adjacent edges of the planar surfaces meet on the said cylindrical circumference.
  • the cross-sectional shape and area of the element is uniform along its length, and the planar surfaces are uniformly shaped and spaced equally around the circumference. There is also provided for there to be either five or six planar surfaces.
  • the reinforcing means is preferably a metal sleeve having a wall thickness of between 1,2 and 3mm.
  • the metal is a steel having at least one of the following characteristics is cold rolled sheeting having a yield stress of roughly 230 MPa; has a tensile strength of approximately 320 MPa; and, has an elongation of between 37% and 43%.
  • the metal sleeve to have at least one indentation extending at least part way around the circumference of the sleeve, the indentation being adapted to cause a weakness in the metal to allow collapse of the metal substantially at this position when the mine support is collapsing under axial load.
  • the indentations can be circumferential and spaced apart along the sleeve, or can be in the form of a spiral formation having a slight pitch.
  • the indentations optionally can also be formed by circumferential rings which have an outwardly extending semi-circular cross-sectional shape, the rings being spaced apart at least part way along the length of the suppport.
  • a timber load supporting element 1 is produced by rounding a rough timber pole, and then removing wood to form longitudinally extending planar surfaces 2.
  • the pole is inserted in a metal sleeve 6 which extends to cover the length of the planar surfaces.
  • the planar surfaces do not extend laterally sufficiently to reduce the radius of the timber between adjacent surfaces, so that the sleeve is in contact with the circumference of the timber pole at all positions other then those lying on a planar surface.
  • the metal sleeve is made from cold rolled steel sheeting having a wall thickness of 2,4mm, a yield strength of approximately 230 MPa, a tensile strength of approximately 320MPa and an elongation of 37 to 43%.
  • the carbon content of the steel is less than between 0.04and 0.08%.
  • a wall thickness range of between 1,2 and 3 mm can be used with appropriate variations in performance.
  • Such sleaving is commercially available in the Republic of South Africa, where it is used as piping for conveyance of agricultural water supply.
  • the sleeve is formed further however to have circumferential rings 8 therearound, spaced apart from the end 5 to extend partway along the length.
  • rings 8 are provided, having outwardly projecting semi-circular cross sectional shapes, which are formed by any suitable method, but can be conveniently formed by deforming the supported sleeve radially outwardly with a turning tool.
  • the support In use, the support is located between a mine hanging and footwall and, under axial compression, the void between the planar surfaces and the surrounding metal sleeve allows for timber fibre expansion into these voids thus causing a controlled collapse of the timber under axial load.
  • the timber commences its disintergration in this manner at the end where the planar surfaces are deepest, since this is the weakest portion of the element.
  • the relatively thin gauge of the steel sleeve permits axial deformation thereof and also assists in controlling the collapse of the aupport, whilst still giving effective transverse support to the wood fibres.
  • the axial rigidity of the prop it is speculated, is maintained since the longitudinal portions of the timber between the planar surfaces are maintained along the length of the support and the periphery thereof, which is not the case in prior art patterns of removal of wood fibre, where a conical or other sharpened end taper is created.
  • the rings on the sleeve assist in allowing the metal sleeve to collapse axially in a concertina-like manner and thus also permit the sleeve to deform axially in controlled manner, without inviting excessive deformation of the sleeve by outward or inward buckling or bulging.
  • a mine support 9 comprisos a length of timbor pole 10 which is of a uniform hexagonal cross-sectional shape, having a metal sleeve 11 therearound which extends from one end and stops short of the other end of the timber pole.
  • the sleeve fits against the longitudinal corners of the intersections of the planes of the planar surfaces forming the polygonal shape.
  • the metal sleeve has an indentation 12 therein extending from the one end a short distance up towards the middle thereof.
  • the indentation is formed by a turning process in which a tool is held against the supported sleeve to cause a groove to be marked in a spiral manner around the tube, to define a spiral wound set of bulges between the grooves.
  • a still further embodiment which comprises a timber pole 13 of uniform hexagonal cross-sectional shape being surrounded by a metal sleeve 14 for the full length of the timber.
  • the sleeve is in contact with the corners of the hexagonal shape.
  • the sleeve has rings 15 at both ends thereof which are formed by circumferential indentations or grooves spaced apart from each sleeve end. The indentations are formed also by a turning process.
  • Figures 6 and 7 show, by way of illustration of the scope of the invention, alternative configurations of planar surfaces for timber elements.
  • Figure 6 shows a tapering triangular cross-sectional shape with the element surface at the position of deepest taper between the planar surfaces being fairly wide, to compensate for the greater amount of timber removed for the planar surfaces than is the case with say the hexagonal shape.
  • the rounded sections of original circumference are used to support a metal sleeve or other circumferential reinforcing member.
  • Figure 7 shows the original circumference of a timber pole with four irregularly placed planar surfaces.
  • the indentations in the sleeve of the embodiments of Figures 4 and 5 assist with the controlled axial collapse of the sleeve by provoking a concertinaring and wrinkling deformation rather than bulges or tearing.
  • the indentations of the embodiments of Figures 4 and 5 for timber of 154mm diameter from corner to opposing corner, should have a spacing of greater than 20mm. Narrower spacing is inclinded to cause too rapid and uncontrolled deformation of the sleeve.
  • the hexagonal shape has been found to provide sufficient longitudinal rigidity along the corners of the hexagonal yet also sufficient void between the planar surfaces and the surrounding sleeve sleeve to provide for wood fibre deformation under axial compression.
  • planar surfaces on the timber element can vary widely and can be varied to obtain a desired yield characteristic. The more timber that is removed the less resistance to compression the support will have, but the yieldability is likely to be better. A balance has to be obtained, for a desired yield characteristic, between providing void space for timber fibre expansion without unduly weakening the support, and maintaining a suitable longitudinal rigidity by providing a number of longitudinal timber areas between planar surfaces which retain the full radial measurement of the timber along their lengths.
  • the planar surfaces can be of other regular geometric figures or can be irregular, and the extent of the timber left between planar surfaces can vary.
  • the reinforcing means can be wound over the pole, can be a strip or band, and need not be metal.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Rod-Shaped Construction Members (AREA)
  • Forms Removed On Construction Sites Or Auxiliary Members Thereof (AREA)
EP84304291A 1983-06-24 1984-06-25 Etançon télescopique de mine Withdrawn EP0130770A3 (fr)

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
ZA834619 1983-06-24
ZA834618 1983-06-24
ZA834618 1983-06-24
ZA834619 1983-06-24
ZA837625 1983-10-13
ZA837625 1983-10-13
ZA837657 1983-10-14
ZA837657 1983-10-14
ZA838465 1983-11-14
ZA838465 1983-11-14
ZA840824 1984-02-03
ZA84824 1984-02-03

Publications (2)

Publication Number Publication Date
EP0130770A2 true EP0130770A2 (fr) 1985-01-09
EP0130770A3 EP0130770A3 (fr) 1986-05-14

Family

ID=27560364

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84304291A Withdrawn EP0130770A3 (fr) 1983-06-24 1984-06-25 Etançon télescopique de mine

Country Status (3)

Country Link
EP (1) EP0130770A3 (fr)
CA (1) CA1218534A (fr)
ZW (1) ZW9984A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103133020A (zh) * 2011-11-28 2013-06-05 美康公司 嵌套的矿井顶部支承件

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642603A (en) * 1926-06-03 1927-09-13 Martin J Conway Reenforced mine prop
DE1088905B (de) * 1958-12-02 1960-09-15 Rheinstahl Gmbh Wanheim Verfahren zur Herstellung konischer zylindrischer Innenstempel
EP0028496A1 (fr) * 1979-11-02 1981-05-13 Mine Support Systems (Proprietary) Limited Etancon en bois
GB2077808A (en) * 1980-05-09 1981-12-23 Longwall Mining Equipment Prop Improvements in props
GB2080364A (en) * 1980-07-22 1982-02-03 Hunt Leuchars & Hepburn Ltd Mine support prop
GB2081340A (en) * 1980-07-22 1982-02-17 Brown Allan Henry George Deformable mine prop
GB2096203A (en) * 1981-04-08 1982-10-13 Longwall Mining Equipment Prop Mine support

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1642603A (en) * 1926-06-03 1927-09-13 Martin J Conway Reenforced mine prop
DE1088905B (de) * 1958-12-02 1960-09-15 Rheinstahl Gmbh Wanheim Verfahren zur Herstellung konischer zylindrischer Innenstempel
EP0028496A1 (fr) * 1979-11-02 1981-05-13 Mine Support Systems (Proprietary) Limited Etancon en bois
GB2077808A (en) * 1980-05-09 1981-12-23 Longwall Mining Equipment Prop Improvements in props
GB2080364A (en) * 1980-07-22 1982-02-03 Hunt Leuchars & Hepburn Ltd Mine support prop
GB2081340A (en) * 1980-07-22 1982-02-17 Brown Allan Henry George Deformable mine prop
GB2096203A (en) * 1981-04-08 1982-10-13 Longwall Mining Equipment Prop Mine support

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103133020A (zh) * 2011-11-28 2013-06-05 美康公司 嵌套的矿井顶部支承件

Also Published As

Publication number Publication date
EP0130770A3 (fr) 1986-05-14
CA1218534A (fr) 1987-03-03
ZW9984A1 (en) 1984-09-19

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Effective date: 19870102

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Inventor name: VENTER, DIRK CORNELIUS STEPHANUS