AU1565302A - Rock bolt - Google Patents
Rock bolt Download PDFInfo
- Publication number
- AU1565302A AU1565302A AU15653/02A AU1565302A AU1565302A AU 1565302 A AU1565302 A AU 1565302A AU 15653/02 A AU15653/02 A AU 15653/02A AU 1565302 A AU1565302 A AU 1565302A AU 1565302 A AU1565302 A AU 1565302A
- Authority
- AU
- Australia
- Prior art keywords
- rock bolt
- tubular body
- sleeve
- rock
- threaded rod
- 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.)
- Granted
Links
- 239000011435 rock Substances 0.000 title claims description 120
- 239000011347 resin Substances 0.000 claims description 39
- 229920005989 resin Polymers 0.000 claims description 39
- 238000009434 installation Methods 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 6
- RGRAYPAANURBGH-UHFFFAOYSA-N OSSSSO Chemical compound OSSSSO RGRAYPAANURBGH-UHFFFAOYSA-N 0.000 claims 1
- 238000002788 crimping Methods 0.000 description 7
- 238000005065 mining Methods 0.000 description 7
- 239000003245 coal Substances 0.000 description 3
- 238000005538 encapsulation Methods 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241000219104 Cucurbitaceae Species 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 235000020354 squash Nutrition 0.000 description 1
Landscapes
- Piles And Underground Anchors (AREA)
Description
S&FRef: 584301
AUSTRALIA
PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT
ORIGINAL
0 *0 0 0 *00 *0 0 0 00 Name and Address of Applicant Actual Inventor(s): Address for Service: DYWIDAG-Systems International Pty Limited 25 Pacific Highway Bennett's Green New South Wales 2290 Australia Mieczyslaw Stanislaw Rataj Spruson Ferguson St Martins Tower,Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Rock Bolt ASSOCIATED PROVISIONAL APPLICATION DETAILS [33] Country [31] Applic. No(s) AU PR3240 [32] Application Date 20 Feb 2001 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815c ROCK BOLT Field of the Invention The present invention relates to mining equipment, and in particular relates to a rock bolt for securing the roof of a mine.
Background of the Invention A known method of installing a resin grouted rock bolt to secure the roof of an underground mine involves drilling a hole to accommodate the bolt and inserting a container of resin into the hole. The bolt is then driven into the hole to puncture the walls of the resin container and mix the resin to secure the bolt in the hole once the resin has "1 0o set.
Due to the nature of the resin being generally used, the clearance between the outer diameter of the bolt and the diameter of the hole has to be minimised to ensure proper mixing of the resin. Typically, the annulus should not be larger than 3mm. In coal mining, the annulus varies between 1.75mm and 2.0mm where standard 22mm diameter S" is bolts are used.
However, holes currently being drilled for bolt installation in hard rock mining are larger as compared to those of coal mining. The annulus in hard rock mining can vary from 5mm to 1 lmm. Therefore, in hard rock mining, a standard 22mm diameter rock S* bolt cannot be used as a resin grouted anchor because the resin does not mix properly in the larger annulus. In hard rock mining, it is not generally practical to drill smaller holes due to limitations of the type of drilling equipment in general use. That is, the annulus can generally only be reduced by using a suitable bolt.
Reduction of the annulus by use of a solid bolt of a larger diameter is not economical and is often impractical. Therefore, to improve the mixability of the resin, specifically modified bolts have been prepared, with varying levels of success.
When resin cartridge is inserted into a hole prior to insertion of a rock bolt, the resin cartridge can readily fall from the hole prior to insertion of the bolt. Accordingly, resin cartridges are typically inserted into the hole at the same time as the rock bolt, with the resin cartridge being pushed into the hole by the upper end of the rock bolt. To facilitate this process, a sleeve is often mounted on the upper end of the rock bolt so as to extend therefrom, providing a cavity within which the resin cartridge can be mounted.
The rock bolt assembly incorporating the bolt sleeve and resin cartridge can then be [R:\LIBLL] 12404specie.doc:keh:yxa:TCW readily inserted into the rock bolt hole. The sleeve, however, becomes lodged within the hole and provides a barrier preventing full encapsulation of the rock bolt in resin.
Object of the Invention It is the object of the present invention to provide an improved rock bolt and rock bolt assembly and/or at least an effective alternative to current rock bolts and rock bolt assemblies.
Summary of the Invention In one broad form the present invention provides a rock bolt comprising: a tubular body having first and second ends, said tubular body first end being lo substantially sealed; and a threaded rod extending from said tubular body second end for receiving a nut; wherein a portion of said tubular body at said second end is crimped onto said .e S"threaded rod.
Preferably, said crimped portion of said tubular body has a length of at least 100mm.
Preferably, said threaded rod is provided with an enlarged head, said enlarged head being disposed within said tubular body.
Preferably, said enlarged head is located a distance from a shoulder defined by the junction between said crimped portion of said tubular body and an adjacent uncrimped portion thereof.
Preferably, said crimped portion of said tubular body is configured such that said threaded rod is displaced relative to said crimped portion upon application of a predetermined tensile load less than the ultimate tensile strength of said tubular body and of said threaded rod.
Preferably, said predetermined tensile load is in excess of 90% of the lesser of said tubular body ultimate tensile strength and said threaded rod ultimate tensile strength.
Preferably said tubular body first end is crimped.
Preferably, said exterior surface of said tubular body is provided with generally helical deformations.
A second threaded rod may extend from said tubular body first end for receiving an expansion shell.
In another broad form the present invention provides a rock bolt assembly comprising: [R:\LIBLL] 12404specie.doc:keh:yxa:TCW a rock bolt having first and second ends, said rock bolt having a threaded portion at said second end; a sleeve having leading and trailing ends and being coaxially mounted on said rock bolt with said leading end extending beyond said rock bolt first end to define a s cavity; a resin cartridge received in said cavity; and a first detent means associated with said sleeve leading end adapted to engage a rock face about a hole in which said rock bolt is to be installed to thereby prevent said sleeve from entering said hole.
Preferably, said first detent means is in the form of a first collar coaxially mounted on said resin cartridge adjacent said sleeve leading end, said collar having a leading face adapted to engage said rock surface and a trailing face adapted to engage said sleeve leading end.
Preferably, said sleeve is readily destructable.
Preferably, said rock bolt assembly further comprises a second detent means adapted to engage said sleeve trailing end on installation of said rock bolt into said hole •e 9. and compress and/or tear said sleeve between said first and second detent means.
Preferably, said second detent means is in the form of a second collar coaxially mounted on said bolt towards said second end thereof, said second collar having a leading 99 20 face adapted to engage said sleeve trailing end and a trailing face adapted to engage a nut threaded onto said rock bolt threaded portion.
Preferably, said first collar trailing face and/or said second collar leading face is provided with an annular tapered surface adapted to tear said sleeve upon engagement therewith.
Preferably, said sleeve is formed of cardboard material.
Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Figure 1 is a fragmentary cross-sectional side elevation view of a tubular rock bolt installed in a rock roof; Figure 2 is a fragmentary cross-sectional side elevation view of an alternate tubular rock bolt installed in a rock roof; [R:\LIBLL] 12404specie.doc:keh:yxa:TCW Figure 3 is a fragmentary cross-sectional side elevation view of a further alternate tubular rock bolt installed in a rock roof; Figure 4 is a fragmentary partially cross-sectioned side elevation view of a rock bolt assembly; and Figure 5 is a fragmentary cross-sectional side elevation view of the upper portion of a further tubular rock bolt installed in a rock roof.
Detailed Description of the Preferred Embodiments With reference to Figure 1, a rock bolt 1 comprises a tubular body 2 having first and second ends 3, 4. A threaded rod 5 extends from the tubular body second end 4. A 0to portion 6 of the tubular body 2 at the second end 4 thereof is crimped onto the threaded oeooo rod 5 so as to fix the threaded rod 5 to the tubular body 2 and enable the transfer of loads, particularly tensile loads, between the two components of the rock bolt 1.
The tensile load able to be transferred between the threaded rod 5 and crimped portion 6 of the tubular body 2 will be likely determined by the length of the crimped portion 6 and the crimping force applied. Typically, the crimped portion will have a length of 100-200 mm to enable sufficient load transfer.
To improve the tensile load transfer capabilities between the threaded rod 5 and tubular body 2, the threaded rod 5 may be provided with an enlarged head 7 which is disposed at the end of the threaded rod 5 within the tubular body 2, as depicted in Figures 2 and 3. The enlarged head 7 may be provided by flattening of the rod end or by any other known means such as by screw threading the head 7 onto the rod 5. The crimping of the crimped portion 6 about the threaded rod 5 provides an annular shoulder 8 within the tubular body 2 at the junction of the crimped portion 6 and the adjacent uncrimped portion. In the rock bolt configuration depicted in Figure 2, the enlarged head 7 bears against the shoulder 8. When a tensile load is imparted on the threaded rod 5, much of this load can effectively be transferred to the tubular body 2 via the bearing of the enlarged head 7 on the tubular body shoulder 8. This load transfer reduces the length of the crimped portion 6 required to provide an effective tensile load transfer during tensioning of the rock bolt and service loads encountered in supporting the rock.
In the rock bolt configuration depicted in Figure 3, the enlarged head 7 is located a distance from the shoulder 8. With this configuration, rock burst conditions can be effectively contained. Upon the occurrence of a rock burst, which results in a sudden large tensile load being applied to the rock bolt, the crimped portion 6 can be configured [R:\LIBLL] 12404specie.doc:keh:yxa:TCW such that the crimped connection between the crimped portion 6 and the threaded rod fails such that the threaded rod 5 will be displaced relative to the crimped portion 6, effectively pulling the threaded rod 5 out of the tubular body 2. Such displacement will continue until the enlarged head 7 comes into contact with the shoulder 8. Engagement between the enlarged head 7 and shoulder 8 prevents further displacement of the threaded rod 5 and enables the tensile load to be carried by the rock bolt 1. This configuration can thus be seen to allow the rock bolt 1 to effectively yield under rock burst conditions and S. allow the immediate rock mass to move some distance to dissipate the kinetic energy within the rock whilst eventually stopping the rock movement and preventing the failure o10 of the rock containment. The yieldability of the bolt will be controlled by the length of the crimped portion 6 and the crimping force used to secure the tubular body 2 to the threaded rod 5. The force at which the crimping connection will fail should be less than the ultimate tensile strength of the tubular body 2 and of the threaded rod 5. The crimp failure load should preferably be in excess of 90% of the lesser of the ultimate tensile strength of the tubular body 2 and of the threaded rod 5 such that only excessive loads will result in yielding of the bolt.
A degree of yieldability of the rock bolt will also be exhibited if the enlarged head 7 is omitted, and the threaded rod 5 still extends into the tubular body 2 beyond the crimped portion 6. Small relative movements between the threaded rod 5 and the crimped 20 portion 6 will still result in the threaded rod 5 engaging the crimped portion 6 along the entire length of the crimped portion 6.
The tubular body first end 3 is at least substantially sealed to prevent the ingress of resin into the interior of the tubular body 2. This sealing can effectively be provided by crimping of the tubular body first end 3.
The exterior surface of the tubular body 2 is here provided with deformations 9 of a generally helical configuration which are rolled into the steel tubular body.
The rock bolt 1 is particularly suitable for use in securing the roofs of hard rock mines which typically have enlarged roof holes drilled as compared to coal mines, as discussed above. For a typical 45mm diameter hole in hard rock, the tubular body will typically have a diameter of approximately 39mm allowing for a small annular gap of approximately 3mm width.
The rock bolt 1 will typically be installed utilising a chemical anchor to secure the first end 3 thereof. Whilst the rock bolt 1 can be installed utilising a resin cartridge to provide a chemical anchor in the usual manner, a preferred rock bolt assembly mounting a [R:\LIBLL] 12404specie.doc:keh:yxa:TCW resin cartridge 104 on the rock bolt tubular body first end 3 is depicted in Figure 4. In this rock bolt assembly, a sleeve 105 having leading and trailing ends 106, 107 is coaxially mounted on the rock bolt 1 with the leading end 106 extending beyond the tubular body first end 3. A resin cartridge 104 is received in the cavity defined in the Sportion of the sleeve 105 extending beyond the tubular body first end 3. A first detent means, here in the form of a first collar 108, is associated with the sleeve leading end 106 and is sized such that, as depicted in Figure 3, it engages the rock face about a hole 100 in which the rock bolt is to be installed, thereby preventing the sleeve 105 from entering the hole. The first collar 108 is formed of plastic material and has a cylindrical tail portion to 109 which fits inside the sleeve 105 and is mounted on the resin cartridge 104. The first collar 108 has a leading face 110 which engages the rock face and a tapered trailing face 111 which engages the sleeve leading end 106.
The sleeve 105 is here formed of a readily destructible material, and in particular cardboard, such that it can be readily compressed or torn during installation, as will be described below. To assist in this regard, a second detent means in the form of a steel second collar 112 is provided on the threaded rod 5 of the rock bolt 1. The second collar 112 has a tapered leading face 113 which engages the sleeve trailing end 107 and a trailing face 114 which engages the nut 102 threaded on to the threaded rod 5. The second collar 112 also engages the mine/roof plate 103. Alternatively, the rock bolt 1 can be 20 configured such that the nut or roof plate forms the second detent means engaging the sleeve trailing end 107.
A tapered plastic cap 115 is mounted on to the leading end of the resin cartridge 104 to protect the cartridge 104 against sharp protrusions and to enable easier insertion of the rock bolt assembly into the hole 100.
During installation, a hole 100 is first drilled in the mine roof in the usual manner. The rock bolt assembly is then pushed into the hole with the plastic cap 115 leading. When the first collar 108 reaches the entrance to the hole, the first collar leading face 110 engages the rock face about the hole, preventing the sleeve 105 from entering the hole. As the rock bolt assembly is further pushed into the hole, the resin cartridge 104 is effectively extruded through the sleeve 105 as it is continued to be pushed by the rock bolt 1 whilst the sleeve 105 is held back from the hole. Once the resin cartridge 104 is entirely within the hole, there is no further need for support by the sleeve 105, with the rock bolt 1 continuing to push the resin cartridge 104 toward the top of the hole 100.
[R:\LIBLL] 12404specie.doc:keh:yxa:TCW As the rock bolt 1 extends through the now stationary sleeve 105 the tapered leading face 113 of the second collar 112 comes into engagement with the sleeve trailing end 107. Further advancement of the rock bolt 1 results in both the second collar leading tapered face 113 and the first collar trailing tapered face 111 forcibly engaging the ends of the sleeve 105. This force applied to the ends of the sleeve 105 causes the sleeve to ride up over the tapered surfaces 111, 113 of the collars 108, 112, resulting in the cardboard material of the sleeve 105 being torn, thereby destroying the sleeve. It is also envisaged that the detent means might alternately be arranged such that the cardboard sleeve is merely compressed and crushed between the detent means.
As the rock bolt 1 is still further advanced, the second collar 112 engages the cylindrical tail 109 of the first collar and squashes the same. The advancement of the second collar 112 is restrained by the roof plate 103 bearing against the rock face. The amount by which the first collar tail 109 is crushed is accordingly largely dependent upon oe• the space available between the roof plate 103 and the rock face, as depicted in Figure 3.
The destroyed cardboard sleeve 105 is also largely housed within the cavity defined between the roof plate 103 and the rock face although some shreds of cardboard may pull e away from the assembly.
Once the resin cartridge 104 reaches the top of the hole, it is punctured by the tubular body first end 3 of the rock bolt 1.
•20 The resin 101 is then mixed by rotation of the rock bolt 1, typically by rotation of the nut 102. The crimping of the tubular body first end 3 provides a flattened end portion which assists in the mixing of the resin. The helix deformations 9 formed in the exterior surface of the tubular body 2 act to pump the resin 101 toward the tubular body first end 3, assisting in the prevention of voids in the resin 101. The helical deformations 9 also provide an improved bond between the tubular body 2 and the resin 101 by way of a keying type effect.
By ensuring that the cardboard sleeve 105, which would typically have a length of the order of 1 metre as compared to the total bolt length of 2.4 metres, does not enter the hole 100, encapsulation of the bottom half of the bolt 1 in resin is not impeded. Full encapsulation provides a more effective and secure installation of the bolt enabling load transfer over the full length of the bolt 1. Whilst it is preferred that the sleeve 105 is destroyed during installation, it is envisaged that the rock bolt assembly might be arranged such that the sleeve 105 is merely ejected from the rear of the bolt during installation.
[R:\LIBLL] 12404specie.doc:keh:yxa:TCW After the resin has cured, the nut 102 and roof plate 103 assembly is tightened onto the threaded rod 5, imparting a tensile stress on the rock bolt 1 which is transferred from the threaded rod 5 to the tubular body 2 via the crimped portion 6. Tensioning of the bolt applies a compressive load which consolidates the roof material.
The sleeve and detent means arrangement described above could equally be applied to various forms of rock bolt other than the specific tubular rock bolt 1 described above.
Where it is desired to utilise a known expansion shell, comprising a wedge and leaves, in addition to the resin cartridge to assist in anchoring the rock bolt, a second threaded rod 10 may be extended from the tubular body first end 3 for receipt of the i. expansion shell 200, as depicted in Figure 5. In such a configuration, the second threaded rod 10 would typically be secured to the tubular body 2 by crimping the tubular body first end onto the second threaded rod Other possible modifications will be apparent to the person skilled in the art.
o g *o [R:\LIBLL] 124O4specie.doc:keh :yxa:TCW
Claims (19)
1. A rock bolt comprising: a tubular body having first and second ends, said tubular body first end being substantially sealed; and a threaded rod extending from said tubular body second end for receiving a nut; wherein a portion of said tubular body at said second end is crimped onto said threaded rod. V
2. The rock bolt of claim 1 wherein said crimped portion of said tubular "e body has a length of at least 100mm. oO.. 10
3. The rock bolt of either of claims 1 and 2 wherein said threaded rod extends into said tubular body beyond said crimped portion.
4. The rock bolt of any one of claims 1 to 3 wherein said threaded rod is provided with an enlarged head, said enlarged head being disposed within said tubular body. Is
5. The rock bolt of claim 4, when appended to claim 3, wherein said S. enlarged head is located a distance from a shoulder defined by the junction between said crimped portion of said tubular body and an adjacent uncrimped portion thereof.
6. The rock bolt of either of claims 3 and 5 wherein said crimped portion of said tubular body is configured such that said threaded rod is displaced relative to said e 20 crimped portion upon application of a predetermined tensile load less than the ultimate tensile strength of said tubular body and of said threaded rod.
7. The rock bolt of claim 6 wherein said predetermined tensile load is in excess of 90% of the lesser of said tubular body ultimate tensile strength and said threaded rod ultimate tensile strength.
8. The rock bolt of anyone of claims 1 to 7 wherein said tubular body first end is crimped.
9. The rock bolt of anyone of claims 1 to 8 wherein said exterior surface of said tubular body is provided with generally helical deformations.
The rock bolt of anyone of claims 1 to 9 wherein a second threaded rod extends from said tubular body first end for receiving an expansion shell.
11. A rock bolt assembly comprising: a rock bolt having first and second ends, said rock bolt having a threaded portion at said second end; [R:\LIBLL 12404specie.doc:keh:yxa:TCW a sleeve having leading and trailing ends and being coaxially mounted on said rock bolt with said leading end extending beyond said rock bolt first end to define a cavity; a resin cartridge received in said cavity; and a first detent means associated with said sleeve leading end adapted to engage a rock face about a hole in which said rock bolt is to be installed to thereby prevent said sleeve from entering said hole.
12. The rock bolt assembly of claim 11 wherein said first detent means is in the form of a first collar coaxially mounted on said resin cartridge adjacent said sleeve 1o leading end, said collar having a leading face adapted to engage said rock surface and a trailing face adapted to engage said sleeve leading end.
13. The rock bolt assembly of either of claims 11 and 12 wherein said sleeve is readily destructible.
14. The rock bolt assembly of claim 13 further comprising a second detent *0* s means adapted to engage said sleeve trailing end on installation of said rock bolt into said hole and compress and/or tear said sleeve between said first and second detent means;
15. The rock bolt assembly of claim 14 wherein said second detent means is in the form of a second collar coaxially mounted on said bolt towards said second end thereof, said second collar having a leading face adapted to engage said sleeve trailing 20 end and a trailing face adapted to engage a nut threaded onto said rock bolt threaded portion.
16. The rock bolt assembly of anyone of claims 13 to 15 wherein said first collar trailing face is provided with an annular tapered surface adapted to tear said sleeve upon engagement therewith.
17. The rock bolt assembly of claim 15 wherein said second collar, leading face is provided with an annular tapered surface adapted to tear said sleeve upon engagement therewith.
18. The rock bolt assembly of any one of claims 11 to 17 wherein said sleeve is formed of cardboard material.
19. A rock bolt substantially as hereinbefore described with reference to any one of Figures 1 to 3 or [R:\LIBLL] 12404specie.doc:keh:yxa:TCW A rock bolt assembly substantially as hereinbefore described with reference to Figure 4. DATED this Nineteenth day of February, 2002 DYWIDAG-Systems International Pty Limited Patent Attorneys for the Applicant SPRUSON FERGUSON S. I. S S S 0SeS 5* S. S OSS S S S *5 0 06 S *S@S 0SS S S SS 0* S S OSSSSO S [R:\LIBLL] l24O4specie.doc:keh:yxa:TCW
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU15653/02A AU777428B2 (en) | 2001-02-20 | 2002-02-19 | Rock bolt |
AU2004202913A AU2004202913B2 (en) | 2001-02-20 | 2004-06-29 | Rock Bolt Assembly |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPR3240A AUPR324001A0 (en) | 2001-02-20 | 2001-02-20 | Rock bolt |
AUPR3240 | 2001-02-20 | ||
AU15653/02A AU777428B2 (en) | 2001-02-20 | 2002-02-19 | Rock bolt |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU2004202913A Division AU2004202913B2 (en) | 2001-02-20 | 2004-06-29 | Rock Bolt Assembly |
Publications (2)
Publication Number | Publication Date |
---|---|
AU1565302A true AU1565302A (en) | 2002-08-22 |
AU777428B2 AU777428B2 (en) | 2004-10-14 |
Family
ID=25616103
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU15653/02A Ceased AU777428B2 (en) | 2001-02-20 | 2002-02-19 | Rock bolt |
Country Status (1)
Country | Link |
---|---|
AU (1) | AU777428B2 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007112481A1 (en) * | 2006-04-06 | 2007-10-11 | Garford Pty Ltd | A yielding rock bolt |
US7338234B2 (en) | 2004-12-20 | 2008-03-04 | Dywidag-Systems International Pty Limited | Rock bolt |
CN109356153A (en) * | 2018-10-29 | 2019-02-19 | 武大巨成结构股份有限公司 | A kind of steel disc has bushing type soil anchor bolt anchor head |
CN112302697A (en) * | 2020-10-26 | 2021-02-02 | 河南理工大学 | Large-deformation energy-absorbing tray device for early warning of roof danger and early warning method thereof |
CN112709588A (en) * | 2021-01-08 | 2021-04-27 | 中煤科工开采研究院有限公司 | Anchor agent protection component |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2019647B3 (en) * | 1986-06-24 | 1991-07-01 | Forges Et Boulonneries D'ars-Sur-Moselle | EXTENSIBLE CONTAINMENT BOLT, CONTAINMENT METHOD, USE OF THE BOLT. |
US5051038A (en) * | 1990-04-06 | 1991-09-24 | Ingersoll-Rand Company | Barrier plug for dynamic rock stabilizing fixture |
-
2002
- 2002-02-19 AU AU15653/02A patent/AU777428B2/en not_active Ceased
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7338234B2 (en) | 2004-12-20 | 2008-03-04 | Dywidag-Systems International Pty Limited | Rock bolt |
WO2007112481A1 (en) * | 2006-04-06 | 2007-10-11 | Garford Pty Ltd | A yielding rock bolt |
AU2007233555B2 (en) * | 2006-04-06 | 2011-04-28 | Garock Pty Ltd. | A yielding rock bolt |
CN109356153A (en) * | 2018-10-29 | 2019-02-19 | 武大巨成结构股份有限公司 | A kind of steel disc has bushing type soil anchor bolt anchor head |
CN112302697A (en) * | 2020-10-26 | 2021-02-02 | 河南理工大学 | Large-deformation energy-absorbing tray device for early warning of roof danger and early warning method thereof |
CN112709588A (en) * | 2021-01-08 | 2021-04-27 | 中煤科工开采研究院有限公司 | Anchor agent protection component |
Also Published As
Publication number | Publication date |
---|---|
AU777428B2 (en) | 2004-10-14 |
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Legal Events
Date | Code | Title | Description |
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DA3 | Amendments made section 104 |
Free format text: THE NATURE OF THE AMENDMENT IS: SUBSTITUTE PATENT REQUEST REGARDING ASSOCIATED DETAILS |