WO2007140159A1 - Tensionable bolt with hanger - Google Patents
Tensionable bolt with hanger Download PDFInfo
- Publication number
- WO2007140159A1 WO2007140159A1 PCT/US2007/069357 US2007069357W WO2007140159A1 WO 2007140159 A1 WO2007140159 A1 WO 2007140159A1 US 2007069357 W US2007069357 W US 2007069357W WO 2007140159 A1 WO2007140159 A1 WO 2007140159A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bolt
- nut
- mine roof
- threads
- stop
- Prior art date
Links
- 239000011347 resin Substances 0.000 claims description 14
- 229920005989 resin Polymers 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 11
- 238000003780 insertion Methods 0.000 claims 1
- 230000037431 insertion Effects 0.000 claims 1
- 238000009434 installation Methods 0.000 abstract 1
- 239000011435 rock Substances 0.000 description 11
- 238000004873 anchoring Methods 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 239000012260 resinous material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
- G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
- G06F16/23—Updating
- G06F16/2365—Ensuring data consistency and integrity
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
- E21D21/008—Anchoring or tensioning means
Definitions
- the present invention relates to a mine roof bolt anchored in a bore hole by mechanical anchoring and resin bonding.
- the roofs of mines are supported by inserting 4 to 6 feet long steel bolts into bore holes drilled into the roof.
- the bolts are then tightened to apply tension to the rock above, making the roof material more stable and supported.
- These bolts may be anchored into the rock by either a mechanical anchor with an expansion assembly at the end of the bolt or may be adhesively bonded to the rock with a resinous material. Both methods of anchoring may also be used on the same bolt.
- Mechanically anchored roof bolts typically have an expansion assembly threaded onto one end of the bolt and a drive head for rotating the bolt. Between the drive head and the mine roof, a mine roof plate is positioned to brace the bolt.
- the expansion assembly usually includes a multi-prong shell supported by a threaded ring with a plug threaded onto the end of the bolt. When the bolt is inserted into the bore hole and rotated, the plug threads downwardly and causes the multi-prong shell to expand outward. The bolt rotates until the shell is tightly engaged with the rock surrounding the bore hole.
- Bolts anchored with resin bonding material typically work by inserting a two component cartridge (one part curable resin and one part curing agent) into the blind end of the bore hole. The mine bolt is then inserted into the bore hole, rupturing the cartridge. The bolt is rotated about its longitudinal axis, shredding the cartridge and mixing the two components together. Rotation of the mine roof bolt continues until the resin fully cures, thereby bonding the bolt to the surrounding rock. Resin anchoring and mechanical anchoring may also be used in combination.
- the mine roof bolt of the present invention which includes an elongated rod having a drive end and anchored end, the drive end bearing threads, a stop in the threads and a nut threaded onto the threads, wherein the stop is positioned to prevent threading of the nut in a direction of the anchored end beyond the stop.
- the present invention also includes a method of supporting a mine roof bolt having steps of inserting a mine roof bolt into a bore hole of a mine roof, the mine roof bolt comprising an elongated rod having a drive end and an anchored end, the drive end bearing threads and a stop on the threads; threading a nut onto the threads until the nut abuts the stop; and continuing to rotate the nut such that the mine roof bolt rotates within the bore hole and is anchored therein.
- Fig. 1 is a side-elevational view of the mine roof bolt of the present invention prior to anchoring with a drive nut;
- Fig. 2 is a side-elevational view of Fig. 1, showing the mine roof bolt fully installed;
- Fig. 3 is a side-elevational view of the mine roof bolt of Fig. 2 with a hanger threaded thereon;
- Fig. 4 is a side-elevational view of the mine roof bolt of Fig. 2 with the drive nut removed and a hanger threaded thereon.
- a mine roof bolt 10 is shown placed into a bore hole 12 drilled into a rock formation 14 to support the rock formation 14 above an underground excavation site such as a mine passageway.
- the bore hole 12 is drilled to a pre-selected depth into the rock formation 14 as determined by the load bearing requirements.
- the bolt 10 includes an elongated rod 16 with an anchored end or blind end 18 to be positioned in the blind end of the bore hole 12 and a threaded drive end 20 that extends into the mine passageway from the open end of the bore hole 12.
- a roof or bearing plate 22 is placed flush with the opening of the bore hole 12 at the drive end 20.
- a nut 24 is threaded onto drive end 20.
- Drive end 20 includes a stop 26 for preventing nut 24 from threading toward blind end 18 beyond a predetermined position.
- the stop 26 is shown in Figs. 1 and 2 as being an interruption in the threads of the drive end 20. Stop 26 may be produced by machine pressing or otherwise deforming threaded end 20 such that a threaded device cannot move past the stop 26.
- the manner of producing the stop 26 and the configuration thereof is not limited, provided that stop 26 prevents movement of nut 24 across the stop 26.
- the stop 26 shown in Figs. 1 and 2 is produced by pinching opposing portions of the rod 16 at two radial locations, thereby disturbing the threads. This is not meant to be limiting as other structures for step 26 are contemplated, such as an additional component fixed to drive end 20.
- expansion assembly 28 is provided at the blind end 18 of the bolt 10.
- expansion assembly 28 includes a threaded tapered plug 30 and a multi-prong shell 32 supported by ring 34.
- the tapered plug 30 is threaded on the rod 16 into the inside of the expansion shell 32.
- Rotation of bolt 10 is accomplished by threading nut 24 upwardly on drive end 20 until nut 24 abuts stop 26. Continued rotation of nut 24 causes the entire bolt 10 to rotate.
- plug 30 threads downwardly on rod 16 and forces shell 32 to expand and engage with a surface of the
- the expansion assembly 28 may include a stop mechanism (not shown) such as disclosed in United States Patent No. 4,419,805 to Calandra, Jr., incorporated herein by reference.
- a stop device temporarily prevents expansion of the expansion shell during the stage of mixing resin with the bolt. As the resin cures, the expansion assembly 28 is prevented from rotating. Further rotation of the bolt 10 fractures the stop device, and the plug is again threaded downwardly on the rod 16 such that the expansion shell expands into gripping engagement with the rock 14 surrounding the bore hole 12.
- the drive end 20 of the rod 16 is sized and configured such that after anchoring bolt 10 in bore hole 12, a free threaded portion 40 extends beyond nut 24 and into the mine passageway.
- An internally threaded accessory or device such as a hanger 42 may be threaded onto the free threaded portion 40 of the rod 16.
- Fig. 3 shows a hanger 42 having a nut portion 44 and a J-shaped portion 46 extending therefrom, but this is not meant to be limiting as other internally threaded components may likewise be threaded onto free threaded portion 40 as desired.
- nut 24 may be removed from the bolt 10 and hanger 42 may be threaded onto free threaded portion 40.
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- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Life Sciences & Earth Sciences (AREA)
- Computer Security & Cryptography (AREA)
- Data Mining & Analysis (AREA)
- Databases & Information Systems (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Structural Engineering (AREA)
- Dowels (AREA)
Abstract
A mine roof bolt (10) is disclosed where the drive end (20) is threaded and includes a stop (26) in the threads such that a nut (24) can be used to rotate the bolt (10) along its longitudinal axis during installation. The bolt (10) also includes additional threading below the nut (24) so that an accessory can be threaded onto the drive end of the bolt.
Description
TENSIONABLE BOLT WITH HANGER CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/809,212 filed May 30, 2006, which is hereby incorporated by reference in its entirety.
BACKGROTOfP OF THE INVENTION Field of the Invention
[0002] The present invention relates to a mine roof bolt anchored in a bore hole by mechanical anchoring and resin bonding. Prior Art
[0003] Typically, the roofs of mines are supported by inserting 4 to 6 feet long steel bolts into bore holes drilled into the roof. The bolts are then tightened to apply tension to the rock above, making the roof material more stable and supported. These bolts may be anchored into the rock by either a mechanical anchor with an expansion assembly at the end of the bolt or may be adhesively bonded to the rock with a resinous material. Both methods of anchoring may also be used on the same bolt.
[0004] Mechanically anchored roof bolts typically have an expansion assembly threaded onto one end of the bolt and a drive head for rotating the bolt. Between the drive head and the mine roof, a mine roof plate is positioned to brace the bolt. The expansion assembly usually includes a multi-prong shell supported by a threaded ring with a plug threaded onto the end of the bolt. When the bolt is inserted into the bore hole and rotated, the plug threads downwardly and causes the multi-prong shell to expand outward. The bolt rotates until the shell is tightly engaged with the rock surrounding the bore hole.
[0005] Bolts anchored with resin bonding material typically work by inserting a two component cartridge (one part curable resin and one part curing agent) into the blind end of the bore hole. The mine bolt is then inserted into the bore hole, rupturing the cartridge. The bolt is rotated about its longitudinal axis, shredding the cartridge and mixing the two components together. Rotation of the mine roof bolt continues until the resin fully cures, thereby bonding the bolt to the surrounding rock. Resin anchoring and mechanical anchoring may also be used in combination.
[0006] By either method of anchoring the mine roof bolt, there is a need to be able to rotate the bolt using a drive head. However, having a drive head permanently fixed to the end of the bolt limits the functionality of the driving end of the mine roof bolt. One solution has been to thread a nut onto the mine roof bolt at the driving end and include a stop (such as an
{WQ349876.1}
interruption) in the threads below the nut to prevent the nut from coming off the bolt. In this manner, the nut can be threaded downwardly until it abuts the stop. Further rotational forces on the nut cause the bolt to rotate in one direction to mix the resin. After mixing is complete, rotation of the nut in the opposite direction tightens the nut against the bearing plate to compress the rock.
[0007] Such prior bolts not only require rotation in different directions when anchoring the bolt with a resin versus a mechanical expansion assembly, but also limit the functionality of the driving end of the bolt. The portion of the bolt below the stop is unusable for any other purpose, such as attaching accessories or holding cables. A need remains for improved functionality of the driving end of the bolt.
SUMMARY OF THE INVENTION
[0008] This need is met by the mine roof bolt of the present invention, which includes an elongated rod having a drive end and anchored end, the drive end bearing threads, a stop in the threads and a nut threaded onto the threads, wherein the stop is positioned to prevent threading of the nut in a direction of the anchored end beyond the stop. [0009] The present invention also includes a method of supporting a mine roof bolt having steps of inserting a mine roof bolt into a bore hole of a mine roof, the mine roof bolt comprising an elongated rod having a drive end and an anchored end, the drive end bearing threads and a stop on the threads; threading a nut onto the threads until the nut abuts the stop; and continuing to rotate the nut such that the mine roof bolt rotates within the bore hole and is anchored therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Fig. 1 is a side-elevational view of the mine roof bolt of the present invention prior to anchoring with a drive nut;
[0011] Fig. 2 is a side-elevational view of Fig. 1, showing the mine roof bolt fully installed;
[0012] Fig. 3 is a side-elevational view of the mine roof bolt of Fig. 2 with a hanger threaded thereon; and
[0013] Fig. 4 is a side-elevational view of the mine roof bolt of Fig. 2 with the drive nut removed and a hanger threaded thereon.
DETAILED DESCRIPTION QF THE INVENTION
[0014] A complete understanding of the present invention will be obtained from the following description taken in connection with the accompanying drawing figures, wherein like reference characters identify the parts throughout.
{W0349876.1}
[0015] For the purposes of the following description, the terms "above," "below," "top," "bottom," "vertical," "horizontal," and derivatives thereof refer to the invention as oriented in the drawing figures. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are exemplary embodiments of the invention. Specific dimensions and other physical characteristics related to the embodiments disclosed herein are not considered to be limiting.
[0016] Referring to Figs. 1 and 2, a mine roof bolt 10 is shown placed into a bore hole 12 drilled into a rock formation 14 to support the rock formation 14 above an underground excavation site such as a mine passageway. The bore hole 12 is drilled to a pre-selected depth into the rock formation 14 as determined by the load bearing requirements. [0017] The bolt 10 includes an elongated rod 16 with an anchored end or blind end 18 to be positioned in the blind end of the bore hole 12 and a threaded drive end 20 that extends into the mine passageway from the open end of the bore hole 12. A roof or bearing plate 22 is placed flush with the opening of the bore hole 12 at the drive end 20. Other components (not shown) may be included adjacent the mine roof such as a mat or a mesh. A nut 24 is threaded onto drive end 20. Drive end 20 includes a stop 26 for preventing nut 24 from threading toward blind end 18 beyond a predetermined position. The stop 26 is shown in Figs. 1 and 2 as being an interruption in the threads of the drive end 20. Stop 26 may be produced by machine pressing or otherwise deforming threaded end 20 such that a threaded device cannot move past the stop 26. The manner of producing the stop 26 and the configuration thereof is not limited, provided that stop 26 prevents movement of nut 24 across the stop 26. In one embodiment, the stop 26 shown in Figs. 1 and 2 is produced by pinching opposing portions of the rod 16 at two radial locations, thereby disturbing the threads. This is not meant to be limiting as other structures for step 26 are contemplated, such as an additional component fixed to drive end 20.
[0018] An expansion assembly 28 is provided at the blind end 18 of the bolt 10. In one non-limiting embodiment, expansion assembly 28 includes a threaded tapered plug 30 and a multi-prong shell 32 supported by ring 34. The tapered plug 30 is threaded on the rod 16 into the inside of the expansion shell 32. Rotation of bolt 10 is accomplished by threading nut 24 upwardly on drive end 20 until nut 24 abuts stop 26. Continued rotation of nut 24 causes the entire bolt 10 to rotate. Upon rotation of the bolt 10 as shown in Fig. 2 (arrow A), plug 30 threads downwardly on rod 16 and forces shell 32 to expand and engage with a surface of the
{W0349876.1}
rock formation 14. Other expansion shell assemblies that may be used in the present invention include bail type shells in which a pair of expansion leaves is supported by a bail that extends over the end of the mine roof bolt and prevents expansion of the leaves from moving axially relative to the bolt until desired. Mine roof bolt 10 may be anchored mechanically, with or without adhesive anchoring. To adhesively anchor bolt 10, a dual component cartridge 36 of resin and curing agent is inserted at the blind end 18 of the bore hole 12. The bolt 10 is pushed upward until the blind end 18 ruptures the cartridge 36 releasing the curable resin and curing agent. Rotating the bolt 10 about its longitudinal axis mixes the components of the cartridge 36 to produce a resin composition 38 that flows downwardly around the bolt 10. The expansion assembly 28 may include a stop mechanism (not shown) such as disclosed in United States Patent No. 4,419,805 to Calandra, Jr., incorporated herein by reference. Such a stop device temporarily prevents expansion of the expansion shell during the stage of mixing resin with the bolt. As the resin cures, the expansion assembly 28 is prevented from rotating. Further rotation of the bolt 10 fractures the stop device, and the plug is again threaded downwardly on the rod 16 such that the expansion shell expands into gripping engagement with the rock 14 surrounding the bore hole 12.
[0019] The drive end 20 of the rod 16 is sized and configured such that after anchoring bolt 10 in bore hole 12, a free threaded portion 40 extends beyond nut 24 and into the mine passageway. An internally threaded accessory or device such as a hanger 42 may be threaded onto the free threaded portion 40 of the rod 16. Fig. 3 shows a hanger 42 having a nut portion 44 and a J-shaped portion 46 extending therefrom, but this is not meant to be limiting as other internally threaded components may likewise be threaded onto free threaded portion 40 as desired. As shown in Fig. 4, after anchoring of bolt 10, nut 24 may be removed from the bolt 10 and hanger 42 may be threaded onto free threaded portion 40.
[0020] While the present invention has been described with reference to a particular embodiment of a mine roof bolt and a method associated therewith, those skilled in the art may make modifications and alterations to the present invention without departing from the spirit and scope of the invention. Accordingly, the foregoing detailed description is intended to be illustrative rather than restrictive. The invention is defined by the appended claim 6, and all changes to the invention that fall within the meaning and range of equivalency of the claims are embraced within their scope.
{W0349876 1}
Claims
1. A mine roof bolt comprising: an elongated rod having a drive end and an anchored end, said drive end bearing threads; a stop on said threads; and a nut threaded onto said threads, wherein said stop is positioned to prevent said nut from threading in a direction of the anchored end beyond said stop.
2. The mine roof bolt of claim 1, wherein said stop comprises an interruption in said threads.
3. The mine roof bolt of claim 2, wherein said interruption comprises a deformation of said rod.
4. The mine roof bolt of claim 1, further comprising an expansion assembly positioned on said anchored end of said rod.
5. The mine roof bolt of claim 1, further comprising a hanger threaded onto said rod, said nut being intermediate said hanger and said stop.
6. The mine roof bolt of claim 5, wherein said hanger comprises a nut portion threaded onto said rod and a J-shaped portion extending from said nut portion.
7. A method of supporting a mine roof comprising: inserting a mine' roof bolt into a bore hole of a mine roof, the mine roof bolt comprising an elongated rod having a drive end and an anchored end, the drive end bearing threads and a stop on the threads; threading a nut onto the threads until the nut abuts the stop; and continuing to rotate the nut such that the mine roof bolt rotates within the bore hole and is anchored therein.
8. The method of claim 7, further comprising threading a hanger onto the threads.
{W0349876.1}
9. The method of claim 7, further comprising threading an expansion assembly on the anchored end of the rod, wherein said step of continuing to rotate the nut causes the expansion assembly to engage with the mine roof.
10. The method of claim 9, further comprising inserting a frangible curable resin cartridge into the bore hole, wherein the resin cartridge ruptures upon insertion of the mine roof bolt and rotation of the bolt mixes the contents of the resin cartridge.
11. The method of claim 10, further comprising threading a hanger onto the threads.
12. The method of claim 11, further comprising removing the nut prior to threading the hanger onto the threads.
{W0349876.1}
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US80921206P | 2006-05-30 | 2006-05-30 | |
US60/809,212 | 2006-05-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2007140159A1 true WO2007140159A1 (en) | 2007-12-06 |
Family
ID=38519601
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2007/069357 WO2007140159A1 (en) | 2006-05-30 | 2007-05-21 | Tensionable bolt with hanger |
Country Status (1)
Country | Link |
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WO (1) | WO2007140159A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102337914A (en) * | 2011-10-28 | 2012-02-01 | 湖南科技大学 | Welding type anchor rod with dynamic and static combination |
CN111594241A (en) * | 2020-05-15 | 2020-08-28 | 浙江聚能岩土锚固研究有限公司 | Shell expansion anchor rod for soft rock and construction method thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3940941A (en) * | 1973-04-02 | 1976-03-02 | Acieries Reunies De Burbach-Eich-Dudelange S.A. Arbed | Anchor bolts for mine roofs and method for installing same |
US4678374A (en) * | 1985-12-13 | 1987-07-07 | Jennmar Corporation | Roof bolt with expansion shell and threaded nut |
US4904122A (en) * | 1987-08-06 | 1990-02-27 | Dyckerhoff & Widmann Aktiengesellschaft | Anchoring device, such as a rock anchor |
EP0376925A2 (en) * | 1986-12-30 | 1990-07-04 | Fosroc International Limited | Rock anchor element |
WO1995000744A1 (en) * | 1993-06-28 | 1995-01-05 | Jeffrey Robert Ferguson | Improvements in rock bolts |
-
2007
- 2007-05-21 WO PCT/US2007/069357 patent/WO2007140159A1/en active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3940941A (en) * | 1973-04-02 | 1976-03-02 | Acieries Reunies De Burbach-Eich-Dudelange S.A. Arbed | Anchor bolts for mine roofs and method for installing same |
US4678374A (en) * | 1985-12-13 | 1987-07-07 | Jennmar Corporation | Roof bolt with expansion shell and threaded nut |
EP0376925A2 (en) * | 1986-12-30 | 1990-07-04 | Fosroc International Limited | Rock anchor element |
US4904122A (en) * | 1987-08-06 | 1990-02-27 | Dyckerhoff & Widmann Aktiengesellschaft | Anchoring device, such as a rock anchor |
WO1995000744A1 (en) * | 1993-06-28 | 1995-01-05 | Jeffrey Robert Ferguson | Improvements in rock bolts |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102337914A (en) * | 2011-10-28 | 2012-02-01 | 湖南科技大学 | Welding type anchor rod with dynamic and static combination |
CN111594241A (en) * | 2020-05-15 | 2020-08-28 | 浙江聚能岩土锚固研究有限公司 | Shell expansion anchor rod for soft rock and construction method thereof |
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