US4056036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Borehole anchor
Assignee: Bergwerksverband GmbH
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Filing: 1976-03-17
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Granted: 1977-11-01
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Expires: 1996-03-17
Abstract
Abstract An anchor assembly or rockbolt for mounting in a borehole in a rock comprises an outer element which is secured proximal to the mouth of the borehole and an inner element which is secured well inside the borehole. The inner and outer elements are connected together in such a manner as to allow mutual limited shifting thereof without disconnection only on stressing of one of the elements relative to the other beyond a predetermined limit. To this end the outer element may be provided with a piston-like inner end that is slidable against a friction coating within a tubular inner element. It is also possible to form the inner and outer elements as separable tube sections interconnected by means of a central rod having a pair of pistons each received in a respective one of the sections and slidable therein on a tight friction lining thereof.
Inventors
- 👤 Gunther Kamann
- 👤 Jurgen Krahe
- 👤 Ulf Zischinsky
- 👤 Wilhelm Gotze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:39
CPC Classifications
E; E21; E21D; E21D20/00; E21D20/02; E21D20/021; E02; E02D; E02D5/00; E02D5/74; E02D5/80; E21D21/00; E21D21/0026; E21D21/0033
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
166 words
An anchor assembly for mounting in a borehole in a rock, said assembly comprising: an outer element defining an axis; means for securing said outer element proximal to the mouth of said borehole; an inner element limitedly axially displaceable relatively to said outer element through a predetermined axial distance; means for securing said inner element in said borehole distal from the mouth of said borehole; a friction surface on one of said elements having a predetermined axial length equal at least to said axial distance; a friction surface on the other of said elements transversely engageable with said surface of said one element and displaceable axially therealong through said distance; and means pressing said surface of said other element transversely against said surface of said one element with a predetermined constant force for interconnecting said inner and outer elements and allowing limited mutual axial shifting thereof through said distance without disconnection only on axial stressing of said elements relative to each other beyond a predetermined limit.
Claim 2
Dependent Claim
166 words
An anchor assembly for mounting in a borehole in a rock, said assembly comprising: an outer element defining an axis; means for securing said outer element proximal to the mouth of said borehole; an inner element limitedly axially displaceable relatively to said outer element through a predetermined axial distance; means for securing said inner element in said borehole distal from the mouth of said borehole; a friction surface on one of said elements having a predetermined axial length equal at least to said axial distance; a friction surface on the other of said elements transversely engageable with said surface of said one element and displaceable axially therealong through said distance; and means pressing said surface of said other element transversely against said surface of said one element with a predetermined constant force for interconnecting said inner and outer elements and allowing limited mutual axial shifting thereof through said distance without disconnection only on axial stressing of said elements relative to each other beyond a predetermined limit.
Claim 3
Dependent Claim
33 words
The assembly defined in claim 1 wherein said means for securing said inner element in said borehole is a mass of adhesive between said inner element and the interior wall of said borehole.
Claim 4
Dependent Claim
26 words
The assembly defined in claim 2, further comprising means rotationally linking said inner and outer elements, whereby rotation of said outer element turns said inner element.
Claim 5
Dependent Claim
22 words
The assembly defined in claim 2 wherein said surfaces are slidably displaceable relative to one another on such stressing along said axis.
Claim 6
Dependent Claim
36 words
The assembly defined in claim 4 wherein said one element frictionally engages said other element, whereby said elements can only shift relative to one another when stressed with a force overcoming the frictional force between them.
Claim 7
Dependent Claim
39 words
The assembly defined in claim 5 wherein said inner element is formed as a sleeve bedded in said mass of adhesive in said borehole, said outer element being a rod lying on said axis and concentric with said sleeve.
Claim 8
Dependent Claim
39 words
The assembly defined in claim 6 wherein said rod has an inner end provided with a cylindrical body constituting the interconnecting means and frictionally radially engaging the inner wall of said sleeve constituting said surface of said inner element.
Claim 9
Dependent Claim
46 words
The assembly defined in claim 7, wherein said interconnecting means includes a friction lining on said inner wall constituting the respective friction surfaces between same and the outer surface of said cylindrical body carried on said rod, said outer surface constituting said the other friction surface.
Claim 10
Dependent Claim
27 words
The assembly defined in claim 6 wherein said rod has a flared inner end constituting the interconnecting means and engageable with the inner wall of said sleeve.
Claim 11
Dependent Claim
49 words
The assembly defined in claim 5 wherein each of said elements is a rod lying on said axis and having an axial extension with a surface lying against the corresponding surface of the other extension, the interconnecting means including means for pressing said surfaces together transversely to said axis.
Claim 12
Dependent Claim
19 words
The assembly defined in claim 10 wherein said means for pressing includes at least one ring surrounding said projections.
Claim 13
Dependent Claim
40 words
The assembly defined in claim 11 wherein said means for pressing includes two such rings and each of said extensions is formed with a laterally projecting abutment engageable with a respective ring for limiting relative axial displacement of said rods.
Claim 14
Dependent Claim
24 words
The assembly defined in claim 11 wherein said extensions are semicylindrical and have relative to the respective rods flat diametrical faces constituting said surfaces.
Claim 15
Dependent Claim
34 words
The assembly defined in claim 5 wherein said elements are coaxial and abutting tube sections, said assembly further comprising a connecting element constituting the interconnecting means and lying within and frictionally interconnecting said sections.
Claim 16
Dependent Claim
36 words
The assembly defined in claim 14 wherein said tube sections are generally cylindrical and said connecting element is a rod having a pair of end portions each slidable piston-fashion within a respective one of said sections.
Claim 17
Dependent Claim
26 words
The assembly defined in claim 15 wherein said tube sections are both part of a common integral tube having a weakened waist section defining said sections.
Claim 18
Dependent Claim
34 words
The assembly defined in claim 16, wherein said tube has an outer end provided with a cover cap and an inner end provided with a cover plate preventing entry of liquid into said tube.
Claim 19
Dependent Claim
21 words
The assembly defined in claim 5, further comprising a polygonal projection on said outer element permitting rotation thereof about said axis.
Claim 20
Dependent Claim
35 words
The assembly defined in claim 5, further comprising a cutting tip on the inner end of said inner element, whereby rotation of said assembly allows said tip to bore into said adhesive before hardening thereof.
Claim 21
Dependent Claim
45 words
The assembly defined in claim 5 wherein said rod has an inner end provided with a body having a frustoconical upper portion tapering toward the mouth of said borehole and constituting the interconnecting means, said body frictionally radially engaging the inner wall of said sleeve.
Claim 22
Dependent Claim
26 words
The assembly defined in claim 1 wherein said means includes a body fixed between said elements and adapted to shear on mutual displacement of said elements.
Claim 23
Dependent Claim
34 words
The assembly defined in claim 1, further comprising means for inhibiting displacement of said elements relative to each other beyond said axial distance even when stressed with an axial force exceeding said predetermined limit.
References Cited (Backward Citations)
US1645903A
Cited
US2615373A
Cited
FR1268624A
Cited
US3298273A
Cited
DE2349659A1
Cited
US3877235A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-31 | 1981-05-02 | 1981-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-31 | 1985-05-02 | 1985-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-31 | 1989-05-02 | 1989-11-01 | $7700.00 | Window Closed / Lapsed |