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US4165946A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of securing a rock bolt

Assignee: SPECIALTILLVERKNINGAR BERTIL EKLUND & CO AB
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Filing: 1977-08-12
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Granted: 1979-08-28
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Expires: 1997-08-12
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Abstract

Abstract When securing a rock bolt in a drilled hole in the rock the bolt having a conical end, is inserted to the desired depth in the hole. A gun, charged with a sleeve, is applied on the outer end of the rock bolt, and the bolt is centered in the gun barrel. The sleeve is shot into the hole at a high speed to be wedged in the gap between the conical end of the bolt and the wall of the hole.

Inventors

  • 👤 Gustav S. Andersson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 11:30
CPC Classifications
E; E21; E21D; E21D21/00; E21D21/002; E21D20/00; E21D20/003

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 118 words
Method of securing a rock bolt in which the bolt, having a conical end, is inserted in a hole drilled in the rock face after which a sleeve is inserted into the hole and wedged in the gap between the conical end of the bolt and the wall of the hole, the sleeve being shot into the hole at high speed with the aid of compressed air or an explosive charge, the sleeve being inserted into the hole by means of a gun barrel applied around the outer end of the bolt, and the outer end of the bolt being centered in the gun barrel by means of a ring of soft material which is perforated upon shooting.
Claim 2
Dependent Claim 118 words
Method of securing a rock bolt in which the bolt, having a conical end, is inserted in a hole drilled in the rock face after which a sleeve is inserted into the hole and wedged in the gap between the conical end of the bolt and the wall of the hole, the sleeve being shot into the hole at high speed with the aid of compressed air or an explosive charge, the sleeve being inserted into the hole by means of a gun barrel applied around the outer end of the bolt, and the outer end of the bolt being centered in the gun barrel by means of a ring of soft material which is perforated upon shooting.
Claim 3
Independent Claim 82 words
A method of securing a rock bolt in a rock face comprising the steps of: drilling a hole having a bottom and a side wall in the rock face; inserting a conical end of a rock bolt to the bottom of the hole so that a gap is defined between the conical end and the side wall; and shooting a sleeve into the hole and along the length of the rock bolt at high speed to wedge the sleeve in the gap.
Claim 4
Independent Claim 82 words
A method of securing a rock bolt in a rock face comprising the steps of: drilling a hole having a bottom and a side wall in the rock face; inserting a conical end of a rock bolt to the bottom of the hole so that a gap is defined between the conical end and the side wall; and shooting a sleeve into the hole and along the length of the rock bolt at high speed to wedge the sleeve in the gap.
Claim 5
Dependent Claim 14 words
The method of claim 2 wherein the shooting step is accomplished using compressed air.
Claim 6
Dependent Claim 15 words
The method of claim 2 wherein the shooting step is accomplished using an explosive charge.
Claim 7
Dependent Claim 17 words
Method according to claim 2, including moving the sleeve at a speed of at least 50 m/sec.
Claim 8
Dependent Claim 32 words
Method according to claim 2, including applying a material to reduce friction, such as polytetrafluoroethylene, to at least one of the conical end of the bolt and the inside of the sleeve.

References Cited (Backward Citations)

US2813449A Cited
US2573880A Cited
US2618192A Cited
US3311012A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-08-27 1983-02-26 1983-08-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-08-27 1987-02-26 1987-08-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-08-27 1991-02-26 1991-08-28 $7700.00 Window Closed / Lapsed

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