AU738529B3

AU738529B3 - Cable Bolt

Info

Publication number: AU738529B3
Application number: AU71702/00A
Authority: AU
Inventors: Mietek Rataj
Original assignee: Ani Corp Ltd
Current assignee: DSI Underground Australia Pty Ltd
Priority date: 1998-01-13
Filing date: 2000-11-20
Publication date: 2001-09-20
Anticipated expiration: 2002-09-20
Also published as: AU7170200A

Description

S&F Ref: 444380D1

AUSTRALIA

PATENTS ACT 1990 DIVISIONAL PETTY PATENT SPECIFICATION

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: The ANI Corporation Limited Level 5, Merlin Centre 235 Pyrmont Street Pyrmont NSW 2009 Australia Mietek Rataj Spruson Ferguson St Martins Tower 31 Market Street Sydney NSW 2000 Cable Bolt The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5844c CABLE BOLT Field of the Invention The following invention relates to cable bolts and their method of installation.

More particularly, though not exclusively, the invention relates to a cable bolt having an attachment extending from one end thereof, which attachment is adapted to be engaged by a tool used for turning the cable bolt for mixing of resin in a borehole of a rock formation. The invention also relates to a cable bolt having an angled end shaped to interact with a mating turning implement.

Cable bolts traditionally have been installed in a rock formation by cement grouting. In this method, the cable is pushed into a pre-drilled hole and the cement grout is pumped into the hole to anchor the cable.

Faster methods of cable bolt installation are currently being developed. These methods are similar to methods used for installation of solid bolts where the bolt is anchored by a resin grout.

In this method, a resin cartridge containing two components of which one is a hardener, is inserted into the pre-drilled hole in the rock formation prior to insertion of the cable bolt. Forcing the cable into the borehole while simultaneously rotating the cable ruptures the resin cartridge or cartridges and mixes the resin components within the annulus between the bolt and the borehole wall.

In order to rotate a cable for resin mixing, some attachment is required to engage the cable with a rotating tool such as a spanner.

Known prior art methods employed a special fitting having a hexagonal barrel and a plug. The barrel has an internally tapered funnel-shaped bore therethrough and a 25 tapered plug having a frusto-conical outer surface that engages the funnel-shaped inner oe oI surface of the drive barrel. The tapered plug has an internal bore concentric with the outer frusto-conical surface and fits over the cable. The hexagonal head drive barrel provides a rigid head for the cable bolt allowing engagement by a spanner. An example of such an arrangement is shown in Australian Patent No. AU-A-50708/96.

Another method of coupling the cable with the rotating tool is described in US Patent No. 5,511,909. The fitting of this reference includes a barrel and plug as described above, although the end portions of the plug members extend out of the barrel. These protrusions being of square or hexagonal shape engage with the rotating spanner.

Another method of rotating a cable bolt in order to mix the resin is disclosed in Australian Patent No. 668515. In this reference, the cable is threaded and a standard nut [R:\LIBLL]08438.doc:Izg i is screwed onto the cable in much the same way as a nut is threadably engaged with a solid bolt.

All of the above described methods are relatively expensive due to the requirement of machining of the hexagonal shaped barrel or plug segments with special protrusions or threading of the cable.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

Disclosure of the Invention There is disclosed herein a cable bolt having a cable with a longitudinal axis, said cable bolt being provided with an engagement means at one end of said cable, said engagement means defining an engagement face for engagement with a tool to effect rotation of said cable bolt about said axis, wherein said engagement means does not protrude laterally beyond said cable at said one end.

Preferably, said engagement means is in the form of an attachment having a noncircular cross-section, said attachment being welded to said one end of said cable and defining a plurality of said engagement faces.

Preferably, said attachment has a square cross section defining four said engagement faces.

Brief Description of the Drawings i" ~Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a schematic perspective view of a cable bolt having an attachment welded to one end thereof, and Fig. 2 is a schematic perspective view of a cable bolt having a slanted surface formed in one end thereof.

Description of the Preferred Embodiments In Fig. 1 of the accompanying drawings there is schematically depicted an end •portion of a cable bolt. This is the end portion which protrudes from a pre-drilled hole in a rock structure when used. That is, it is the end of the cable remote from the end which pierces the resin grout capsule. A square shaped section 1 is attached to the cable as shown, typically by means of welding 3. The transverse maximum dimension of the attachment 1 is smaller than the outside diameter of the cable 2 so as to allow for easy installation of a barrel and wedges.

[R:\LIBLL]08438.doc:Izg The fact that the attachment 1 does not protrude beyond the perimeter of the cable 2 enables pre-tensioning equipment which can only be used on a cable with no protrusions to be used.

The installation spanner (not shown) will have a socket with a square aperture to engage with the square attachment in order to rotate the cable. Of course, the attachment 1 could be any non-circular shape such as hexagonal.

A further embodiment of the invention is depicted in Fig. 2. In this embodiment, the cable bolt 2 has a slanted end 4 which extends at an angle which is typically in the range of 300 to 600 from the direction of extent of the cable bolt 2. The flat surface of the 1o slanted end 4 is adapted to match with a similarly angled surface in a spanner having a corresponding recess to enable engagement between the cable and the spanner sufficient to enable rotation of the cable by rotation of the spanner so as to mix the resin components at the other end of the cable bolt. The slanted end 4 may be reinforced by welding of the flat face 4.

is It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.

S. For example, a pair of oppositely disposed tapered surfaces 4 might be provided in the end of the cable bolt 2 rather than a single face 4.

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Claims

1. A cable bolt having a cable with a longitudinal axis, said cable bolt being provided with an engagement means at one end of said cable, said engagement means defining an engagement face for engagement with a tool to effect rotation of said cable bolt about said axis, wherein said engagement means does not protrude laterally beyond said cable at said one end.

2. The cable bolt of claim 1, wherein said engagement means is in the form of an attachment having a non-circular cross-section, said attachment being welded to said one end of said cable and defining a plurality of said engagement faces.

3. The cable bolt of claim 2, wherein said attachment has a square cross section defining four said engagement faces. Dated 20 November, 2000 The ANI Corporation Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON i [R:\LIBLL]08438.doc:lzg