AU747891B2

AU747891B2 - Laminated mesh sheeting

Info

Publication number: AU747891B2
Application number: AU44468/99A
Authority: AU
Inventors: John William McLaughlin
Original assignee: SOUTHERN WIRE Pty Ltd
Current assignee: SOUTHERN WIRE Pty Ltd
Priority date: 1998-08-27
Filing date: 1999-08-12
Publication date: 2002-05-30
Anticipated expiration: 2019-08-12
Also published as: AU4446899A

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT

S

Name of Applicant: Actual Inventor Address for service is: Southern Wire Pty Ltd John William McLaughlin WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Laminated Mesh Sheeting" Details of Associated Provisional Application No(s): PP5525 The following statement is a full description of this invention, including the best method of performing it known to me:- -2-

TITLE

"LAMINATED MESH SHEETING" FIELD OF THE INVENTION The present invention relates to a laminated mesh sheeting. More particularly, the laminated mesh sheeting of the present invention is in one form intended for use in mining applications requiring ground support.

BACKGROUND OF THE INVENTION Presently, welded mesh products are utilised in underground mining applications in which it is required to prevent rock falls, for example underground passages or e.oo: 10 drives. A typical installation involves placing a series of sheets of welded steel 0. mesh arranged to overlap at their edges, against the walls and roof of a drive using the lifting frame of a rock-bolting machine, rock-bolting these sheets into position and spraying thereover with "shotcrete", a sprayable concrete product.

The welded steel mesh sheet utilised typically has a 100 mm x 100 mm aperture 15 and is formed from 4 5 mm wire. Sheet sizes are typically 2.4 m x 3 m, although °0 longer sheets have been known to be used in special instances.

The above described process requires the mesh sheet to be relatively stiff. This stiffness allows it to retain its shape on the lifting frame during lifting and rockbolting. However, this does not allow the mesh sheet to follow the contours of the rock face and consequently decreases the effectiveness of the rock-bolting and shotcreting process, and requiring greater amounts of shotcrete. Still further, the standard welded mesh sheet does not provide particularly good shotcrete adhesion, the intersection points or nodes of the mesh being relatively infrequent and also not providing good binding characteristics.

-3- The laminated mesh sheeting of the present invention has as one object thereof to overcome the above problems associated with the prior art, or at least to provide an effective alternative thereto.

The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a laminated mesh 15 sheeting comprising at least two sheets of chainwire or chainlink mesh arranged so as to have their planar surfaces laying substantially adjacent each other, and such that the interwoven wires forming each sheet are offset with respect to the 0% e longitudinal orientation of those wires in the adjacent sheet or sheets, wherein the at least two sheets are fastened together.

el .;i 20 Preferably, the sheets comprising the laminated mesh sheeting are fastened together at intervals about a periphery thereof. Additional fastening may be provided at intervals across the adjacent planar surfaces of the sheets.

Still preferably, the offset in the orientation of the adjacent sheets is at or near 900.

In accordance with the present invention there is further provided a method for R, supporting a surface, the method comprising the steps of: 3/1 preparing a laminated mesh sheeting by overlaying two or more sheets of chainwire or chainlink mesh in an offset manner; positioning the laminated mesh sheeting or chainlink against a surface to be supported; 9 9 9 9 99 9** -4fastening the laminated mesh sheeting to the surface; and coating the surface and ground support with a sprayable binding product.

Preferably, the offset in the orientation of the two sheets of chainwire mesh is at or near 900 BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example only, with reference to one embodiment thereof and the accompanying drawings, in which:- S.Figures l(a) and each show a partial plan view of a single sheet of chainwire mesh, the combination showing how such are offset to provide the laminated mesh sheeting of the present invention; and Figure 2 is a partial plan view of a laminated mesh sheeting in accordance with the present invention.

DESCRIPTION

In Figure 1 there is shown a portion of a chainwire mesh sheet 10, the mesh 15 sheet 10 comprising mesh links 12, which are each in turn defined by neighbouring elongate elements 14 that extend longitudinally through the sheet The elongate elements 14 are interwoven at nodes 15 with their adjacent elongate elements 14 to form the mesh sheet 10 in known manner. Arrows 16 indicate generally the direction of orientation of the elongate elements 14 within the sheet In Figure l(b) there is shown a portion of a chainwire mesh sheet 18, the mesh sheet 18 comprising mesh links 20, which are each in turn defined by neighbouring elongate elements 22 that extend longitudinally through the sheet The elongate elements 22 are interwoven at nodes 23 with their adjacent elongate elements 22 to form the mesh sheet 18 in known manner. Arrows 24 indicate generally the direction of orientation of the elongate elements 22 within the sheet 18.

In Figure 2 there is shown a laminated mesh sheeting 26 in accordance with the present invention, the sheeting 26 comprising the mesh sheets 10 and 18, of Figures 1(a) and respectively overlain together such that the elongate elements 14 and 22 forming each are oriented in an offset manner. Preferably, this offset is at or near 900 as shown in Figures 1(a) and However, it is to be understood that this offset need be present only in an amount that provides a level of stability or stiffness to the laminated mesh sheeting in both lateral and longitudinal directions with respect thereof. In this arrangement, one substantially planar face of each sheet 10 and 18 lays adjacent the other.

The mesh sheets 10 and 18 are provided with a plurality of fastening means interconnecting same about the periphery of the laminated ground support and preferably also at points spaced over the surface thereof. It is envisaged that the fastening means may comprise any suitable form and may include commercially ~available fasteners, clips, tape, tie wire or even welds. The fastening means contribute to the working of the invention particularly as the laminated mesh sheeting is positioned adjacent a surface and their role thereafter is minimal.

In use as a ground support, the laminated mesh sheeting 26 of Figure 2 is positioned on a lifting frame (not shown) of known type and held in position against a rock surface (not shown). Rock bolting is then conducted in known manner to positively locate the laminated mesh sheeting 26 against the surface.

This process is repeated with a number of laminated mesh sheets forming an overlapping pattern across the rock surface. Shotcrete or its equivalent is then applied, by spraying, over the laminated mesh sheets.

The chainwire mesh sheets 10 and 18 of the present invention provide advantages over prior art mesh in that adhesion for Shotcrete is improved through A the nodes of intersection, 15 and 23, of the elongate members 14 and 22. The laminated mesh sheeting is more easily moulded to conform to the contours of the rock surface due to its flexible nature when compared with prior art mesh. This is expected to reduce the volume of Shotcrete required, thereby speeding up the process and reducing costs.

Whilst the laminated mesh sheeting 26 of the present invention is sufficiently stiff or resistant to hold its shape on the known lifting frame, this can not be said of a single sheet of chainwire mesh. Such tends to flop or sag over the edges of the lifting frame and is consequently difficult to utilise for this purpose.

Accordingly, the laminated mesh sheeting 26 of the present invention provides advantages above simple chainwire mesh sheets and wire mesh sheets when used as a ground support.

It is envisaged that the laminated ground support of the present invention may be used in applications that do not also require the use of Shotcrete.

•It is further envisaged that the chainwire mesh sheets 10 and 18 of the present invention may comprise differing diameter wire. For example, sheet 10 may be formed of 4 mm wire whilst sheet 18 may be formed of 2.5 mm wire. The subsequent laminated mesh sheet has the necessary stiffness but is less expensive to produce than a product formed entirely of 4 mm wire.

S• It is still further envisaged that more than two sheets of the chainwire mesh may be used to prepare the laminated mesh sheeting of the present invention. In such an arrangement it is envisaged that at least two sheets of the sheeting will be offset in orientation.

Modifications and variations such as would be apparent to a skilled addresses are considered to fall within the scope of the present invention.

Claims

1. A laminated mesh sheeting comprising at least two sheets of chainwire or chainlink mesh, arranged so as to have their planar surfaces laying substantially adjacent each other, and such that the interwoven wires forming each sheet are offset with respect to the longitudinal orientation of those wires in the adjacent sheet or sheets, wherein the at least two sheets are fastened together.

2. A laminated mesh sheeting according to claim 1, in which the sheets comprising the laminated mesh sheeting are fastened together at intervals about a periphery thereof.

3. A laminated mesh sheeting according to claim 2, in which additional fastening means are provided at intervals across the adjacent planar surfaces of the sheets.

4. A laminated mesh sheeting according to claim 1, 2 or 3, in which the offset in ~15 the orientation of the adjacent sheets is at or near 900. A laminated mesh sheeting according to claim 1, which two sheets are provided, the orientation of the sheets being offset by 900 .9.9

6. A laminated mesh sheeting according to any one of claims 1 to 4, in which greater than two sheets comprise the sheeting, at least two sheets thereof being offset in orientation.

7. A laminated mesh sheeting according to any one of the preceding claims, in 99 which the wires in one sheet are of differing diameter to that of the or each other sheet.

8. A method for supporting a surface, the method comprising the steps of: -8- preparing a laminated mesh sheeting by overlaying two or more sheets of chainwire or chainlink mesh, at least two of which are offset in orientation; positioning the laminated mesh sheeting against a surface to be supported; fastening the laminated mesh sheeting to the surface; and coating the surface and ground support with a sprayable binding product.

9. A method according to claim 7, in which the offset in the orientation of the mesh sheets is at or near 900

10.A laminated mesh sheeting substantially as hereinbefore described with 10 reference to the accompanying drawings. o Dated this day of TWETHFTH AUGUST 1999 Southern Wire Pty Ltd 15 Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant •ooo•