AU7249800A - A mesh strap - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant ONESTEEL REINFORCING PTY LIMITED Invention Title: A MESH STRAP The following statement is a full description of this invention, including the best method of performing it known to me/us: r 2 A MESH STRAP FIELD OF THE INVENTION The present invention relates generally to a method of forming elongate wire mesh straps, and in particular loops within ends of longitudinal wires of said straps. The invention further relates to elongate straps of wire mesh and in particular mesh straps for linking to and anchoring a retaining wall.

SUMMARY OF THE INVENTION According to one aspect of the present invention there is provided a method of forming a loop in an end portion of at least one longitudinally extending wire of an elongate strap of wire mesh including a plurality of said *"longitudinal wires welded to a plurality of transverse wires, said method comprising formation of the loop e following fabrication of the wire mesh.

0e ee* Preferably formation of the loop involves bending of the end portion back toward the wire. More preferably, the end portion is bent through an angle greater than 180 degrees.

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Preferably the end portion is laterally offset from a corresponding straight portion of the wire. More preferably the loop is closed by contact of a side wall of the end portion and a side wall of the corresponding straight portion of the wire. It has been found that the resilience of the material, which is usually steel, from which the wire is fabricated promotes this contact between the end and straight portion of the wire.

3 Preferably formation of the loop involves bending of the end portion about an elongate mandrel having its axis oriented substantially perpendicular to that of the respective longitudinal wire. More preferably said wire is bent about the mandrel using a bending element which is designed to operatively cooperate with the mandrel so as to deform the end portion of said longitudinal wire about the mandrel.

Preferably formation of the loop also involves welding of the end portion to the respective longitudinal wire. More preferably said welding involves setting of the end portion and the longitudinal wire between a pair of electrodes, adjacent surfaces of said wire contacting one another, and passing electrical current through the *"contacting surfaces via the electrodes so as to effect a resistance-type weld. In one embodiment the end portion o and the longitudinal wire are clamped between the gelectrodes.

According to another aspect of the invention there is provided an elongate strap of wire mesh including a plurality of longitudinally extending wires welded to a plurality of transversely extending wires, an end portion of at least one of said wires being bent back toward the wire to form a loop, said end portion being disposed alongside and laterally offset from said wire.

Preferably the end portion is bent through an angle of from between 210 to 270 degrees, relative to an axis of the wire, so as to form the loop. More preferably an end of the end portion of the wire is laterally or radially offset relative thereto.

4 Preferably the loop of each of the longitudinal wires defines a plane which is oriented substantially perpendicular to that of the elongate strap.

Preferably the loop(s) of the elongate strap are adapted to link to a panel of a retaining wall wherein the strap is anchored within the ground and oriented perpendicular to the retaining wall to at least inhibit lateral displacement of the wall.

According to a further aspect of the invention there is provided an elongate wire having at least one end provided with a loop formed by bending of an end portion of said wire through an angle greater than 180 degrees.

Preferably the end portion is bent through an angle of from between 210 to 270 degrees, relative to an axis of the wire, so as to form the loop. More preferably an end of the end portion of the wire is laterally or radially offset relative thereto.

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BRIEF DESCRIPTION OF THE DRAWING S"In order to achieve a better understanding of the nature Soo.o.

of the present invention a preferred embodiment of a method of forming elongate wire mesh straps together with a wire mesh strap will now be described, by way of example only, with reference to the accompanying drawing in which: Figure 1 is a perspective view of an elongate wire mesh strap together with an enlarged end portion of the wire mesh strap.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in Figure 1 there is an elongate wire mesh strap including four longitudinally extending wires 12A to 12D equally spaced and arranged parallel to one another and welded to a plurality of transversely oriented wires such as 14A and 14B also being equally spaced and disposed parallel to one another. This portion of the wire mesh strap 10 is fabricated in accordance with conventional wire welded mesh manufacturing techniques.

According to one embodiment of the invention loops designated as 16A to 16D are formed in an end portion of the respective longitudinal wires 12A to 12D. The loops 16A to 16D are formed in the metal mesh 10 once it has been fabricated into its mesh structure. The loops such as 16A are adapted to align with corresponding loops cast in a panel of a retaining wall (not shown). A shear pin (not shown) passes through both the loops 16A to 16D of the mesh strap 10 and the corresponding loops of the panel of the retaining wall so as to link the mesh strap 10 to the retaining wall panel. The mesh strap 10 may be one of a series of spaced apart straps which are anchored horizontally within the soil adjacent the retaining wall so as to inhibit lateral displacement of the wall.

In a preferred embodiment the loops 16A to 16D are formed in the wire mesh straps 10 at a bending station (not depicted). This particular bending station is designed such that simultaneous formation of the loops 16A to 16D is effected in one operation with a consistent bend on each of the longitudinal wires 12A to 12D. The longitudinal wires 12A to 12D are each bent around a central mandrel using a parallel striking pin (both not 6 depicted) which runs concentrically around the mandrel.

The end portion of each of the longitudinal wires 12A to 12D is bent back toward itself through an angular displacement of approximately 220 degrees. That is, in this embodiment the loops 16 are each formed by a resulting total bend of about 400 degrees. Furthermore, an end of the end portion of each of the longitudinal wires such as 12A to 12D is laterally offset relative to a corresponding straight portion of the wire 12A to 12D.

This allows said end to pass to the side of and preferably contacts the longitudinal wire such as 16A. It has been found that the resilience of the material, which is usually steel, from which the wire is fabricated promotes this contact between the end and straight portion of the wire.

Each of the loops 16A to 16D defines a plane which is orientated substantially perpendicular to that of the elongate strap 10. This assists with insertion of the shear pin through the loops 16A to 16D when linking the wire mesh strap 10 to the retaining wall panel. It should also be appreciated that the loops such as 16A to 16D may be formed by bending the end portion through greater than 0o S"180 degrees although an angular displacement of between .eeoei about 210 to 270 degrees is preferred.

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In the wire mesh strap 10 of this particular construction each of the loops 16A to 16D is welded via a resistance type welder. Each loop such as 16A is fed between a pair of electrode jaws which are closed under pressure to ensure contact between adjacent surfaces of the longitudinal wire such as 12A and its corresponding end portion. An electric current is then passed across this 7 point of contact via the pair of electrode jaws wherein a resistance-type weld is formed. Once the weld has cooled sufficiently the pair of electrode jaws are retracted and moved to an adjacent loop such as 16B in preparation for its resistance type weld. This particular configuration of the loop with contact being formed by peripheral surfaces of a single longitudinal wire such as 12A allows the weld to be induced using resistance welding. In this example the two adjacent peripheral surfaces of the longitudinal wire such as 12A are forced together and a current is "fired" across the total width of the junction or contact area. Heat is generated where the longitudinal wire such as 12A contacts itself which in turn initiates the weld.

This particular embodiment of the invention allows a manufacturer to firstly produce a wire mesh panel and thereafter form the required loops. The preferred bending process allows the manufacturer to bend all of the longitudinal wires on the strap or panel together. These features together with the formation of a resistance-type weld speeds up the manufacturing process and allows considerable cost savings.

Generally, the wire mesh straps such as 10 are each cut from a panel of wire mesh which is formed according to conventional techniques. The straps 10 may be separated from the wire mesh panel either at a weld mesh machine or as a separate operation using a guillotine or other cutting apparatus. When separation of the straps 10 is performed at the weld mesh machine cutting blades are set up at predetermined positions so as to cut each of the transverse wires such as 14A and 14B once this wire has 8 been welded to the longitudinal wire such as 12A with which it intersects. Alternatively, when the separation is effected as a separate operation, each of the mesh panels is taken to a guillotine or cutting station where it is fed into position and cut to form the individual straps such as The completely formed mesh straps such as 10 may be galvanised in a galvanising bath. In this instance the strap 10 is immersed in a hot dipped galvanised coating bath in a conventional manner.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described.

All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

In the preceding summary of the invention, except where S* the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", that is the features specified may be associated with further features in various embodiments of the invention.

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Claims (19)

1. A method of forming a loop in an end portion of at least one longitudinally extending wire of an elongate strap of wire mesh including a plurality of said longitudinal wires welded to a plurality of transverse wires, said method comprising formation of the loop following fabrication of the wire mesh.

2. A method as defined in claim 1 wherein formation of the loop involves bending of the end portion back toward the wire.

3. A method as defined in claim 2 wherein the end portion is bent through an angle greater than 180 degrees.

4. A method as defined in any one of the preceding claims wherein the end portion is laterally offset from a corresponding straight portion of the wire.

5. A method as defined in claim 4 wherein the loop is closed by contact of a side wall of the end portion and a side wall of the corresponding straight portion of the wire.

6. A method as defined in any one of the preceding claims wherein formation of the loop involves bending of the end portion about an elongate mandrel having its axis oriented substantially perpendicular to that of the respective longitudinal wire.

7. A method as defined in claim 6 wherein said wire is bent about the mandrel using a bending element which is 10 designed to operatively cooperate with the mandrel so as to deform the end portion of said longitudinal wire about the mandrel.

8. A method as defined in any one of the preceding claims wherein formation of the loop also involves welding of the end portion to the respective longitudinal wire.

9. A method as defined in claim 8 wherein said welding involves setting of the end portion and the longitudinal wire between a pair of electrodes, adjacent surfaces of said wire contacting one another, and passing electrical current through the contacting surfaces via the electrodes so as to effect a resistance-type weld.

.1 0. A method as defined in claim 9 wherein the end portion and the longitudinal wire are clamped between the electrodes.

11. An elongate strap of wire mesh including a plurality of longitudinally extending wires welded to a plurality of transversely extending wires, an end portion of at least one of said wires being bent back toward the wire to form S"a loop, said end portion being disposed alongside and laterally offset from said wire.

12. An elongate strap as defined in claim 11 wherein the end portion is bent through an angle of from between 210 to 270 degrees, relative to an axis of the wire, so as to form the loop. 11

13. An elongate strap as defined in claim 12 wherein an end of the end portion of the wire is laterally or radially offset relative thereto.

14. An elongate strap as defined in any one of claims 11 to 13 wherein the loop of each of the longitudinal wires defines a plane which is oriented substantially perpendicular to that of the elongate strap.

15. An elongate strap as defined in any one of claims 11 to 14 wherein the loop(s) of the elongate strap are adapted to link to a panel of a retaining wall wherein the strap is anchored within the ground and oriented perpendicular to the retaining wall to at least inhibit lateral displacement of the wall.

16. An elongate wire having at least one end provided *o :with a loop formed by bending of an end portion of said wire through an angle greater than 180 degrees.

17. An elongate wire as defined in claim 16 wherein the Sc.. end portion is bent through an angle of from between 210 to 270 degrees, relative to an axis of the wire, so as to form the loop.

18. An elongate wire as defined in claim 17 wherein an V. e end of the end portion of the wire is laterally or radially offset relative thereto.

19. A method of forming a loop in an end portion of a wire of an elongate strap, said method being substantially as herein described. 12 An elongate strap substantially as herein described with reference to the accompanying drawing. Dated this 22 ndday of December 2000 ONESTEEL REINFORCING PTY LTD By their Patent Attorneys GRIFFITH HACK doe 0 #44s. .00. 0 :*doe 0 00