WO2016063097A1

WO2016063097A1 - Fence panel manufacture

Info

Publication number: WO2016063097A1
Application number: PCT/IB2014/002166
Authority: WO
Inventors: Vlado Bucarizza
Original assignee: COCHRANE GULF FZE
Current assignee: COCHRANE GULF FZE
Priority date: 2014-10-20
Filing date: 2014-10-20
Publication date: 2016-04-28
Anticipated expiration: 2017-04-20

Abstract

A fence panel formed from two transversely extending arrays of spaced apart, parallel wires and a number of reinforcing elements wherein wires are welded together at points of contact in a first stage, and the reinforcing elements are welded to some of the wires, at points of contact, in a second stage.

Description

FENCE PANEL MANUFACTURE BACKGROUND OF THE INVENTION

[0001] This invention relates to the manufacture of a fence panel which comprises first and second transversely extending arrays of wires which are welded to one another at points of contact and a number of reinforcing elements which are welded to wires in the second array and optionally to wires in the first array.

[0002] Problems linked to the manufacture of the panel include the following:

1. it is time-consuming to weld the reinforcing elements to the wires;

2. the welding causes the panel to be distorted from a flat shape; and

3. the welding degrades the quality of a galvanising layer on the wires.

[0003] The reinforcing elements e.g. flat bar, round bar, angle sections or the like, are larger in cross-section than the wires and differential heating effects arising from the amount of energy needed to weld two wires together compared to the amount of energy needed to weld a wire to a reinforcing element leads to the end panel being distorted even if automated jigging and welding techniques are used.

[0004] An object of the invention is to address the aforementioned problems.

SUMMARY OF THE INVENTION

[0005] The invention provides a method of making a fence panel which includes the steps of: (a) providing a plurality of spaced apart, parallel, co-planar first wires which extend in a first direction; (b) providing a plurality of spaced apart, parallel, co-planar first reinforcing elements which extend in the first direction;

(c) forming an array of the first wires and the first reinforcing elements by positioning at least one first reinforcing element between a respective adjacent pair of the first wires;

(d) moving the array in a plurality of successive steps in the first direction through a welding arch;

(e) providing a plurality of second wires; and

(f) at the welding arch, at least for each step of movement, locating a respective second wire which extends in a second direction which is transverse to the first direction, over the array and welding this second wire to the first wires and to the first reinforcing elements at each point of contact between this second wire and the first wires and the first reinforcing elements.

[0006] Optionally, in step (f) in a first stage operated at a low heat, the second wire is welded to each of the first wires at respective points of contact and in a second stage, conducted with the wires and reinforcing elements at the same positions, the second wire is welded to each of the first reinforcing elements at respective points of contact, at a higher heat than what is employed in the first stage.

[0007] The method may include the step of tensioning at least each second wire when it is welded to the first reinforcing elements and the first wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The invention is described by way of examples with reference to the accompanying drawings in which: [0009] Figure 1 is a plan view of fence panel during manufacture;

[0010] Figure 2 is a side view of the fence panel during manufacture; and

[0011] Figures 3 and 4 show fence panels which have been manufactured according to the invention. DESCRIPTION OF PREFERRED EMBODIMENTS

[0012] Figure 1 shows in plan and Figure 2 is a side view of a fence panel during manufacture.

[0013] First wires 10, which extend in a direction 14, are positioned parallel to one another in a co-planar arrangement, spaced apart by a distance 16. At regular intervals adjacent first wires are positioned apart by a spacing 20 which is more than twice the distance 16. A reinforcing element 24 is centrally positioned in each spacing 20.

[0014] Jigs and locating components 30 (schematically shown) directly space the wires 10 and reinforcing elements 24 apart.

[0015] The wires 10 and the reinforcing elements 24 form an array 32 which is supported on a bed 34 and, optionally, on rollers 36 which facilitate movement of the array 32 in the direction 14, past a welding arch 38 which includes an upper component 40 which is movable vertically, to and fro, towards and then away from a lower anvil 42.

[0016] The component 40 has spaced apart welding electrodes 44 positioned so that a respective electrode 44 is above a wire 10 and above a first reinforcing element 24. [0017] At the welding arch successive second wires 46 are fed in a direction 48 transversely to the direction 14, to overlie the array 32 which is moved, in the direction 14, in a plurality of successive steps. Each step covers a distance 50. Thus, successive second wires 46 are spaced apart by the distance 50. A second wire 46 which is fed to overlie the array 32 is positioned directly below the component 40 and above the anvil 42.

[0018] The second wire 46 is tensioned, using an appropriate mechanical device, not shown, and the component 40 is then caused, by means of a controller 52, to move downwardly. The electrodes 44 force the second wire 46 against the first wires 10 and the reinforcing elements 24, which are above the anvil 42. Welding currents which are passed between the electrodes and the anvil flow through the points of contact between the second wire 46 and the underlying first wires 10 and reinforcing elements 24. The second wire is thus resistance- welded to the first wires and reinforcing elements.

[0019] The array 32 is then advanced by the distance 50 and a succeeding second wire 46 is fed into position between the component 40 and the anvil 42 and is welded to the first wires and to the reinforcing elements.

[0020] The process continues to make up a mesh panel 60 of the kind shown in Figure 3. The panel 60 has second wires 46 which are equally spaced apart by a distance 62, transversely-extending first wires 10 which are spaced apart by a distance 64 and which are welded to the wires 46 and, at regular intervals between adjacent groups of the first wires 10, a respective reinforcing element 24 which is welded to the second wires 46.

[0021] It has been found that the application of a tensile force to each wire 46 during the welding process helps to remove stresses in the direction 48. The tensioning force applied to each transverse wire 46 can be adjusted to assist in ensuring that a planar panel is produced by the manufacturing process.

[0022] In a variation, reinforcing elements 70 are fed at regular intervals, in place of a respective wire 46, in the direction 48. Each reinforcing element 70 is then welded to the first wires 10 and to the reinforcing elements 24 at respective points of contact. Groups of wires 46 extend between successive reinforcing elements 70 in the direction 48 as shown in a panel 72 in Figure 4.

[0023] Each reinforcing element 24, 70, may be of any particular cross-sectional shape and size and for example, may be round, oval or square in cross-section. It is preferred though that each reinforcing element is a strip of flat-bar. This type of material is difficult to cut with a bolt cutter. Consequently, although the wires between adjacent pairs of flat-bar strips may be severed, with relative ease, the flat-bar strips present a formidable barrier which makes it difficult for an intruder to breach the panel 60, or the panel 72.

[0024] In a variation of the invention the welding process at the anvil 42 is conducted in two stages. In a first stage electrodes which are in register with points of contact with the wire 46 and the wires 10 are activated at a low heat level to weld the second wire 46 to each of the first wires 10. At this stage no welding takes place between the second wire and the reinforcing elements 24.

[0025] In a second stage, which is conducted with the array of wires still in the same position, the electrodes which overlie the points of contact between the second wire 46 and the elements 24 are activated to operate at a substantially higher heat level than the heat level used in the first stage, to weld the second wire to the elements 24. [0026] The heat levels can be controlled by varying the welding current. Alternatively, use is made of a timer which makes the welding step in the second stage of a longer duration than in the first stage so that more heat is generated to take account of the thermal mass of each reinforcing element 24. [0027] The two-stage process, running at different heat levels, produces a welded panel which is structurally sound with integral and effective welds between the different components and no deformation of the panel, attributable to heat effects, occurs.

[0028] The production process is more efficient in respect of time and output than the processes described in the preamble hereof and the quality of the finished panel is significantly better than what is produced by such processes. The controller 52 enables the welding process to be accurately regulated inter alia in respect of the force which is applied by the component 40 to the wires 10 and 46 and to the reinforcing elements 24, between the electrodes 44 and the anvil 42, and in respect of the energy output per welding step.

Claims

1 . A method of making a fence panel which includes the steps of:

(a) providing a plurality of spaced apart, parallel, co-planar first wires which extend in a first direction;

(b) providing a plurality of spaced apart, parallel, co-planar first reinforcing elements which extend in the first direction;

(e) providing a plurality of second wires; and

2. A method according to claim 1 wherein in step (f) in a first stage operated at a low heat, the second wire is welded to each of the first wires at respective points of contact and in a second stage, conducted with the wires and reinforcing elements at the same positions, the second wire is welded to each of the first reinforcing elements at respective points of contact, at a higher heat than what is employed in the first stage. A method according to claim 1 which includes the step of tensioning at least each second wire when it is welded to the first reinforcing elements and the first wires.

A fence panel produced by the method of claim 1.

A fence panel which includes first and second transversely extending arrays of wires which are welded to one another at points of contact and a number of reinforcing elements which are welded to wires in the second array and optionally to wires in the first array, wherein the reinforcing elements are selected from flat bars, round bars and angle sections.