AU2005202308B2 - Safety Netting - Google Patents

Description

30-MAY-005 15:24 A J PARK 64 4 472 3358 P.05/27 Regulation 3.2 0 en

AUSTRALIA

PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventor: Address for service in Australia: Invention Title: DOUGLAS PAUL BISHOP DOUGLAS PAUL BISHOP A J PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT 2601, Australia Safety Netting The following statement is a full description of this invention, including the best method of performing it known to me.

392268-1 COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 09-NOV-2005 11:02 A J PARK 09-N)--00511:0 A PRI<4 4 472 3358 P.09/12 tt~) -2- Cl SAFETY NETTING Z Field of the Invention 0 5 The Present invention relates to sulbty netting for use in the building industry. In particular, the invention is concerned with a mesh netting for installing on a roofing framework, which may act 00 as a safety netting.

o Background of the Invention o Traditionally, wire netting has been installed between rafters or purlins to support lining and/or insulation before the attachment of roof cladding. However, there is a safety risk to the builders installing the insulation or cladding, as they are often required to balance on the rafters or purlins of the roofing framework, which tend to be spaced quite a distance apart. Traditionally, if a builder lost his balance when installing the insulation or cladding, there would have been nothing to break his fall.

Although netting has been used for a long time in the roofing industry, it is unlikely to have the inherent strength to withstand the body weight of a falling person. For example, US Patent No.

4,047,346 discloses the use of conventional "chicken wire" with a sheet of material seated thereon, and optionally separate insulation, for lining a roof In terms of' safety, this patent discloses an apparatus for applying the wire mesh and the sheet material, which includes a worker's platform for supporting a worker. However, this apparatus would be costly to manufacture and relatively bulky to trainsport between sites. In view of the need for a worker's platform, it is unlikely that the conventional "chicken wire" mesh would have enough inherent strength to withstand a person falling onto it.

US Patent No. 4,557,092 discloses an insulating material for a roof that has a facing component and a reinforcing component integrally formed as part thereof. The reinforcing component provides safety to a worker should they inadvertently step onto the insulting material. However, this three layered insulation structure would be bulky to transport and expensive to manufacture.

US Patent No. 4,081,159 describes a netting for reinforcing concrete for covering underwater pipes.

As an additional design requirement, New Zealand and Australian safety standard AS/NZS 39077.3 COMS ID No: SBMI-01 91 8898 Received by IP Australia: lime 09:01 Date 2005-11-09 09-NOV-2005 11:03 A I PARK 09-N-205 1:03 s mv4 4 472 3358 P.10/12 ci 43 89:1996 requires that a safety netting be able to withstand a 165kg mass being dropped on it from a height of 1400mm.

It is an object of te present invention to provide a safety netting which overcomes or ameliorates o 5 the disadvantages referred to above, or provides the public with a useful choice.

00 Summary of tbo Invention CI The term 'comprising' as used in this specification and claims means 'consisting at least in part cI 10 of, that is to say when interpreting statements in this specification and claims which include that o term, the features proeced by that term in each statement all need to be present but other features CI can also be present.

In accordance with a first aspect of the present invention, there is provided a wire netting comprising:, wire mesh having interenmected wires between 0,9mm and 1.2mm in thickness, the interconnected wires defining discontinuous lines of twisted wire junctions, with each junction comprising two twisted wires of the mesh; and a plurality of longitudinally-extending support wire arrangements, each support wire arrangement comprising two support wires, affixed to the wire mesh through the associated twisted wire junctions such that the netting is capable of withstanding a 165kg human falling onto the mesh from a height of 1400mm.

It will be appreciated that the wire mesh forms a substrate to hold the support wire arrangements in a preferred configuration. These junctions in the wire mesh may be 'icnitted" or woven together. More preferably, each junction may have two reverse-twisted wires. The support wires may be passed through the wire junctions and affixed by being woven into the light gauge wire mesh.

In a most preferred form of the invention, the wire mesh has hexagonal shapead openings, the hexagonal openings. The support wire arrangements may extend along some or all of the twisted wire junctions. Preferably the support wire arrangements extend through every alternate line of twisted wire junctions, 390877,3 COMS ID No: SBMI-01 918898 Received by IP Australia: Time 09:01 Date 2005-11-09 30-MAY-2005 15:25 A J PARK 30-PY-00515:5 PJ PRK64 4 472 3358 P.08/27 o 4- Without being limited to being incorporated into a hexagonal wire mesh, the support wire arrangements may extend parallel to each other. Preferably, the support wires are tite aound each other in each support wire arrangement. In a preferred embodiment, the Support Wire 0 arrangements lie substantially co-planar with untwisted portions of the mesh.

00 The thickness of each of the two support wires making up each support wire arrangement is o preferably 1.2mm.

o The netting preferably includes least three support wire arrangements, wherein the support wire '4h 10 arrangements are substantially equally spaced. It will be appreciated that if the heavier gauge o support wires are incorporated into a repeating pattern of the light gauge wire mesh, then an equal spacing will thereby -be provided.

The support wire arrangements are configured to meet the criteria of withstanding a 165 kg mass dropped from a height of 1400 mm. This enables the netting to be used as a safety netting on a roof structure to protect workman working thereon. The gauge and spacing between adjacent support wires may therefore vary and yet still meet the safety criteria. In a preferred embodiment, the spacing between adjacent support wire arrangements may be about 113 mm. In a preferred embodiment, the wire netting includes seventeen support wire arrangements.

Preferably, the wire netting turther comprises a longitudinally-extending selvedge at each of two outer sides thereof. Each selvedge may comprise two wires. The thickness of each of the two wires making up each selvedge is preferably 1mmn, The two wires in each selvedge are preferably twisted around each other.

In accordance with a second aspect of the present invention, there is provided a roof structure, comprising: a framework having roof supports;, and wire netting comprising: wire mesh having interconnected wires of between 0.9mm and 1.2mm in thickness, the interconnected wires defining discontinuous lines of twisted wire junctions, with each junction comprising two twisted wires of the mesh; and a plurality of support wires affixed to the wire mesh through the associated twisted wire junctions; wherein the wire netting extends between adjIacent roof supports and is secured to the roof structure and is configured such that the netting is capable of withstanding a 165kg 390877-1 COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15:25 A J PARK 30-Y-205 52 FlJ PRK64 4 472 3358 P.09/2? human falling onto the mnesh from a height of 1400mm.

Preferably, both ends of at least some Ofthe support wire arrangements are secured to the roof structure.

00 The wire netting is preferably as defined in the first aspect above.

0) ci in accordance with a third aspect of the present invention, there is provided a method of installing o safety netting on a roof structure, the method including: VC) 10 laying wire netting as defined in the first aspect above between adjacent roof supports; and o securing both ends of at least some of the support wire arrangements to the roof structure.

Preferably, at least a majority of the support wire arrangements are secured at both ends thereof.

The wire netting may be provided in the form of a roll.

in a preferred embodiment the roll of netting is laid onto the roof structure with the outer end of the roll having the associated ends of the support wire arrangements affixed to a top plate or adjacent purlin of the roof structure; the netting is rolled to the pitch of the roof structure; and the support wire arrangements are affixed to the apex of the roof structure. Preferably, the roll of netting is laid onto the roof structure with the outer end of the roll having the associated ends of the support wire arrangements affixed to a top plate or adjacent purlin of the roof structure; the netting is rolled over the top of the pitch of the roof structure to the opposite outside edge of the roof structure; and the support wire arrangements are affixed to the top plate or adjacent purlin.

Preferably, insulating material is placed on the installed netting; and roofing material is placed thereon, The invention consists in the foregoing and also envisages constructions of which the following gives examples.

Brief Description of the Drawings One preferred form of the present invention will now be described with reference to the accompanying drawings in which: COMS ID No: SBMI-01271 900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15:26 A J PARK 30-Y-205 5:6 P3 PPK64 4 472 3358 P.10/27 o -6- Figure 1 shows the safety netting in accordance wiha firt preferred embodiment of the present invention; Figure 2a shows a reverse twist wire junction Of the safety netting of Figure 1; and o Figure 2b shows a reverse twist wire junction of the safety netting of Figure 1 with a longitudinally extending support wire held therein; 00 Figure 3 shows the safety netting of Figure 1 attached to the rafters of a roof o Figure 4 shows a safety netting in accordance with a second preferred embodiment of the en present invention; o Figure shows a reverse twist wire junction of the safety netting of Figure 4 with two V) 10 longitudinally extending support wires held therein; and o Figure 6 shows the safety netting of Figure 4 attached to the rafters of a roof Detailed Description of the Preferred Embodiment The safety netting I shown in Figure 1 includes a hexagonal mesh 2 having a plurality of hexagonal portions 4, 4a in a 2-dimensional honeycomb structure, with a longitudinally extending selvedge 3 at each outer side thereof Due to the honeycomb pattern of the hexagonal mesh 2, each hexagonal portion 4 is offset transversely by half its width to its longitudinally neighbouring portion 4a, Each hexagonal portion 4 and 4a includes two longitudinal sides extending in the longitudinal direction, each comprising a wire junction 5 and 5a respectively. Due to the structure of the hexagonal mesh 2, there are effectively discontinuous lines of wire junctions 5 and respectively extending in the longitudinal direction.

The safety netting 1 additionally includes a plurality of longitudinally extending support wires 6 each corresponding to, and held within, arn effective longitudinal line of wire junctions Each wire junction 5, being the junction that does not have a longitudinally extending support wire 6 held therein, comprises a first wire 12 and second wire 13, initially twisted around each other twice in a first rotational direction, then twisted around each other twice in a second rotational direction being opposite to the first rotational direction. This is known in the art as a reverse twist method. At the end of wire junction 5, the first and second wires 12, 13 extend diagonally in transversely opposite directions to respective support wires 6. First wire 12 and second wire 13 from the transversely neighbouring, wire junction 5 are twisted round support wire 6 twice in the first rotational direction, followed by twice in the second rotational direction, forming wire junction 5a. In the same manner, second wire 13 anid first wire 12 from the opposite transversely neighbouring wire junction 5 are twisted round the neighbouring support wire 6 300R77-i COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 09-NOV-2005 11-'03 A J PARK 09-W-205 1:0 P PPK4 4 472 3350 P.11/12, Ni twice in the first rotational direction, followed by twice in a second rotational direction, forming a >_neighbouring wire junction St Respective first and second wires 12,13 extend diagonally in the Z samne longitudinal direction, but tansversely back towards each other. These wires are then twisted around each other twice i the first rotational direction, followed by twice in the second o 5 rotational direction, to form respective fur-ther wire junctions 0 Mn particular line of wire junctiotts includes the same wires 12 and 13. This applies for each line of o junctions 5 or 5a. The remaining sides of hexagonal portions 4, 4a comprise -the single wires 12 0 Ni At tbe outer sides of the hexagonal mesh 2, the outer side wires of the hexagonal portions 4a are twisted around the respective selvedges 3.

The hexagonal mesh is suitably made of suitably soft galvanised iron wire (3 8OMPa 1mm diameter, whereas the selvedges 3 each suitably comprise two 1mm diameter wires.

Suitably the longitudinal support wires are of 1.6mm. diameter..

An advantage of utilising twisted wire junctions is that no welding or resin are required to formi the safety netting, reducing manufacturing costs.

Due to the offset nature of the hexagonal portions 4, 4a each support wire 6 bisects alternate hexagonal portions 4 in a longitudinal direction along the netting 1.

Suitably there is a spacing of about 113mm between the two wire junctions 5 of each hexagonal portion 4, and the two wire junctions 5a of each of the hexagonal portions 4a. Therefore there is an associated spacing between each of the support wires 6 of' about 11 3mm. Typically the safety netting 1 is made in a sheet of such a width to incorporate two selvedges and seventeen (not shown) support wires 6. In other words the safety netting typically has a width of approximately 2034mm.

The number of wires, their diameters and spacing, and the mesh sizing in the safety netting 1 are such that it is able to withstand a 165kg mass being dropped on it from a height of 1400mm when the netting is attached to a roofing structure. This complies with the required safety factor outlined in the relevant Australian and New Zealand safety standard. A method of testing this safety netting and the safety netting described hereinafter is outlined on pages 12 to 14 of 390877-.3 COMS ID No: SBMI-01918898 Received by IP Australia: Time 09:01 Date 2005-11-09 09-NOV-2005 11:04 A J PARK 09-NIJ-005±1:4 PJ PRK4 4 472 33513 P.1±2/12 ci AS/NZS 4389:1996. It will be obvious that depending on local requirements, the safety netting configuration may be altered to give the required strength characteristics without departing from the scope of the invention. Furthermore, the use of smaller diameter wires in the hexagonal mesh, two wires for each selvedge and larger diamneter wires as the support wires enables the safety o 5 netting to exhibit the required strength characteristics while offering cost savings over using larger diameter wire for the entire safety netting.

00 0) Mc Due to the small wire diameters of the safety netting 1, it may be manufactured as a roll for o portability and ease of use.

ci o The safety netting may be fastened to either the railers or purlins et a roofing structure using 0 fastening means. ON installation, a roll (not shown) of safety netting 1 is placed on the framework of the roof, and the end of the roll is attached to the top plate 11I by attaching the ends of the support wires 6 to the top plate 11I with staples 8, as shown in Figure 2. Alternatively, if the top plate 11 is steel, holes may be drilled therein and the support wires threaded through the holes.

The safety netting 1 is unrolled in an upwards direction either to the pitch of the roof (not shown), to which the safety netting is attached, or the unrolling continues right over the roof and the safety netting is attached to the top plate (not shown) at the lower end of the roof on. the opposite side.

As the safety netting I is unrolled, it is positioned such that the selvedges 3 are aligned with the railers 7. The safety netting I is pulled taut, and the selvedges 3 are attached to the rafters 7 with staples 8. Alternatively, if the width of the netting is greater than the spacing between adjacent railers, the support wires 6 of the safety netting I may be aligned with the rafters 7 and attached thereto with staples.

A layer of insulating material 9. types of which are common in the art, is seated on the safety netting 1. Roofing cladding 10 is then positioned on the layer of insulating material 9 which is compressed. The roofing cladding 10 is ten fastened tothe ra&-ers 7 using fasteners (not shown), holding the insulation material 9 in a compressed manner between the roofing cladding 10 and the safety netting 1.

The foregoing describes only one embodiment of the present invention and modifications can be made thereto without departing from the scope of the present invention as determined by the following claims. For example, the spacing and thickness of the support wires in the netting may vary within predetermined ranges and yet the netting is able to satisfy the criteria of supporting a 39077-3 TOTAL P.12 COMS ID No: SBMI-01 91 8898 Received by IF' Australia: Time 09:01 Date 2005-11-09 30-MAY-2005 15:27 A 3 PARK 30-RY-00515:7 F J PRK64 4 472 3358 P.13/27 0 0 ci 0 en 00 0 en ci 0 ci 0 0 ci -9weight dropped onto it. The followinig table is a guide to the range of support wire spacing and thickness; WIRE SIZES

SPACING

mm 170 mm 1.7mnu 129 mm 1.6 mm 113 mm I.4mmn 86 mm 1.2mmu 63nmin 1.1 mm 53 mm mm 42 mm A safety netting 10 1 in accordance with a second preferred embodiment of the present invention is shown in Figures 4 to 6. Like reference numerals are used to indicate like parts to the netting described with reference to Figures 1 to 3, with the addition of 100. The modified safety netting 1 includes a hexagonal mesh 102 having a plurality of hexagonal portions 104, 104a in a 2dimensional honeycomb structure, with a longitudinally extending selvedge 103 at each outer side thereof. Due to the honeycomb pattern of the hexagonal mesh 102, each bexagonal portion 104 is offset transversely by half its width to its longitudinally neighbouring portion 1 04a. Each hexagonal portion 104 and 104a includes two longitudinal sides extending in the longitudinal direction, each comprising a wire junction 105 and 105a respectively. Due to the structure of the hexagonal mesh 102, there are effectively discontinuous lines of wire junctions 105 and 105~a respectively extending in the longitudinal direction.

The safety netting 10 1 additionally includes a plurality of longitudinally-extending support wire arrangements 106 each corresponding to, and held within, an effective longitudinal line of wire junctions 105a. As can be seen fromn the figures, each longitudinally-extending support wire arrangement 106 has two longitudinally-extending support wires 1 06a, 1 06b. The longitudinallyextending support wires 1 06a, I106b in each support wire arrangement 106 are twisted around each other along their length, as shown in Figure 5. In an alternative embodiment, the support wires 1 06a, 1 06b in each support wire arrangement 106 may lie generally parallel in a side-byside configuration, rather than being twisted around each other. In either configuration, the 300877-1 COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15t2? A J PARK 30-RY-00515:7 R 3 PRK64 4 472 3358 P.14/27 o support wire arrangements 106 preferably lie generally co-planar with the untwisted portions of the mesh.

o Each wire junction 105, being the junction that does not have a longitudinally extending support wire arrangement 106 held therein, comprises a first wire 112 and second wire 113, initially 00 twisted around each other twice in a first rotational direction, then twisted around each other O twice in a second rotational direction being opposite to the first rotational direction. This is eN known in the art as a -reverse twist method. At the end of wire junction 105, the first and second O wires 112, 113 extend diagonally in transversely opposite directions to respective support wire arrangements 106. First wire 112 and second wire 113 from the transversely neighbouring wire O junction 105 are twisted around support wire 106 twice in the first rotational direction, followed by twice in the second rotational direction, forming wire junction 105a. In the same manner, second wire 113 and first wire 112 from the opposite transversely neighbouring wire junction 105 are twisted around the neighbouring support wire arrangement 106 twice in the first rotational direction, followed by twice in a second rotational direction, fantning a neighbouring wire junction 10O5a. Respective first and second wires 112, 113 extend diagonally in the same longitudinal direction, but transversely back towards each other. These wires are then twisted around each other twice in the first rotational direction, followed by twice in the second rotational direction, to form respective further wire junctions 105.

This pattern is continued throughout the safety netting 101. Therefore each j unction 105 along a particular line of wire junctions includes the seine wires 112 and 113. This applies for each line of junctions 105 or 1 05a. The remaining sides of hexagonal portions 104, 104a comprise the single wires 112 cr 113.

At the outer sides of the hexagonal mesh 102, the outer side wires of the hexagonal portions 1 04a are twisted around the respective selvedges 103.

The hexagonal mesh is suitably made of suitably soft galvanised iron wire (38OM~a 1mm diameter, whereas the selvedges 103 each suitably comprise two 1 nu diameter wires (preferably of the samne material). As shown in Figure 4, the two wires of each selvedge 103 are preferably twisted around each other along their length, but that is not essential. Suitably the longitudinal support wires 1 06a, 1 06b in each longitudinal support wire arrangement are of 1.2mmr diameter each, and again are preferably mnade of suitably soft galvanised wire (3SOMPa- .590877-1 COMS ID No: SBMI-01271900 Received by IP Australia: lime 13:32 Date 2005-05-30 30-MAY-2005 15:28 A J PARK 30-Y-205 5:8 PJ PRK64 4 472 3358 P.15/2? An advantage of utilising twisted wire junctions is tht no welding or resi are required to for the safety netting, reducing manufacturing costs.

o Due to the offset nature of the hexagonal portions 104, 1 04a each support wire arrangement 106 bisects alternate hexagonal portions 104 in a longitudinal direction along the netting 101.

00 o Suitably there is a spacing of about II 3nu between the two wire junctions 105 of each hexagonal portion 104, and the two wire junctions 105a of each of the hexagonal portions 104a.

O Therefore there is an associated spacing between each of the support wire arrangements 106 of Vfl about 11 3mm, centre to centre. Typically the safety netting 101 is made in a sheet of such a width O to incorporate two selvedges and seventeen (not shown) support wire arrangements 106. The embodiment shown in Figures 4 to 6 also differs in that the longitudinal dimension of each hexagonal portion is about half the size of tbat shown for the embodiment of Figures 1 to 3. In the preferred embodiment, the length of each hexagon of the mesh in the longitudinal direction is about 95 mm, apex to apex.

The number of wires, their diameters and spacing, and the mesh sizing in the safety netting 10 1 are such that it is able to withstand a 165kg mass being dropped on it from a height of 1400mm when the netting is attached to a roofing structure. This complies with the required safety factor outlined in the relevant Australian and New Zealand safety standards. It will be obvious that depending on local requirements, the safety netting configuration may be altered to give the required strength characteristics without departing from the scope of the invention. Furthermore, the use of smaller diameter wires in the hexagonal mesh, two wires for each selvedge and two wires for each support wire arrangement enables the safety netting to exhibit the required strength characteristics while offering cost savings over using larger diameter wire for the entire safety netting. Further, utilising two support wires for each support wire arranagement provides some additional safety to the netting. If one of the support wires was to disconnect or break in use, the other support wire in the support wire arrangement would still provide useful strength for the safety netting. Imnproved strength characteristics are obtained by twisting the wires 1 06a, 106b around each other, as shown Figures 4 to 6.

Due to the small wire diameters of the safety netting 10 1, it may be manufactured as a roll for portability and ease of use.

The safety netting may be fastened to either the rafters or purlins of a roofing structure using fastening means, On installation, a roll (not shown) of safety netting 10 1 is placed on the 390877-1 COMS ID No: SBMI-01271900 Received by IP Australia: Time (i-tm) 13:32 Date 2005-05-30 30-MAY-2005 15:2e A J PARK 3t3MPY200 159 R5 PRK64 4 472 3359 P.16/27 tt~) -12framework of the roof, and the end of the roll is attached to the top plate 111 by attching the ends of the support wires 1 06a, 1 06b in each support wire arrangement 106 to the top plate I111. This attachment could be by way of staples as described above. Alternatively, if the top plate Ill is o steel, holes may be drilled therein and the support wires threaded through the holes. The support Mn wires could then be twisted around part of the top plate to maintain them in position, or a fastener 00 such as a rivet or the like could be used to attach the wires to the top plate.

0 en The safety netting 101 is unrolled in an upwards direction either to the pitch of the roof (not o shown), to Which the safety netting is attached, or the unrolling continues right over the roof and the safety netting is attached to the top plate (not shown) at the lower end of the roof on the o opposite side. As the safety netting 101 is unrolled, it is positioned such that the selvedges 103 ci are aligned with the rafters 107. The safety netting 101 is pulled taut, and the selvedges 103 are attached to the rafters 107 with staples 108. Alternatively, if the width of the netting is greater than the spacing between adjacent rafters, the support wire arrangemnents 106 of the safety netting 1 may be aligned with the rafters 107 and attached thereto with staples.

A layer of insulating material 109, types of which are common in the art, is seated on the safety netting 101. Roofing cladding 110 is then positioned on the layer of insulating material 109 which is compressed. The roofing cladding 110 is then fastened to the rafters 107 using fasteners (not shown), holding the insulation material 109 in a compressed manner between the roofing cladding 110 and the safety netting 101.

The foregoing describes a further embodiment of the present invention and modifications can be made thereto without departing from the scope of the present invention as determined by the following claims. For example, the spacing and thickness of the support wires and support wire arrangements in the netting may vary within predetermined ranges and yet the netting is able to satisfy the criteria of supporting a weight dropped onto it. The following table is a guide to the range of approximate support wire spacing and thickness. The wire size is per support wire, when two support wires are used in each support wire arrangement.

300877-1 COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15:29 A J PARK 30-Y-205 529 i PfRK64 4 472 3358 P. 17/27 13 WIRE SIZES (each support

SPACING

wire) 1.6mnu 170 r= 1.4m 129rm 1.2 mm 113mnu 1. 1TMm 86 mm MM 63 mm 0.9 MM 53nm 0.8 MM 42 nun 390877-1 COMS ID No: SBMI-01271900 Received by IP Australia: lime 13:32 Date 2005-05-30

Claims (2)

1. 30-MAY-2005 15:29 A 3" PARK 64 4 472 3358 P.18/27 -14- 0 Cl THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS 1. A wire netting comprising: o wire mesh having interconnected wires between 0.9mm and 1.2mm in thickness, the interconnected wires defining discontinuous lines of twisted wirejunctions, with each junction comprising two twisted wires of the mesh; 0and a plurality of longitudinally-extending support wire arrangements, each support wire arrangement comprising two support wires, affixed to the wire mesh through the associated o twisted wire junctions such that the netting is capable of withstanding a 165kg human falling onto the mesh from a height of 1400mm. 0 0 2. The wire netting according to claim 1, wherein each of the junctions comprises two reverse-twisted wires, 3. The wire netting according claim 1 or 2, wherein the wire mesh has hexagonal shaped openings. 4. The wire netting according to claim 3, wherein the hexagonal shaped openings define the discontinuous lines of wire junctions. The wire netting according to claim 4, wherein the support wire arrangements extend through alternate lines of twisted wire junctions. 6. The wire netting according to any one of claims 1 to 5, wherein the support wire arrangements extend substantially parallel to each other. 7. The wire netting according to claim 6, wherein the support wires are twisted around each other in each support wire arrangement. 8. The wire netting according to any one of clains I to 7, wherein the support wire arrangements lie substantially co-planar with untwisted portions of the mesh. 9. The wire netting according to any one of claims 1 to 8, wherein the thickness of each ofthe two support wires making up each support wire arrangements is 1.2mm. The wire netting according to any one of claims 1 to 9, including at least three support wire 390?877-) COMS ID No: SBMI-01271900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15!29 A J PARK 30-Y-205 5:9 R5 PRK64 4 472 3358 P.19/27 arrangements, wherein the support wire arrangements aesubstantiallyeqalspcd 11. The wire netting according to claim 10, wherein the spacing between adjacent support wire o arrangements is about 113mm. 12. The wire netting according to claim 11, wherein the wire netting includes seventeen 00 support wire arrangements. o13. The wire netting according to any one of claims 1 to 12, wherein the wire netting further comprises a longitudinally-extending selvedge at each of two outer sides thereof. 014. The wire netting according to claim 13, wherein each selvedge comprises two wires. The wire netting according to claim 14, wherein the thickness of each of the two wires making up each selvedge is 1mm. 16. The wire netting according to claim 14 or 15, wherein the two wires in each selvedge are twisted around each other. 17. A wire netting substantially as hereinbefore described with reference to any embodiment shown in the accompanying drawings. 18. A roof structure, comprising: a framework having roof supports; and wire netting comprising: wire mesh having interconnected wires of 'between 0.9mm and 1.2mmn in thickness, the interconnected wires definiing discontinuous lines of twisted wire junctions, with each junction comprising two twisted wires of the mesh; and a plurality of support wires affixed to the wire mnesh through the associated twisted wire junctions;, wherein the wire netting extends between adjacent roof supports and is secured to the roof structure and is configured such that the netting is capable of withstanding a 165kg human falling onto the mesh from a height of 1400mm. 19. A roof structure as claimed in claim 18, wherein both ends of at least some of the support wire arrangements are secured to the roof structure.
2. 390877-1 COMS ID No: SBMI-01271 900 Received by IP Australia: Time 13:32 Date 2005-05-30 30-MAY-2005 15:29 A J PnRK 30-PY-00515:9 93 PRK64 4 472 3356 P.20/27 0 -16- A roof structure as claimed in claim 18 or 19, wherein the wire netting is as claimed in any Ct oneof claims Ito 17. o) 21. A method of installing safety netting on a roof structure, the method including: laying wire netting according to any one of claims I to 17 between adjacent roof supports; and o0 securing both ends of at least some of the support wire arrangements to the roof structure. o) 22. The method according to claim 21, wherein at least a majority of the support wire arrangements are secured at both ends thereof. Cl23. The method according to claim 21 or 22, wherein the wire netting is provided in the form of a roll. 24. The method according to claim 23, wherein the roll of netting is laid onto the roof structure with the outer end of the roll having the associated ends of the support wire arrangements affixed to a top plate or adjacent purlin of the roof structure; the netting is rolled to the pitch of the roof structure; and the support wire arrangements are affixed to the apex of the roof structure. The method according to claim 24, wherein the roll of netting is laid onto the roof structure with the outer end of the roll having the associated ends of the support wire arrangements affixed to a top plate or adjacent purlin of the roof structure;, the netting is rolled over the top of the pitch of the roof structure to the opposite outside edge of the roof structure; and the support wire arrangements are affixed to thie top plate or adjacent purlin. 26. The method according to any one of claims 18 to 25, wherein insulating material is placed on the installed netting; and roofing material is placed thereon. 27. A method of installing safety netting on a roof structure as claimed in any one of claims 18 to 26, substantially as herein described with reference to any embodiment disclosed. Dated this 'ay of MI2005 By their Patent Attorneys AJPARK On beafo Aplicant Per: 3"077-1 COMS ID No: SBMI-01 271 900 Received by IP Australia: Time 13:32 Date 2005-05-30