AU694515C

AU694515C - An intruder resistant screen

Info

Publication number: AU694515C
Application number: AU24001/95A
Authority: AU
Inventors: John Charles Pepperell; Norman Cecil Waterman
Original assignee: IPH International Pty Ltd
Current assignee: IPH International Pty Ltd
Priority date: 1994-08-30
Filing date: 1995-06-08
Publication date: 2002-02-21
Anticipated expiration: 2015-06-08
Also published as: AU2400195A; AU694515B2

Description

TITLE "AN INTRUDER RESISTANT SCREEN" FIELD OF THE INVENTION THIS INVENTION relates to an intruder resistant screen particularly useful for both security and insect screening of windows, doorways and the like.

BACKGROUND OF THE INVENTION

Screens or grilles are sometimes used to improve the security of a building. For example, steel bar grilles have been used to deter intruders from entering a premises through a window or door.

When used for a window the steel bar grilles are bolted to a wall surface adjacent the window. When used for a doorway the steel bar grilles are pivotally mounted to the doorway and operate as an extra door.

Steel bar grilles are generally considered unsightly and are therefore usually only used for industrial buildings, shops and some places of business. Furthermore, the spacing between the steel bars of the grilles is usually wide enough to allow bolt cutters or hacksaws to cut the bars and therefore such grilles do not always provide adequate security.

An alternative to steel bar grilles are security screens which are often used to deter intruders from entering a premises through a window or door. Security screens comprise an extruded frame with a wide grate mesh covering the area enclosed by the extruded frame. The wide grate mesh typically has elongate members of 7mm diameter with mesh gaps of approximately 60mm. The mesh is normally fitted into a slot in the frame and is not usually clamped to the frame. One reason for this is because the wide grate mesh is usually made from expanded aluminium which is not suited to bolting due to the spaced small surface areas of the mesh which contact the frame. In addition, the contours of the mesh would require accurate and specific alignment of bolt holes for each screen which is labour intensive. Accordingly, it is possible for a potential intruder to remove the unbolted mesh partly or completely from the frame. Such security screens also suffer from the same disadvantages as steel bar grilles in that the mesh can be cut by bolt cutters or hacksaws.

The above described screens or grilles can provide limited security even when their associated window or door is opened for ventilating a premises. However, these screened or grilles are not effective for insect screening and therefore fine mesh screens are sometimes used in conjunction with security screens or grilles for the purpose of insect screening. The fine mesh is usually either mounted to a wooden frame or mounted to a spline of the extruded frame of the screen in which a rubber strip is used to maintain edges of the mesh in the spline.

The above fine mesh screens are not intruder resistant as the wooden frame can be easily broken or the mesh can be easily removed from the spline. Furthermore, the fine mesh which is used is often made of thin nylon or thin metal strands which can be easily broken. Accordingly, to provide limited security and insect screening both fine mesh screens and security screens or grilles are often used which has the disadvantage of increased manufacturing or installation costs.

SUMMARY OF THE INVENTION It is an object of the invention to provide an intruder resistant screen which overcomes or at least alleviates at least one of the problems associated with prior art screening of doorways, windows or the like. According to one aspect of the invention there is provided an intruder resistant screen including: a frame comprising elongate frame members each having a channel section engaging a respective corner stake in each end thereof; a woven wire intruder resistant mesh covering an opening enclosed by said frame said mesh having spacings between adjacent wefts or warps of no greater than 2.2mm; and a plurality of clamping members co-acting with respective fastening means to thereby clamp said mesh to said frame.

Suitably, each one of said frame members has at least two co-acting said clamping members integral therewith.

Alternatively, each one of said frame members may have a first one of said clamping members integral therewith co-acting with one or more separately formed second said clamping members. Accordingly, the second said clamping members may be non-integral with a said frame member. Suitably, said clamping members extend along the length of a respective frame member.

Alternatively, said second clamping members may include a plurality of washers or shoulder portions of a respective said fastening means. The woven wire is preferably stainless steel wire of a diameter between 0.5mm to 1.2mm.

Suitably, said spacings are in the range between 1mm to 2.1mm.

The frame members may be extruded lengths, roll formed lengths or press formed.

Suitably, the frame members are extruded aluminium lengths.

Preferably, said channel section may be open or alternatively closed. Suitably, said clamping members are located inwardly relative to said channel section.

Preferably, there is a wall section integral with said channel section, said wall section extending inwardly of said channel section and spaced from said clamping members.

Alternatively, one of said clamping members may form part of said wall section.

Preferably, there is a lip section adjacent a free end of said wall, wherein said lip section extends towards said mesh.

Suitably, said lip section may co-act with one of said clamping members to thereby clamp said mesh therebetween.

Suitably, there is a flange section integral with and extending inwardly from said channel section.

Preferably, said flange section and said wall section provide a recess accommodating an edge of a said second one of said clamping members.

Suitably, said flange section abuts said second one of said clamping members .

Preferably, said screen has cover engagement means for allowing a cover strip to be mounted thereto and thereby concealing said fastening means when said screen is viewed from an inner side.

Suitably, said cover engagement means includes two parallel slots. Alternatively, said cover engagement means may be a channel in said frame member.

The fastening means may be rivets or screws. The screws may be self tapping or otherwise. Alternatively, the fastening means may be snap fitments

Suitably, said wall section conceals said fastening means when said screen is viewed from an outer side. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be readily understood and put into practical effect, reference will now be made to preferred embodiments in which: FIG 1 is a perspective view of an intruder resistant screen,

FIG 2 is a cross sectional view through A-A of FIG 1 illustrating a first embodiment of the invention, FIG 3 is an exploded perspective view illustrating how frame members of FIG 2 form a corner section,

FIG 4 is a cross sectional view through A-A of FIG 1 illustrating a second embodiment of the invention,

FIG 5 is a cross sectional view through A-A of FIG 1 illustrating a third embodiment of the invention,

FIG 6 is an oblique cross sectional view through A-A of FIG 1 illustrating a fourth embodiment of the invention, and

FIG 7 is an oblique cross sectional view through A-A of FIG 1 illustrating a fifth embodiment of the invention. PETAI ED PESCRIPTION

With reference to FIG 1 there is illustrated an intruder resistant screen 1 having a frame 2 comprised of elongate frame members 3 with an intruder resistant mesh 4 clamped to frame members 3. Mesh 4 covers the opening enclosed by frame

2. Mesh 4 is a woven grid, of stainless steel wire which has dimensions selected from table 1 below. TABLE 1

Number of Mesh Wire Diameter Mesh open area weft/warp Wires per 25mm in mm spacings in mm

14 x 14 08 298% 01mm

14 x 14 07 362% 11mm

14 x 14 05 310% 13mm

12x 12 10 254% 10mm

12x12 09 332% 12mm

12x 12 07 436% 14mm

12x12 06 518% 15mm lOx 10 1.2 281% 13mm

10x10 10 348% 10mm

10 x 10 09 423% 16mm

10x10 0.8 462% 17mm lOx 10 07 518% 18mm

8x8 12 389% 20mm

8x8 10 452% 21mm

8x8 09 518% 22mm

Referring to FIGS 2 and 3, an embodiment of one of frame members 3 is illustrated. Frame member 3 is formed from extruded aluminium and has a channel section 5 for receiving a corner stake 10 at each of its ends. Accordingly, frame 2 is formed to a desired shape and dimensions by cutting suitable lengths of each frame member 3 and assembling the lengths with mitred corners. Located inwardly of channel 5 is an integral clamping member 6 and a non-integral clamping member 7 which is a separately formed from frame member 3. Both clamping members 6,7 are of an ider'ical length and extend along the length of frame member 3. Spaced holed are drilled along clamping members 6,7 and receive fastening means in the form of a pop-rivets 8 which co-act with clamping members 6,7 to clamp mesh 4 to frame 2.

An integral wall section 9 spaced from clamping members 6,7 also extends inwardly from channel section 5. At the free end of wall section 9 is a lip section 11 which extends towards mesh 4 and co-acts with clamping member 7 to also clamp mesh 4. This therefore provides a clamping arrangement which reduces the possibility of an intruder forcing, for example, a lever between clamping members 6,7.

A flange section 12 integral with an extending inwardly from channel section 5 forms, with wall section 9, a recess 13 which accommodates an edge of clamping member 7 and an edge of mesh 4. Flange section 12 abuts clamping member 7 and assists in keeping clamping members 6,7 parallel during clamping. Further, clamping member 7 has two parallel slots 14,15 for attaching a flexible covering strip 16 which therefore covers the heads of pop-rivets 8.

As shown in FIG 3 two frame members 3 are attached together at a corner of frame 2 by corner stake 10 being inserted into a channel section 5 of two mitred frame members 3. Holes are then drilled into edges of frame members 3 and corner stake 10. Pop-rivets 17 are then inserted for securing frame members 3 to corner stake 10. Illustrated in FIG 4 is a second embodiment of one of frame members 3 which is either roll formed or extruded. In this embodiment clamping member 6 is part of wall section 9 and self tapping screws 18 co- act with clamping members 6,7 to clamp mesh 4 to frame 2.

Referring to FIG 5 a third embodiment of one of frame members 3 is illustrated. Each frame member 3 is press formed to provide a channel 20, integral clamping members 21,22 co-acting with rivets 24 to clamp mesh 4 to frame 2.

There is also a wall section 25 and parallel slots 26,27 for attachment of a cover strip. Frame members 3 are attached by corner stakes inserted in channel 20 as described above.

Illustrated in FIG 6 is a fourth embodiment of one of frame members 3. In this embodiment there are two clamping members 30, 37, wherein clamping member 37 is 0 a free end of lip section 11. An intermediate wall portion 33 provides two channels, one being a clamping member 30 engagement channel 34 for receiving engagement legs of clamping member 30 the other being a mesh receiving channel 36.

The walls of channel 34 have snap fitment protrusions 32 for engagement with snap fitment protrusions 33 at the ends of two parallel legs 35 extending from clamping member 30. Mesh 4 is clamped to frame member 3 by bending and edge of mesh 4 and inserting it into channel 36. Clamping member 30 is then inserted into channel 34 in which snap fitment protrusions act as a fastening means thereby mesh 4 is clamped between clamping members 30 and 37. Referring to FIG 7 a fifth embodiment of one of frame members 3 is illustrated. In this embodiment there is a first clamping member 38 integrally formed with frame member 3. First clamping member 38 is spaced from a wall section 39 and apertures 40 are drilled along the length of clamping member 38 to receive fastening means in the form of pop-rivets 40. Each one of pop-rivets 40 has an associated washer 41 acting as a second clamping means. Accordingly, mesh 4 is clamped to frame 2 between washers 41 and clamping member 38. In an alternative form if the heads of pop- rivets are wide enough, the shoulder portion thereof can act as a clamping member instead of washers 41. A cover strip 42 with a channel 43 can be inserted into a complimentary channel 44 of frame member 3 thereby concealing pop-rivets 40 when viewed from an inner side and wall section 39 conceals pop- rivets 40 when viewed from an outerside. Cover strip 42 has a recess 45 for engagement with a lip section 46 of frame member 3 which assists in maintaining attachments of cover strip 42 to frame member 3.

In use intruder resistant screen 1 may be mounted on hinges in a doorway or secured in any known manner to a window frame. Mesh 4 provides difficulties for intruders as a sufficiently large hole to gain entry cannot be easily sawn or cut by bolt cutters due to the mesh grade which also provides insect screening. Furthermore, when stainless steel mesh 4 is used these difficulties for potential intruders can be compounded due to the properties of stainless steel which can blunt cutting tools.

The clamping of the mesh provides additional intruder resistance in which wall sections 9 (or 25) are located on the outside of the doorway or window so that for example rivets 8 are concealed from a potential intruder.

When viewed on the inside, rivets 8 are hidden by cover 16 which is of a colour matching jaw member 7.

Although the invention has been described with reference to preferred embodiments, it is to be understood that the invention is not limited to the specific embodiments described herein.

Claims

CLAIMS :

1. An intruder resistant screen including: a frame comprising elongate frame members each having a channel section engaging a respective corner stake in each end thereof; a woven wire intruder resistant mesh covering an opening enclosed by said frame said mesh having spacings between adjacent wefts or warps of no greater than 2.2mm; and a plurality of clamping members co-acting with respective fastening means to thereby clamp said mesh to said frame.

2. An intruder resistant screen as claimed in claim 1 , wherein each one of said frame members has at least two co-acting said clamping members integral therewith.

3. An intruder resistant screen as claimed in claim 1 , wherein each one of said frame members has a first one of said clamping members integral therewith co-acting with one or more separately formed second said clamping members.

4. An intruder resistant screen as claimed in claim 2, wherein said clamping members extend along the length of a respective frame member.

5. An intruder resistant screen as claimed in claim 3, wherein said clamping members extend along the length of a respective frame member.

6. An intruder resistant screen as claimed in claim 3, wherein said second clamping members include a plurality of washers or shoulder portions of a respective said fastening means.

7. An intruder resistant screen as claimed in claim 1 , wherein the woven wire is stainless steel wire of a diameter between 0.5mm to 1.2mm.

8. An intruder resistant screen as claimed in claim 7, wherein said spacings are in the range between 1mm to 2.1mm.

9. An intruder resistant screen as claimed in claim 8, wherein the frame members are extruded aluminium lengths.

10. An intruder resistant screen as claimed in claim 1 , wherein said clamping members are located inwardly relative to said channel section.

11. An intruder resistant screen as claimed in claim 1 , wherein there is a wall section integral with said channel section, said wall section extending inwardly of said channel section and spaced from said clamping members.

12. An intruder resistant screen as claimed in claim 11 , wherein one of said clamping members forms part of said wall section.

13. An intruder resistant screen as claimed in claim 11, wherein there is a lip section adjacent a free end of said wall, and wherein said lip section extends towards said mesh.

14. An intruder resistant screen as claimed in claim 12, wherein there is a lip section adjacent a free end of said wall, and wherein said lip section extends towards said mesh.

15. An intruder resistant screen as claimed in claim 13, wherein said lip section co-acts with one of said clamping members to thereby clamp said mesh therebetween.

16. An intruder resistant screen as claimed in claim 14, wherein said lip section co-acts with one of said clamping members to thereby clamp said mesh therebetween.

17. An intruder resistant screen as claimed in claim 11, wherein there is a flange section integral with and extending inwardly from said channel section.

18. An intruder resistant screen as claimed in claim 17, wherein said flange section and said wall section provide a recess accommodating an edge of a said second one of said clamping members.

19. An intruder resistant screen as claimed in claim 18, wherein said flange section abuts said second one of said clamping members.

20. An intruder resistant screen as claimed in claim 1 , wherein said screen has cover engagement means for allowing a cover strip to be mounted thereto and thereby concealing said fastening means when said screen is viewed from an inner side.

21. An intruder resistant screen as claimed in claim 20, wherein said cover engagement means includes two parallel slots.

22. An intruder resistant screen as claimed in claim 20, wherein said cover engagement means is a channel in said frame member.

23. An intruder resistant screen as claimed in claim 1 , wherein the fastening means include rivets or screws.

24. An intruder resistant screen as claimed in claim 1 , wherein the fastening means are snap fitments.

25. An intruder resistant screen as claimed in claim 11, wherein said wall section conceals said fastening means when said screen is viewed from an outer side.