GB2404215A

GB2404215A - Security shutter

Info

Publication number: GB2404215A
Application number: GB0317210A
Authority: GB
Inventors: Graham Edwin Danks
Original assignee: INSULATED ROLLER SHUTTER PRODU
Current assignee: INSULATED ROLLER SHUTTER PRODU
Priority date: 2003-07-23
Filing date: 2003-07-23
Publication date: 2005-01-26
Anticipated expiration: 2023-07-23
Also published as: GB0317210D0; GB2404215B

Abstract

A security shutter comprises a plurality of elongate laths 22 connected together along adjacent longitudinal side edges 23, 24 so as to be articulated with respect to each other. At least some of the laths 22 are provided with at least one elongate reinforcing member 7 of cut-resistant ceramic material extending lengthwise of the lath 22. The ceramic material may be wrapped in an outer skin of a fibre reinforced resin matrix. Each reinforcing member 7 may be in the form of a rigid rod or bar. Each lath 22 may comprise a facing strip to which the reinforcing members 7 are secured. Each lath 22 may further comprise a backing strip defining a cavity with the facing strip. The cavities 25 may contain insulation material 27 which may be in the form of inserts each provided with a formation to receive a reinforcing member 7.

Description

24042 1 5

SECURITY SHUTTER

This invention relates to security shutters for access openings such as doors and windows.

It is known to provide doors and windows with security shutters to prevent unauthorised access. Such shutters are widely used to prevent burglars obtaining access to business premises outside normal working hours when the business is closed and the premises are empty. The shutters cover the doors and windows and prevent or inhibit forced entry.

Known security shutters typically comprise an assembly of elongate members commonly referred to as laths arranged horizontally and connected together along adjoining longitudinal side edges by articulated joints that permit relative pivotal movement of the laths to enable the shutter to be rolled-up, folded or otherwise retracted so that the doors or windows can be opened when the business is open and the premises are occupied.

The laths are usually made of metal, for example steel or aluminium, which are normally resistant to impact forces from hammers or the like.

However, known shutters with metal laths are increasingly at risk from attack with powerful cutting equipment such as high speed disc cutters that can cut an opening in the shutter relatively easily to allow a burglar to gain access to the premises.

The present invention has been made from a consideration of the foregoing problem.

More especially, the present invention seeks to provide a security shutter that is resistant to attack by cutting equipment.

It is a preferred object of the present invention to provide a security shutter with reinforcing means to prevent or inhibit attack by cutting equipment.

According to a first aspect of the present invention, we provide a security shutter comprising a plurality of elongate laths connected together along adjacent longitudinal side edges so as to be articulated with respect to each other wherein at least some of the laths are provided with an elongate reinforcing member of cut-resistant ceramic material extending lengthwise of the lath.

By this invention, the ceramic material of the reinforcing members is highly resistant to cutting and prevents or inhibits any attempt to obtain entry by cutting through the shutter.

Only some of the laths may be provided with reinforcing members to reduce cost and/or weight of the shutter. For example, alternate laths may be provided with reinforcing members. In general, the number and spacing of the reinforcing members should be sufficient to prevent an opening being cut in the shutter to permit access to the premises being protected by the shutter. In some arrangements, all of the laths may be provided with reinforcing members.

Preferred ceramic materials are those which combine high hardness with low density enabling reinforcing members to be provided that are both strong and lightweight. Suitable ceramic materials are sintered high alumina content ceramics, preferably containing at least 90% alumina and more preferably at least 95% alumina.

Ceramic materials are typically stronger in compression than tension and may craze under impact forces, for example when struck. Accordingly, the ceramic material is preferably wrapped in an outer skin of a fibre reinforced resin matrix that bonds to the ceramic material and provides the required tensile strength.

The fibres may be continuous fibres in any form such as a woven strip, tape or in bundles. Suitable fibres include glass, aramid, PBO, polyethylene or carbon fibres. The resin matrix may be any type that can impregnate the fibres and bond to the ceramic material such as epoxy, polyester, polyurethane, acrylic or phenolic resins.

In this way, the ceramic material provides an inner core and the fibre reinforced resin matrix forms an outer skin which hardens so that the reinforcing member is in the form of a rigid rod or bar. The reinforcing member is preferably of uniform cross-section throughout its length and may be of round, oval, square, rectangular or any other cross-section as desired.

Preferably, each lath comprises a metal facing strip and the reinforcing members are located behind the facing strips so as to be concealed behind the shutter when the shutter is in its operable position covering an access opening. In this way, the reinforcing members are not readily accessible from the outside of the premises being protected by the shutter and any attempt to remove the reinforcing members is hindered.

In one embodiment, the reinforcing members are secured to the rear surface of the facing strips by any suitable means, for example by bonding with an adhesive.

In another embodiment, each lath further comprises a metal backing strip defining a cavity with the facing strip and the reinforcing members are located in the cavities.

The reinforcing members may be secured to the rear surface of the facing strips but more preferably the reinforcing members are secured to the front surface of the backing strips by any suitable means, for example by bonding with an adhesive.

In this way, the reinforcing members are less susceptible to damage by impact forces applied to the facing strips, for example by striking the facing strips with a hammer. Moreover, even if the reinforcing members are dislodged from the backing strips by impact forces applied to the facing strips, they remain within the cavities and the resistance of the shutter to attack by cutting equipment is not reduced to any significant extent.

The cavities may contain insulation material. The insulation material may be in the form of a pre-formed insert for location in the cavities. The inserts may be provided with a formation to receive the reinforcing members.

According to a second aspect of the present invention, we provide a lath for a security shutter, the lath comprising an elongate metal strip having longitudinal edge formations for connecting the strip to an adjacent strip for relative pivotal movement about a longitudinal axis, and an elongate member of cut-resistant ceramic material extending lengthwise of the strip on one side.

The lath may comprise a metal facing strip with the cut-resistant member secured to the back of the facing strip, for example by adhesive bonding.

Alternatively, the lath may comprise metal facing and backing strips defining a cavity with the cut-resistant member located in the cavity, preferably secured to the front of the backing strip, for example by adhesive bonding.

According to a third aspect of the present invention, we provide a method of reinforcing a security shutter by providing one or more laths of the shutter with an elongate member of cut-resistant ceramic material to resist attack with cutting equipment.

The ceramic material may be in the form of an elongate rod or bar extending lengthwise of the lath.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings wherein: Figure 1 is a transverse section through a portion of a security shutter according to a first embodiment of the invention; Figure 2 is a transverse section through a portion of a security shutter according to a second embodiment of the invention; Figure 3 shows a modification to the security shutter of Figure 3; and Figure 4 is a perspective view of the reinforcing member of the laths shown in Figures 1 to 3 with part of the fibre reinforced skin removed to show the ceramic core.

Referring first to Figure 1 of the accompanying drawings, there is shown a first embodiment of a security shutter 1 for an access opening (not shown) of a building such as a door or window. The shutter 1 comprises a plurality of elongate laths 2 (three shown in Figure 1) connected together along adjoining longitudinal side edges 3, 4.

In use, the laths 2 extend horizontally across the opening and the ends are received in channel section guides (not shown) secured on each side of the opening. The guides facilitate rolling the shutter 1 up and down to uncover/cover the opening as desired. The shutter 1 is stored in a housing (not shown) secured above the opening when not in use and can be extended from the housing when it is desired to cover the opening.

The shutter 1 may be extended/retracted manually. Alternatively, the shutter 1 may be extended/retracted by drive means, for example a reversible electric motor. A fastening device (not shown) may be provided to secure the shutter 1 in the extended position.

In this embodiment each lath 2 is in the form of a metal strip, for example steel or aluminium strip. The metal strip may be formed in long lengths, for example an extrusion, from which the laths 2 can be cut to the required length for the width of the opening to be protected.

The longitudinal side edges 3, 4 of the laths 2 are folded over to form integral hinge formations 3a, 4a of part circular section. The hinge formations 3a, 4a on adjacent side edges 3, 4 of adjoining laths 2 are engageable to provide limited pivotal movement between the laths 2 about a longitudinal axis to allow the shutter 1 to be rolled-up/rolled-down to uncover/cover the opening as previously described.

Each lath is also shaped between the longitudinal side edges 3, 4 to provide a convex outer or front surface 5 which in use faces to the outside of the opening being covered, and a concave inner or rear surface 6 which in use faces to the inside of the opening.

In accordance with the present invention, elongate reinforcing members 7 are secured to the inner surface 6 of at least some of the laths 2. In this embodiment, reinforcing members 7 are shown secured to alternate laths 2 but it will be understood that this is not essential and that other arrangements of the reinforcing members 7 may be employed as desired.

In general, the number and spacing of the reinforcing members 7 is chosen to prevent an aperture being cut in the shutter 1 large enough for a person to get through.

The reinforcing members 7 may be secured to the inner surface 6 by any suitable means, for example by adhesive bonding. Alternatively or additionally, we may provide a cover strip (not shown) secured to the inner surface 6 to prevent the reinforcing members 7 being detached from the shutter 1 by impact forces.

Each reinforcing member 7 is similar and as best shown in Figure 4 is in the form of an elongate rigid rod 8 of rectangular cross-section. It will be understood, however, that the rod may be of square, circular or other cross-section as desired. The rod 8 comprises an inner core 9 made up of a plurality of blocks 9a of ceramic material secured together and an outer skin 10 of fibre reinforced resin material enclosing the blocks 9a.

A suitable ceramic material is a sintered high alumina content ceramic with an alumina content of at least 90% and preferably at least 955to.

This material has a high hardness that resists cutting and a low density that reduces the weight of the reinforcing members 7. It will be appreciated, however, that other ceramic materials may be employed.

The blocks 9a of ceramic material may be secured together by adhesive to form rods 8 of any desired length for a given application. Suitable adhesive include epoxy, polyurethane, acrylic, cyanoacrylate, polysulphide. The ceramic core 9 is strong in compression but weak in tension and may craze under impact forces, for example when struck.

The outer skin 10 provides the core 9 with tensile strength to withstand impact forces when struck. The outer skin 10 may be formed by continuous fibres impregnated with a resin matrix wrapped around the core 9. The fibres can be in any form such as woven, tape or in bundles and may be of any suitable type, for example glass, aramid, PRO, polyethylene, or carbon fibres. The resin matrix may be of any suitable type that impregnates the fibres and bonds to the ceramic material, for example, epoxy, polyester, polyurethane, acrylic, phenolic.

In use, when the shutter 1 is extended to cover an access opening and secured, the reinforcing members 7 are concealed behind the laths 2 and their presence and position is not apparent to a potential burglar. If an attempt is made to cut an aperture in the shutter 1 using a disc cutter or other high powered equipment capable of cutting through the metal laths 2, the disc comes into contact with on or more of the reinforcing members 7. The ceramic core 9 of the reinforcing members 7 is resistant to cutting and prevents an aperture being cut in the shutter 1 large enough for a person to pass through. In this way, when the shutter 1 is extended to cover the opening, it provides an effective barrier against attempts to gain access to the building by cutting through the shutter 1.

Referring now to Figure 2, there is shown a second embodiment of a security shutter 21 according to the present invention which comprises a plurality of elongate laths 22 connected together along adjoining longitudinal side edges 23,24 by engagement of integral hinge formations 23a, 24a that permit limited pivotal movement of the laths 22 relative to each other about a longitudinal axis for extending/retracting the shutter 21 as described previously.

In this embodiment, each lath 22 comprises an assembly of two identical metal strips 22a, 22b connected together by engagement of the hinge formations 23a, 24a to define an internal cavity 25 of rectangular cross section. In use, the metal strip 22a is a facing strip on the outside of the opening being protected and the metal strip 22b is a backing strip on the inside of the opening. The metal strips 22a, 22b may be cut to length from a metal strip of long length for assembly to form laths 22 of the required length for the width of the opening to be protected.

In this embodiment, two reinforcing members 7 are located within the cavities 25 of all the laths 22 and are secured to the inner surface 26 of the backing strip 22b. In this way, the reinforcing members 7 are spaced from the front surface of the lath 22 and the risk of the reinforcing members 7 being damaged by impact forces applied to the shutter 21 is reduced. Furthermore, even if the reinforcing members 7 are dislodged from the backing strips 22b they remain within the cavities 25 and are still effective to resist cutting through the shutter 21 with a disc cutter or the like to form an aperture for a person to get through.

In a modification (Figure 3), the cavities 25 are provided with insulation material in the form of a pre-formed insert 27 of rectangular section with a longitudinal channel 28 to receive the reinforcing members 7. The inserts 27 may be made of any suitable material and are shaped to substantially fill the cavities 25. In this embodiment, the reinforcing members 7 are secured to the backing strips 22b but they could be loose and held in place by the inserts 27 or secured in the channel 28.

It will be understood that the invention is not limited to the embodiments above-described and that the concept of providing a shutter curtain with a member of cut-resistant ceramic material may be applied to other types and constructions of shutter curtains employed to prevent unauthorised access to buildings through doors and windows.

For example, while the invention has been described with particular reference to shutter curtains that can be extended/retracted in a vertical direction, it can be applied to shutter curtains that can be extended/retracted in a horizontal direction as well as to shutter curtains that can be folded in a concertina fashion horizontally or vertically.

Other constructions and applications of the invention will be apparent to those skilled in the art.

Claims

1. A security shutter comprising a plurality of elongate laths connected together along adjacent longitudinal side edges so as to be articulated with respect to each other wherein at least some of the laths are provided with an elongate reinforcing member of cut-resistant ceramic material extending lengthwise of the lath.

2. A security shutter according to claim l wherein alternate laths are provided with reinforcing members.

3. A security shutter according to claim l wherein all of the laths are provided with reinforcing members.

4. A security shutter according to any preceding claim wherein the ceramic material combines high hardness with low density.

5. A security shutter according to any preceding claims wherein the ceramic material has a high alumina content.

6. A security shutter according to claim 5 wherein the ceramic material contains at least 90% alumina.

7. A security shutter according to claim 6 wherein the ceramic material contains at least 95% alumina.

8. A security shutter according to any preceding claim wherein the ceramic material is wrapped in an outer skin of a fibre reinforced resin matrix that bonds to the ceramic material.

9. A security shutter according to claim 8 wherein the fibres are continuous fibres.

10. A security shutter according to claim 8 or claim 9 wherein the fibres are in the form of a woven strip, tape or in bundles.

11. A security shutter according to any one of claims 8 to 10 wherein the fibres are selected from the group comprising glass, aramid, PBO, polyethylene and carbon fibres.

12. A security shutter according to any one of claims 8 to 11 wherein the resin matrix impregnate the fibres and bonds to the ceramic material.

13. A security shutter according to any one of claims 8 to 12 wherein the resin matrix is selected from the group comprising epoxy, polyester, polyurethane, acrylic and phenolic resins.

14. A security shutter according to any preceding claims wherein the each reinforcing member is in the form of a rigid rod or bar.

15. A security shutter according to any preceding claim wherein each reinforcing member is of uniform cross-section throughout its length.

16. A security shutter according to any preceding claim wherein each reinforcing member is of round, oval, square, or rectangular crosssection.

17. A security shutter according to any preceding claim wherein each lath comprises a metal facing strip and the reinforcing members are located behind the facing strips so as to be concealed behind the shutter when the shutter is in its operable position covering an access opening.

18. A security shutter according to claim 17 wherein the reinforcing members are secured to the rear surface of the facing strips.

19. A security shutter according to claim 17 wherein each lath further comprises a metal backing strip defining a cavity with the facing strip and i the reinforcing members are located in the cavities.

20. A security shutter according to claim 19 wherein the reinforcing members are secured to the rear surface of the facing strips.

21. A security shutter according to claim 20 wherein the reinforcing members are secured to the front surface of the backing strips.

22. A security shutter according to any of claims 19 to 21 wherein the cavities contain insulation material.

23. A security shutter according to claim 22 wherein the insulation material is in the form of a pre-formed insert for location in the cavities.

24. A security shutter according to claim 23 wherein the inserts are provided with a formation to receive the reinforcing members.

25. A lath for a security shutter according to claim 1, the lath comprising an elongate metal strip having longitudinal edge formations for connecting the strip to an adjacent strip for relative pivotal movement about a longitudinal axis, and an elongate member of cut- resistant ceramic material extending lengthwise of the strip on one side.

26. A method of reinforcing a security shutter by providing one or more laths of the shutter with an elongate member of cut-resistant ceramic material to resist attack with cutting equipment.

27. A security shutter substantially as hereinbefore described with reference to Figures I and 4 of the accompanying drawings.

28. A security shutter substantially as hereinbefore described with reference to Figures 2 and 4 of the accompanying drawings.

29. A security shutter substantially as hereinbefore described with reference to Figures 2 and 4 of the accompanying drawings as modified by Figure 3 of the accompanying drawings.

30. A method of reinforcing a security shutter substantially as hereinbefore described with reference to the accompanying drawings.