AU712342B2

AU712342B2 - Fence-mountable barriers

Info

Publication number: AU712342B2
Application number: AU47903/96A
Authority: AU
Inventors: Kerran Campbell; Lynn Kilpatrick
Original assignee: Gryffin Pty Ltd
Current assignee: Gryffin Pty Ltd
Priority date: 1996-03-06
Filing date: 1996-03-06
Publication date: 1999-11-04
Anticipated expiration: 2016-03-06
Also published as: AU4790396A

Description

AUSTRALIA

P/00/011 28/5/91 Regulation 3.2 Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventors: Address for Service: Invention Title: TO BE COMPLETED BY APPLICANT GRYFFIN PTY LTD KERRAN CAMPBELL and LYNN KILPATRICK CALLINAN LAWRIE, 278 High Street, Kew, Victoria 3101, Australia "FENCE-MOUNTABLE BARRIERS" The following statement is a full description of this invention, including the best method of performing it known to us:- 6/3/96JB8615.CS,1 FENCE-MOUNTABLE BARRIERS This invention relates to fence-mountable barriers. More particularly it relates to barriers which may be mounted on or adjacent to walls or fences to inhibit the scaling thereof.

BACKGROUND OF THE INVENTION In the field of high security perimeter fencing there are three basic components that any system should address: Detect. Delay. Respond. Once the overall risk factor has been established, a balance should be established between these three factors. Assuming that an attempt to breach the boundary can be detected (by an alarm system, for example) then a level of difficulty in penetrating or surmounting the barrier (wall, fence) needs to be established to match the estimated response time (the delay in getting appropriate security staff to point of incidence). This period is generally accepted to be four minutes. At present, assuming that the barrier is strong enough to provide the necessary delay in the penetration attempt, one looks at increasing the delay time at the top of the barrier. Options commercially available at present range from traditional agricultural barbed wire or revolving ooo• spikes, through razor ribbon, to tubular air conditioning ducting.

The disadvantages in spikes and razor ribbon are not only that their appearance precludes them from certain applications but that the spikes and barbs are a natural anchor for breaching aids and in fact can aid the climber to reach the apex of the fence and help to anchor his or her equipment (mattress, blanket etc.) in place.

6/396JB861 5.SPE,2 A common alternative in current use is the tubular drum. Manufactured from numerous materials in various forms around the world, it has an advantage in that it has a smooth surface and, assuming that it is mounted on a structure with a smooth face, gives no opportunity for the use of grappling hooks. A disadvantage with this alternative is that in the event of a successful anchoring of a rope over the barrier and possibly aid from the other side, its smoothness allows for a person to be hauled over quickly and quietly, in fact it is possible with the help of a vehicle to get a considerable amount of people over in a very short period of time. There are two other techniques for defeating this system each of which is not in the public domain.

Another alternative trialled in North America and Britain lies in manufacturing a mesh fence in the form of a curve from its base to a point whereby the climber is climbing the inside of the curve until he reaches a point where the fence does not afford him any more foot holds. At this point he is at the apex and innermost point of the fence and needs to get his feet up and over to be able to climb onto the fence. The general practice is to dispose barbed wire or razor ribbon at this point. This fence has the climbing resistance but has numerous disadvantages not only in its difficulty in manufacture and installation.

It is an object of the proposed invention to overcome shortcomings referred to in the alternatives listed above.

SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a barrier to hinder persons attempting to scale a wall or fence to the outside, including a 3 6/3/96JB8615.SPE,3 M M a plurality of members longitudinally spaced with respect to the wall or fence by so small a distance as to prevent passage of a small person between said members, said members extending downwardly and away from the general plane of said wall or fence, the ends of the members nearer the wall or fence are affixed adjacent a longitudinal edge of a cowl or hood-like member, the other longitudinal edge of which is adapted to be fitted along the general plane of the wall or fence.

Preferably the ends of the members nearer the wall or fence are affixed adjacent a longitudinal edge of a cowl or hood-like member, the other longitudinal edge of which is disposable along the top of the wall or fence, such that the fixed ends of the members are horizontally spaced from the general plane of the wall or fence.

*W Preferably the horizontal spacing of the fixed ends of the members from the o° wall or fence is such that a person attempting to scale the wall or fence with the

S*°

V. aid of a rope or similar article is 90% or more of a body length from the inner side ii of the wall or fence.

Preferably the cowl or hood-like member is arcuate and convex-upwards in cross-section, the arc being of more than 901 but less than 1800 whereby the members are downwardly declined by an angle of between 0 and The members preferably are manufactured from a substantially rigid material such as rolled or laterally deformed galvanised steel plate. Preferably the members S are elongate or fingerlike and are at least a body length long. The members may be fixed to the cowl or hood-like member by welding, rivets, bolts or other means or may be welded to members which are fixed to the cowl or hood-like member. The barrier may be constructed in discrete lengths which can be joined together to form a contiguous longitudinal barrier atop a wall or fence.

24/08/99, td8615.spe,4 0 0 The cowl preferably has smooth imperforate surfaces. Preferably it is manufactured from a material or materials strong enough not to distort under load and to withstand relevant wind loading. The shape of the cowl may be reinforced by ribs having profiles generally conforming to that of the cowl. The ribs may be provided with means for securely receiving members. It is highly preferable that the whole structure is manufactured with no grip points. It is also highly preferable that the base of the radius curve of the cowl starts at the top of the wall or fence on the side opposite to the attack side. The distance that the cowl protrudes into the attack side is important in that it should be sufficient to prevent a climbing rope being near enough to the inner vertical surface of the fence or wall such that that inner surface could be an aid to a climber. The length and angle of declination of the members are such that when a climber using a rope reaches the underside of the cowl, he will need to leave the rope to climb out and downward along the members, the rope now being far enough from him as to be' of no further use. With the use of stiff metal members, there is the distinct likelihood of them permanently distorting when interfered with in the process of a person trying to surmount them. This is often seen as an advantage as it is a visual sign that an attempt to breach has been made, whether successful or not.

One purpose of the invention is to prevent a fence or wall being traversed by a person aided by simple climbing aids such as rope etc. The basic principle of the invention is that a person using a form of rope to scale a fence fitted with the invention, will reach the undersurface of the cowl and be restricted by the members from obtaining ready access to the upper side of 6/3/96JB8615.SPE,5 the cowl. This results from the fact that a rope, once thrown over the fence and weighted or anchored to the other side, will fall between the members.

The length of the members and their downward angle requires the person to climb out along to the end of the members and then onto and over them without the aid of any foot or hand holds. The cowl is designed to be deep enough that when a rope is hanging between the members at their base, it is far enough away from the vertical surface of the fence as to prevent that vertical surface being used as an aid. In addition, whereas a simple large diameter metal drum presents difficulties in scaling but can be scaled with the aid of a rope fixed to a point outside the fence or wall, the present invention °e ~has the added advantage that the fixed members prevent a person being hauled over the wall by persons or machine on the other side.

The invention is more visually appealing and less aggressive than spikes or razor ribbon. It does not have the disadvantage of the anchoring ability of spikes and razor ribbon. The members which are a significant part of the 0- invention not only force the climber down and away from the apex of the °eo° fence but also prevent his being pulled over by a force on the other side of the SaSS fence. The distance that the cowl extends from the inner vertical surface of the fence prevents it from becoming an aid.

DESCRIPTION OF PREFERRED EMBODIMENTS In order that the invention may be clearly understood and readily put into practical effect, preferred non-limitative embodiments of a fencemountable barrier will now be described with reference to the accompanying drawings in which:- 6/3/96JB861 5.SPE,6 Figure 1 is a downward perspective view, partly cut away, from the inner or attack side of a wall of an embodiment of the invention adapted for mounting on a wall; Figure 2 is a downward perspective view, also partly cut away, of another embodiment adapted for mounting on posts or poles; Figure 3 is a view from one end of the embodiment shown in Figure 2; Figure 4 is an enlarged view of the region denoted by the letter B in the embodiment shown in Figure 2 being the interface between the cowl and the fingers; and Figure 5 is an enlarged view of the region denoted by the letter A in the co ~view of the embodiment shown in Figure 3.

In Figure 1 the numeral 10 designates generally a length or section of a fence-mountable barrier fixed to a wall 12. The length of barrier includes a plurality of downwardly and inwardly projecting longitudinal members or fingers 14 horizontally spaced from, and longitudinally spaced with respect to, wall 12, said fingers 14 being of galvanised steel. The spacing between the SeeS fingers is such that a person cannot pass between adjacent fingers. The barrier also includes an arcuate curved cowl 16 periodically reinforced by ribs 18 having profiles generally conforming to the arc of the cowl. The fingers 14 are securely mounted at their ends nearer the wall by welding to a hollow member 20, of rectangular cross-section, which is mounted securely along the inner, or free, longitudinal edge 22 of cowl 16 in receiving means 24 extending between the inner or free ends of ribs 18. The hollow member 20 is also secured to the free edge 22 of cowl 16. The outer ends 28 of the ribs are 6/3/96JB861 5.SPE,7 affixed to mounting brackets 26 which in turn are affixed to the upper edge of wall 12 so that the outer longitudinal edge 30 of cowl 16 is aligned with the outer face of the wall 12. The cowl, which is formed from galvanised steel plate, curves inwardly of said wall, and the members fixed at the inner longitudinal edge of the cowl extend downwardly and away from the wall.

In Figures 2, 3, 4, and 5, a length of barrier, designated generally by the numeral 10Oa, is substantially as shown in Figure 1, apart from the provision of a downwardly bent cowl portion 23 along the inner longitudinal edge 22a of cowl 16a. Barrier length 10Oa is depicted as mounted on steel I beams 32 which can be deployed within or adjacent an existing wall or fence or on which a wall or fence may be fixed, eg, by welding.

In Figure 3 the numeral 34 denotes the centre of curvature of cowl 16a and of the upper edge of rib 18, while the numeral 36 denotes the centre of curvature of the lower edge 38 of rib 18. The extent of curvature and the size of the 'radius of curvature' of the cowl are such that a person attempting to scale the wall from the inside will have to first climb up an aid such as a rope oil• without the assistance of contact with the wall and then climb downwardly and along fingers 14 in order to clamber round them and get over the wall.

The lengths of fingers 14, indicated by measurement 39, are at least a standard body length, i.e. about 170 cm. The free ends 40 of each of fingers 14 taper to a point thereby increasing the difficulty of clambering round them.

It will be appreciated that he free ends 40 must be at a height above the ground to render it very difficult, if not impossible, for a person to jump up and grasp the fingers.

6/3/96JB8615.SPE8 M A means of affixing fingers 14 adjacent free end 22a of cowl 16a is shown in Figure 4 and 5. Fingers 14 are arc welded to hollow rectangular bar which is bolted to receiving means 24 disposed at the free ends of ribs 18.

The heads 40 of bolts 42 are hidden by cowl 16a and portion 23 of cowl 16a is fixed to hollow rectangular bar 20 by rivets 44. The nuts 46 on bolts 42 are locked in place after tightening by conventional means, thereby making it very difficult to dismantle the resulting assembly. The ribs 18 are welded on to the underside of cowl 16a and do not have projections or flanges which might provide grip points and thereby enable a person attempting to surmount the

I'

t barrier some purchase. Adjoining lengths or sections of barrier 10 or 10Oa may o be securely linked by bolts passing through overlapping protruding ends of receiving means 24 and hollow rectangular bars ooo° It will be appreciated that not only is a fence or wall provided with a o:o barrier as described above very difficult to scale from within, but also it is more difficult to scale from without, generally requiring the assistance of a

C

ladder or grappling hook and rope.

ease It is believed that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts and that changes may be made in the form, construction and arrangement of the fence-mountable barriers described without departing from the scope and spirit of the invention or sacrificing all of its material advantages, forms hereinbefore described being merely preferred embodiments hereof.

6/3/96JB8615.SPE,9

Claims

1. A barrier to hinder persons attempting to scale a wall or fence to the outside, said barrier including a plurality of members longitudinally spaced with respect to the wall or fence by so small a distance as to prevent passage of a small person between said members, said members extending downwardly and away from the general plane of said wall or fence, the ends of the members nearer the wall or fence are affixed adjacent a longitudinal edge of a cowl or hood-like member, the other longitudinal edge of which is adapted to be fitted along the general plane of the wall or fence.

2. A barrier as claimed in claim 1 wherein the horizontal spacing of the fixed ends of the members from the wall or fence is such a person attempting to scale the wall or fence with the aid of a rope or similar article is at least a body length from the inner side of the wall or fence.

3. A barrier as claimed in claim 1 wherein the cowl or hood-like member is arcuate and convex-upwards in cross-section, the arc being of more than 901 but *000 less than 1800 whereby the members are downwardly declined by an angle of between 00 and 900.

4. A barrier as claimed in anyone of the preceding claims, wherein the members are manufactured from a substantially rigid material.

5. A barrier as claimed in anyone of the preceding claims wherein the members are elongate or fingerlike and extend at least a standard body length.

6. A barrier as claimed in any one of preceding claims, wherein the cowl or hood-like member has smooth imperforate surfaces.

7. A barrier as claimed in any one of claims 1 to 6, wherein the cowl or hood-like member is provided with a plurality of ribs having profiles generally conforming to that of the cowl or hood-like member.

8. A barrier as claimed in claim 7 wherein at least some of said plurality of ribs are provided with means for securely receiving said members. 24/08/99, td8615.spe,10

9. A barrier as claimed in claim 8 wherein said means for securely receiving said members are provided adjacent the longitudinal edge of said cowl or hood-like member remote from said wall or fence.

A barrier as claimed in claim 7 wherein at least some of said plurality of ribs are provided with means for securely attaching said barrier on said wall or fence.

11. A barrier as claimed in claim 7 wherein at least some of said plurality of ribs are provided with means for securely mounting said barrier adjacent said wall or fence.

12. A barrier as claimed in any one of claims 3 to 11 wherein the starting point of the arc of the cowl or hood-like member nearer said wall or fence is located adjacent the top of the outer side of said wall or fence.

13. A barrier substantially as hereinbefore described with reference to any one of the accompanying drawings. DATED this 24th day of August, 1999. GRYFFIN PTY LTD By their Patent Attorneys: SL** CALLINAN LAWRIE 24/08/99, td8615.spe, 11