SECURITY FENCE

Abstract: A security fence mounted to a stable base (22) comprises multiple laterally spaced fence posts (12), interconnected with horizontal rails (14), Each said fence post comprises a lower end portion (18) anchored to a foundation (20) in the stable base (22) with the remaining major portion (15) of the height thereof inclined at a mean angle of between 50° to 65° to the horizontal, the posts being inclined to a common side and extending, preferably arcuately, to a point wherein said upper terminal end portion (24) is positioned so as to preclude direct simultaneous physical access to said upper terminal end portion (24) and either said base (22) or the foot (at 26) of the inclined portion (15). Fence panelling (16) is fixed to and between said posts and extends over the height thereof. An extension (30) may be fixed to the upper terminal end portion (24) of each post to project inwardly and downwardly to the common side to which the posts incline, and panelling (32) is mounted on and extends between the extensions (30). A dual fence installation is also described which precludes scaling from both sides.

Description: The present invention is concerned with fences, and more particularely security fences as might be found around confinement areas, prisons, and the like. Such fences also are frequently provided to exclude persons from areas for both protection of the person, as at construction sites, and for protection of the site itself, as at industrial sites, secret installations, and even homes or residential areas. The conventional fence, when a question of security is involved, will normally consist of multiple vertical posts projecting perpendicularly upward from a stable support base, normally the ground, with the posts mounting panelling or partitions which in the most common form will consist of a continuous length of wire mesh. Such basic fences, while providing a barrier against any casual desire to move from one side of the fence to the other, do provide ready handholds and footholds and can be easily scaled by a determined person or persons. In an attempt to enhance the effectiveness of such fences, it has been proposed that angled extensions, with wire strands or the like, be mounted to the upper ends of the posts to extend upwardly and inwardlly toward one side of the fence. Such extensions are normally relatively short with the outer or free edges thereof generally easily accessed by a person giving both a handhold and a foothold on the vertical fence itself. As such, the portion of the barrier which provides the maximum effectiveness, when considering a person of reasonable agility, is at the extreme top of the fence. The fence of the present invention is specifically constructed to provide a positive barrier, against a person attempting to climb the fence, throughout the full height of the fence. In conjunction with the structure of the fence having enhanced barrier forming capabilities, it is also of particular significance that the construction be economically feasible both in materials and installation procedures. In regard thereto, the fence of the invention includes ground-anchored generally upright posts which define the sole supports for the fence and which in turn mount the barrier panelling, normally in the nature of a wire mesh. As such, the materials differ little from those of a conventional fence. According to the present invention there is provided a security fence mounted to a stable base and defining a barrier to preclude passage of a person from a first side thereof to a second side thereof, said security fence comprising multiple laterally spaced fence posts, said fence posts being positioned to define a line dividing an area into first and second sides, each said fence post comprising a lower end portion anchored to the stable base with the remainder of the post supported therefrom and terminating in an upper terminal end portion, each said post, for a major portion of the height thereof terminating at said upper terminal end portion, being continuously inclined towards a common side, at a mean angle of between about 50° to about 65° to the horizontal, and said posts extending inclined to a point wherein said upper terminal end portion is positioned at a height above said base sufficient to preclude direct simultaneous physical access to said upper terminal end portion and said base, and at a position laterally removed from said lower end portion sufficient to preclude direct simultaneous physical access to said upper terminal end portion and the corresponding post below said continuously inclined major portion of that post, there being fence panelling fixed to and between said posts and coextensive with the height thereof. The aspect of the invention considered particularly unique is the formation of the fence posts, in the installed fence, to specifically angle inwardly toward the side of the fence to which a person is to be confined. This inward angling of the fence posts, and hence the entire fence, is effected by utilizing fence posts anchored to project vertically upwardly from the ground or stable base and, at a premediated height, to incline upwardly and laterally, either unidirectionally or preferably arcuately, from the vertically disposed and anchored lower end portions of the posts. The angle of straight-line or arcuate inclination is such as to effectively preclude, due to the "overhung" nature of the fence, throughout at least the major portion of the height thereof, the establishment of a foothold. In other words, anyone attempting to scale the fence would be limited to only the use of his hands for the full effective height of the fence above the point at which a person can reach by standing on the ground. As one tries to scale the fence, the higher one goes, the further one's feet move from the ground and lower portion of the fence. A person attempting to establish both a handhold and a foothold would be positioned substantially on his back, and thus normally incapable of maintaining any sort of foothold. It is contemplated that the inclined portion of the fence extend at a mean angle of between 50°-65° to the horizontal, with the optimum angle being 52°. Advantageously, this inclination can follow an arcuate path which is continuously laterally offset from the vertical and defines an arc of about 60°. The radius of this arc extends approximately 400 cm to 430 cm, and preferably 417 cm (13 feet, 8 inches), from a centre of rotation which may be 40 cm to 45 cm, and preferably 43 cm (1 foot, 5 inches), below the vertical height at which the arc commences. Such a 60° arc has been found to afford a desirable combination of usable area adjacent the fence and a high degree of effectiveness, in combination with maximum strength, in precluding any attempt to scale the fence. The height of the lower generally vertical portion of the fence may be up to 180 cm (or 6 feet), and preferably its height is about 120 cm (or 4 feet). Based on the above, the height of the fence will be up to 520 cm (or 17 feet), and preferably it is approximately 335 cm to 457 cm (11 to 15 feet), depending on the height of the vertical portion, with the inclined portion extending for a height of at least 335 cm (11 feet). Similarly, the lateral reach of the fence, from its anchored base to the upper terminal end portion thereof, will preferably be approximately 200cm to 230 cm, and preferably 218 cm (8 feet). So dimensioned, the upper terminal end portion of the fence will be of a height above the support base, for example the ground, sufficient to preclude direct simultaneous physical access to both this upper end portion and the ground. At the same time, the lateral extent of the upper end portion will be such as to simultaneously preclude direct physical access to the terminal end portion and any portion of the fence below the continuously inclined major portion thereof. As desired, the upper end of the fence, at the terminal end portion, can be finished by an inwardly and downwardly inclined section formed either by reversely turning the upper ends of the posts themselves, or by affixing downwardly and inwardly incline extensions to the post ends. In each case, appropriate panelling, by wire strand, wire mesh, or the like, will extend along the turned end sections. The invention will be described by way of example with reference to the accompanying diagrammatic drawings in which:- Figure 1 is a partial perspective view of a portion of a fence constructed in accord with the present invention; Figure 2 is an enlarged vertical cross-sectional schematic view through the fence of Figure 1; and Figure 3 is a partial perspective of a variation of the invention wherein a dual fence construction is utilized, precluding access from either side of the construction to the other. Referring now more specifically to the drawings, a section of typical fence 10, constructed in accordance with the present invention, has been illustrated, in perspective, in Figure 1. The fence 10 includes multiple laterally spaced generally upright fence posts 12, stabilizing cross rails 14 and fence panelling 16, normally in the nature of wire mesh. As in a conventional fence, the fence posts will be positioned to define a line or barrier dividing an area into opposed or first and second sides to preclude passage from one side to the other. It is a primary intention of the invention to provide a superior barrier while, at the same time, utilising basic fence construction techniques and materials. Pursuant thereto, and noting in particular Figure 2, the fence posts 12 of the fence 10 of the present invention are specifically configured to incline toward one side of the fence and into or over the area to which persons are to be confined or restricted, whether this be within a prison facility or the like or outside a restricted area. The lower end portion 18 of each fence post 12 will normally be anchored within an appropriate concrete foundation or the like 20 provided within a stable base 22, normally the ground. The embedded depth "A" of the anchored lower end 18, while normally approximately 90 cm (or 3 feet), will vary as necessary with ground and climatic conditions. Each post 12, for a major portion (15) of the exposed height thereof, will extend along an inclined, and preferably and as illustrated, a continuously arcing path, terminating in a point of maximum height at the upper terminal end portion 24. While the inclination of the posts 12, may commence immediately at ground level, it is preferred that the inclination of the posts begin at a predetermined point 26 which is spaced above ground level, each post being vertical or perpendicular to the ground in the post portion 13 which extends between the point 26 and portion 18 of the post anchored in foundation 20 in the stable base 22 or the ground. The provision of such a vertical post portion 13, normally of a height "B" of the order of say 120 cm (4 feet), is considered desirable under particular circumstances in order to avoid an unnecessary restriction of the area immediately adjacent the base of the fence, and also for the purpose of providing passage closely adjacent to the fence, for patrols or the like. As will be appreciated, the fence posts 12 all incline to the same or a common side of the fence 10 with the major inclined portion 15 of the posts, and hence the fence, terminating at the upper terminal end portion 24. The upper terminal end portion 24 is positioned at a height above the base or ground 22 sufficient to preclude direct simultaneous physical access to both the upper terminal end portion 24 an the ground. As such, it is contemplated that, in a typical installation, the upper terminal end portion be up to 520 cm and preferably 460 cm (or 15 feet) above ground level and at a height "C" which is 330 cm (11 feet), or so, above the point 26 at which the inclination is initiated. Similarly, the upper terminal end portions 24 are preferably laterally removed or positioned from the vertical portion of the posts, or from the point 26 of initiation of the inclination, by a distance "D", of approximately 220 cm (8 feet). In defining the inclination of the inclined portions 15 of the posts 12, each post will follow an arc of about 60°, defined from a point of rotation 28 on a radius "R" which is approximately 400 to 430 cm, and preferably 420 cm (13 feet, 9 inches) from point 26. Point 28 is at a vertical distance "E" of approximately 45 cm, (1 foot, 6 inches) below the height of point 26, that is the point at which the inclination is initiated, and at a perpendicular distance "F" of about 415 cm (13 feet, 7-1/8 inches) from the lower vertical section of the post 12. Formed in this manner, the point 26, at which the inclination is initiated, the upper terminal end portion 24, and the centre of rotation 28 of each post will define an equilateral triangle, with three included 60° angles. The horizontal at the height of point 26 has been indicated as line x-x in Figure 2. The means inclination to the horizontal x-x, defined by an imaginary line between lower point 26 and upper end portion 24, will optimally be say 52°; and this angle to the horizontal may fall within a range of 50° to 65°. With the posts so configured, a fence defined thereby will be substantially impossible to scale, by a person with normal agility, when moving from the side toward which the inclination is directed. The height of the fence (B plus C) will preclude access to the upper terminal end portion 24 thereof, and the inclination will simultaneously preclude any possibility of one person obtaining a foothold should he attempt to traverse the fence. Thus any one attempting to scale the fence, will be able to rely solely on the strength of his hands and arms and there is no possibility of scaling the fence in the manner in which a conventional vertical fence can be scaled. Further, the task of attempting to negotiate the fence by reliance solely on handholds can be made increasingly difficult by the use of a smaller or more tightly woven mesh toward the upper portion of the fence 10, and/or by using sharp wire for the panelling at the upper regions of the fence. For purposes of additional strength and stability, the laterally spaced fence posts 12 will be braced and interconnected by rails 14 coplanar therewith and welded or otherwise mechanically connected, at the opposed end thereof, to adjacent ones of the posts 12. Such rails will additionally help to support and anchor the panelling or mesh 16 which, as shown in Figures 1 and 2, will be applied to the posts 12 and rails 14 to the side toward which the fence inclines, thus also precluding any possibility of reliance on the rails by anyone attempting to scale the fence. When formed as above described, the use of say 8.9 cm (3-1/2 inches) diameter steel pipe is contemplated for thr posts and rails. As an additional security feature, the upper terminal end portions 24 of the posts can each be provided with a downwardly and outwardly inclined rigid section or extension in the form of struts 30 secured in any appropriate manner, for example by the use of brackets, welding, or the like. These extending struts 30 will in turn mount, stretched transversely therebetween, additional panelling 32 consisting of strands of barbed wire or other forms of wire mesh panelling such as razor wire. In an advantageous construction, the main fence panelling 16 comprises a wire mesh with defined openings of a predetermined size, with the additional panelling 32 comprising a wire mesh with defined openings of a size substantially smaller than said openings of the mesh of the main fence panelling 16, said additional panelling 32 being fixed to and between said posts 12, the main panelling 16 terminating below said upper terminal end portions 24, and the additional panelling 32 extending between the main fence panelling 16 and said upper terminal end portions 24. The wire used in the main fence panelling 16 and/or in the additional panelling 32 may be sharp eg. razor wire. Figure 3 illustrates a variation wherein dual fences 10 are used as a means for precluding movement in both directions. Here, corresponding oppositely inclined posts 12 are provided in pairs and anchored in common footings 20. The posts 12 of each pair incline upward and laterally outward relative to each other from the embedded and anchored adjacent lower end portions 18 to the laterally spaced upper terminal end portions 24. Each set of similarly directed inclined posts 12 will be stabilised by transverse rails 14, and appropriate wire mesh 16 or the like will be secured to the posts 12 and rails 14 of each set to the side toward which the posts 12 incline, thereby providing the fence panelling. The height of the combination fence of Figure 3 will follow the general parameters suggested with regard to the previously described single fence 10. Basically, it is contemplated that the combination fence, at the upper terminal end portions, be approximately 335 to 457 cm (11 to 15 feet) high, with the lateral offset to each side, from the anchored lower end portions, being at least 220 cm (or say 8 feet). It is intended that the fence of the invention provides a situation wherein a person attempting to scale the fence, cannot reach the upper portion of the fence and simultaneously reach any point whereat an appropriate foothold can be obtained; thus he must place reliance solely on whatever handholds might be available. Moreover, the provision of handholds, particularly toward the upper portion of the fence, can be limited by the use of small wire meshing, that is fence wire meshing defining openings of limited size, and/or by employing sharp wire in these upper regions. As suggested in Figure 3, the fence assembly of the invention can be arranged in oppositely inclined pairs of generally identical fences to preclude movement from either side of the fence to the other. Preferably, the dual oppositely inclined fences will have their posts in adjacent pairs mounted in common foundations.

Claims: 1. A security fence mounted to a stable base and defining a barrier to preclude passage of a person from a first side thereof to a second side thereof, said security fence (10) comprising multiple laterally spaced fence posts (12), said fence posts being positioned to define a line dividing an area into first and second sides, each said fence post comprising a lower end portion (18) anchored (at 20) to the stable base (22) with the remainder of the post supported herefrom and terminating in an upper terminal end portion (24), characterized in that each said post (12), for a major portion (15) of the height thereof terminating at said upper terminal end portion (24), is continuously inclined towards a common side, at a mean angle of between about 50° to about 65° to the horizontal, and said posts (12) extending inclined to a point wherein said upper terminal end portion is positioned at a height (B plus C) above said base sufficient to preclude direct simultaneous physical access to said upper terminal end portion (24) and said base (22), and at a position laterally removed from said lower end portion (18) sufficient to preclude direct simultaneous physical access to said upper terminal end portion (24) and the corresponding post (12) below said continuously inclined major portion of the post, and in that fence panelling (16) is fixed to and between said posts (12) and coextensive with the height thereof. 2. A security fence according to claim 1 and further characterized in that an extension (30) is fixed to the upper terminal end portion (24) of each post (12) and projects inwardly and downwardly to the common side to which the posts incline, fence panelling (32) being mounted on and extending between the extensions fixed to the respective posts (12). 3. A security fence mounted according to claim 1, and further characterized in that each said post (12) includes a vertical section (13) extending upwardly from said stable base, and wherein said inclined portion (15) comprising a major portion of the height of the post (12), extends in an arc from the top (26) of said vertical section and terminates at said upper terminal end portion (24). 4. A security fence according to claim 3, and further characterized in that additional security means in the form of struts (30) together with additional fence panelling extends outwardly and downwardly from the upper terminal end portions (24) of said posts (12) and terminates at a vertical level above the tops (26) of the lower vertical sections of the posts (12). 5. A security fence according to claim 4, and further characterized in that said fence panelling (16) comprises a wire mesh with defined openings of a predetermined size, said additional panelling (32) comprising a wire mesh with defined openings of a size substantially smaller than said openings of the main fence panelling (16), said additional panelling (32) being fixed to and between said posts (12), said main fence panelling (16) terminating below said upper terminal end portions (24), and said additional panelling (32) extending between said main fence panelling (16) and said upper terminal end portions (24). 6. The security fence of claim 1 wherein each said post includes a minor portion (13) of the height thereof extending perpendicular to the base (22) generally vertically to a height of up to 180 cm above the base and extending between the anchored lower end portion (18) and the major inclined portion (15). 7. The security fence of claim 1 wherein said major inclined portion (15) of each post (12) is of a generally arcuate configuration. 8. The security fence of claim 1 wherein said upper terminal end portion (24) is at least 330 cm above the anchored lower end portion (18). 9. The security fence of claim 1 including rails (14) engaged with and extending between adjacent posts (12), said rails being coplanar with said posts. 10. The security fence of claim 4 wherein said additional panelling (32) consists of wire strands or wire mesh which panelling (32) terminates in inwardly spaced relation to the posts to the common side to which the posts incline. 11. The security fence of claim 7 wherein the arcuate configuration of the major portion (15) of each post defines an arc of between 55° and 65°, and preferably 60°, from a centre of rotation (28) at a radial distance of (R) between 400 cm and 430 cm, and preferably 417 cm (13 feet, 8 inches). 12. A security fence installation including a first fence (10) as defined in any preceding claim and wherein a second fence is located alongside the first fence, the bases of the two fences being juxtaposed and the bases consisting of lower parts of posts disposed generally vertically and fixed closely adjacent side-by-side in the stable base. 13. A fence installation as claimed in claim 12, and wherein the two fences are generally similar, the one to the other. 14. A fence installation as claimed in claim 12, and comprising generally coextensive first and second sets of aligned fence posts (12), the posts of each set having portions (15) which are continuously inclined to a common side, and with the posts of the first and second sets being inclined to opposite sides from adjacent lower end portions (18) to laterally spaced upper terminal end portions (24), said posts being arranged in pairs of one post from each set, and fence panelling (16) fixed to each set of fence posts coextensive therewith. 15. The security fence installation in claim 13 wherein the inclined portion (15) of each fence post (12) has an arcuate configuration. 16. A security fence mounted to a stable base and defining a barrier as a confinement or exclusive means to preclude passage of a person from a first side thereof to a second side thereof, said security fence (10) comprising multiple laterally spaced fence posts (12), said fence posts (12) being positioned to define a line dividing an area into first and second sides, each said fence post comprising a lower end portion anchored to the stable base with the remainder of the post supported therefrom and terminating in an upper terminal end portion, characterized in that each said post (12) includes a generally vertical section (13) extending upwardly from said stable base (22), and an arcuately inclined portion (15), comprising a major portion of the height of the post, extending upwardly from said vertical section (13) and terminating at said upper terminal end portion (24), said arcuately inclined portion (15) extending through an arc of between 55° and 65°, and preferably 60°, from a centre of rotation (28) at a radial distance (R) of between 400 cm and 430 cm, and being inclined at a mean angle of between 55° and 65° to the horizontal, said posts (12) all being inclined to a common side and extending to a point such that said upper terminal end portion (24) is positioned at a height (B plus C) above said base (22) sufficient to preclude direct simultaneous physical access to said upper terminal end portion (24) and said base (22), and said posts extending to a position so laterally removed from said lower end portion (13) as to preclude direct simultaneous physical access to said upper terminal end portion (24) and the vertical section (13) of that post below said continuously inclined major portion (15) thereof, fence panelling (16) being fixed to and between said posts and extending substantially coextensive with the height thereof, 17. A security fence according to claim 16, and further characterized in that there is included additional security fence means (30) and additional fence panelling (32) which extends downwardly and outwardly from the upper terminal end portions of said posts and terminates at a level which is above the tops of the vertical sections (13) of the posts. 18. A security fence according to claim 17, and further characterized in that said fence panelling (16) comprises a wire mesh with defined openings of a predetermined size, said additional panelling (32) comprising a wire mesh with defined openings of a size substantially smaller than said opening of the mesh of the main fence panelling (16), said mesh of said additional panelling (32) being fixed to and between said posts (12), and in that the main fence panelling (16) terminates at a level below said upper terminal end portion (24), while the additional panelling (32) extends between the main fence panelling (16) and said upper terminal end portion (24).

Inventors: MACDOUGALL, ELLIS CAMPBELL
Applicants: MACDOUGALL, ELLIS CAMPBELL
Application year: 1986
Main classification: E04H17
IPC codes: E04H17