GB1584760A

GB1584760A - Fences

Info

Publication number: GB1584760A
Application number: GB4553577A
Authority: GB
Original assignee: FENSECURE Ltd
Current assignee: FENSECURE Ltd
Priority date: 1978-05-23
Filing date: 1978-05-23
Publication date: 1981-02-18

Description

(54) IMPROVEMENTS RELATING TO FENCES (71) We, FENSECURE LIMITED, a British Company of Rose Street, Bradley, Bilston, West Midlands do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to fences comprising metal pales secured to substantially horizontal rails which are supported by posts or the like.

The invention has been developed for use in a security fence. The purpose of a security fence is to prevent access by unauthorised persons to a secure area enclosed by the fence.

Security fences generally comprise metal posts, metal rails and metal pales, the pales being secured to the rails by fasteners, for example rivets or bolts. The pales are formed of sheet or strip metal and have a cross section including flanges or other formations which stiffen the pales. Nevertheless, known security fences are vulnerable to damage which enables an unauthorised person to move the pales and gain access to the secure area. Such damage can be caused by driving a chisel between a pale and the head of a fastener securing the pale to a rail. In this way, the head can be sheared off the fastener and the rail freed.

It is an object of the present invention to provide a security fence which is less vulnerable than are known security fences to damage which enables unauthorised persons to pass through the fence.

According to the invention there is provided a fence comprising metal pales secured to rails by headed fasteners wherein there are local recesses in surfaces of the pales which face away from the rails (hereinafter called "the front surface"), the recesses surround respective apertures in the pales, the fasteners extend through said apertures and heads of the fasteners are disposed at least partly in the local recesses.

The front faces of the pales will in the use of the invention face outwardy of the secure area enclosed by the fence, presenting an obstacle to intruders. By virtue of the disposition of at least part of the heads of the fasteners in said local recesses, considerable difficulty will be encountered by any person attempting to break of the heads of the fasteners, by the method hereinbefore described.

By qualifying the recesses as "local" we mean that the whole of each recess lies near to the aperture, as distinct from extending along the entire length of the pale.

The recesses are preferably formed by displacing metal away from the front faces of the pales and so forming local projections at the rear faces of the pales, whereby the thickness of the metal surrounding the aperture is not significantly reduced. This, as distinct from forming the recesses by the removal of metal in a counter-sinking operation, in which the thickness of the metal surrounding the aperture would be reduced, ensures that there is no significant loss in strength of parts of the pale surrounding the aperture.

Preferably, however metal is displaced outwardly away from the longitudinal axis of the aperture, to provide a raised rim extending around the aperture, an inner face of the rim being generally in the form of frustrum against which the head of the fastener seats. When the recess is formed in this manner, a reinforcing formation is in effect afforded around each aperture, which may have the effect of marginally increasing the strength of the pale in this region. Thus, attempts to prise the pales away from the rail by effecting a tearing of the metal surrounding the head of the fastener is resisted, to a significantly greater extent than would be the case were the pale afforded with a conventional countersink.

Each pale may have a cross-section generally in the form of an arch, having at a central region a domed portion which provides a convex portion of the front surface and a concave portion of the rear surface, said local recesses being formed in said domed portion.

Claims

a cross-section generally in the form of an

arch, having at a central region domed portion which provides a convex portion of the front surface and a concave portion of the rear surface, said local recesses being formed in said domed portion.

5. A fence constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.