Patent ID: 12234663

DETAILED DESCRIPTION

FIG.1of the accompanying drawings illustrates a coil10of a high tensile steel core wire12mounted for rotation about an axis14. A coil16of an alloy strip18is rotatable about an axis20. The core wire12and the strip18are drawn by means of machines, not shown, and are passed through one or more sets of rollers24to form a product26which is shown in plan inFIG.2and in cross section inFIG.3taken on a line3-3inFIG.2. The rollers24are used to deform a central section30of the strip18so that it extends closely around a greater portion of the circumference of the core wire12. A first flange36extends to one side of the core wire12and a second flange38extends in an opposing direction on the other side of the core wire. The flanges36and38are coplanar and smooth. Edges40of the flanges are smooth.

As shown schematically inFIG.3Athe product26is then passed through rollers42, to form a deterrent material44, according to the invention. Each of the flanges36and38has a plurality of evenly spaced corrugated formations46.FIG.5shows the material44in plan.FIG.6shows the material44taken on a line6-6inFIG.5.FIG.4illustrates from one side the deterrent material44and shows the flange38with the corrugated formations46which comprise a repetitive series of ribs50and channels52. The rib and channel formations50and52are repeated in each flange36,38along the length of the deterrent material44. The material44is shown in perspective inFIG.7.

In a subsequent operation an elongate length of the deterrent material44is wound into an array56of helical coils60which are centred on an elongate axis62—seeFIG.8. In order to stiffen the array56each coil60is wound in a way which ensures that the flanges36and38lie in a plane which is at an angle of 90° relative to the axis62.FIG.9illustrates one helical coil60when the array56is viewed in the direction of an arrow marked9inFIG.8. The flange36with the corrugated formations46is on a radial outer side of the core wire12and the flange38with the corrugated formations46is on a radial inner side of the core wire12.

The outer flange36travels on a path about the axis62which is longer than the path travelled by the inner flange38. To allow this to take place while still maintaining the flange36in a plane which is at a right angle to the axis62, the corrugations46in the flange36are extended or stretched in the longitudinal direction of the flange relative to the corrugations46in the flange38. The depth of each channel52in the corrugations46in the flange36is decreased to D1. The depth of each channel52in the corrugations46in the flange38is D2. The result is that D1<D2—seeFIG.10.

At selected locations adjacent coils60are tied together by means of strong clips70, which are notionally indicated inFIG.8. The arrangement is such that the helical configuration of coils can be collapsed one on the other into a compressed and flat stacked assembly suitable for storage and for transport purposes. On the other hand if the array is to be deployed then one end of the collapsed assembly is anchored and the other end is pulled in the direction of the longitudinal axis62so that the coils can take up an operative extended helical configuration in which the coils are spaced apart from one another.

FIG.11shows three helical coils60A,60B and60C which are attached to one another by clips72to form a deterrent structure74. The coils60B and60C are side by side and rest on the ground. The coil60A is positioned above the lower coils60B and60C. The formation of the structure is exemplary only and not limiting. The number of coils can be increased or decreased according to requirement. The structure can be heightened (vertically) by stacking additional coils on top of one another.

The coils60A,60B and60C are collapsed into a concertina formation for storage and transport purposes. To facilitate handling of the structure74a respective triangular bracket76is attached to each end78of the deterrent structure74. Cross bars80which are fixed at spaced apart intervals along the length of the structure74between the upper coil60A and the lower coils60B and60C help to maintain the coils in the illustrated relative positions when the concertina formation is longitudinally extended. To deploy the structure74one end thereof is anchored and the bracket76at the other end of the structure is pulled so that the compressed coils60A,60B and60C can take up an extended helical configuration.

The orientation of the flanges36and38to lie in a plane which is at a right angle to the longitudinal axis62means that the helical coils60, when extended to form a barrier, are substantially stiffened compared to the case in which the flanges36and38lie on the surface of a cylinder centred on the axis62i.e. where the flanges are parallel to the axis62. As the helical configuration is substantially stiffened a person attempting to flatten the helical coils encounters meaningful resistance. This is not the case if the flanges have the planar configuration referred to.

The use of the alloy, e.g. a mild steel alloy or an aluminium alloy, in the strip has two principal benefits. The alloy is more malleable than steel and the deformation of the corrugations when the deterrent material44is formed into the array56of helical coils60is facilitated. Another benefit is that the edges40of the alloy flanges36,38are not as harsh as steel edges. This factor is important in providing a barrier which can act as a physical impediment to prevent access to a restricted area but in such a way that a person contacting a flange is less likely to be injured or hurt by an edge of the flange.