Security barrier

Abstract

A security barrier ( 1 ) comprises four elements ( 2, 3, 4 and 5 ), each bolted to the top of a wall W. Each element comprises a generally disc-shaped plate having a central recessed portion ( 10 ) and an annular main portion ( 12 ) integrally connected to the recessed portion ( 10 ) by a shoulder ( 13 ). A support ( 11 ) for each element comprises a bolt ( 15 ) and a spacer ( 16 ), the bolt ( 15 ) extending through an aperture ( 18 ) in the centre of the element. Each plate has a toothed edge ( 19 ), all around the circumference. Alternate elements have the plates facing in opposite directions so that they are offset in plan by double the depth of the shoulder ( 13 ), and so can be interleaved. The element plates are generally parallel to the plane of the wall. With any of a variety of plate materials and thicknesses the barrier may be adapted to any of a range of security applications.

1 . A security barrier for a wall or fence (W), the barrier comprising at least one barrier element ( 2 - 5 ), each barrier element comprising a plate ( 9 ) which does not provide a finger grip between its edges, and means ( 11 ) for mounting the plate on a wall or fence so that the plate is free to rotate about its own axis. 
     
     
         2 . A security barrier as claimed in  claim 1 , wherein the mounting means ( 11 ) is configured for rotation of the plate ( 9 ) about an axis which is at an angle to a longitudinal direction of the wall or fence. 
     
     
         3 . A security barrier as claimed in  claim 2 , wherein the mounting means ( 11 ) is configured for rotation of the plate ( 9 ) about an axis which is substantially perpendicular to said longitudinal direction. 
     
     
         4 . A security barrier as claimed in  claim 2 , wherein the mounting means ( 11 ) is configured for rotation of the plate ( 9 ) about an axis which is substantially perpendicular to a plane of the wall or fence (W). 
     
     
         5 . A security barrier as claimed in  claim 1 , wherein there are a plurality of elements ( 2 - 5 ) mounted in a row. 
     
     
         6 . A security barrier as claimed in  claim 5 , wherein the elements are mounted so that at least some plates ( 9 ) overlap with their edges being mutually offset in the axial direction. 
     
     
         7 . A security barrier as claimed in  claim 1 , wherein at least one plate comprises a central portion ( 10 ) and an annular outer portion ( 12 ) and the portions are mutually offset in an axial direction. 
     
     
         8 . A security barrier as claimed in  claim 7 , wherein the portions are interconnected by a shoulder ( 13 ). 
     
     
         9 . A security barrier as claimed in  claim 1 , wherein the edges of the plates ( 9 ) have features ( 19 ). 
     
     
         10 . A security barrier as claimed in  claim 9 , wherein the features are teeth ( 19 ). 
     
     
         11 . A security barrier as claimed in  claim 1 , wherein the edges of the plates ( 51 - 54 ) do not have features. 
     
     
         12 . A security barrier as claimed in  claim 1 , wherein each mounting means comprises means ( 11 ) for independently mounting the plate on a wall or fence. 
     
     
         13 . A security barrier as claimed in  claim 1 , wherein the mounting means ( 11 ) comprises a bolt ( 15 ) extending through the plate ( 9 ) and a spacer ( 16 ) for retaining axial position of the plate with respect to the bolt. 
     
     
         14 . A security barrier as claimed in  claim 1 , wherein the mounting means comprises a slot ( 115 ) in the plate ( 111 - 114 ) and a bolt or pin extending through the slot, to provide a default plate rotational orientation. 
     
     
         15 . A security barrier as claimed in  claim 14 , wherein the plate ( 81 - 84 ,  101 - 104 ,  111 - 114 ) is not circular in shape. 
     
     
         16 . A security barrier as claimed in  claim 1 , wherein the plate has a blunt edge. 
     
     
         17 . A security barrier as claimed in  claim 1 , wherein the plate is of plastics material. 
     
     
         18 . A security barrier as claimed in  claim 1 , wherein the plate has a thickness of 0.5 mm to 15 mm at the edge. 
     
     
         19 . A security barrier as claimed in  claim 18 , wherein the plate is of metal material and has a thickness at its edge in the range of 0.5 mm to 4.0 mm. 
     
     
         20 . A security barrier as claimed in  claim 18 , wherein the plate is of plastics material and has a thickness at its edge in the range of 2 mm to 10 mm. 
     
     
         21 . A security barrier as claimed in  claim 1 , wherein the mounting means comprises a support adapted to be secured to a wall or a fence, and a plurality of elements mounted on the support. 
     
     
         22 . A security barrier as claimed in  claim 21 , wherein the mounting means comprise an length of angle bar and fasteners securing the plates to the bar. 
     
     
         23 . A wall or fence comprising a security barrier as claimed in  claim 1  mounted at the top of the wall or fence, the elements being mounted so that the plates rotate about an axis at an angle to the longitudinal direction of the wall or fence. 
     
     
         24 . A wall or fence as claimed in  claim 23 , wherein the axes are substantially perpendicular to the longitudinal direction of the wall or fence. 
     
     
         25 . (canceled)