Security barriers

Abstract

A security barrier is disclosed for controlling the passage of vehicles along a vehicle throughway ( 16 ). The security barrier comprising upper and lower barrier members ( 20, 22, 120, 122, 220, 222, 320, 322 ). The upper barrier member ( 20, 120, 220, 320 ) is pivotally mounted for movement between a closed configuration, in which a barrier portion of said upper barrier member ( 20, 120, 220, 320 ) extends across the vehicle throughway ( 16 ), and an open configuration in which the barrier portion is raised to permit passage of a 10 vehicle along the vehicle throughway ( 16 ). The upper and lower barrier members ( 20, 22, 120, 122, 220, 222, 320, 322 ) are operably linked so that pivoting of the upper barrier member ( 20, 120, 220, 320 ) to the open configuration causes the lower barrier member ( 22, 122, 222, 322 ) to be lowered, and pivoting of the upper barrier member ( 20, 120, 220, 320 ) to the closed configuration causes the lower barrier member ( 22, 122, 222, 322 ) to be raised.

1 . A security barrier for controlling passage of vehicles along a vehicle throughway, the security barrier comprising: 
 upper and lower barrier members,    the upper barrier member being pivotally mounted for movement between a closed configuration, in which a barrier portion of said upper barrier member extends across the vehicle throughway, and an open configuration in which the barrier portion is raised to permit passage of a vehicle along the vehicle throughway,    the lower barrier member being mounted by at least one pivoting linkage to a part of the security barrier that is stationary during use, the at least one pivoting linkage being rotatable relative to the stationary part of the security barrier within a vertical plane that is orientated generally perpendicularly to the direction of motion of vehicles along the vehicle throughway,    wherein the upper barrier member is operably linked to the lower barrier member such that pivoting of the upper barrier member to the open configuration causes the lower barrier member to be lowered and pivoting of the upper barrier member to the closed configuration causes the lower barrier member to be raised.    
   
   
       2 . A security barrier as claimed in  claim 1 , wherein the security barrier is arranged so that a counterbalancing moment is exerted on the upper barrier member in the rotational direction opposite to that of the moment caused by the weight of the upper barrier member.  
   
   
       3 . A security barrier as claimed in  claim 2 , wherein the counterbalance moment is predominantly caused by the weight of the lower barrier member.  
   
   
       4 . A security barrier as claimed in  claim 3 , wherein the upper barrier member is pivotally mounted at a point between its ends, the upper barrier member thereby comprising an extension portion that extends to the other side of said pivot point to the barrier portion, the extension portion of the upper barrier member being operably linked to the lower barrier member such that the lower barrier member acts to counterbalance the weight of the barrier portion of the upper barrier member.  
   
   
       5 . A security barrier as claimed in  claim 4 , wherein the lower barrier member and the extension portion of the upper barrier member are operably linked by a mechanical linkage.  
   
   
       6 . A security barrier as claimed in  claim 5 , wherein the mechanical linkage comprises a connecting member that extends between the extension portion of the upper barrier member, and the lower barrier member.  
   
   
       7 . A security barrier as claimed in  claim 5 , wherein the mechanical linkage comprises a connecting member that extends between the extension portion of the upper barrier member, and an intermediate component that is itself mechanically linked to the lower barrier member.  
   
   
       8 . A security barrier as claimed in  claim 6 , wherein the connecting member is rigid in form, and is pivotally attached to the extension portion of the upper barrier member.  
   
   
       9 . A security barrier as claimed in  claim 6 , wherein the length of the connecting member between the extension portion of the upper barrier member, and either the lower barrier member or the intermediate component, is variable such that said length increases as the lower barrier member is lowered and decreases as the lower barrier member is raised.  
   
   
       10 . A security barrier as claimed in  claim 9 , wherein the connecting member is flexible, and the upper barrier member includes a cam about which the flexible member travels such that the effective length of the connecting member is varied.  
   
   
       11 . A security barrier as claimed in  claim 1 , wherein the lower barrier member is connected by a first pivoting linkage to a pillar or the like at the other side of the vehicle throughway to the extension portion, the lower barrier member being suspended by pivoting linkages from the extension portion of the upper barrier member and the pillar at the other side of the vehicle throughway.  
   
   
       12 . A security barrier as claimed in  claim 1 , wherein the lower barrier member is mounted by first and second pivoting linkages, the first and second linkages being of identical length and orientated parallel to each other such that the lower barrier member is maintained in a horizontal orientation at all times.  
   
   
       13 . A security barrier as claimed in  claim 1 , wherein the lower barrier member is received within a channel formed in the ground surface such that the upper surface of the lower barrier member lies substantially flush with the ground level.  
   
   
       14 . A security barrier as claimed in  claim 1 , wherein the security barrier includes a ramp that is formed on the upper surface of the ground across the vehicle throughway, and includes a channel within which the lower barrier member is received such that the upper surface of the lower barrier member lies substantially flush with the upper surface of the ramp.  
   
   
       15 . A security barrier as claimed in  claim 14 , wherein the ramp is formed from suitable road-building materials, and the side walls of the channel are lined, and thereby supported, by one or more support members.  
   
   
       16 . A security barrier as claimed in  claim 1 , wherein the lower barrier member has such a form that when it is lowered into abutment with the ground a vehicle is able to drive over it without undue hindrance.  
   
   
       17 . A security barrier as claimed in  claim 1 , wherein the lower barrier member is of greater weight and strength than the upper barrier member.  
   
   
       18 . A security barrier as claimed in  claim 17 , wherein the cross-sectional shape of the lower barrier member is chosen so as to maximise the strength of the security barrier in the event of impact by a vehicle.  
   
   
       19 . A security barrier as claimed in  claim 18 , wherein the lower barrier member is of channel section.  
   
   
       20 . A security barrier as claimed in  claim 1 , wherein the upper barrier member pivots about a fixed point in a pillar or the like mounted to one side of the vehicle throughway, said pillar or the like including means for rotating the upper barrier member about a pivot axis.  
   
   
       21 . A security barrier as claimed in  claim 20 , wherein the free end of the barrier portion is received, when the upper barrier member is in the closed configuration, within a support positioned adjacent the opposite side of the vehicle throughway to that at which the upper barrier member is pivotally mounted.  
   
   
       22 . A security barrier as claimed in  claim 21 , wherein the upper barrier member is pivotally mounted between two pillars at one side of the vehicle throughway, and the free end of the upper barrier member is received, in the closed configuration, between two pillars at the other side of the vehicle throughway.  
   
   
       23 . A security barrier as claimed in  claim 22 , wherein the lower barrier member extends beyond both of the pillars at each side of the vehicle throughway.  
   
   
       24 . A security barrier as claimed in  claim 23 , wherein the ends of the lower barrier member are enlarged.  
   
   
       25 . A security barrier as claimed in  claim 1 , wherein the security barrier includes a pair of portal frames that together define the lateral limits of the vehicle throughway.  
   
   
       26 . A security barrier as claimed in  claim 25 , wherein the portal frames each define an opening, and the lower barrier member is arranged within these openings at all times during use.  
   
   
       27 . A security barrier as claimed in  claim 1 , wherein the masses of the upper barrier member and the lower barrier member are selected so as to conserve gravitational potential energy between the closed and open configurations.  
   
   
       28 . A security barrier as claimed in  claim 1 , wherein the lower barrier member is suspended beneath two upper barrier members that are each pivotally mounted on a pillar or the like and are directed towards each other.  
   
   
       29 . A method for making a security barrier for controlling passage of vehicles along a vehicle throughway, the method comprising: 
 pivotally mounting at least one upper barrier member for movement between a closed configuration and an open configuration; and    mounting at least one lower barrier member with at least one pivoting linkage to a part of the security barrier that is stationary during use, the at least one pivoting linkage being rotatable relative to a base;    wherein the upper barrier member is operably linked to the lower barrier member such that pivoting of the upper barrier member to the open configuration causes the lower barrier member to be lowered and pivoting of the upper barrier member to the closed configuration causes the lower barrier member to be raised.    
   
   
       30 . A security barrier for controlling passage of vehicles along a vehicle throughway, the security barrier comprising: 
 two or more upper barrier members;    at least one lower barrier member;    the two or more upper barrier members are each pivotally mounted for movement between a closed configuration, in which a barrier portion of each of the two or more upper barrier members extends across at least a portion of the vehicle throughway, and an open configuration in which the barrier portion of each of the two or more upper barrier members is raised to permit passage of a vehicle along the vehicle throughway,    the lower barrier member is mounted by at least one pivoting linkage to a part of the security barrier that is stationary during use, the at least one pivoting linkage is rotatable relative to the stationary part of the security barrier within a vertical plane that is orientated generally perpendicularly to the direction of motion of vehicles along the vehicle throughway,    wherein the two or more upper barrier members are operably linked to the lower barrier member such that pivoting of the two or more upper barrier members to the open configuration causes the lower barrier member to be lowered and pivoting of the two or more upper barrier members to the closed configuration causes the lower barrier member to be raised.