Abstract:
A security cover is used in conjunction with a visually pleasing picket fence barrier. The security cover, having a C-shaped cross section, restricts access to bolts used to couple each picket to top and bottom support beams and thereby prevents tampering with the fence.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a method and system for providing a tamper proof modular fence and more specifically to a device for preventing the dismantling of the modular fence. 
   BACKGROUND 
   Physical barriers in the form of fences are used to surround various facilities ranging from private homes to government installations. The fence barrier employed in a particular facility are generally selected in accordance with relevant aesthetic and security considerations. For example, a low cost chain link fence is generally used in low security facilities, which do not require a visually pleasing surrounding fence. Other facilities require a more aesthetically pleasing fence. One such fence is a modular fence, including steel pickets, constructed in a configuration similar to a typical wooden picket fence. 
   In a typical configuration, upper and lower support beams are coupled to each of the vertical pickets in the fence section. Each support beam includes a plurality of bores adapted to match the coupling bores in the pickets. An upper support beam is coupled to a top coupling bore in each picket. A lower support beam is coupled to a lower coupling bore in each picket. In the typical implementation, a bolt is fitted through each picket bore and corresponding support beam bore. Hence, the plurality of vertical pickets is secured to the support beams by bolts fitted through corresponding bores in both. Moreover, the pickets are usually fitted onto the fence section at the field, i.e., after the supporting posts have been installed at the facility to be surrounded. This provides valuable flexibility in allowing for less than level positioning of the supporting posts, since the bolts allow the pickets to pivot and adjust to various angular orientations, thus remaining vertical despite an incline placement, for example. It may be appreciated that if the pickets are welded to the support beams, the adjustment for a skewed placement could not be made. However, the valuable flexibility provided by the use of field installable bolts detracts from the security function of the fence by allowing a potential intruder to dismantle the fence by removing the bolts. Accordingly, there is a need for a method and system for preventing a potential intruder from tampering with the fence while maintaining the flexibility provided by the use of field installable pickets. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, a security cover is provided to restrict access to the bolts securing the pickets to the support beams. The security cover provides a physical enclosure that restricts access to each bolt head used to secure a support beam to the corresponding pickets and prevents the bolt from being removed so as to dismantle the pickets. 
   In one embodiment, the present invention provides a fence section that includes a first vertical support post and a second vertical support post, each including a bracket having a substantially vertical bore. The bracket extends substantially perpendicular from the support post in the direction of the other support post. The fence section includes a lower support beam and an upper support beam, each including a plurality of spaced horizontal bores directed in perpendicular to the plane defined by the first and second supporting posts. Each support beam also includes a pair of distal flanges having vertical bores adapted to mate with the vertical bores of a corresponding supporting post bracket. The fence section additionally includes a plurality of vertical pickets, each including an upper bore adapted to mate with a bore of the upper support beam and a lower bore adapted to mate with a bore of the lower support beam. A plurality of bolts are used to couple each vertical picket upper bore to a corresponding upper support beam bore and couple each vertical picket lower bore to a corresponding lower support beam bore. 
   The fence section also includes a cover having a C-shaped cross section. The cover has a plurality of vertical openings to allow each said vertical pickets to pass through the cover. The cover includes a pair of vertical surfaces extending substantially perpendicular to the vertical opening surface. The cover further has a first distal vertical bore at a first end of the cover and a second distal vertical bore at a second end of the cover. The first and second distal bores adapted to mate with corresponding vertical bores in the upper and lower support beams and with corresponding vertical bores in the supporting post brackets. The vertical surfaces of the cover are adapted to impede access to the bolts securing the pickets to the supporting beams when the cover is secured to the supporting post brackets and to the support beam by the distal bores. A plurality of security fasteners, each fitted within each of a cover distal bore, a supporting beam flange bore, and a supporting post bracket, are used to rigidly secure the bores in alignment therebetween and are adapted to prevent removal of each cover from the corresponding support beam. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: 
       FIG. 1  illustrates a frontal view of a typical picket fence section; 
       FIG. 2  illustrates a frontal view of the coupling structure for coupling a supporting post to a support beam in the fence section of  FIG. 1 ; 
       FIG. 3  illustrates a security cover of a fence section in accordance with the invention; 
       FIG. 4  illustrates an exploded view of a fence section including the security cover of  FIG. 3  in accordance with the invention; and 
       FIG. 5  illustrates a cross-section of a side view of the support beam and cover of the fence section of FIG.  4 . 
   

   DETAILED DESCRIPTION 
     FIG. 1  illustrates a typical modular steel picket fence structure. A first support post  20  and a second support post  22  are provided to define a section of the fence there between. Each such section includes a plurality of vertical steel pickets  28  secured to a pair of horizontal support beams  24  &amp;  26 . It may be appreciated that the fence structure may be composed of other materials such as . . . 
     FIG. 2  illustrates the coupling structure between the first support post  20  and the upper support beam  24 . The upper support beam  24  is coupled to the first supporting post  20  by a flange  42  having a vertical bore. An L-shaped bracket  44  on the first supporting post  20  is provided with a corresponding vertical bore, adapted to align with the vertical bore of the beam flange  42 . A bolt  52  and corresponding nut  50  are used to secure the beam flange  42  to the supporting post bracket  44 , as is shown. An identical flange and bracket arrangement is provided on a second end of the support beam  24  and the second support post  22  so as to allow for securing the upper support beam between the first  20  and second support posts. The lower support beam  26  is coupled to the first and second support posts  20 ,  22  in a manner similar to that discussed with reference to the upper support beam  24  as may be appreciated. 
     FIG. 3  illustrates a cover  30  adapted to enhance security in the fence section of FIG.  1 . The cover  30  includes a pair of distal vertical bores  34  &amp;  36  adapted to match the vertical bores in the brackets of the supporting posts  20 ,  22 . A plurality of interior vertical picket openings  38  are provided, each adapted to allow for insertion of a single picket therethrough. The cover  30  includes a pair of vertical planer surfaces extending from the center surface, which includes the picket openings  38 . The vertical surfaces are adapted to at least extend to cover the bolts used to secure the pickets to the supporting beams  24 ,  26 . 
     FIG. 4  is an exploded view of the security cover  30  of  FIG. 3 and a  corresponding upper support beam  24  in a fence section of the invention. As may be appreciated, the security cover is adapted for arrangement with the lower support beam  26  and corresponding support post brackets in the same manner as will be discussed below with reference to the upper support beam  24 . As may further be appreciated, a first security cover is arranged with the lower support beam  26  prior to installation of a second security cover  30  with the upper support beam  24 . As discussed above, each picket  28  is coupled to the upper support beam  24  by a pair of corresponding bores, one in each of the support beam and the picket. A bolt  54  is threaded through the bore to secure the picket top portion to the upper support beam  24 . Each of the pickets  28  is also fitted through the corresponding opening in the security cover  30  to allow the security cover to rest on the upper support beam  24 . 
     FIG. 5  illustrates a cross-section of a side view of the security cover  30  as fitted onto the upper support beam  24 . As may be appreciated, the vertical surfaces of the security cover  30  extend to cover the bolts  54  coupling the pickets  28  to the upper support beam  24 . Any attempt to draw the bolts  54  away from the pickets  28  will be resisted by impacting the vertical surfaces of the cover  30 . 
   Referring back to  FIG. 4 , each distal bore  34  &amp;  36  of the security cover  30  is adapted to match corresponding bores in a supporting post bracket  44  and the upper support beam flange  42 . A single bolt  52  is fitted through the cover bore  34 , the upper support beam bore  44 , and the support post bracket bore  42 . The bolt  52  is fitted with a special safety nut  50 . The safety nut  50  includes an internally threaded smooth conical head that is coupled to a hexagonal gripping ring. The hexagonal ring is adapted to break off the conical head in response to application of torque beyond a threshold. This allows for securing the nut  50  to a corresponding bolt  52 , followed by breaking off the gripping ring. Without the gripping ring, removal of the smooth conical nut from the bolt is extremely difficult. Identical safety nuts are employed on both sides of the upper support beam as well as both sides of the lower support beam. 
   Accordingly, by employing only four safety bolt and nut combinations per fence section, in conjunction with a pair of security covers, an entire set of picket coupling points to both upper and lower support beams is protected. This provides significant cost savings in both labor and materials as well as an increase in speed and ease of installation. 
   The foregoing merely illustrates the principles of the present invention. Those skilled in the art will be able to devise various modifications, which although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope.