Patent Publication Number: US-9410298-B2

Title: Structural tube based movable vehicle crash barrier gate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part application of application Ser. No. 14/331,244 filed on Jul. 15, 2014, the descriptive portions being incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Maintaining the security of sensitive facilities from terrorist attack or unauthorized entry is of great concern. This has led to the installation of a wide array of protective barrier designs meant to prevent an unauthorized vehicle or vehicles from penetrating the secured area, and to maximize the distance between a potentially explosive laden vehicle and the facility. Barrier protection includes both traditional vehicle access points and facility perimeters that might be vulnerable to a vehicle traveling overland. 
     The design of crashworthy barrier gates is further complicated by the need provide at least two configurations, one for stopping a vehicle attempting to penetrate the gate and a second for selectively permitting a vehicle to pass through the gate as well as a convenient means for moving the gate between the two configurations. Energy absorbing features employed in fixed barrier designs are not always practical in movable barrier designs. Thus, the movable barrier designs tend to be more robust to withstand the impact energy and complex as the barrier must be movable to permit vehicle access. Both demands increase cost. 
     It would be advantageous to provide an alternative vehicle crash gate fabricated from standard shaped structural materials that could be easily installed around a desired area to be protected from vehicular intrusion and simply operated. Additional advantages would be realized by a vehicle crash gate system having an aesthetically pleasing appearance once installed. Still further advantages would be realized by a vehicle crash gate system requiring minimal maintenance once installed. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention, in any of the embodiments described herein, may provide one or more of the following advantages: 
     It is an object of the present invention to provide a vehicle crash gate having a connection between horizontal and vertical members capable of withstanding anticipated vehicular impact loads. An elongate horizontal rail spanning the gate opening is provided with one or more deformable flanges adjacent to each end. Vertical members disposed on opposing sides of the gate opening each include a vertically oriented channel configured to receive the rail ends and flanges. The channels extend vertically for at least the distance necessary to move the horizontal rail between a position through which a vehicle may pass through the gate and a position which prevents vehicle passage. The vertical member is reinforced proximate to the raised rail position necessary to stop a vehicle for additional post strength. Upon vehicle impact, deformation of the flanges dissipates energy that would otherwise detach the connection between the horizontal rail and the vertical members. 
     It is a further object of the present invention to provide an energy dissipating connection for joining a horizontal rail member to a vertical post member in a vehicle crash barrier that incorporates deformable flanges attached adjacent to an end of the horizontal rail member which are engaged in a receiver in the post member that permits vertical movement of the horizontal rail member. The deformable flanges are configured to deform upon a vehicle impact with the rail member prior to significant deformation of the post member and the rail member to which the flanges are attached. Deformation of the flanges dissipates energy necessary to arrest vehicle movement with limited penetration into the secured area established by the crash barrier. 
     It is another object of the present invention to provide a vehicle crash barrier with a movable horizontal gate member having an energy-dissipating connection between the horizontal and vertical members that is easily operated. The horizontal gate member is provided with one or more deformable flanges adjacent to each end. Vertical post members each include a vertically extending channel for receiving the rail ends and flanges. The channels are configured to permit vertical movement of the gate member, but prevent the passage of the flanges through a channel opening. A drive apparatus is provided to raise and lower the gate member within the channels. 
     It is a further object of the present invention to provide a vehicle crash barrier having a vertically movable horizontal gate member that is durable in construction, inexpensive of manufacture, carefree of maintenance, easily assembled, and simple and effective to use. 
     These and other objects are achieved in accordance with the instant invention by providing a vehicle crash barrier gate constructed primarily of structural tube members and having an energy-absorbing connection between horizontal movable gate member and vertical post members. The gate member is provided with one or more deformable flanges adjacent to each end. Each post includes a vertically extending channel for receiving a respective gate member end and the flanges. An inwardly facing, vertically aligned opening in each channel allows the gate member to extend therethrough and span the space between the posts. The vertical extent of the openings spans the required vertical movement of the gate member. One or more reinforcing elements are disposed on the posts proximate to the elevation at which the gate member is positioned to prevent vehicle passage to strengthen the vertical post structure. A drive apparatus is provided to move the gate member vertically between an open position, typically at grade level, and a closed position, typically elevated above grade level. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  in a perspective view of a movable vehicle crash barrier gate embodying aspects of the present invention shown in a raised or deployed configuration; 
         FIG. 2  is a partial elevation view of the movable gate of  FIG. 1  shown in a lower configuration such as would permit the passage of a vehicle therethrough; 
         FIG. 3  is an exploded partial elevation view of a vertical post member shown illustrating the connection between post member and gate beam member wherein the gate beam member is in an intermediate vertical position; 
         FIG. 4  is a cut-away elevation view of the post member of  FIG. 3 ; 
         FIG. 5  is a plan view of one of the gate posts of the instant invention; 
         FIG. 6  is a partial perspective view of the end of the gate beam member showing the arrangement of the energy dissipating flanges; and 
         FIG. 7  is a partial perspective view of the upper end of the gate post member. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “upward” or “downward” are used as a matter of mere convenience, and are relative to the generally level ground or any references to “horizontal” or “vertical” planes. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already be widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail. When referring to the figures, like parts are numbered the same in all of the figures. 
     The vehicle barrier at issue in this application is designed to withstand at least the testing requirements delineated in ASTM F2656, “Standard Test Method for Vehicle Crash Testing of Perimeter Barriers.” The concepts of the instant invention may be used to create barriers that satisfy the requirements of other crash barrier standards, both existing and as may be developed in the future. 
     Turning now to the drawings,  FIGS. 1 through 7  illustrate aspects of an energy absorbing vehicle barrier gate  10  incorporating preferred embodiments of this invention. Referring to  FIG. 1 , the energy absorbing vehicle barrier  10  includes a pair of spaced-apart, upstanding gate post members  20  partially embedded in the ground  5  and a generally horizontally arranged movable gate beam member  40  extending between the two gate post members  20 . The gate post members  20  may further be configured to permit connection of static rail members  95  in addition to the movable gate beam member  40  as part of a larger crash barrier system of limitless length or to close off potential vehicular entry paths adjacent to the gated opening. Details of the static fence post and horizontal beam member connection are provided in Applicant&#39;s co-pending application Ser. No. 14/331,244. 
     Each gate post member  20  includes an embedded portion  21  that extends below grade a sufficient amount to provide the necessary anchorage for the barrier gate  10 . Concrete is typically used to reinforce the embedded portion anchorage. The embedded portion  21  may also include outward extending anchors and the like to better engage the concrete reinforcement material and further strengthen the post anchorage in the ground. An exposed portion  22  of each post  20  extends above the ground to elevate the movable gate member  40  to a desired elevation above the ground surface. 
     The gate post members  20  are preferably connected by a trough member  80  which spans the distance defining the gate opening width. The trough member  80  is vertically positioned at grade level and configured with a trough extending below grade level into which the gate beam member  40  may be positioned to allow vehicles to pass through the gate without damage to the gate beam member. The trough member  80  strengthens the barrier gate  10  structure by structurally connecting the gate posts. The connected gate posts  20  also establish the spacing between the posts to provide consistent spacing and parallel movement tracks for the movable gate member  40 . 
     Each post member  20  is formed from a hollow structural tube having a side wall  24  partially surrounding an open interior cavity  26 . The interior cavity  26  is open at the distal end  23  of the post member  20 . The interior cavity  26  includes a generally C-shaped channel  25  that extends for the length of the exposed portion  22  and partially into the embedded portion  21 . The channel  25  includes a travel slot  27  bounded on either side by bearing ends  29  defining an opening in the side wall  24  of the gate post member  20  through which the gate beam member  40  may protrude. The travel slots  27  on the adjacent gate post member is inwardly facing to permit each end of the gate beam member  40  to pass through a respective travel slot  27  so that both ends of the gate beam member are supported. Reinforcing members  33  may be provided to strengthen the bearing ends. Additional stiffening members  31  may be provided in the interior cavity  26  to further strengthen the post member  20  without impeding movement of the gate beam member  40  or its lifting apparatus. 
     A gate beam elevator  70  is provided for each gate post member  20  to vertically support the gate beam member  40  at a desired elevation above the ground and to manage vertical movement of the gate beam member between the raised and open positions. The elevator  70  is preferably disposed within a housing  75  connected to the top end of the post. Each beam elevator is operably connected by connectors  76  to a respective end  42  of the gate beam member  40  within the channel  25 , typically with a chain  74  or the like operably connected with a driving apparatus  72  disposed proximate to the distal end  23  of the gate post for moving the chain and thereby moving the gate beam member  40 . The interior cavity  26  preferably includes at least one divider member  31  to separate the channel  25  from a second interior cavity portion  28 . In the embodiment shown, a counterbalance  78  travels within the second interior cavity portion  28  to offset the mass of the gate beam portion  40  and reduce the power necessary to move the gate beam. 
     Each end  42  of the gate beam member  40  includes one or more energy dissipating flanges  60  extending outwardly from the exterior surface of the gate member. In the embodiment shown, a generally non-deformable stop flange  61  is connected adjacent to the end  42  of the gate beam member. Inwardly disposed along the gate beam member  40  are additional deformable flanges  62 ,  63  as needed to provide the energy dissipation during a vehicle impact with the gate beam member  40 . The flanges  60  are configured to fit within the channel  25  with the gate beam member  40  projecting through the travel slots  27  to the space between the gate posts  20  and allow the gate beam member  40  move vertically within the channels  25 . The inward facing surface on the innermost flange  63  is adjacent to the interior surface of the bearing ends  29 , and sized so that the flanges  60  will not pass through the travel slot  27  absent deformation of the flanges  60 , the bearing ends  29 , or both. 
     The distal end of the gate post  20  is reinforced by a top cap  34  which connects to the periphery of the distal end  23  and bridges the travel slot  27  to join the bearing ends  29 . The top cap  34  includes a downwardly extending skirt  36  which is outwardly positioned in relation to the side wall  24  and any reinforcing members  33  to strengthen the top structure of the post and limit deformation of the bearing ends  29  of the side wall as the gate beam member is deflected during vehicular impacts. The top cap  34  also provides a convenient structure for attaching the gate beam elevator  70 . The top cap  34  may be fastened into position using bolts or the like to prevent unintentional removal or dislodgement during an impact. To further strengthen the gate post  20 , an external gusset  32  is provided at a vertical location on the gate post proximate to the vertical location of the gate beam member  40  when in the raised position. In the preferred embodiment, the gate beam member  40 , when in the raised position, is vertically adjacently below the top cap  34  and adjacently above the external gusset  32 . 
     In a preferred embodiment, the post and gate beam members are fabricated from hollow structural steel tube having a generally rectangular cross section. One such structural steel tube is manufactured in accordance with material specification ASTM A500. Wall thickness and external dimensions of the structural tube may be selected upon the desired vehicle stopping capability. The embedment depth of the post members, size of the embedded anchorage, and height of the rail member above the ground may also be varied to tailor the vehicle arresting capability of the vehicle barrier. In the exemplar embodiment, the gate post members are formed from 12×12×½ ASTM A500, Gr. B structural tube steel embedded 78 inches into the ground and the top end of the post extending 42 inches above the ground. The gate beam member is formed from 4×12×½ ASTM A500, Gr. B structural tube steel with the major axis vertically oriented with the longitudinal centerline of the gate beam positioned approximately 32 inches above the ground when the gate is in the raised position. 
     The deformable flanges  62 ,  63  and the stop flange  61  are fabricated from steel plate and welded to the structural tube. The thickness of the stop flange  61  preferably exceeds the wall thickness of the structural tube comprising the rail member  40 . The relative sizing allows the relative order and magnitude of deformation of the various elements in the connection to be controlled during a vehicle impact. In the exemplar embodiment, the stop flange is fabricated from a 10×17 inch plate of 1-inch thick ASTM A-36 plate material welded to the rail. The plate extends beyond the outer periphery of the rail approximately 2⅜ inches, but allows the rail end with flanges to be inserted into the post member. The thickness of the deformable flanges  62 ,  63  is preferably less than the rail member wall thickness so that they will begin to deform upon vehicle impact to dissipate energy before substantial deformation the tube walls of the post member, rail member, or stop flange occurs. In the exemplar embodiment, the deformable flanges are fabricated from ¼-inch thick ASTM A-36 plate material welded to the rail. The dimensions of the deformable flanges are preferably the same as the stop plate. 
     When assembled, the deformable flanges  62 ,  63  are positioned inwardly adjacent to the bearing ends  29  of interior side wall  24  of the gate post member. The channel  25  is sufficiently sized in relation to the flanges  60  so that vertical movement in the channel is permitted without significant longitudinal movement (in the axis of the gate beam member). Longitudinal movement of the gate beam member  40  away from the post, such as that caused by a vehicular impact, is resisted by the deformable flanges  62 ,  63  in contact with the inwardly facing surfaces of the bearing ends  29 . The bearing ends  29  are reinforced by the proximate top cap  34  with its downwardly extending skirt  36 , reinforcing members  33 , if provided, and the external gusset  32  to limit deformation of the bearing ends  29  as the deformable flanges  62 ,  63  begin to deform. Increasing tension forces in the gate beam member cause the outermost deformable flange  63  to deform, absorbing energy of the impact as the flange bends. As the impact load continues, the outermost flange  63  will eventually deflect until it contacts the adjacent deformable flange  62 , which will then begin to deform, continuing to absorb energy of the impact. Continued deformation of the deformable flanges  62 ,  63  will eventually bring them into contact with the stop flange  61 . The stop flange  61  is thicker than either of the deformable flanges (by a factor of four in the preferred embodiment). The stop flange  61  is also thicker than the wall thickness of the gate beam member  40 ; however, the stop flange may also be deformed dependent upon the magnitude of the vehicle impact. The number, sizing, and spacing of the deformable flanges may be varied to achieve the required energy dissipation. The stop flange prevents the rail member from disengaging from the post member unless the vehicle impact forces grossly exceed the material strength of the post and rail members. 
     Naturally, the invention is not limited to the foregoing embodiments, but it can also be modified in many ways without departing from the basic concepts. It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.