Abstract:
Embodiments of the present disclosure relate generally to an arresting fence system that is deployable in order to bring a traveling vehicle to a stop through controlled deceleration. An arresting system (including an arrestor net, an energy absorber, and a release mechanism) is integral to a gate carriage that may be movable in order to position the fence system in the desired position. The gate carriage can be incorporated into a new or existing fence to restrict access to a desired location.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/088,001, filed Dec. 5, 2014, titled “Movable Arresting System Fence,” the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    Embodiments of the present disclosure relate generally to an arresting fence system that is deployable in order to bring a traveling vehicle to a stop through controlled deceleration. An arresting system (including an arrestor net, an energy absorber, and a release mechanism) is integral to a gate carriage that may be movable in order to position the fence system in the desired position. The gate carriage can be incorporated into a new or existing fence to restrict access to a desired location. 
       BACKGROUND 
       [0003]    There may be instances when it is desirable to stop a moving vehicle. For example, systems to arrest vehicles may find use in connection with restricted government or military locations. Systems may also find use in various commercial applications. In some instances, spikes that can deflate the vehicle&#39;s tires may be used, but such systems are generally not portable. Tire deflation barriers can also allow the vehicle to drive a substantial distance past the barrier. If the vehicle tires are puncture resistant, such a system will not stop the vehicle at all. In other instances, concrete barriers may be used. However, such barriers can require expensive installation equipment and are not easily moved. Because concrete barriers often rely on their own weight to prevent or stop a traveling vehicle, their size and mass can prevent their successful use in a mobile or emergency situation. 
         [0004]    Other vehicle stopping solutions have been to provide a lowering boom that can raise and lower between an up position and a down position or that can extend and retract between deployed and undeployed positions. However, such booms can be broken and avoided if an approaching vehicle is traveling up to and past the boom at a sufficient vehicle speed. Further vehicle stopping systems may use a net that is raised or lowered from the roadway surface (or from beneath the roadway surface). For example, there are systems that raise a net above the roadway, stowing the net in a tower structure. The overhead towers can require clearances from existing telephone poles, power cable systems, or other structures. They can also be subject to Department of Transportation structural design constraints. In use, the nets may be lowered onto the roadway. However, such nets often require complicated or extensive recesses to be installed below the surface, necessitating extensive excavation. Additionally, such nets are not always movable or deployable in a desired location. Arresting systems that use nets are generally permanent in nature, such that posts are installed in the ground with a net extending therebetween. The posts are generally installed with a concrete footing. In other examples, the posts may be anchored to structures, such as trailers or trees. These systems are not designed to be moveable or deployable in a desired location. 
         [0005]    Vertical pivot gates also exist. These gates may be crash resistant, meaning that they can withstand the impact of a moving vehicle. However, these gates do not allow for any vehicle run out. Their goal is to stop a moving vehicle in the shortest distance possible and do not consider any effects that can result in damage to the vehicle and potential injury to vehicle occupants. 
         [0006]    Accordingly, there is a need for a movable, lightweight, and quickly deployable vehicle arresting fence system that can effectively stop a moving vehicle without injuring the vehicle occupants or others in the vicinity, and without causing substantial property damage. 
       BRIEF SUMMARY 
       [0007]    Embodiments of the invention described herein thus provide systems and methods for an arresting fence system. In one example, there is provided a vehicle arresting system, comprising: a gate carriage configured for movement into and out of a path to be blocked, the gate carriage comprising: an arrestor net configured to engage a moving vehicle, one or more release mechanisms for releasing the arrestor net upon a specified load; one or more energy absorbers associated with the net; and one or more gate carriage restraints for securing the gate carriage in place. The one or more gate carriage restraints may comprise arrestment restraints. The one or more gate carriage restraints may comprise a roadway channel. 
         [0008]    In another example, there is provided a method of arresting the vehicle, comprising: moving a movable arresting system fence into a closed path position; capturing a movable vehicle via the fence. 
         [0009]    In a further embodiment, there is provided a vehicle arrestment system for use in connection with a fencing system, comprising: a movable gate carriage configured for movement into and out of an opening defined by the fencing system to be blocked, the movable gate carriage comprising: an arrestor net configured to engage a moving vehicle, one or more release mechanisms for releasing the arrestor net upon a specified load; one or more energy absorbers associated with the net; a moving system configured to cause movement of the movable gate carriage into and out of a blocking position with respect to the opening; and one or more gate carriage restraints for securing the gate carriage in place. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows a front perspective view of one embodiment of a movable arresting system fence. 
           [0011]      FIG. 2  shows a front perspective of an alternate embodiment of a movable arresting system fence. 
           [0012]      FIGS. 3A and 3B  show front plan views of a fencing system incorporating a movable fence.  FIG. 3A  illustrates the movable fence and a clear path position.  FIG. 3B  illustrates the movable fence in a closed path position. 
           [0013]      FIG. 4  show views of a vehicle being stopped by the movable fence system described herein.  FIG. 4A  shows a front plan view of the movable fence system in a ready/closed path position.  FIG. 4B  shows a front plan view of a vehicle making contact with the fence.  FIG. 4C  shows a top plan view of a vehicle making contact with the fence with the one or more energy absorbers activated. 
           [0014]      FIG. 5  shows a side view of a roadway channel that may receive an arresting fence system described herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Embodiments of the present invention provide an arresting fence system  10 . In certain embodiments, the fence system  10  may be movable or deployable upon demand. It may have rollers or a pivoting system that can facilitate movement of the fence system  10  with respect to a more permanent fencing system. The fence system  10  is designed to bring a traveling vehicle to a stop through controlled deceleration. In use, the fence  10  may be positioned across a restricted area or other area into which vehicle traffic should be halted. The fence  10  is configured to be movable, such that it can be re-positioned as desired. 
         [0016]    In general, the arresting fence system  10  may include a net secured to one or more energy absorbers that bring the vehicle to a stop. In use, the net is engaged by the vehicle and is released via release mechanism such that the net then envelopes the vehicle. The energy absorber can transmit a restraining force through the net to the vehicle, bringing it to a stop within the desired distance. 
         [0017]    As illustrated by  FIG. 1 , the arresting fence system  10  may generally include components mounted on a movable gate carriage  12 . The movable gate carriage  12  may include a channel section  14  that can extend between arrestment restraints  16 . In one example, the channel section  14  can roll between secured arrestment restraints  16 . In another example, an arrestment restraint  16  may be positioned at either end of the channel section  14  and move therewith. The arrestment restraints  16  can help secure the gate carriage  12  of the arrestment fence system  10  once it has been located in the desired position. 
         [0018]    In one example, the arrestment restraints  16  may include first and second elements  46  positioned with a space  60  therebetween. In use, ends of the movable gate carriage  12  may be moved laterally into the space  48  between the arrestment elements  46  in order to provide a barrier to entry to the area to be protected. The movable gate carriage  12  may be moved via rolling. For example, the gate carriage  12  may roll laterally into the space  60  created between arrestment restraints  16 . In order to position the fence  10 , one or more rollers  18  may be positioned along the channel section  14 . In one example, one or more rollers  18  may be positioned at ends of the channel section  14 . In another example, one or more rollers  18  may be positioned midway along the channel section  14  in order to help support the channel section  14  and assist its movement. The rolling may be accomplished manually by pushing the gate. In another example, the rolling may be accomplished by an electromechanical actuator or other electronic system. Once positioned between the arrestment restraints  16 , the movable carriage should not need further restraints. However, it is possible to padlock/key the gate in the closed position if desired. 
         [0019]    In an alternate embodiment, it is possible for the movable gate carriage  12  to operate via pivoting. One example is illustrated by  FIG. 2 . As illustrated, the movable gate carriage  12  may be pivoted upwardly with respect to a pivot point  48 . This may be done manually or via an electric actuator. For example, the gate carriage  12  may be pivoted down into the entryway/space  60  between arrestment restraints  16 . Regardless of which movement system is used, once the gate is properly positioned, the arresting fence system  10  operation works the same. 
         [0020]    Once the fence  10  has been located in the desired position, the arrestment restraints  16  secure the movable gate carriage  12  in place. The movable gate carriage  12  may travel between the arrestment restraints  16 . The restraints  16  may be elements  46  that are anchored in the ground (or anchored to a more complete fencing system  50 ) and are configured to hold the movable gate carriage  12  in place, opposing the forces imposed during vehicle investment. However, it should be understood that alternate arrestment restraints  16  may be used. For example, as illustrated by  FIG. 5 , a roadway channel  62  may be formed as a shallow recess in the roadway/road surface. The entire channel section  14 /gate carriage  12  may be positioned in the channel  62 . In use, the channel  62  serves to restrain the arresting fence system  10  against forces generated via vehicle impact. The roadway channel  62  may replace arrestment restraints  16  by providing a function similar to the support/arrestment they would otherwise provide. When the arresting fence system  10  is not in use, the roadway channel  62  may be covered in order for the road surface to be usable. 
         [0021]    The channel section  14  may also have one or more side supports  20  extending therefrom. It is generally expected for two side supports  20  to be present, one positioned on each end of the channel section  14 . The side supports  20  are generally positioned along sides of the channel section  14 , leaving a central portion  22  to be spanned by an arrestor net  24 . The arrestor net  24  may be secured to the side supports  20  using any appropriate securement system. In one example, a support cable  26  may be used to secure the arrestor net  24  to the side support  20 . The support cable  26  may have a lower portion secured to the gate carriage  12 , may extend over or through or otherwise be secured with respect to the side support  20 . The support cable  26  is used to assist in supporting of the side supports  20  against the net weight/catenary forces. 
         [0022]    For safety and workability, one or more release mechanisms  40  may be associated with the arrestor net  24 . In one example, an upper portion  28  of the arrestor net  24  may be secured to a release mechanism  40 . The release mechanism  40  may be secured to the side support  20 . In one example, this securement may be via a cable/turnbuckle arrangement attached to an eye bolt on the side support pole  20 . In use, the arrestor net  24  will be released from the side supports  20  via the release mechanism  40 . 
         [0023]    In one example, the release mechanism  40  may be a shear pin arrangement that will release the net at a specified load. The release load is designed to be slightly above the force required to support the net at its design height. Upon vehicle impact, the force is exceeded, and the release mechanism  40  is actuated. In another example, the release mechanism  40  may be a transition zone controller as shown and described by U.S. Pat. No. 8,007,198. In a further example, the release mechanism  40  may be a textile release similar in operation to a textile brake. 
         [0024]    It is also possible to provide one or more energy absorbers  32  connected to or otherwise associated with the net  24 . The energy absorber  32  is generally designed to have a release load that is a larger than the release load of the release mechanism  40 . The general goal of the one or more energy absorbers  32  is to absorb energy from a vehicle impact and provide an appropriate amount of runout space for the vehicle, with the intention of limiting vehicle damage and act and injury. 
         [0025]    The one or more energy absorbers  32  may be a textile brake or any other appropriate energy absorber system. For example, an exemplary textile brake may be the Textile Modular Brake manufactured and sold by Zodiac Aerospace Engineered Arresting Systems Corporation, of Aston, PA, the present assignee of this application. In another example, the energy absorber  32  may be a water twister rotary hydraulic energy absorber manufactured and sold by Zodiac Aerospace Engineered Arresting Systems Corporation, of Aston, Pa., the present assignee of this application. In another example, the energy absorber  32  may be a Zodiac Transition Zone Controller (TZC), as described by U.S. Pat. No. 8,007,198 titled “Arresting Systems and Methods.” In another example, the energy absorber  32  may be a friction brake set at a predetermined load. This may be an application of a friction brake or clutch assembly, equipped with a textile tape on a reel. Other energy absorbers  32  are possible for use and are considered within the scope of this disclosure. In any event, the energy absorber  32  may be provided with a predetermined runout based on available space with the intent to stop the vehicle with minimal damage or occupant injury. Parameters that may be adjusted in order to determine the appropriate energy absorber  32  for use in connection with fence system  10  may include but are not limited to vehicle weight, vehicle speed, available runout (vehicle travel) distance, or combinations thereof. The energy absorbers can be configured to provide a vehicle runout as defined by customer requirements, local regulations, or unique installation limitations. 
         [0026]    The energy absorber  32  may be mechanically attached to both the net  24  and to the movable gate carriage  12 . In the example shown, a lower portion  34  of the net  24  may be secured to or otherwise cooperate with one or more energy absorbers  32 . There may be an energy absorber  32  provided at the base of each of the side supports  20 . In one example, it is possible for an extension  36  of the energy absorber  32  to form the lower portion  34  of the net  24 . 
         [0027]    In use, the arresting forces will be transferred from the vehicle to the arrestor net  24 , to the energy absorber  32 , to the movable gate carriage  12 . The position of the movable gate carriage  12  will be maintained due to the arrestment restraints  16  or the roadway channel  62 . 
         [0028]    An optional frangible channel section  38  may be provided. The optional frangible channel section  38  may reduce the catenary of the arrestor net  24  that would otherwise occur due to gravity and thereby release or reduce loads. The frangible net section  38  may reduce the support tension required in the net suspension and the release mechanism load. It can also provide a visual signal to the driver of the vehicle that the barrier is in place. It can collapse upon vehicle contact with minimal damage to the vehicle. In one example, the frangible channel section  38  may be made from a lightweight material that can easily break. For example, it may be fiberglass or extruded plastic. While the frangible channel section  38  provides vertical support, it is relatively weak in the horizontal direction and fractures upon vehicle impact with the arrestor net  24 . 
         [0029]    In one example, the frangible channel section  38  includes one or more pins  64  located along its ends, and optionally periodically along the length. These pins  64  may support the upper horizontal portion  28  of the arrestor net  24 . These pins  64  may help prevent the net from the sagging. The additional supports along the net links can help reduce the tensile force required to keep the net at the desired height. This, in turn, can reduce the design load on the release mechanism  40 , the side support  20 , and the support cable  26 . 
         [0030]    The arrestor net  24  may be manufactured out of any appropriate material that has sufficient strength to arrest a traveling vehicle. In one example, the net may be constructed from nylon 6-6 flat webbing. In another example, the net may be constructed from material currently used by aircraft catch nets. In another example, the net may be manufactured at a higher strength tensile material, such as steel or aramid cable. In another example, the net may be manufactured of a first material and have a second, stronger material interwoven therewith or otherwise incorporated therein. 
         [0031]    The arresting fence system  10  can provide a barrier that can be incorporated as part of a perimeter fencing system  50 , as illustrated by  FIG. 3 . As shown, the fencing system  50  may have arrestment restraints  16  installed at edges  52 . When the fence system  10  is not in use, it may be rolled or pivoted aside to create a clear path  54 , illustrated by  FIG. 3A . When the fence system  10  is in use, it may be rolled or pivoted to obstruct the clear path, illustrated by FIB.  3 B. In another example, the fence system  10  can provide a barrier that can be incorporated as part of a bollard arrangement. The movable gate carriage  12  is designed to move laterally to provide a barrier to entry into the area being protected. 
         [0032]    As illustrated by  FIG. 4 , the sequence of operation of the net may be carried out as follows. These steps may generally occur once the movable gate carriage  12  is positioned in front of the opening  54 :
   1. The vehicle (V) travels into the arrestor net  24 .   2. The release mechanisms  40  on either side of the net  24  release under a design load, allowing the net  24  to envelope and travel with the vehicle.   3. The energy absorbers  32 , connected to the net  24 , provide a restraining force which is transmitted to the vehicle V until it comes to a stop.   4. The arrestment restraints  16  prevent carriage  12  movement due to the arrestment loads.   
 
         [0037]    It should be understood that other methods of the decelerating a vehicle using the systems described herein are possible. Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the disclosure or the following claims.