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CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. Ser. No. 11/393,269 filed on Mar. 30, 2006 entitled “Arresting Systems and Methods,” now allowed, the contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to systems and methods for impeding movement of moving objects and more particularly, although not necessarily exclusively, to bidirectional, reusable systems and methods for arresting travel of ground-based vehicles. 
       BACKGROUND OF THE INVENTION 
       [0003]    U.S. Pat. No. 6,843,613 to Gelfand, et al. discloses an energy absorbing system forming part of an automobile barrier for placement preferably at a railroad crossing. The system includes a net stored in a pit spanning a roadway and parallel to railroad tracks. The net may be raised as an automobile approaches along the roadway in a particular travel direction; should the automobile not stop timely it will collide with the net, causing the automobile to cease travel prior to reaching the tracks. 
         [0004]    The system of the Gelfand patent also contemplates placing a second automobile barrier opposite the railroad tracks from the first barrier. Such a two-barrier system is depicted especially in  FIGS. 1A-1B  of the Gelfand patent, with one net impeding automobile travel in a first direction along the roadway and the other net impeding travel in the direction opposite the first direction. In this sense each barrier of the Gelfand patent is only unidirectional, as the structure used to absorb energy functions only when the net is displaced toward the railroad tracks. 
         [0005]    U.S. Pat. No. 6,779,756 to Lopez, owned commonly with this application, describes other systems for arresting aircraft or other vehicles. Designed typically for above-ground installation, these systems include dual arresting tapes provided on spools with brake assemblies positioned within hubs of the spools. The arresting tapes are designed for connection to a cable crossing a runway (or other travel area), with the cable being engaged typically by a tail hook associated with the vehicle to be arrested. For purposes of this application, the entire contents of both the Lopez and Gelfand patents are incorporated herein by this reference. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides alternate systems and methods for arresting, or otherwise impeding, movement of objects such as vehicles. Systems of the invention may be bi-directional in operation and may be reset for reuse relatively rapidly after having been deployed. Such systems additionally may use some or substantially all of available stopping space when deployed, potentially reducing likelihood of injury to occupants of arrested vehicles. 
         [0007]    Present systems preferably use a net as a barrier to travel. They additionally may include brake-in-spool assemblies and arresting tapes similar to those of the commonly-owned Lopez patent. In one version of the invention, retractable stanchions raise and lower the net from a laterally-slotted beam embedded in a roadway (or similar) surface. When undeployed, therefore, the net is typically positioned below grade. However, in another version of the invention the net rests above ground and is lowered from its resting position when deployed. In either version, sheave rollers may be included to permit bi-directional use of the systems. 
         [0008]    Thus, at least some embodiments of the invention may comprise a pair of energy absorbers, in the form of brake assemblies, positioned at opposite sides of a roadway, runway, or other to-be-traveled surface. The assemblies may include tape reels, with associated tapes indirectly connected to each end of a net via a tape connector. Cooperating stanchions at each end of the net operate to raise or lower the net as needed, and sheave rollers through which the tapes pass rotate suitably to impede motion of the object engaging the net. 
         [0009]    It thus is an optional, non-exclusive object of the present invention to provide systems and methods of absorbing energy so as to slow a moving object. 
         [0010]    It is also an optional, non-exclusive object of the present invention to provide systems and methods of impeding movement of a vehicle or other object occupied by humans. 
         [0011]    It is an additional optional, non-exclusive object of the present invention to provide systems of arresting vehicles, which systems may operate regardless of direction of travel of the vehicles along roadways. 
         [0012]    It is another optional, non-exclusive object of the present invention to provide systems of arresting vehicles, which systems may be reset and reused. 
         [0013]    It is a further optional, non-exclusive object of the present invention to provide systems and methods of arresting vehicles employing nets that may be either raised or lowered for deployment. 
         [0014]    It is, moreover, an optional, non-exclusive object of the present invention to provide systems and methods of arresting vehicles utilizing friction brakes in connection with the nets. 
         [0015]    Other objects, features, and advantages of the present invention will be apparent to those skilled in the relevant art with reference to the remaining text and drawings of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a cut-away, partial schematic view of an in-ground version of a system of the present invention. 
           [0017]      FIGS. 2A-B  are another view of the system of  FIG. 1  with selected components enlarged, with  FIG. 2A  depicting the system as deployed and  FIG. 2B  detailing the undeployed system. 
           [0018]      FIGS. 3A-B  are views of an above-ground version of a system of the present invention, with  FIG. 3A  illustrating the system prior to deployment and  FIG. 3B  illustrating the deployed system. 
           [0019]      FIG. 4  is a plan view of a net useful as part of the systems of  FIGS. 1-3B . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Depicted in FIGS.  1  and  2 A-B is exemplary system  10  of the present invention. System  10  is denoted “in-ground” because many of its components are below grade (at least prior to deployment). Those skilled in the relevant field will recognize that not all components of system  10  need necessarily be below grade prior to deployment, so system  10  may be constructed differently than as shown in FIGS.  1  and  2 A-C. 
         [0021]    Nevertheless, system  10  preferably includes module  14 , which beneficially may be a pre-cast block or beam of concrete. Module  14  typically will be elongated, with a length greater than the width of the roadway, runway, or other travel surface with which it is deployed. When positioned across such travel surface, therefore, module  14  will span its width. 
         [0022]    Module  14  additionally is designed to be embedded in the travel surface with its upper surface  18  flush therewith. Upper surface  18  itself thus may form part of the travel surface. Accordingly, module  10  should be of sufficient strength to bear loads consistent with vehicular traffic to which it will be exposed. 
         [0023]    Preferably included within module  14  is a longitudinally-extending slot  22  that likewise spans the width of the travel surface with which it is deployed. Positioned within slot  22  may be an arrestor assembly  26  comprising, among other items, net  30 . Net  30  may be made of natural or synthetic fabric (or both) or of any other material capable of withstanding contact with a moving vehicle while tensioned consistent with the invention. 
         [0024]      FIG. 4  depicts an exemplary configuration of net  30 , with three spaced, generally-horizontal beams  34 , a selected number of spaced, generally-vertical beams  38  as required for the width of the travel surface, and triangular sections  42  forming ends  46  and  50 . Preferred versions of net  30  are made of synthetic fiber. However, those skilled in the art will understand that net  30  may be constructed other than as depicted and described herein. 
         [0025]    Also included as part of arrestor assembly  26  may be stanchions  54 . Each of a pair of stanchions  54  may be positioned adjacent an end  46  or  50  of net  30 . Stanchions  54  function to raise net  30  out of slot  22  (i.e. above the travel surface) for deployment as shown in  FIGS. 1 and 2A . They also serve to lower net  30  into slot  22  (i.e. below the travel surface) when not in use—as shown in  FIG. 2B . 
         [0026]    Preferred versions of stanchions  54  are electrically operated using motors  58 . Stanchions  54  may be operated manually or otherwise as desired, however. In areas subject to low temperatures, heaters may be included as part of arrestor assembly  26  so as to facilitate operation of motors  58  and corresponding stanchions  54 . 
         [0027]    FIGS.  1  and  2 A-B illustrate additional components of system  10 . Such components may include brake assemblies  62 , tape connectors  66 , and sheave rollers  70 , all of which preferably are (but need not necessarily be) located above grade. Advantageously one brake assembly  62 , connector  66 , and sheave roller  70  is associated with each end  46  and  50  of net  30  so that two of each component are included within system  10 . Conceivably, however, more than two of each component may be employed if appropriate to do so. 
         [0028]    Incorporated into each brake assembly  62  may be (at least one) reel  74  containing (at least one) tape  78 . Reels  74  normally are oriented generally horizontally, so that they rotate about generally vertically-oriented axes. Assembly  62  may be constructed and operate generally as detailed in the Lopez patent: When a vehicle contacts and deforms deployed net  30 , each tape  78  may unwind from its reel  74  while a brake within assembly  62  exerts force on the reel  74 . Tapes  78  thus help absorb energy caused by the vehicle dynamically loading net  30 . Although tapes  78  may unspool to any extent necessary to effect the purposes of system  10 , applicants believe lower-weight passenger automobiles frequently may be stopped within approximately thirty-five feet of run-out of each tape  78  and heavy passenger vehicles stopped with as little as one hundred feet of run-out of tapes  78 . Brake assemblies  62  alternatively may be rotary hydraulic brakes such as those provided by Engineered Arresting Systems Corporation of Aston, Pa. under, e.g., the name “Water Twister.” 
         [0029]    Tapes  78  connect to respective ends  46  and  50  of net  30  via connectors  66  and sheave rollers  70 . Threading tape  78  through sheave rollers  70  permits it to bear against (and therefore cause to rotate) either roller  82 A or roller  82 B, depending on the direction the to-be-arrested vehicle is moving relative to net  30 . Connections preferably occur at loops  84 A and  84 A at respective ends  46  and  50 , with cable, rope, or similar material  83  connecting the loops  84 A and  84 B to tape connectors  66 . Such material  83  may be separate from beams  34  or a continuation of one or more of such beams  34 . 
         [0030]    Slot  22  preferably is approximately two inches wide, while tape  78  preferably is six inches wide and made of nylon or polyester. Again, however, neither width is critical. Instead, either or both of slot  22  and tape  78  may have different measurements if desired, and tape  78  may be made of other materials. 
         [0031]    Optionally included as part of system  10  may be shear links designed to connect beams  34  to stanchions  54  and maintain the beams  34  under additional tension. These links may release under the stress of vehicle engagement, in which event their replacement would be required before system  10  is reused. Tapes  78  further are designed to be rewindable onto reels  74  post-use, so that system  10  may be reused without replacement of the tapes  78 . Finally, a cover may be employed over slot  22  to reduce foreign objects from entering the slot  22 , as long as the cover does not impede deployment of net  30 . 
         [0032]      FIGS. 3A-B  illustrate an alternative system  10 ′ of the present invention. Components of system  10 ′ are located above grade, so that the system  10 ′ may be denoted an “above-ground” version of the invention. Rather than including slot  22  in which net  30  rests between deployments, system  10 ′ includes superstructure or frame  86  extending above grade. Frame  86  includes opposed legs  90  to either side of travel surface T and between which net  30  extends. Net  30  normally is retracted at the top  94  of frame  86 , well above the travel surface as shown in  FIG. 3A . For deployment, net  30  may travel down legs  90  so as to be adjacent travel surface T (as illustrated in  FIG. 3B ). Preferably tapes  78  do not connect to net  30  until the net  30  is positioned as shown in  FIG. 3B , likely requiring use of quick-connect/disconnect fasteners as part of system  10 ′. 
         [0033]    Sensors associated with the travel surface may provide signals actuating either system  10  or system  10 ′. Should sensors for system  10  indicate that a travelling object should be arrested, system  10  would activate, with motors  58  causing stanchions  54  to expand. Such expansion of stanchions  54  in turn raises net  30  above the travel surface, thereby placing net  30  in the path of the to-be-arrested object. In certain embodiments of the invention the act of raising net  30  requires only two to three seconds, although faster or slower rise times may occur as appropriate. Further, net  30  need not be fully raised to function as an arrestor, as raising only a portion of net  30  above grade may be sufficient to arrest some vehicles and other objects. 
         [0034]    Activation of system  10 ′ is generally similar. If associated sensors indicate need to arrest an object traveling toward system  10 ′, net  30  is lowered along legs  90  into position adjacent travel surface T and connected to tapes  78 . These actions preferably require only three to five seconds, although again shorter or longer lowering times may occur. 
         [0035]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention.

Summary:
Systems and methods for arresting vehicles or other moving objects are detailed. The systems may be bi-directional, so as to arrest vehicles on either side of a barrier. They additionally may be reset for reuse relatively rapidly following deployment.