You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 10/991,030, filed Nov. 17, 2004, now U.S. Pat. No. ______, which is hereby incorporated by reference. 
         [0002]    This invention relates to a retractable energy absorbing system where the system can be used to dissipate energy such as, e.g., the energy of a vehicle. The system may be used in a variety of applications, including HOV lane traffic control, drawbridges, security gates, or crash cushion applications. In one application, the system may be mobile, so that it may be moved between locations. 
       SUMMARY OF THE DISCLOSURE 
       [0003]    The present disclosure relates to an energy absorbing system. In one aspect, the energy absorbing system includes a supporting member, a barrier mechanically coupled to the supporting member, the barrier pivotable between a first angular position and a second angular position, an energy absorber, at least a portion of which is immovably fixed, that is mechanically coupled to the supporting member, wherein the energy absorber absorbs energy when the supporting member travels from a first lateral position to a second lateral position, and a first rotation limiter mechanically coupled to one of the barrier and the supporting member that limits the barrier from pivoting beyond the second angular position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0004]      FIG. 1  shows a side view of a retractable energy system according to an aspect of the present disclosure. 
           [0005]      FIGS. 2   a - 2   c  show a perspective view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0006]      FIGS. 3   a - 3   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0007]      FIGS. 4   a - 4   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0008]      FIGS. 5   a - 5   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0009]      FIGS. 6   a - 6   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0010]      FIGS. 7   a - 7   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0011]      FIGS. 8   a - 8   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0012]      FIGS. 9   a - 9   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0013]      FIG. 10  shows a perspective view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0014]      FIG. 11  shows a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0015]      FIG. 12  shows a front view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0016]      FIGS. 13   a  and  13   b  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure. 
           [0017]      FIGS. 14   a  and  14   b  show a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0018]      FIG. 15  shows a perspective view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0019]      FIGS. 16   a  and  16   b  show a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0020]      FIG. 17  shows a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0021]      FIGS. 18   a  and  18   b  show a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0022]      FIGS. 19   a  and  19   b  show a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0023]      FIGS. 20   a  and  20   b  show a side view of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0024]      FIGS. 21   a - 21   c  show views of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0025]      FIGS. 22   a - 22   c  show a top view of channels and shear pins according to another aspect of the present disclosure. 
           [0026]      FIGS. 23A and 24A  show side views of a retractable energy absorbing system according to another aspect of the present disclosure. 
           [0027]      FIGS. 23B and 24B  show top views of channels and shear pins according to another aspect of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    Referring to the drawings, wherein like reference numerals represent identical or corresponding parts throughout the several views, and more particularly to  FIG. 1 , a side view of a general layout of an embodiment according to one aspect of the system of the present disclosure is shown. The system may include impact barrier  2 , sled  4 , hinge  6 , and one or more energy absorbers  8 , which may be any device or system that dissipates, redirects or absorbs energy. Impact barrier  2  and sled  4  may be fabricated from metal, rebar reinforced rubber, ceramic, plastic or composite material. Hinge  6  may be a solid pin, gear and shaft, or sprocket gear. Energy absorber  8  may be shock absorber having piston  10 . In other aspects, energy absorber  8  may include a dynamic breaking system, one or more shear pins, springs, foams, pneumatics, hydraulics, woven cable or cloth, friction bearings, breakable concrete or crushable metals or systems utilizing gravity or counterbalance weights. 
         [0029]    To provide flexibility, piston  10  may connect to sled  4  via flange  14 . Impact barrier  2  may be arranged so that it may be in at least a raised position, as shown in  FIG. 1 , or a lowered position. Raised position of impact barrier  2  may be substantially perpendicular to the ground or may be at another angle to the ground, such as a 45 degree angle. In one aspect, a vehicle  20  traveling on a roadway at ground level  18  may make contact with impact barrier  2 , thereby causing impact barrier  2  and sled  4  to travel horizontally, thereby causing energy absorber  8  to absorb energy and the vehicle  20  to decelerate. 
         [0030]      FIGS. 2   a - 2   c  show a perspective view of a retractable energy absorbing system according to another aspect of the present disclosure.  FIGS. 2   a  and  2   b  show a perspective view of a retractable energy absorbing system with impact barrier  2  in a lowered position and raised position, respectively.  FIGS. 2   a  and  2   b  show the system prior to impact, with impact barrier  2  and sled  4  in an original position and pistons  10  in a compressed state. Energy absorbers  8  may be immovably fixed at, above or below ground level  18 .  FIG. 2   c  shows the system with the impact barrier  2  and sled  4  displaced from the original position in a direction of impact and shows pistons  10  in an extended state. Note that, as compared to the arrangement of  FIG. 1 , the energy absorbers  8  in  FIGS. 2   a - 2   c  have been repositioned. 
         [0031]    Impact barrier  2  and/or sled  4  may have a sloped or tear-drop shape on at least one side as shown in  FIG. 2   a,  so that they may act similarly to a speed bump while permitting a vehicle to pass over when in the lowered position. In an aspect shown in  FIGS. 13   a  and  13   b,  the shapes of impact barrier  2  and sled  4  may be inverted so that a vehicle encounters a non-sloped or flat shape. 
         [0032]      FIGS. 3   a - 3   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure.  FIGS. 3   a - 3   d  show energy absorber  8  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  to expand. In  FIG. 3   a,  impact barrier  2  is shown in a lowered position, and in  FIG. 3   b,  impact barrier  2  is shown in a raised position.  FIGS. 3   a  and  3   b  show impact barrier  2  and sled  4  above ground level  18 , with energy absorber  8  located below ground level  18 . As shown in  FIGS. 3   a  and  3   b,  connector  12  and flange  14  may attach energy absorber  8  to sled  4 , for example, at or near distal and proximal ends, respectively. In this and other aspects, piston  10  of energy absorber  8  may be connected to flange  14  via connector  12 . Connector  12  may include a ‘U’ shaped joint and flange  14  may fit inside connector  12  and be secured by a pin (not shown). In other aspects, flange  14  may be located underneath or to the side of sled  4  depending on the location of energy absorber  8 . 
         [0033]    As shown in  FIGS. 3   c  and  3   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorber  8  located within housing  16 . As yet another alternative, energy absorber  8  may be partially above and beneath ground level  18 . For illustrative purposes,  FIGS. 3   c  and  3   d  show impact barrier  2  in a lowered position as well as in a raised position (in dashed lines). 
         [0034]    In various aspects of the system of the present disclosure, one or more energy absorbers  8  may be attached at or between proximal and distal ends of sled  4 , above, at or below ground level  18  and may be attached to sled  4  using flange  14 , connector  12 , hinge  6 , other connection device or any combination thereof. Housing  16  may be used to facilitate portability and may provide a secure, sealed enclosure for the preservation of the internal workings of the system from contaminants and moisture. 
         [0035]      FIGS. 4   a - 4   d  show a side view of a retractable energy absorbing system according to additional aspects of the present disclosure.  FIGS. 4   a - 4   d  show energy absorber  8  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  to compress.  FIGS. 4   a  and  4   b  show impact barrier  2  and sled  4  above ground level  18 , with energy absorber  8  located below ground level  18 . As shown in  FIGS. 4   a  and  4   b,  connector  12  and flange  14  may attach energy absorber  8  to sled  4 , for example, at or between proximal and distal ends, respectively. 
         [0036]    As shown in  FIGS. 4   c  and  4   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorber  8  located within housing  16 . As with the arrangement of  FIGS. 3   a - 3   d,  energy absorber  8  of  FIGS. 4   a - 4   d  may be partially above and beneath ground level  18 . 
         [0037]      FIGS. 5   a - 5   d  show a side view of a retractable energy absorbing system according to further aspects of the present disclosure.  FIGS. 5   a - 5   d  show energy absorbers  8  and  9  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  to extend and piston  11  to compress.  FIGS. 5   a  and  5   b  show impact barrier  2  and sled  4  above ground level  18 , with energy absorbers  8  and  9  located below ground level  18 . As shown in  FIGS. 5   a  and  5   c,  pistons  10  and  11  may attach to flanges  14  and  15  respectively at a distal end of sled  4 . As shown in  FIGS. 5   b  and  5   d , piston  10  may attach to flange  14  at a proximal end of sled  4  via connector  12  and piston  11  may attach to flange  15  at a distal end of sled  4  via connector  13 . 
         [0038]    As shown in  FIGS. 5   c  and  5   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorbers  8  and  9  located within housing  16 . Once again, energy absorber  8 , shown in  FIGS. 5   a - 5   d  may be partially above and below ground level  18 . 
         [0039]      FIGS. 6   a - 6   d  show a side view of a retractable energy absorbing system according to further aspects of the present disclosure.  FIGS. 6   a - 6   d  show energy absorber  8  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  to extend.  FIGS. 6   a  and  6   b  show impact barrier  2  and sled  4  above ground level  18 , with energy absorber  8  located at the side of sled  4  at or above ground level  18 . Energy absorber  8  may attach to sled  4 , for example, at or between distal and proximal ends. As shown in  FIGS. 6   a  and  6   c,  piston  10  may attach to sled  4  at hinge  6 . As shown in  FIGS. 6   b  and  6   d,  piston  10  may attach to flange  14  at or near a distal end of sled  4 . 
         [0040]    As shown in  FIGS. 6   c  and  6   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorber  8  located on or within housing  16 . 
         [0041]      FIGS. 7   a - 7   d  show a side view of a retractable energy absorbing system according to further aspects of the present disclosure.  FIGS. 7   a - 7   d  show energy absorber  8  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  of energy absorber  8  to compress.  FIGS. 7   a  and  7   b  show impact barrier  2  and sled  4  above ground level  18 , with energy absorber  8  located at the sides of sled  4  at or above ground level  18 . Energy absorber  8  may attach to sled  4  at or between proximal and distal ends. As shown in  FIGS. 7   a  and  7   c,  piston  10  may attach to sled  4  at hinge  6 . As shown in  FIGS. 7   b  and  7   d,  piston  10  may attach to flange  14  at or near a distal end of sled  4 . 
         [0042]    As shown in  FIGS. 7   c  and  7   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorber  8  located on or within housing  16 . 
         [0043]      FIGS. 8   a - 8   d  show a side view of a retractable energy absorbing system according to further aspects of the present disclosure.  FIGS. 8   a - 8   d  show energy absorbers  8 ,  9  and  9   a  arranged in a manner such that an application of force to impact barrier  2  may cause piston  10  to extend and pistons  11  and  11   a  to compress.  FIGS. 8   a  and  8   b  show impact barrier  2  and sled  4  above ground level  18 , energy absorbers  8  and  9  located below ground level  18 , and energy absorber  9   a  located at the side of sled  4  at or above ground level  18 . As shown in  FIG. 8   a,  pistons  10 ,  11  and  11   a  may attach to flanges  14 ,  15  and  15   a  respectively at or near a distal end of sled  4 . As shown in  FIG. 8   b,  piston  10  may attach to flange  14  at or near a proximal end of sled  4  and pistons  11  and  11   a  may attach to flanges  15  and  15   a  at or near a distal end of sled  4 . 
         [0044]    As shown in  FIGS. 8   c  and  8   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorbers  8 ,  9  and  9   a  located within or above housing  16 . As with previous aspects, the various energy absorbers may be partially above or below ground level  18 . 
         [0045]      FIGS. 9   a - 9   d  show a side view of a retractable energy absorbing system according to aspects of the present disclosure.  FIGS. 9   a - 9   d  show energy absorbers  8 ,  8   a  and  9  arranged in a manner such that an application of force to impact barrier  2  may cause pistons  10  and  10   a  to extend and piston  11  to compress.  FIGS. 9   a  and  9   b  show impact barrier  2  and sled  4  above ground level  18 , energy absorbers  8  and  9  located below ground level  18 , and energy absorber  8   a  located at the side of sled  4  at or above ground level  18 . As shown in  FIG. 9   a,  pistons  10  and  11  may attach to flanges  14  and  15  at or near a distal end of sled  4 , and pistons  10   a  may attach to hinge  6 . As shown in  FIG. 9   b,  piston  10  may attach to flange  14  at or near a proximal end of sled  4 , pistons  10   a  and  11  may attach to flanges  14   a  and  15 , respectively, at or near a distal end of sled  4 . 
         [0046]    As shown in  FIGS. 9   c  and  9   d,  impact barrier  2  and sled  4  may be arranged above ground level  18  using housing  16 , with energy absorbers  8 ,  8   a  and  9  located within or above housing  16 . As with previous aspects, the various energy absorbers may be partially above or below ground level  18 . 
         [0047]      FIG. 10  shows a perspective view of a retractable energy absorbing system according to another aspect of the present disclosure. In this aspect, impact barrier  2  includes deployment arms  30 , shown in an upright position, and net  32 . When impact barrier  2  is in a lowered position, as shown in  FIG. 11 , net  32  may rest within net pit  36 , which is formed to accommodate net  32 . Net pit  36  may be connected to and travel with impact barrier  2  and sled  4  upon application of force to impact barrier  2 . 
         [0048]    In this and other aspects, impact barrier  2  may be raised and/or lowered using a raising/lowering device  34  and shaft  44 . Raising/lowering device  34  may be, for example, an electric rotary motor, which may be connected to and travel with impact barrier  2  and sled  4 . In one aspect, raising/lowering device  34  may be controlled by a computer system (not shown) operated automatically and/or by a user. In other aspects, the impact barrier  2  may be raised/lowered manually using, for example, a lever, spring, hydraulic jack, air cylinder, rotation mechanism or counterweight. 
         [0049]    As shown in  FIGS. 10 ,  11  and  12 , impact barrier  2 , sled  4  and net pit  36  may be arranged atop housing  16 , with energy absorber  8  located within or above housing  16 . Alternatively, energy absorbers  8  may be arranged in a number of configurations, including those described above. 
         [0050]      FIG. 12  shows a front view of a retractable energy absorbing system according to another aspect of the present disclosure. As shown, sled  4  and/or net pit  36  may have rails  38  that fit in channels  40  and provide guidance in a direction when force is applied to sled  4 . Channels  40  may have drainage holes  42 . When housing  16  is present, channels  40  may be located within housing  16 . In other aspects, channels  40  may be fixed to or in the ground. 
         [0051]    As shown in  FIGS. 14   a,    14   b,    15 ,  16   a  and  16   b,  brackets  50  and  52  may be attached to impact barrier  2  and/or sled  4  and may limit the rotation of impact barrier  2  and provide support. The angle of rotation of impact barrier  2  may be determined by the size and arrangement of brackets  50  and  52 . In one aspect, brackets  50  and  52  may be constructed of steel or other rigid material. 
         [0052]    In an effort to reduce the loads experienced by brackets  50  and  52  as well as the overall system during impact, a variety of cushioning techniques may be applied to brackets  50  and  52 . One such example is a foam cushion, which may be several inches thick depending on the nature of the application and may provide cushioning between the contact surfaces of brackets  50  and  52  during impact. As shown in  FIGS. 16   a  and  16   b , another example of cushioning may be a bracket energy absorber  54 , such as a spring or self-contained shock-absorber that may be attached to the side of or in between brackets  50  and  52  using shafts  56 , and that may resist the rotation of impact barrier  2  during impact. 
         [0053]    As shown in  FIG. 17 , an impact barrier cover  60  may cover some or all of the impact barrier  2  and may protect a vehicle  20  and impact barrier  2  from damage, particularly during low speed impacts. The impact barrier cover  60  may be constructed using thick, compressible material (e.g. foam rubber) that deforms locally. 
         [0054]    As shown in  FIGS. 18   a  and  18   b,  the retractable energy absorbing system may include wheels  70 , and/or casters, tracks/treads, rollers, etc. to facilitate transportation and orientation. Wheels  70  may be used in conjunction with trailer-hitches, goose-neck attachments, or fifth-wheel style attachments. Wheels  70  may be affixed to the unit using axle  72 , or using independent axle, tandem axle, removable, or hinged wheels. 
         [0055]    As shown in  FIGS. 19   a  and  19   b,  the retractable energy absorbing system may include treads  80  driven by sprockets  82 . Sprockets  82  may be connected to a power and control system (not shown) that may be operated by a user to position the retractable energy absorbing system. 
         [0056]    As shown in  FIGS. 20   a  and  20   b,  additional energy dissipation may occur when guide  90  is present which controls the movement of sled  4  and may cause connector  12 , flange  14 , impact barrier  2  and sled  4  to travel along the slope of guide  90  as piston  10  expands and energy absorber  8  pivots on hinge  91 .  FIGS. 20   a  and  20   b  show such a system with housing  16  located partially below ground level  18 , before and after impact, respectively. In another aspect,  FIGS. 21   a,    21   b  and  21   c  show a system with housing  16  located above ground level  18 , with  FIG. 21   c  showing a top view. 
         [0057]    Similarly, with respect to  FIGS. 10-12 , rails  38  and channels  40  may be used in energy dissipation, for example, by having rails  38  and/or guides  40  arranged on an increasing slope, thereby causing the impact barrier  2 , sled  4  and net pit  36  to follow along that slope as they travel after impact. 
         [0058]    As shown in  FIGS. 22   a,    22   b,    22   c,    23   a,    23   b,    24   a,  and  24   b,  channels  40  may be fitted with an arrangement of one or more supplemental energy absorbers, such as breakable shear pins  92 . Rails  38  may slide along channels  40  and break shear pins  92  causing sled  4  to decelerate as it travels. Shear pins  92  may break at shear zones  94 , upon application of force based on specified shear strengths. Shear pins  92  may be arranged uniformly or at increments based on the type of installation. Similarly, guide  90  may be fitted with such supplemental energy absorbers. 
         [0059]    Although illustrative embodiments have been described herein in detail, it should be noted and will be appreciated by those skilled in the art that numerous variations may be made within the scope of this invention without departing from the principle of this invention and without sacrificing its chief advantages. 
         [0060]    Unless otherwise specifically stated, the terms and expressions have been used herein as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof and this invention should be defined in accordance with the claims that follow.

Summary:
An energy absorbing system. The energy absorbing system includes a supporting member, a barrier mechanically coupled to the supporting member, the barrier pivotable between a first angular position and a second angular position, an energy absorber, at least a portion of which is immovably fixed, that is mechanically coupled to the supporting member, wherein the energy absorber absorbs energy when the supporting member travels from a first lateral position to a second lateral position, and a first rotation limiter mechanically coupled to one of the barrier and the supporting member that limits the barrier from pivoting beyond the second angular position.