Abstract:
A method for protecting cables and posts from damage by providing at least one first sleeve cut to a desired length, positioning each first sleeve over the cable, inserting a screw through an aperture on a last first sleeve positioned on the cable until the screw contacts the cable, providing a second sleeve having an inside diameter greater than an outside diameter of the first sleeve, positioning the second sleeve over the first sleeves, tensioning the cable, securing an end of the cable, sliding the second sleeve over the end, positioning a removable collar assembly between the first and second sleeves, maintaining the first and second sleeves from overlapping the removable collar and each other, maintaining the first and second sleeves from connection with each other, removing the holding screws from the last first sleeve, and rotating the sleeves and the removable collar assembly independently from each other.

Description:
[0001]    The present application is a divisional of pending patent application Ser. No. 12/583,903, filed on Aug. 27, 2009, entitled “Impact Load Deflector Sleeve and Removable Collar Assembly for Cable and Post Protection, which is a continuation-in-part of patent application Ser. No. 11/261,175, filed on Oct. 28, 2005, entitled “Impact Load Deflector Sleeve and Removable Collar Assembly for Cable and Post Protection, now abandoned, which is a continuation-in-part of patent application Ser. No. 10/976,201, filed on Oct. 28, 2004, entitled “CNC Impact Load Deflector Sleeve and Removable Collar for Cable and Post Protection”, now abandoned. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to an apparatus for the protection of cables and posts (or columns) against the dynamic loads from rolling stones, vehicular impact, ice impact or other forms of transient loads and, more particularly, the invention relates to a CNC impact load deflector sleeve and removable collar installable on the cable holding the fence post, which, in turn, stretches rock fall drape net, which constitutes a rock fall mitigation fence system (RFMFS). 
         [0004]    2. Description of the Prior Art 
         [0005]    A rock fall mitigation fence (RFMF) is frequently used to protect the traveling vehicles against potential hazards of falling rocks. The fence system is composed of the fence cable, fence posts, and rock fall drape net resting on the cable, which, in turn, is stretched and supported on the fence posts and cable anchors. The fence posts are embedded in rock and the cable is connected to the ground anchor embedded in rock. The RFMFS functions as a flexible fence system for retaining falling rocks by dissipating their dynamic energy during the back and forth swing upon rock impact. The mass of falling rocks varies a great deal. It can range from a few hundred pounds to many tons. 
         [0006]    When falling from the hill/mountain top or slope, a falling rock gains momentum as it rolls down the slope. When it comes in contact with a RFMFS, the rock rotates at an extremely high angular velocity, can sever fence-supporting cables, and knocks out or severely bends fence posts, cuts anything it touches. The failure of the RFMFS allows the falling rocks to land on the highway or, in some cases, on top of a moving vehicle, as demonstrated in the rock fall in Georgetown, Colorado on Apr. 8, 2004. To date the only mechanism for the failure prevention of the RFMFS is to use stronger nets, cables and posts. The literature search including the search on the US Patent and Trademark web site and the communication with fence installers did not reveal any other fence cable or post protection apparatuses as the CNC Impact Load Deflector Sleeve (CNC//ILDS) and Removable Collar (RC) submitted in this invention that deflect the moving rocks and impact force, and, thereby, reduce the chance of cable and post failures. Accordingly there exists a need for a mechanism for deflecting falling rocks and impact force, reducing the chance of fence failure and enhancing the safety of the traveling public. 
       SUMMARY 
       [0007]    The present invention is a guard system for protecting cables or posts from damage by falling rocks and other dynamic forces. The guard assembly comprises a first sleeve rotatably positionable about one of the cables or the posts and a second sleeve rotatably positionable about the cable or the post. A removable collar assembly is positioned between the first sleeve and the second sleeve for maintaining the spacing between the first sleeve and the second sleeve with the removable collar assembly comprising a first removable collar and a second removable collar. The first removable collar has a first slot for receiving the cable or post and the second removable collar has a second slot for receiving the cable or post with the first slot extending from a perimeter of the first removable collar to a point past a center point of the first removable collar and the second slot extending from a perimeter of the second removable collar to a point past a center point of the second removable collar. The first sleeve is free from any overlap and connection with the removable collar assembly and the second sleeve is free from any overlap and connection with the removable collar assembly. The first sleeve, the second sleeve, and the removable collar assembly are independently rotatable from each other. 
         [0008]    In addition, the present invention includes a method for protecting cables and posts from damage by falling rocks and other dynamic forces. The method comprises providing at least one first sleeve cut to a desired length, positioning each first sleeve over the cable, inserting a holding screw through an aperture on a last first sleeve positioned on the cable until the holding screw contacts the cable, providing a second sleeve having an inside diameter greater than an outside diameter of the first sleeve, positioning the second sleeve over the first sleeves, tensioning the cable, securing an end of the cable, sliding the second sleeve over the end, positioning a removable collar assembly between the first sleeve and the second sleeve, maintaining the first sleeve and the second sleeve from overlapping the removable collar and each other, maintaining the first sleeve and the second sleeve from connection with each other, removing the holding screws from the last first sleeve, and rotating the first sleeve, the second sleeve, and the removable collar assembly independently from each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a sectional view illustrating an impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, prior to a large sleeve being positioned over the looped cable; 
           [0010]      FIG. 2  is a sectional view illustrating an impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, subsequent to the large sleeve being positioned over the looped cable; 
           [0011]      FIG. 3  is a sectional view illustrating a pair of constructed removable collars of the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, with the removable collars bolted together; 
           [0012]      FIG. 4  is a side view illustrating the pair of constructed removable collars of the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention; 
           [0013]      FIG. 5  is a top view illustrating a single removable collar of the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention; 
           [0014]      FIG. 6  is a top view illustrating the pair of constructed removable collars of the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention; 
           [0015]      FIG. 7  is a sectional view illustrating the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, with the small sleeve having a beveled inner edge; 
           [0016]      FIG. 8  is a sectional view illustrating the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, with the sleeve positioned over a post; and 
           [0017]      FIG. 9  is a top plan view illustrating the impact load deflector sleeve and removable collar assembly for cable and post protection, constructed in accordance with the present invention, with the sleeve positioned over a post. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    As illustrated in  FIGS. 1 and 2 , the present invention is an impact load deflector sleeve and removable collar assembly, indicated generally at  10 , for cable  12  and post  13  protection. It should be noted that the post  13  can be I-shaped, H-shaped, or an I-beam and is not limited by the description or drawings. 
         [0019]    The impact load deflector assembly  10  of the present invention includes a plurality of small sleeves  14 , a large sleeve  16 , a plurality of washers  18  between each adjacent small sleeve  14 , and a removable collar assembly  20  positioned between one of the small sleeves  14  and the large sleeve  16 . The collar assembly  20  can also be positioned between adjacent large sleeves  16 . Furthermore, as will be described in further detail below, there can be a plurality of small sleeves  14  and/or a plurality of large sleeves  16  and the number of sleeves  14 ,  16  is not limited by the drawings and description herein. 
         [0020]    The impact load deflector assembly  10  of the present invention allows the small sleeves  14  and the large sleeve  16  to deflect a rolling rock or other dynamic force upon contact and, thereby, reduces the failure potential of the fence cable  12 . It should be noted that the washers  18  can be any desired diameter including having a diameter larger than the diameter of the small sleeves  14 , having a diameter smaller than the diameter of the large sleeves  16 , and having a diameter larger than the diameter of the large sleeves  16 . 
         [0021]    The small sleeves  14  and the large sleeve  16  are preferably a cylindrical tube of any appropriate material made to loosely embrace a cable or a post to allow its near frictionless rotation about the cable or post. The length of the small sleeves  14  and the large sleeve  16  are determined by the field conditions present at the cable installation site and the desires of the construction team. 
         [0022]      FIGS. 3-7  illustrate the removable collar assembly  20  of the impact load deflector assembly  10  of the present invention. The removable collar assembly  20  can be easily installed and removed from the cable  12  for easy construction and repair. The removable collar assembly  20  is positioned between two different-size sleeves to prevent the smaller sleeve  14  from sliding or slipping into the large sleeve  16 . 
         [0023]    The removable collar assembly preferably includes a first removable collar  22  and a second removable collar  24 . Each removable collar  22 ,  24  has a substantially circular cross-sectional configuration with a slot  26  formed therein extending from a perimeter of the removable collar  22 ,  24  to a point past a center point. In addition, each removable collar  22 ,  24  has a first aperture  28  and a second aperture  30  for receiving a bolt  32  or other releasable fastening mechanism. 
         [0024]    To assemble or construct the removable collar assembly  20  for use with the impact load deflector assembly  10  of the present invention, first, the cable  12  or post is inserted into the slot  26  on the first removable collar  22 . As illustrated in  FIG. 6 , the second removable collar  24  is positioned about the cable  12  or post such that the slots  26  of each removable collar  22 ,  24  are opposite each other. A first bolt  32  is inserted into the first aperture  28  of the first removable collar  22  and the second aperture  30  of the second removable collar  24  and a second bolt  32  is inserted into the second aperture  30  of the first removable collar  22  and the first aperture  28  of the second removable collar  24 . A nut  34  or other tightening mechanism is releasably secured to each of the bolts  32  to maintain the first removable collar  22  to the second removable collar  24 . Further construction of the impact load deflector assembly  10  will be discussed below. 
         [0025]    The load impact deflector assembly  10  of the present invention reduces the impact load effect on both cables  12  and fence posts by deflecting the falling rocks upon contact.  FIGS. 1 and 2  illustrate the load impact deflector assembly  10  installed about the cable  12 . The small sleeves  14  and large sleeve  16  are preferably cylindrical and constructed from an appropriate material (e.g., steel) and have an appropriate diameter, length, and thickness for embracing a cable  12  or post with a clearance for near frictionless rotation. The thickness and material type of the sleeves  14 ,  16  are preferably selected to provide sufficient strength to prevent the puncture by the rolling rocks. The washers  18  can be positioned between adjacent small sleeves  14  to maintain the spacing of the small sleeves  14  and inhibit contact between adjacent small sleeves  14 . 
         [0026]    Upon contacting any high-speed rolling rock, the load impact deflector assembly  10  rotates nearly frictionless about the cable  12  and, thereby, avoids cable cut. It should be noted that the sleeves  14 ,  16  and removable collars  22 ,  24  can be constructed from any material deemed corrosion resistant, and sufficiently strong against the destructive force of rolling stones, wind, vehicular impact, or any other forms of impact force. In addition to the above, the small sleeves  14  of the load impact deflector assembly  10  have a beveled inner edge. Preferably, the bevel is at a forty-five)(45°) degree angle and is beveled to one-half the thickness of the wall of the small sleeve  14 . The purpose of the bevel is that if the small sleeves  14  are hit in such a manner that they deflect at a sharp angle, the edge of the sleeve  14  will not cut into the cable  12 . 
         [0027]    To mitigate the failure potential of a rock fall mitigation fence system, the sleeves  14 ,  16  of the load impact deflector assembly  10  can be installed along the entire length of the cable  12  and/or the post. The functionality of the load impact deflector assembly  10  is explained as follows:
       The load impact deflector assembly  10  rotates nearly freely around the cable  12  and post that they are protecting.   Upon contacting a sleeve  14 ,  16 , the impact force from a rolling rock or any other impact sources, causes the sleeves  14 ,  16  to rotate.   The action of sleeve rotation deflects the impact force and rock.   The deflection of the impact force reduces the damage potential of the cable  12  and post.
 
The removable collar assembly  20  is preferably installed between a small sleeve  14  at the lowest point of the cable  12  and a large sleeve  16  for protecting the connection just above the ground anchor and the small sleeve  14  for protecting the cable  12  right above the cable connection.
       
 
         [0032]    The construction of the load impact deflector assembly  10  of the present invention will now be discussed. As understood by those persons skilled in the art, the following description is just one manner of constructing the load impact deflector assembly  10 . 
         [0033]    Before the load impact deflector assembly  10  installation, the fence, fence post, cable anchors, and fence supporting cable are installed by a qualified fence installer. At this time the cable where the sleeves are to be installed is loose. The procedure for the load impact deflector assembly  10  sleeve installation is specified as follows:
       1. First, the small sleeves  14  cut to a desired length according to field conditions are positioned over the cable  12  or post with a washer  18  between each adjacent small sleeve  14 . Slide a washer  18  onto the cable  12 .   2. Slide a small sleeve  14  onto the cable  12 .   3. Slide on another washer  18  followed by another small sleeve  14 .   4. Repeat the above until the desired portion of the cable  14  is covered with small sleeves  14 . The number of small sleeves  14  and washers  18  are dependent on the length of the cable  12  or post.   5. The last small sleeve  14  installed on the cable  12  is the sleeve  14  with the temporary assembly holding bolt  36  (this small sleeve  14  is cut to length to fit the length of cable  12  as needed) and the bolt  36  is tightened to the cable  12 . Note: the bolt  36  is removed at the end of the installation procedure and discarded. It is imperative that the bolt be removed as to facilitate the last small sleeve  14  to rotate as required when impacted with a load.   6. Wrap the cable  12  around a cable anchor  13 .   7. After the last small sleeve  14  is temporarily fixed in place with the temporary assembly holding bolt  36 , a sufficient number of large sleeves  16  are installed around the small sleeves  12 . The large sleeves  16  can be hooked behind the temporary assembly holding bolt  36  hold them in place while the cable  12  is tensioned and clamped.   8. Tension the cable  12  to the manufactures recommended tension and clamp the cable  12  with cable clamps  14  to hold the cable in tension. Note: The tension is used to support the fence posts and fence.   9. Slide the large sleeves  16  down to cover the wrapped around and clamped part of the cable  12 .   10. Install the first removable collar  22  between the last small sleeve  14  and the first large sleeve  16 . Position the removable collar  22  such that the first removable collar  22  with the welded nuts  34  is positioned inside the large sleeve  16  and the cable  12  centered in the slot  26 . Then, the second removable collar  24  is fitted onto the bottom part of the first removable collar  22  with the cable  12  centered and the slot  26  opening in the opposite direction with respect to the first removable collar  22 . The bolts  32  are inserted through the two pairs of matching holes  28 ,  30  on the removable collars  22 ,  24  and bolts  32  tightened. Now the cable  12  is centered in the hole formed by the two removable collars  22 ,  24 .   11. The temporary assembly holding bolt  36  is now removed and discarded.   12. The installation procedure is now complete.       
 
         [0046]    When any sleeve  14 ,  16  is damaged or the fence repairs require the removal of the sleeves  14 ,  16 , the following procedures are to be followed:
       1. Obtain the proper size bolt  36  for the temporary assembly holding bolt  36 , install it in the last small sleeve  14 , and tighten it to the cable  12 .   2. Remove the removable collars  22 ,  24 .   3. Slide the large sleeves  16  over the small sleeves  16  and rest them on the temporary assembly holding bolt  36 . The cable clamps  40  are now exposed.   4. Loosen the cable clamps  40  and remove the cable  12  from the cable anchor  13 . Now, the cable is untensioned.   5. Remove the large sleeves  16 .   6. Loosen the temporary assembly holding bolt  36  and remove the small sleeves  14  and washers  18 .   7. Remove all damaged sleeves  14 ,  16  and repair the fence, if necessary.   8. Replace all damaged sleeves  14 ,  16  with new ones and follow the installation procedures reinstall all the sleeves  14 ,  16  and associated part, tension the cable  12  to manufactures specifications.       
 
         [0055]    The removable collar assembly  20  of the impact load deflector assembly  10  inhibits the small sleeve  14  from slipping into the large sleeve  16 . The fence system has to be structurally designed. Many instances of fence failures showed that the falling rocks severed the cables  12 , and uprooted or severely bent the fence post. The failure of a rock fall mitigation fence system imposes a safety risk of traveling motorists from falling rocks as demonstrated in the recent rock fall event along Interstate Highway I 70 near Georgetown, Col. on Apr. 8, 2004. To reduce the risk of failure of a rock fall mitigation fence system, the fence cable needs to be protected from the cut by the large falling rock and the sleeve in the present invention provides such protection. In an event of need for sleeve replacement, the removable collar assembly  20  enhances the constructability because it can be easily opened and removed, the large sleeve  16  slips over the small sleeve  14  and cable  12  unbolted to allow sleeve  14 ,  16  removal and repair. 
         [0056]    Besides, the impact force from falling rocks, the sleeves  14 ,  16  and removable collar assembly  20  of the impact load deflector assembly  10  of the present invention also provide a means of deflecting impact (or dynamic) forces, like those from vehicular impact, and ice impact, etc. 
         [0057]    In sum, the sleeves  14 ,  16  and removable collar assembly  20  of the impact load deflector assembly  10  of the present invention are designed to provide a means of protecting fence cables  12  and posts  13 . Without such protection, a conventional rock fall protection fence frequently fails upon impact from large falling rocks spinning at a high angular velocity and with an immense momentum, as demonstrated in many rock fall-induced fence failures. The sleeves  14 ,  16  embrace a cable  12  or post  13  to deflect falling rocks spinning at a high angular velocity and associated impact forces and, thereby, protect them by avoiding detrimental blows from the falling rocks. The removable collar assembly  20  is used when two different-size sleeves are used avoiding a smaller sleeve  14  from slipping into a larger sleeve  16  and to assure the protection the sleeves  14 ,  16  are designed. The washers  18  between the small sleeves  14  allow the small sleeves  14  to spin better when hit. Additionally, the removable collar assembly  20  enhances the constructability and eases the maintenance of a rock fall mitigation fence system. The sleeves  14 ,  16  together with the removable collar assembly  20  embraces the fence cable and post, provides a means of their protection, and enhances the safety of traveling motorists. 
         [0058]    It should be noted that the removable collar assembly  20  is designed and shaped such that none of the sleeves  14 ,  16  overlap with the removable collar assembly  20 . It should also be noted that the sleeves  14 ,  16  are free from connection with the removable collar assembly  20  such that the sleeves  14 ,  16  and the removable collar assembly  20  are independently rotatable from each other. 
         [0059]    In sum, when falling from the hill/mountain top or slope, a falling rock gains momentum as it rolls down the slope. The rock is rotating at a very high angular velocity and cuts the cable  12  like a saw blade. When it comes in contact with a RFMFS, the rock rotates at an extremely high angular velocity, can sever fence-supporting cables, and knocks out or severely bends fence posts, cuts anything it touches. The cable protection sleeve  14 ,  16  rotates when struck by a rock moving at high velocity and with or without angular momentum. Because the rock statistically does not hit the cable  12  or the sleeves  14 ,  16  exactly at the center of gravity, the sleeve  14 ,  16  rotates giving the cable  12  the time to move and allow the rock to go around the cable and not cutting the highly tensioned cable  12 . Without the sleeve  14 ,  16 , the cable  12  is cut and the fence fails allow the rock to continue on towards roads, buildings or other features that the fence is designed to protect. Tests conducted by CDOT on the ILD sleeves verified that rotating rocks are deflected by cables protected by the ILD sleeves and are cut by the same rocks under the same conditions without the ILD sleeves. 
         [0060]    The foregoing exemplary descriptions and the illustrative preferred embodiments of the present invention have been explained in the drawings and described in detail, with varying modifications and alternative embodiments being taught. While the invention has been so shown, described and illustrated, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention, and that the scope of the present invention is to be limited only to the claims except as precluded by the prior art. Moreover, the invention as disclosed herein, may be suitably practiced in the absence of the specific elements which are disclosed herein.