Abstract:
A non-slip overlash jig for pulling cable along a support line via a towrope such that when the towrope is slack, the overlash jig does not retreat along the support line thereby slacking the cable. The non-slip overlash jig includes a housing having a roller and a clamping mechanism for engaging the cable. The roller is rotatably mounted to the housing and includes a one-way roller bearing that prevents sliding of the non-slip overlash jig when there is slack in the towrope.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims benefit of copending and co-owned U.S. Provisional Patent Application Ser. No. 60/953,646 entitled “Non-Slip Overlash Jig”, filed with the U.S. Patent and Trademark Office on Aug. 2, 2007 by the inventor herein, the specification of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to an improved overlash jig. More particularly, the invention relates to a device for pulling cable along an existing line such as the lines between utility poles. The invention more specifically relates to a device for pulling cable that remains in place without introducing slack on the cable when the device is no longer under tension. 
         [0004]    2. Background 
         [0005]    Utility poles support different types of cables that provide services to consumers. These services may include electricity, cable television, telephone, and internet connections, among others. Often, power companies own the poles that support such cables. The owners usually charge other companies who want to utilize the existing poles to support cables for their particular services. 
         [0006]    In order to upgrade services to consumers, such as coaxial or fiber optic cables, between utility poles, companies typically lash one or more new cables to existing cables already connected to the utility poles. A new cable is installed between the utility poles using a device that hangs on and rolls along an existing cable. The new cable is secured to one end of the device and a towrope is secured to the other end of the device. The device is then pulled along the existing cable using the towrope. The new cable follows and is then attached to the existing support cable. 
         [0007]    These devices, called overlash jigs, are normally utilized to “pull” a new cable “and keep it in line with” an existing cable. In some embodiments, the rope connects the jig to a vehicle/other towing device or other means for pulling it along the path of the existing cable. In some cases, the cable is pulled by a member of a ground crew. 
         [0008]    Generally, the towrope remains continuously under tension and the device pulls a new cable into place. Sometimes, the tension on the towrope may be relaxed accidentally or by necessity. For example, when the vehicle or person towing the device stops, when the tow line breaks, or when an obstacle needs to be overcome. Additionally, when a second pole is encountered in the stringing operation, the pulling stops while the jig is disengaged, moved past the pole, and reengaged. In such situations, the jig may travel backwards due to the new cable&#39;s own weight. Such backward travel may result in personal injuries or damage to the cables and equipment. While some prior art devices use clamps to prevent backward motion of the device, they are only used in new construction or initial installation of lines wherein the prior art device rides on a support line, which is basically wire rope approximately ¼″ in diameter. Often new cable is added to existing cable packages, which consist of two or more coaxial/fiber optic cables that were previously overlashed to the support line. This requires a device that will ride on a larger cable package, other than a support line. 
       SUMMARY OF THE INVENTION 
       [0009]    One embodiment of the present invention provides an improved non-slip overlash jig for installing cable between utility poles. The non-slip overlash jig prevents backward travel of the device when the jig is not being pulled. A preferred embodiment of the invention provides that such an overlash jig include a one-way roller bearing and clamping device that prevents rearward travel of the jig when the towing rope is slackened. 
         [0010]    Accordingly, it is an object of the present invention to enable an overlash jig that avoids the disadvantages of the prior art. 
         [0011]    Another object of the present invention is to enable a non-slip overlash jig. A related object of the present invention is to enable an overlash jig using one-way roller bearings. 
         [0012]    Another object of the present invention is to enable the installation of multiple cables at the same time utilizing an existing cable to support the overlash jig of the present invention. A further object of this invention is to allow the installation of cables upon supporting cable packages of different diameters. 
         [0013]    This invention addresses the issue of adding new cable to existing cable/wire packages. The device will ride on existing cable packages while towing one or more coaxial/fiber optic cables. It also has a braking mechanism to stop it from rolling backwards when the towrope is slackened. In a preferred embodiment, the device can clamp to any size cable/fiber optic package up to 2¾ inches in diameter. The invention comprises a three-sided frame with a rubber pulley on one end. The rubber pulley has a one-way roller bearing installed to allow the pulley to roll in only one direction. On the other end is a rubber braking mechanism with the same shape as the pulley. This mechanism is spring loaded to allow the device to clamp to any size cable/fiber optic package. 
         [0014]    Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which: 
           [0016]      FIG. 1  is a left perspective view of a non-slip overlash jig with a closed clamping mechanism. 
           [0017]      FIG. 2  is a front view of a non-slip overlash jig. 
           [0018]      FIG. 3  is a rear view of a non-slip overlash jig. 
           [0019]      FIG. 4  is a bottom perspective view of a non-slip overlash jig. 
           [0020]      FIG. 5  is a left perspective view of a non-slip overlash jig with an open clamping mechanism. 
           [0021]      FIG. 6  is a left perspective view of a non-slip overlash jig with a closed clamping mechanism 
           [0022]      FIG. 7  is a rear perspective of a non-slip overlash jig with a closed clamping mechanism. 
           [0023]      FIG. 8  is a front perspective of the clamping mechanism. 
           [0024]      FIG. 9  is a close elevational view of a non-slip overlash jig being pulled by a rope and towing a cable. 
           [0025]      FIG. 10  is an elevational view of a non-slip overlash jig being pulled by a rope and towing a cable. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    The invention summarized above and defined by the enumerated claims may be better understood by referring to the following description, which should be read in conjunction with the accompanying drawings in which like reference numbers are used for like parts. This description of an embodiment, set out below to enable one to build and use an implementation of the invention, is not intended to limit the invention, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form. 
         [0027]    Referring to the drawings, a non-slip overlash jig  100  of the present invention is shown in  FIGS. 1-4 . The overlash jig  100  has three primary parts. The first part is a housing  101  that includes a front sidewall  102 , a rear sidewall  104 , a bottom sidewall  107 , a left sidewall  120 , and a right sidewall  122 . One or more linking rings  109  are attached to the rear sidewall  104 , and a tow ring  111  is attached to the bottom sidewall  107 . 
         [0028]    The second part is a connecting arm  117 . The connecting arm  117  has four parts: an elongated arm portion  118 , a top  124 , a hook  126 , and a guide  130 . A bottom end of the arm  118  connects to the housing  101  and extends generally perpendicularly away from the housing  101 . A top end of the arm portion  118  is connected on a distal end to an end  132  of the top  124 . The top  124  extends generally perpendicularly away from the arm portion  118  towards the inside of the overlash jig  100 . A second end  133  of the top  124  connects to the hook  126 . The hook  126  extends generally perpendicularly downwards from the top  124  towards the housing  101 . The hook  126  is connected to at least one roller  128  and a guide  130 . The at least one roller  128  is mounted on an axle  129  by a one-way roller bearing  137  that allows the at least one roller  128  to rotate in only one direction. One end of the axle  129  is attached to the hook  126 ; the other end is attached to the arm portion  118 , such that the axle  129  is substantially parallel to the top  124 . The guide  130  keeps the overlash jig  100  in line with and prevents the overlash jig  100  from riding up over the existing cable. The roller  128  is sized and configured to rollingly engage a pre-existing support cable. 
         [0029]    The third part of the overlash jig  100  is a clamping mechanism  115  that allows the non-slip overlash jig  100  to clamp to any size cable or fiber optic package. As shown in  FIGS. 5 and 6 , the clamping mechanism  115  includes a spring mechanism  501 , a lever arm  506 , a static end  509  having at least one bumper  513  (best seen in  FIG. 7 ), and an adjusting nut  511 . In one embodiment of the present invention, the at least one bumper  513  has the same shape as the roller  128 . Both the roller  128  and the bumper  513  have a concave structure allowing them to cradle an existing cable package. The at least one bumper  513  is sized and configured to engage the pre-existing support cable although the bumper  513  does not rotate on the lever arm  506 . As shown in  FIG. 8 , the lever arm  506  is pivotally attached to the housing  101 . The spring mechanism  501  provides a biasing force tending to urge the lever arm  506  toward parallel alignment with the connecting arm  117 . In a preferred embodiment, the overlash jig  100  can be used on cable packages up to 2¾ inches in diameter. With an appropriately sized roller  128  and bumper  513 , other sized cable packages can be accommodated. The roller  128  engages the top of the support cable and the clamping mechanism  115  keeps the overlash jig  100  in place while it is being pulled. The clamping mechanism  115  also assists in braking the overlash jig  100  when tension is removed from the towrope. The one-way bearing  137  of roller  128  is installed such that movement of the overlash jig  100  along a pre-existing cable is in a direction away from the clamping mechanism  115 . The one-way bearing  137  of roller  128  prevents backward motion of the overlash jig  100 , and the bumper  513  of the clamping mechanism  115  provides additional resistance to movement of the jig  100 . The adjusting nut  511  adjusts the length of travel of the lever arm  506  to accommodate various size cable packages. 
         [0030]    It is understood that an existing cable upon which the non-slip overlash jig  100  travels may vary in size. In some cases, this change in size is due to previous installations of other cables. The previous installations result in an existing cable with multiple lines lashed to the underlying cable and with an increased diameter. In one preferred embodiment, the invention may be utilized on cable packages up to 2¾ inches in diameter. Other sizes may also be accommodated. 
         [0031]    It is contemplated that the roller  128  and the bumper  513  of the clamping mechanism  115  may be constructed of a number of materials such as elastic, rubber, metal, and other materials whose structure prevents the overlash jig from sliding when the one-way bearing  137  for roller  128  locks. 
         [0032]    As shown in  FIG. 9 , in one preferred embodiment of the present invention, the non-slip overlash jig  100  of the present invention is utilized to rollingly engage and travel along an existing cable  901  connected between two supporting structures to carry a new line  905  from one supporting structure to the next. The existing cable  901  may correspond to service lines, such as telephone, cable, internet access, fiber optics, and others that provide a service to an end user. The supporting structures may include utility poles, buildings, or other structures connected by the existing cable  901 . The existing cable  901  generally extends horizontally from a first support point on one structure to a second support point on a second structure. The non-slip overlash jig  100  is utilized to install a line  905  of cable from the first supporting structure to a second supporting structure. It is contemplated that the new line  905  may utilize the same support points that the existing cable  901  utilizes, or new support points on each supporting structure. 
         [0033]    The invention has been described with references to a preferred embodiment. While specific values, relationships, materials and steps have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with such underlying concept. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive.