Abstract:
A cable is moved through a cable fitting (for example, a BUB fitting) into a first opening of the fitting and out of a second opening of the fitting. A roller support structure is mounted on a fitting such that a set of rollers supported by the roller support structure is disposed inside the interior volume of the fitting. A spacer is disposed between the roller support structure and the fitting. An end of a cable is then moved into a first opening of the filling, over the rollers, and out of the fitting through the second opening. Once the cable has rolled over the rollers a desired distance though the fitting, the spacer is removed and the rollers are detached from the roller support structure. The rollers are slipped out around the cable and extracted from the interior volume. The roller support structure is then unmounted from the fitting.

Description:
BACKGROUND INFORMATION  
       [0001]      FIG. 1  shows a cable fitting  8  (sometimes referred to as a conduit fitting) which is comprised of a first opening  25 , a second opening  26 , cover plate retaining holes  21 - 24  and an interior volume  27  that is disposed between the first opening  25  and the second opening  26 . The cable fitting is designed such that a cable can occupy the interior volume  27 . The cable fitting also includes cover plate retaining holes  21 - 24  that permit the mounting of a cover plate to the cover plate plane of the cable fitting  8  once a cable has been installed into the fitting.  
         [0002]      FIG. 2  is a diagram describing how a cable  20  is moved through two cable fittings, a first cable fitting  17  and a second cable fitting  18 . The cable  20  in this diagram is a three conductor 500 MCM electrical cable which is approximately three inches in diameter, heavy and difficult to maneuver. The cable  20  will be pulled from the cable tray  13 , through first cable fitting  17  and then through second cable fitting  18 . Conduit  9  is protective tubing which the cable  20  is also pulled through and is located between the cable tray  13  and then connected to the first opening  25  of first cable fitting  17 , between the second opening  26  of first cable fitting  17  and first opening of second cable fitting  18 . Additional conduit is also attached to the second opening  26  of second cable fitting  18  and extends beyond the second cable fitting  18 . In this diagram the first cable fitting  17  is separated from second cable fitting  18  by approximately four-hundred feet. Installation of the cable  20  through first cable fitting  17  and out of second cable fitting  18  requires two cable pulls. The first pull involves pulling enough cable  20  to reach the second cable fitting  18 , over four-hundred feet in length, from cable tray  13 , through conduit  9 , and through the first opening  25  of first cable fitting  17 . Three pulling wheels with anchor plates  10 - 12 , a pulling wheel  15  and a tugging machine  16  are used to pull the cable  20  through first cable fitting  17  in the direction of the first pull. Pulling wheel  15  is attached to the bumper of a stationary truck. The pulling wheels with anchor plates  10 - 12  are anchored into concrete. Tugging machine  16  pulls the cable  20  from the first opening of first cable fitting  17  in the direction of the first pull around pulling wheel  10 , then around pulling wheel  15  to pulling wheel  11  and then around pulling wheel  12 .  
         [0003]     Once the first pull has been completed, the entire length of cable is available to be hand fed back into the second opening  26  of the first cable fitting  17 . In order to complete the first pull, anchor locations are necessary for the three pulling wheels with anchor plates  10 - 12  and pulling wheel  15  anchored to the truck bumper. The entire length of cable is exposed during the first pull and may have to be laid adjacent a roadway and marked with warning tape or cones. Additionally, damage from contact with automobile traffic is possible when the cable is exposed in this manner. To arrange the pulling wheels with anchor plates  10 - 12 , the tugging machine  16 , pulling wheel  15  and to handle the heavy cable and feed it back into the first cable fitting  17  requires, approximately, a team of eight persons working one eight hour day.  
         [0004]     Once the first pull is completed, a second pull is necessary to pull the cable  20  through the second opening  26  of the first cable fitting  17  through conduit and through the first opening of cable fitting  18 . The cable fitting is pulled in the direction of the second pull through the first opening in the second cable fitting  18  by pulling motor  19 .  
         [0005]     Because pulling the cable through fittings as described is labor intensive, of significant duration and exposes the electrically conducting cable  20  to hazards, another method is desirable to reduce the amount of labor and time required to install cable through cable fittings and one that reduces the possibility of damage to the cable.  
       SUMMARY  
       [0006]     A cable (for example, a large diameter electrical cable) is moved through a cable fitting (for example, a Crouse Hinds four inch BUB fitting) into a first opening of the fitting and out of a second opening of the fitting. This avoids having to pull the entire length of cable out of the fitting through the cover plate opening of the fitting, and then having to feed the end of the cable back into the cover plate opening and through the second opening in a second pull to complete threading the cable through the fitting. Two cable pulls are avoided. Only a single pull is necessary.  
         [0007]     A novel roller support structure is mounted on a cable fitting such that a set of rollers supported by the roller support structure is disposed inside the interior volume of the cable fitting. Spacers are disposed between the roller support structure and the fitting so that the rollers are disposed a distance off the inside bottom surface of the cable fitting. An end of a cable is then moved into a first opening of the filling, over the rollers, and out of the fitting through the second opening. Once the cable has rolled over the rollers a desired distance though the fitting, the spacers are removed. Removing the spacers allows the roller support structure to drop down toward the inside bottom surface of the cable fitting. This provides a separation between the tops of the rollers and the bottom of the cable. The rollers can then be lifted up and out of retaining J-shaped channels in the roller support structure. In this fashion, the rollers are detached from the roller support structure. The rollers are then slipped out around the cable (between the cable and the interior sidewalls of the cable fitting) and are extracted from the interior volume. The roller support structure is then unmounted from the fitting. The cover plate is attached to the cable fitting, thereby completing installation of the cable. Only one cable pull is involved.  
         [0008]     The roller support structure may involve a frame, to which a first removable side plate and a second removable side plate are attached. A first end of each roller is supported by the first side plate, whereas a second end of each roller is supported by the second side plate. The rollers can be detached from the roller support structure after cable installation by detaching one of the side plates from the frame. The side plates can then be flared with respect to one another such that the bottom edges of the side plates are moved apart. This flaring allows the rollers to fall out of supporting holes or grooves in the side plates. Once the rollers are released from the side plates, the rollers can be extracted from underneath the cable and can be removed from the fitting.  
         [0009]     In another embodiment, rather than a roller support structure that involves a machined frame and separate side plates, the roller support structure may be of unitary construction. The roller support structure may, for example, be a single piece of cast aluminum with removable rollers. Making the roller support structure of a single cast piece reduced cost associated with manufacturing and the roller support structure. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.  
         [0011]      FIG. 1  is a drawing of a cable fitting.  
         [0012]      FIG. 2  is a diagram showing wire being pulled through a cable fitting without the use of the invention.  
         [0013]      FIG. 3  shows a roller support structure.  
         [0014]      FIG. 4  is a side view of a roller support structure.  
         [0015]      FIG. 5  is a view of a roller support structure and spacers.  
         [0016]      FIG. 6  is a view of a roller.  
         [0017]      FIG. 7  is a flowchart of a novel method of using a roller support structure to move cable through a cable fitting.  
         [0018]      FIG. 8  shows a roller support device attached to a cable fitting.  
         [0019]      FIG. 9  is a cross sectional side view of a roller support structure  30  mounted on a cable fitting.  
         [0020]      FIG. 10  is a diagram showing a cable being moved through the roller support device.  
         [0021]      FIG. 11  is a diagram of a roller support device, spacers and a cable fitting.  
         [0022]      FIG. 12  is a diagram showing a roller extraction tool, a roller and a cable.  
         [0023]      FIG. 13  is another diagram of a roller support device attached to a cable fitting. 
     
    
     DETAILED DESCRIPTION  
       [0024]     Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings. An embodiment in accordance with one novel aspect of the invention is shown by  FIGS. 3-6  and  FIGS. 8-11 .  
         [0025]      FIG. 3  shows a roller support structure  30  which comprises a frame  31 , a first side plate  32 , a second side plate  33 , and anchor connection member  34 . The roller support structure additionally comprises rollers  35 - 39 . The rollers  35 - 39  are disposed axially between first side plate  32  and the second side plate  33  and are connected to each side plate by an axle  70  which extends through each of the rollers  35 - 39 . First side plate  32  and second side plate  33  each contain five “J” shaped channels  45 - 49 . These “J” shaped channels can either be completely through side plates  32  and  33  or partially through side plates  32  and  33  leaving the outside of side plates  32  and  33  smooth. If the “J” shaped channel is only partially through each side plate  32  and  33 , the axles  70  of rollers  35 - 39  would not be able to slip out of “J” shaped channels  45 - 49 . Each of the “J” shaped channels  45 - 49  permits one of rollers  35 - 39  to be connected between first side plate  32  and second side plate  33 . Each of the “J” shaped channels  45 - 49  also permits one of rollers  35 - 39  to be disconnected between first side plate  32  and second side plate  33 . The anchor connection member  34  extends from one side of frame  31  to the opposite side of frame  31  and is removable from frame  31 . Anchor connection member  31  permits the roller support structure to be connected to an anchor when cable is being moved through the cable fitting. Pulling a large diameter cable may involve pulling tensions of thousands of pounds. This force pulls the rollers down and thereby forces the roller support structure down against the cable fitting with considerable force. This force may be so great that it crushes or damages the cable fitting or conduits to which the cable fitting is attached. Connecting the anchor connection member  31  to an anchor (for example, heavy vehicle or structural beam) allows some or all of this force to be absorbed by the anchor, thereby preventing the force from being transferred to the cable fitting and causing potential damage.  
         [0026]     Also shown in  FIG. 3  are attachment holes  41 - 44 . Attachment holes  41 - 43  are disposed on the top surface of the frame  31  of the roller support structure  30  and extend through the frame to the planar bearing surface of the roller support structure. The attachment holes are for mounting and unmounting the roller support structure  30  to the cable fitting  8 .  
         [0027]      FIG. 4  is a side view of the roller support structure and illustrates fasteners  52 - 56  which are placed along the frame  31  of the roller support structure and are used to connect the side plate  32  to the frame  31 . Fasteners  52 - 56  allow removal of first side plate  32  in case of failure of the fitting or to facilitate unmounting of the roller support structure  30  from a cable fitting  8 . Second side plate  33  is also connected to the roller support structure in the same manner. This figure also contains an illustration of the cable  20  disposed between the first side plate  32  and second side plate  33  and above rollers  35 - 39 .  
         [0028]      FIG. 5  is a view of the roller support structure  30 , a first spacer  50  and a second spacer  51 . The first spacer  50 , contains two attachment holes  57 ,  58  that extend through the top plane of the first spacer  50  through first spacer  50  to the bottom surface plane of the first spacer  50 . The second spacer  51 , contains two attachment holes  59 ,  60  that extend through the top plane of the second spacer  51  through the second spacer  50  to the bottom surface plane of the second spacer  51 . All interior edges of roller support structure  30 , first spacer  50 , and second spacer  51  are smooth to prevent damage to the insulation of cable  20  during installation of cable into a fitting.  
         [0029]      FIG. 6  is a detailed diagram of roller  35 . The roller  35  comprises a concave roller channel  73 , axle  70  which extends through the length of the roller. A brass roller bushing  71  is placed around the axle  70  of roller  35  to allow the roller to spin about the axle. Axle stop  72  is present on each end of the axle to prevent the axle from slipping out of the side plate.  
         [0030]      FIG. 8  shows the roller support structure  30  mounted to the cable fitting  8  at the location of cover plate plane  80 . First spacer  50  is inserted between the cable fitting  8  and the roller support structure. Second spacer  51  is inserted between the roller support structure  30  and the cable fitting  8  at a location opposite first spacer  51 . The roller support structure  30  is designed such that the attachment holes  57  and  58  of first spacer  50  are aligned with both attachment holes  43  and  44  of the roller support structure  30  and cover plate retaining holes  21  and  23  of the cable fitting  8 . Similarly, the attachment holes  59  and  60  of first spacer  50  are aligned with both attachment holes  41  and  42  of the roller support structure  30  and cover plate retaining holes  21  and  23  of the cable fitting  8 . The alignment of the attachment holes  41  -  44  of the roller support structure  30 , attachment holes  57  and  58  of the first spacer  50  and attachment holes  59  and  60  of second spacer  51  with the cover plate retaining holes  21 - 24  of the cable fitting  8  facilitate mounting and unmounting of the roller support structure  30  from the cable fitting  8 .  
         [0031]      FIG. 9  is a cross sectional side view of the roller support structure  30  mounted on a cable fitting  8 . The bearing surface of the roller support structure is mounted upon a cover plate mating surface of the cable fitting  8  which is disposed within a cover plate plane  80 . Opposite the cover plate plane of the cable fitting  8  is an inside bottom surface plane in which an inside bottom surface of cable fitting  8  is disposed. The location of the plurality of rollers  35 - 39  are shown disposed within the interior volume  27  of cable fitting  8  between the cover plate plane  80  of cable fitting  8  and the inside bottom surface.  
         [0032]      FIG. 7  is a simplified flowchart diagram of a novel method in accordance with one embodiment. In the initial step  200 , the roller support structure  30  is mounted to cable fitting  8 .  FIG. 8  shows the roller support structure  30  mounted to a cable fitting  8 . In this figure, the side plates and rollers are disposed within the internal volume of cable fitting  90 . First spacer  50  and second spacer  51  are positioned between the roller support structure  30  and the cable fitting  90 . Attachment points  41  are placed on the roller support structure  30  and spacers  50 - 51  such that they are in alignment with commercially available cable fittings such as a Crouse Hinds, Appleton and O-Z/Gedney cable fittings.  
         [0033]     Next, in step  201 , a cable  20  is moved through the first opening  25  of the cable fitting  8  over the rollers  35 - 29  of roller support device  30 , then out of the second opening  26  of the cable fitting  8 . This moving may entail first pulling a high tension pulling rope through the conduit, over the rollers, and through the cable fitting  8 , to the location to where the cable  20  is fed into the conduit. An end of cable  20  is attached to the high tension pulling rope with a swivel, and the high tension pulling rope is pulled back through the conduit and cable fitting  8  thereby moving the cable  20  through the cable fitting  8 .  
         [0034]      FIG. 10  shows a cable  20  being drawn out of a first conduit  100  through first opening  25  of cable fitting  8 , over rollers  35 - 39  of the roller support structure  30 , and then into second conduit  101 . The rollers are positioned such that a minimum bend radius  103  is maintained as the cable moves from the first conduit  100 , through the cable fitting  8  along an arc of curvature  106 , and then into second conduit  101 . This is to prevent damage to the cable and is especially useful when pulling delicate cables, such as when fiber-optic or similar cables are pulled through cable fittings. The roller support structure  30  and side plates  32  and  33  are designed such that they have smooth edges that will not allow damage to insulation of cable  20  as it is being pulled through the cable fitting  8  and roller support structure  30 .  
         [0035]     In a third step  202 , first and second spacers  50  and  51  are removed to facilitate removal of the rollers.  
         [0036]      FIG. 11  shows removal of the spacers by pulling the first spacer  50  in direction “A” and second spacer  51  in direction “B”. First spacer  50  and second spacer  51  are shown between roller support structure  30  and cable fitting  8 . First spacer  50  is shown partially extending outwards in direction A from roller support structure  30  and cable fitting  8 . Second spacer  51  is shown partially extending outwards in direction B from roller support structure  30  and cable fitting  8 . After the cable  20  has been fully moved through cable fitting  8 , the first spacer  50  and second spacer  51  can be fully removed from between cable fitting  8  and roller support structure  30  by further extending them outwards in direction A and direction B respectively. By removing both first spacer  50  and second spacer  51  from in between the roller support structure  30  and cable fitting  8 , the roller support structure can be lowered allowing the plurality of rollers  35 - 39  to be removed by sliding the roller axles  70  up, over and down through the “J” shaped channels and out into the interior volume  27  of the cable fitting  8 .  
         [0037]     In the fourth step,  203 , rollers  35 - 39  are removed by the roller extraction tool  75 . The roller extraction tool  75  is used to lift the rollers up and out of “J” shaped roller channels  45 - 49 . The rollers  35 - 39  then fall to the space between the space underneath the cable and inside bottom surface of the cable fitting and fall into the cable fitting.  
         [0038]      FIG. 12  shows roller extraction tool  75 , cable  20  and roller  35 . The roller extraction tool is designed such that it can extract roller  35  up over and down through the “J” shaped channel  45  once the spacers have been removed. After the roller is detached the roller will remain in the interior volume  27  of the cable fitting disposed between the cable  20  and the inside bottom surface of cable fitting  8 . The roller extraction tool  75  is first used to detach roller  35  from between first and second side plates  32  and  33  by lifting the roller and sliding it out of “J” shaped channel  45 . Roller extraction tool  75  may then be used to extract roller  35  from the interior volume  27  of cable fitting  8  by slipping roller  35  from between the cable and the interior sidewalls of the cable fitting.  
         [0039]      FIG. 13  is another embodiment of in accordance with the invention. In this embodiment the bearing surface of roller support structure  30  is mounted to the cover plate mating surface of cable fitting  8 . First side plate  32  and second side plate  33  and plurality of rollers  34 - 39  are disposed outside of the interior volume of cable fitting  8 .  
         [0040]     In a second embodiment, a novel cable fitting includes a plurality of rollers that are part of the cable fitting. The rollers may, for example, be disposed along the inside bottom surface of the cable fitting. In one example, a ninety degree cable fitting for electrical conduit (the overall dimensions of the cable fitting are similar to a Crouse Hinds BUB or Appleton UB fitting, but the novel cable fitting is about one half inch wider) is provided. From five to twelve rollers are held captive and non-removable within the interior volume of a cast steel or aluminum conduit body. The rollers are placed and/or positioned in such a fashion as to allow the cable to be pulled out one end of the conduit and through the fitting, passing over the series of captive rollers, and into the other connecting conduit, all the while maintaining a radius that meets six hundred volt and fiber optic cable manufacturers&#39; recommendations. These rollers have a concave-shaped channel to cause the cable to run toward the center of the rollers when pulled. Each roller has a steel axle with brass bushings.  
         [0041]     Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims