Patent Publication Number: US-2021194232-A1

Title: High voltage conductor cover with fenders over retaining pin holes

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. application Ser. No. 16/442,231, filed on Jun. 14, 2019, entitled Dielectric Cover for High Voltage Component With Hood Over Hole for Retaining Pin, by Michael Lynch, incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a dielectric cover for high voltage power line insulators and conductors (wires) and, in particular, to an insulator cover system that has an extended fender over retaining pin holes. 
     BACKGROUND 
     A wood or metal utility pole is typically used for supporting high voltage (HV) conductors (e.g., twisted wire strands) in a power distribution system. Each pole has secured to it one or more crossarms that support insulators which, in turn, support the HV conductors. The insulators are typically ceramic or a polymer. A conductor is typically secured over the top of each insulator, or along its side, via a metal tie wire, a bracket, a clamp, or other means. 
       FIG. 1  is a perspective view of a top portion of a crossarm  10  of a utility pole. An insulator  12  is affixed to the crossarm  10  with a bolt  14 . A generally horizontal conductor  16  seats in a top groove in the insulator  12  or along the neck area  18 . There are many different designs of such insulators, and  FIG. 1  shows a conventional design. A common feature of such insulators is a narrow neck area  18  and a wider skirt  20 . 
     One known problem with exposed insulators and conductors is that large birds or other wildlife may alight on the grounded crossarm and short out phases or short a conductor to ground. Insulating (e.g., plastic) covers that cover the insulator  12  and a portion of the conductor  16  extending from the insulator  12  are known. 
       FIG. 2  is taken from the Applicant&#39;s U.S. application Ser. No. 16/779,169, incorporated herein by reference.  FIG. 2  is a side view of a dielectric cover  24 , such as a molded plastic, covering the insulator  12  of  FIG. 1  and a portion of the conductor  16  for protecting wildlife and preventing outages from wildlife. The cover  24  comprises an insulator cover  26  and two identical attachable arms  28  and  30 . 
     Holes  36  extend through the cover  24  and arms  28 / 30  and below the conductor  16 . Retaining pins, described later, are inserted through the holes  36  and pass through corresponding holes on the opposite side under the conductor  16 , which secures the cover  24  in place. The pins and the cover  24  may be manipulated by a hot stick while high voltage is conducted by the conductor  16  so there is no loss of power to the consumer when the cover  24  is installed. 
     The bottom of the insulator cover  26  rests on the wide skirt  20  of the insulator  12 , or the top of the insulator abuts against the ceiling of the insulator cover  26 , depending on the type of insulator used. 
     The pins and cover  26  have been used in the field, and a flashover problem has been discovered in rare instances. Such a flashover incurs a substantial expense since a lineman must replace a fuse. The flashover issue was presented by the utilities company to the Applicant for analysis. The Applicant has concluded that the flashover was due to conductive liquid entering the hole  32 , then running along the retaining pin and creating a low resistance path between a high voltage component and ground (e.g., a roosting bird). The low resistance path (caused by the liquid) between the pin portion on the outside of the cover and the pin portion closest to the high voltage components caused an arc between the bird (roosting on the end of the pin) and the nearest grounded structure, such as a metal or wooded support structure. The liquid running along the pin in one case was due to a bird defecting on the pin while perhaps roosting on the pin. Bird droppings contain a relatively high concentration of salt, which causes the liquid to be conductive. Alternatively, rain or snow may be the cause of the liquid running along the pin. 
     What is needed is an improvement to the prior art cover that prevents flashovers due to conductive liquid entering the holes. 
     SUMMARY 
     Arched fenders are added over the insulator cover&#39;s holes (for retaining pins) to act as roofs or shields. The fenders may extend out from the cover by about one inch or more to shield the holes and pins. The pins have a ring (at least partially shielded by the fenders) at the end to allow the lineman to grasp the ring by a hot stick for insertion and removal of the pins. 
     The fenders have multiple purposes. The fenders effectively prevent birds roosting on the ring of the pins (whose bodies are directly below the HV conductor), increase the dielectric surface length between the top of the cover and the electrical conductor above the pins, and protect the pins from contamination issues which would reduce the dielectric properties of the pins. Contamination issues that are prevented, which potentially cause a flashover, include birds defecating on the pins (which can create a conductive path between the bird and the inside of the cover) and atmospheric moisture such as rain, snow, and ice on the pins. 
     Other features of the cover system are also described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a crossarm of a utility pole supporting a conventional insulator and HV conductor. 
         FIG. 2  is a side view of a conventional dielectric cover covering the insulator of  FIG. 1  and a portion of the conductor for preventing outages from wildlife. 
         FIG. 3  is a side view of Applicant&#39;s new insulator cover, having arched fenders over the holes to shield the holes and ends of the pins from contamination. Also shown are optional attachable arms for the cover. 
         FIG. 4  is a top down perspective view of the Applicant&#39;s new cover of  FIG. 3 . An optional shell fits over the cover to effectively extend the depth of the cover by, for example, one or more inches to laterally cover a metal top of the insulator if a K-Line™ type insulator is used with a large metal top. 
         FIG. 5  is a top down semi-transparent view of the cover of  FIGS. 3 and 4 . 
         FIG. 6  is a perspective view of a dielectric retaining pin, where concentric skirts (tapering outward) are distributed along the body of the pin to increase the surface distance along the pins and to prevent liquid from running along the length of the pin. 
         FIG. 7  is a perspective view of a dielectric retaining pin, where concentric ribs (generally constant thickness) are distributed along the body of the pin. 
         FIG. 8  is a perspective view of a dielectric retaining pin having a smooth body and a resilient portion near its flange, where the body is shorter than the pins of  FIGS. 6 and 7  (for the same cover) so that the end of the pin does not extend beyond the fender. 
         FIG. 9  is a perspective view of a fuse cutout cover where the fenders are circular and surround the two ends of the pin 360 degrees for additional protection of the pins from contaminating liquids. The pin from  FIG. 8  is used in  FIGS. 9-12 . 
         FIG. 10  is a perspective view of the opposite side of the cover of  FIG. 9 . 
         FIG. 11  is a back view of the cover of  FIGS. 9 and 10 . 
         FIG. 12  is a semi-transparent view of the cover of  FIG. 11 , showing how the ends of the pin, except the ring portion, are surrounded by the circular fenders. 
     
    
    
     Elements labeled with the same numerals in the various figures may be identical or similar. 
     DETAILED DESCRIPTION 
       FIG. 3  is a side view of Applicant&#39;s dielectric cover  34 , such as a molded plastic, covering an insulator  36 . Any type of insulator may be covered. In one embodiment, the bottom of the cover  34  rests on the top rib  37  of the insulator  36  to prevent wildlife from getting under the cover  34 . The insulator  36  may have a recessed top for supporting a HV wire and may also include a metal clamp for the wire. The cover  34  also covers a conductor (e.g., conductor  16  in  FIG. 1 ) extending from the insulator  36  for protecting wildlife and preventing outages from wildlife.  FIG. 3  also shows two identical attachable arms  38  and two arm adapters  40 . 
     Holes  42  extend through the cover  34  and below the conductor. Identical retaining pins  44  are inserted through the holes  42  and pass through corresponding holes on the opposite side under the conductor, which secures the cover  34  and arms  38  in place. The pins  44  and the cover  34  may be manipulated by a hot stick while high voltage is conducted by the conductor so there is no loss of power to the consumer when the cover  34  is installed. The hot stick has a hook that engages holes in the cover  34 , or the top handle  48 , and a ring  50  in the pins  44 . More detail of the pins  44  is shown in  FIGS. 6 and 7 . 
     An optional shell  52  is fitted over the cover  34  to effectively extend the vertical length of the cover  34  in the event that a K-Line™ type insulator is used that has a large metal top, where the shell  52  laterally shields the metal top. The shell  52  is not used with standard insulators. 
     Multiple holes  42  are shown, which enable the lineman to use the optimal holes for the particular insulator used. A minimum of vertical play is desired when securing the cover  34  over the insulator  36 . 
     Ideally, the bottom of the cover  34  rests on the top rib  37  of the insulator  36 . 
       FIGS. 4 and 5  better show the pins  44  and arched fenders  56  over the pins  44  and holes  42 . The fenders  56  act as roofs or shields. The fenders  56  extend out from the cover  34  by about one inch or more to shield the holes  42  and to fully or partially shield the rings  50  of the pins  44  while allowing the lineman to grasp the rings  50  of the pins  44  by a hot stick. The fenders  56  can extend out any suitable length to shield the end of the pins and the holes  42 . The fenders  56  are shown semi-hemispherical to make it difficult for birds to roost on the fenders  56 . The fenders  56  extend down to the bottom of the cover  34  to laterally shield the pin  44  and holes  42 . 
     In the example of  FIG. 5 , the fenders  56  do not fully cover the rings  50  to allow a lineman to easily grasp the rings  50  with a hot stick.  FIG. 5  illustrates the fenders  56  partially covering the rings  50  when looking directly down on the cover  34 . Birds do not roost on the rings  50  because the fenders  56  interfere with the roosting. Even if a bird roosted on the rings  50 , the bird&#39;s defecation would not enter the holes  42  or run along the body of the pins  44  due to the fenders  56 . 
     The fenders  56  have multiple purposes. The fenders  56  effectively prevent birds roosting on the pin  44  (whose bodies are directly below the HV conductor), increase the dielectric surface length between the top of the cover  34  and the electrical conductor above the pins  44 , and protect the pins  44  from contamination issues which would reduce the dielectric properties of the pins  44 . Contamination issues include birds defecating on the pins  44 , which can create a conductive path between the bird and the inside of the cover  34 , and atmospheric moisture such as rain, snow, and ice on the pins  44 . 
     Other shapes and sizes of fenders can also be used. Other names for the fenders  56  include hoods, shields, and roofs. 
     The pins  44  have a resilient end  58  that allows insertion of the pins  44  with a relatively light pushing force and removal of the pins  44  with a stronger pulling force. 
     There are a variety of insulator shapes, and the insulator  36  is just an example. The insulator cover  34 , arms  38 , and optional shell  52  may be molded to accommodate any standard insulator shape and any K-Line™ type insulator shape while still retaining all aspects of the invention. 
     In one example, the cover  34  may have a vertical depth of 4-5 inches (which accommodates the thickness of the wire). 
       FIGS. 6 and 7  illustrate dielectric retaining pins  60  and  62  that may be used to secure dielectric covers over high voltage components. The covers may be the insulator cover  34 , cutout covers (such as described in Applicant&#39;s U.S. application Ser. No. 16/442,231), or any other type of insulating cover, typically for protecting wildlife from electrocution. 
     In one embodiment, the pins  60  and  62  are about 4 inches long, and the drawings have generally accurate relative dimensions. The pins  60  and  62  are an injection molded polymer. 
     The pin  60  of  FIG. 6  has skirts  64 , and the pin  62  of  FIG. 7  has ribs  66  along the body of the pins. The pin  60  or  62  is inserted through the cover&#39;s holes  42  ( FIG. 3 ) until the expanded portion  68  of the pin  60 / 62  abuts the cover  34 . The expanded portion  68  provides one level of prevention of liquids entering the cover  34  via the pin  60 / 62  and holes  42 . 
     In the event a liquid enters the cover  34  via the pin  60 / 62  (such as during a storm), the skirts  64  or ribs  66  not only block the liquid from running along the body of the pin but add a significant surface leakage distance along the pin&#39;s body. This greatly increases the flashover voltage and the insulating properties of the cover assembly in high moisture conditions. 
       FIG. 8  is a perspective view of a dielectric retaining pin  72  having a smooth body  74  and a resilient portion  76  near its flange  80 , where the body  74  is shorter than the pins of  FIGS. 6 and 7  (for the same cover) so that the end  81  of the pin  72  does not extend beyond the cover&#39;s fender. The grasping ring  82  is further from the flange  80  compared to the pins of  FIGS. 6 and 7  to cause the ring  82  to extend out beyond the cover&#39;s fender when the flange  80  abuts the cover&#39;s outer surface. The resilient portion  76  easily bends when pushing the pin  72  in and locks the pin  72  in place so the flange  80  abuts the cover. The pin  72  is more difficult to remove. 
     The pin  72  is a single molded polymer piece. The relative dimensions are substantially accurate in  FIG. 8 . For a seven inch pin  72 , the body  74  (between the end  81  and the flange  80 ) is approximately five inches long, the width of the body  74  is approximately one-quarter inch, the distance between the flange  80  and the far end of the ring  82  is approximately two inches, and the resilient portion  76  is approximately one-quarter inch long. The width of the resilient portion  76  is approximately one-eighth inch so easily bends when inserting the pin  72  into the cover hole. The body  74  of the pin  72  is smaller than the cover hole, and the resilient portion  76 , when not compressed, is slightly larger than the cover hole. 
     The resilient portion  76  has an angled part  83  (that is easily compressed) and a flat part  85 . When the pin  72  is fully inserted into the cover hole, the resilient portion  76  snaps back, the pin  72  is locked into place, and the flange  80  abuts the outer surface of the cover. There are identical resilient portions  76  on opposite sides of the pin  72 . Pulling on the pin  72  causes the flat part  85  of the resilient portion  76  to bend so the pin  72  can be removed. In the example, the resilient portion  76  is spaced approximately one-eighth inch from the flange  80 . The distance would be greater for a thicker cover material. 
     The pin  72  may be used with the cover  34  or the fuse cutout covers described below. 
     In another embodiment, which is not optimal, the pin  72  is shorter and only extends through one hole in the cover. That is sufficient to retain the cover in place when the resilient portion  76  secures the pin  72  in place. 
       FIG. 9  is a perspective view of a fuse cutout cover  84  where the fenders  86  are circular and surround the two ends of the pin  72  360 degrees for additional protection of the pins  72  from contaminating liquids. In such a case, the arched roof fenders  56  of  FIGS. 3-5  are modified to fully surround the bottoms of the retaining pin holes. The fuse cutout  88  is conventional and comprises an insulator  90 , a blowable fuse  92 , a mechanism (at the bottom of the fuse  92 ) that causes the fuse to pivot outward and downward when blown to create a wide clearance between the top of the fuse  92  and a high voltage top connector  93 , and a ring  94  that can be pulled by a hot stick to pull the fuse  92  outward to open the circuit. A high voltage wire (not shown) extends from the top of the cutout  88  and through a top opening  95  of the cover  84 . The cover  84  has a rear slot for the wire so it can be installed when the wire is energized. 
     In one embodiment, the fenders  86  can be attachable to an existing cover so a new mold for the cover does not have to be made. The attachment may be done adhesively, or by heat fusing, or by using bolts or tabs, etc. 
       FIG. 9  shows the rings  82  of the pins  72  extending beyond the fenders  86 . The pins  72  are inserted through two of the three cover holes  96  for retaining the cover  84  over the cutout  88 . Some types of cutouts block one of the holes, so the other two holes are used for the pins  72 . The pins  72  go under the top connector  93  of the cutout  88  to prevent the cover  84  being lifted off the cutout  88  in high winds. 
       FIG. 10  is a perspective view of the opposite side of the cover  84  of  FIG. 9 . Note how the ends  81  of the pins  72  are surrounded by the fenders  100 . 
       FIG. 11  is a back view of the cover  84  of  FIGS. 9 and 10 , and  FIG. 12  is a semi-transparent view of the cover of  FIG. 11 .  FIGS. 11 and 12  show the rear slot  102  for the wire, the fenders  86  (which allow access to the ring  82  by a hot stick), and the fenders  100  (which surround the ends  81  of the pins  72 ). In  FIG. 12 , the fenders  86  do not surround the hole in the ring  82 . 
     To additionally prevent liquid entering the pin holes, a resilient washer may be installed between the flange of the pin and the cover. 
     Having described the invention in detail, those skilled in the art will appreciate that, given the present disclosure, modifications may be made to the invention without departing from the spirit of the inventive concept described herein. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.