Abstract:
Method and apparatus for protecting wildlife from contact with an energized fuse assembly known as a “cutout”, also known as a “disconnect”. The cutout is shrouded from above and three sides. One side is left open to facilitate installation or removal of a fuse holder assembly. The shroud is formed to allow the use of a hot-stick for installation and removal of a fuse holder assembly into a fuse receptacle formed by upper and lower contact assemblies held in opposition to each other by an insulator. The shroud provides a slot enabling installation when a wire is connected to the upper contact assembly. A pin is used to hold the shrouding in place.

Description:
RELATED APPLICATIONS  
       [0001]    This present application is related to a provisional application serial No. 60/435,836 filed on Dec. 19, 2002, entitled “Method and Apparatus for Protection of Wildlife from Contact with Power Phase Cutout Mechanism”, by Lynch, currently pending, for which the priority date for this application is hereby claimed. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates generally to protection of wildlife environments; and specifically to a prevention of electrocution or shock resulting from contact with power cutout or disconnect mechanisms.  
         BACKGROUND OF THE INVENTION  
         [0003]    An increasingly sensitive environmental issue is that of preventing injury to wildlife that may occur as a result of contact with energized electrical distribution components. Modernly, electrical distribution systems rarely provided any type of electrical barrier between energized components and other objects. For instance, electrical conductors that carry electrical power from power-pole to power-pole are typically devoid of any type of insulation. In the general sense, this is quite acceptable since electrical injury typically requires a complete circuit path phase to ground or phase to phase. Hence, a small bird may land on an electrical conductor without any adverse effects. This is because the small bird contacts only one electrical conductor and the current flowing through the conductor cannot find a “path to ground”.  
           [0004]    It is only when a living creature, including man or beast, contacts an exposed electrical conductor or other energized component and electrical current can find a path to ground that severe injury can occur. This type of unfortunate incident is more likely to occur where exposed electrical conductors are in close proximity to a grounded object or to another conductor or component that is carrying an opposite phase of a particular circuit.  
           [0005]    In one example, a conductor, which is typically electrically isolated from a power pole by means of an insulator, can be contacted by a lineman or wildlife that has climbed the power pole. In such case, the living creature is in close enough proximity to ground by virtue of being in contact with the power pole that the slightest contact with an exposed electrical conductor or other energized component may prove fatal. Larger birds, such as raptors, are often killed when they land on or attempt to land on an exposed electrical conductor near a power-pole or on the power-pole itself. When landing on the conductor near a power-pole, a larger bird can touch the power-pole with a wing and provide a path to ground. A large bird may also short two opposite phases together. This results in a short circuit where electrical current flows through the body of the unfortunate bird from one phase to the other.  
           [0006]    Modern electrical distribution techniques employ various types of components to affect the delivery of electrical power to residential, commercial and industrial customers. In order to effectively manage the delivery of power, one component used in today&#39;s power delivery schema is a power interruption device known as a “cutout”. Various forms of cutouts exist and most follow the general form of that described by Biller in U.S. Pat. No. 4,414,527. The modern cutout comprises an insulator that may be mounted onto a power pole or other support structure. The insulator (reference No.  14  in the referenced patent) supports an upper and lower contact assembly. The contact assemblies hold a fuse holder assembly that completes an electrical circuit between the two contact assemblies. Thus the opposing upper and lower contact assemblies form a “fuse receptacle” capable of receiving a fuse holder assembly.  
           [0007]    Each contact assembly further comprises a conductor connector. The conductor connectors are used for connecting the cutout to a tap-point comprising the power distribution system on one end and for connecting the cutout to an electrical load. Typically, a cutout is installed between an energized electrical conductor that carries electrical power from power-pole to power-pole and a step-down transformer. In one application, a cutout is generally mounted on the power pole just below a cross-member that is used to support the inter-pole conductors. The step-down transformer, which is also usually mounted proximate to the cutout, typically receives electrical power from the electrical conductor and reduces the electrical power to a lower voltage level suitable for distribution to an end customer.  
           [0008]    The entire cutout assembly poses a threat not only to wildlife, but also to lineworkers. This is because the upper and lower contact assemblies are not insulated. Lineworkers accept the risk of working with high-voltage electrical power as one of many occupational hazards that are encountered on the job and with foreknowledge of the hazard avoid contacting an energized cutout. Raptors and other large birds often use power-poles, their associated supporting member and components for perching and hunting. Many times, raptors and other large birds return to the power-pole with prey that they intend to consume. Because of the usual manner in which a cutout is mounted, slightly below the power-pole&#39;s cross-member, a larger bird can use the cutout as a shelf; ideal for helping manipulate their quarry during consumption. As soon as the raptor contacts the non-insulated, energized cutout assembly it can be severely injured or killed. Other animals, e.g. squirrels, can suffer the same fate as raptors and other large birds.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention comprises a method for protecting wildlife from potential electrocution and electrical shock through inadvertent contact with an energized cutout. Generally, a cutout is mounted on a power pole and is used as a fusing circuit between a high-voltage power tap on a distribution system and a transformer. However, the scope of the present invention is not intended to be limited to this one example application.  
           [0010]    A cutout typically comprises an upper connector and contact assembly that is held in opposition to a lower connector and contact assembly by an insulator. The insulator holds the upper and lower contact assemblies in opposition to each other so as to form a fuse receptacle. The present invention provides for a method for protecting wildlife by shrouding the upper connector, the upper contact assembly and a volume of space proximate to the upper end of the fuse receptacle formed by the two contact assemblies. The volume protected by the shroud is made large enough to accommodate not only the upper end of a fuse holder assembly, but also a pull-ring integral to a fuse holder assembly. Such a ring may be used to facilitate the removal of the fuse holder assembly from the fuse receptacle. Even though shrouds are provided, the present method requires that the dielectric integrity of the insulator is to be maintained while the shroud is disposed in an operational position. According to one alternative method, the dielectric integrity of the insulator is maintained by not electrically bridging any of one or more skirts typically integral to the insulator.  
           [0011]    Accordingly, shrouding of a cutout may be accomplished by positioning a shroud over an upper conductor that may be attached to the upper connector. The shroud may then be drawn over the upper end of the cutout assembly. This may be done while the conductor is energized. Once in position, the shroud is held in place by a pin that penetrates two sides of the shroud and is positioned beneath the upper contact assembly.  
           [0012]    Alternative methods of the present invention provide for shrouding the upper conductor that is used to connect the upper contact assembly to a tap-point in a power distribution system. In one illustrative variation of the present method, the lower connector, the lower contact assembly and a volume surrounding the lower end of the fuse receptacle are also shrouded.  
           [0013]    The present invention further comprises a cutout cover assembly. According to one example embodiment, a cutout cover assembly comprises a first shroud section, a second shroud section and a third shroud section. Generally, the first shroud section blends into the second shroud section. In like manner, the second shroud section blends into the third shroud section. Each shroud section comprises walls and a top surface.  
           [0014]    The walls of the first shroud section are used to envelope a portion of the perimeter of an insulator and a top surface is supported by the upper edge of this wall. The second shroud section continues with two opposing walls that stem from the two ends of the wall surrounding the insulator and which straddle the upper contact assembly. The third shroud section again continues with two opposing walls in order to envelope a volume of space in proximity to the upper end of the fuse receptacle and, according to one embodiment, slope outward and down away from the upper contact assembly to form a funnel-shape.  
           [0015]    The second shroud section, according to one alternative embodiment, further comprises pin holes placed in the two opposing walls and a further placed below either the upper contact assembly or the hook assembly.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The foregoing aspects are better understood from the following detailed description of one embodiment of the invention with reference to the drawings, in which:  
         [0017]    [0017]FIG. 1 is a pictorial representation of an electrical cutout assembly;  
         [0018]    [0018]FIGS. 2 and 3 are, respectively, a pictorial diagram that depicts the position of a shroud when it is installed on a cutout and a flow diagram that depicts one illustrative variation of the present method;  
         [0019]    [0019]FIG. 3A is a pictorial representation of an insulator that illustrates application of a method for maintaining the dielectric integrity of the insulator;  
         [0020]    [0020]FIG. 4 is a pictorial diagram that depicts one illustrative method according to the present invention for shrouding the upper portion of a cutout;  
         [0021]    [0021]FIG. 5 is a pictorial diagram that depicts one example method for securing a shroud unit installed on a cutout;  
         [0022]    [0022]FIG. 6 is a pictorial diagram that depicts one alternative method for securing a shroud unit once it is installed on a cutout;  
         [0023]    [0023]FIGS. 7 and 8 are pictorial representations that depict one example of a derivative method of the present invention for shrouding a conductor;  
         [0024]    [0024]FIG. 9 is a pictorial diagram that depicts one example embodiment of a cutout cover according to the present invention; and  
         [0025]    [0025]FIGS. 10 and 11 are, respectively, a perspective and profile pictorial diagrams that depict one alternative method for shrouding a lower contact assembly of a cutout.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    [0026]FIG. 1 is a pictorial representation of an electrical cutout assembly. Electrical power distribution systems disseminate electrical power through a distribution grid. When power is delivered from the distribution grid, it is normally received at a very high voltage. The high-voltage power is generally transformed to a lower voltage by a transformer before it is delivered to a power consumer such as a home or a business. It should be noted that these two classes of power consumers are cited as example users of a typical power distribution system and are not intended to limit the scope of the present invention.  
         [0027]    It is not uncommon for a distribution system to distribute electrical power at voltage levels; as high as 69,000 volts and more. A cutout  10  comprises an insulator  15  which is used to support an upper contact assembly  25 . The upper contact assembly usually includes an upper connector  20 . The insulator  15  is used to provide electrical isolation between the upper contact assembly  25  and a mounting bracket  50  and a lower contact assembly  60 .  
         [0028]    The cutout  10  is typically installed between a tap-point on a distribution system and a transformer that receives high-voltage distribution power. The transformer converts the received power to a lower voltage level suitable for delivery to a consumer. The cutout  10  is generally mounted on a power pole by means of the mounting bracket  50 . The upper connector  20  is used to connect an electrical wire  55  to the upper contact assembly  25 . The other end of the electrical wire  55  is generally connected to a high-voltage tap-point provided by the power distribution system.  
         [0029]    The cutout  10  further comprises a lower contact assembly  60 . The lower contact assembly is generally supported by an opposing end of the insulator  15 . The upper and lower contact assemblies ( 25 ,  60 ) generally form a fuse receptacle capable of receiving a fuse holder assembly  35 . Generally, the lower contact assembly  60  further comprises a lower connector  65  that may be used to electrically connect the lower contact assembly  60  to a transformer used to step-down power to a lower voltage suitable for delivery to a consumer.  
         [0030]    The fuse holder assembly  35  typically provides a pull-ring  40 . The upper contact assembly  25  further comprises a hook assembly  30 . The hook assembly  30  may be used as an attachment point for a “load-breaking” tool. The load-breaking tool may be attached to the hook assembly  30  and the pull-ring  40  in order to facilitate removal of the fuse holder assembly  35  from the fuse receptacle formed by the upper and lower contact assemblies ( 25 ,  60 ). The operation of the load-breaking tool as described herein is well-known and further discussion of its operation and interaction with the hook assembly  30 , the fuse holder assembly  35  and its integral pull-ring  40  is not needed to teach those skilled in the art of electrical power distribution.  
         [0031]    In most instances, the fuse holder assembly  35  comprises a fuse. The pull-ring  40  included in the fuse holder assembly  35  is generally not insulated. The upper  25  and lower  60  contact assemblies are also not insulated. Neither is the electrical wire  55  that connects the upper contact assembly  25  to the high-voltage tap-point. In most instances, installation of the cutout  10  is effected toward the top most portion of a power pole such that it may pose an electrocution hazard to wildlife that may come in contact with the electrically exposed upper  25  and lower  60  contact assemblies.  
         [0032]    [0032]FIGS. 2 and 3 are, respectively, a pictorial diagram that depicts the position of a shroud when it is installed on a cutout and a flow diagram that depicts one illustrative variation of the present method. When the cutout  10  is mounted onto a power pole  80  by means of the mounting bracket  50 , it is the upper contact assembly  25  and its associated connection wire  55  that pose the greatest threat to wildlife. Accordingly, the method of the present invention provides for shrouding the upper connector (step  90 ), shrouding the upper contact assembly (step  95 ) and shrouding the upper portion of the fuse receptacle (step  100 ) formed by the upper and lower contact assemblies ( 25 ,  60 ). In one variation of the present method, shrouding of the upper contact assembly comprises an additional step of shrouding the hook assembly  30 . According to yet another variation of the present method, shrouding of the fuse receptacle comprises shrouding of a volume capable of receiving the upper end of a fuse holder assembly  35  and its associated pull-ring  40 . In yet another alternative example method, the dielectric integrity of the insulator  15  is maintained (step  107 ). According to one alternative method, the dielectric integrity of the insulator is maintained by avoiding bridging of skirts  305  included in the insulator  15 .  
         [0033]    According to yet another derivative method of the present invention, an additional step may be applied wherein the lower connector  65  and the lower contact assembly  60  are also shrouded (step  105 ). According to yet another variation of this method, an opening  85  is provided to the volume surrounding the upper portion of the fuse receptacle formed by the upper and lower contact assemblies ( 25 ,  60 ). In yet another variation of the present method, the opening is formed to facilitate attachment of the load-breaking tool to the hook assembly  30  and to a ring  40  included on the fuse holder assembly  35  such that the load breaking tool can be applied an some angle offset from an axial axis  111  defined by the fuse holder assembly  35  when it is disposed in the fuse receptacle formed by the upper and lower contact assemblies ( 25 ,  60 ). The opening, according to one alternative method, is provided in a funnel-like shape fashioned in one end of a shrouded unit  110  that may be disposed over the upper end of a cutout  10 .  
         [0034]    [0034]FIG. 3A is a pictorial representation of an insulator that illustrates application of a method for maintaining the dielectric integrity of the insulator. A common misconception is that electricity flows through a wire, often referred to as a “conductor”. This is not true. Electricity actually flows over the surface of a material and not through the material. In order to provide sufficient dielectric capability, the surface area of an insulator must be large enough so as to exhibit a sufficient leakage distance between an energized conductor and ground. A cutout  10  includes an insulator  15  applied in a manner so as to electrically insulate a conductor from ground.  
         [0035]    As depicted in the figure, an insulator is typically fabricated in a form that includes some quantity of skirts  305 . The collective surface area of the skirts  305  must then provide sufficient leakage distance between a first terminal  300  and a second terminal  310 , which is most likely grounded, but may be attached to a second phase that is not in phase with power applied to the first terminal  300 . As can be appreciated from this figure, breaching the distance between two skirts  305  does not merely result in a reduction of some vertical distance d  315 , but rather reduces the surface area  320  around the entire skirt  305 .  
         [0036]    Accordingly, in order to maintain the dielectric integrity of an insulator  15 , any shroud placed proximate to the isolative material from which the insulator  15  is formed must not short the surface area of a skirt  305 . This, according to one alternative method, is accomplished by not bridging the apex  325  of one skirt  305  to the apex  330  another skirt  305  included in the insulator  15 .  
         [0037]    [0037]FIG. 4 is a pictorial diagram that depicts one illustrative method according to the present invention for shrouding the upper portion of a cutout. One aspect of the present method that provides for shrouding of an upper connector  20 , an upper contact assembly  25  and a volume capable of receiving the upper-end of a fuse holder assembly  35  (i.e. the upper-end of the fuse receptacle formed by the upper and lower contact assemblies ( 25 ,  60 )) may be achieved by positioning a shroud  110  over a conductor  55  which is connected to the upper connector  20 . According to this illustrative variation of the present method, a shroud  110  may be positioned over a conductor  55  and the shroud  110  may then be drawn over the upper end of the cutout  10 . One example embodiment of a shroud  110  that enables this method comprises a slot  120  for receiving the conductor  55 . As such, the shroud  110  may be installed onto the cutout  10  without the need to first disconnect the conductor  55  from the connector  20 . This method may also be employed where power continues to flow through the conductor  55 . Hence, one alternative method according to the present invention provides for a step wherein shrouding of a cutout  10  is accomplished whilst the cutout  10  is energized.  
         [0038]    [0038]FIG. 5 is a pictorial diagram that depicts one example method for securing a shroud unit installed on a cutout. Generally, once a shroud unit  110  is drawn over the upper end of a cutout  10 , it is susceptible to various forces, such as wind and other weather, which may act to dislodge the shroud unit  110  from its intended installation position. To preclude this, one variation of the present method provides for the installation of a pin  140  through a first side  130  of the shroud  110  and through a side of the shroud  110  opposing said first side. As the pin  140  is disposed through the two sides, it is positioned so as to be beneath the upper contact assembly  25 . Hence, any forces acting to dislodge the shroud cover  110  may be opposed when the pin  140  encounters the upper contact assembly  25 . According to one variation of the present method, the pin  140  comprises an eyelet  145 . The eyelet  145  facilitates the installation of the pin  140  using an installation tool known as a “hot-stick”. By using this or other types of tools to manipulate the pin  140 , the cutout cover  110  may be secured in place by personnel working either at ground level, off a power pole or out of a bucket truck.  
         [0039]    [0039]FIG. 6 is a pictorial diagram that depicts one alternative method for securing a shroud unit once it is installed on a cutout. A first securing method provides for the installation of a pin beneath the upper contact assembly  25  (as depicted by a first pin placement  160 ).  
         [0040]    [0040]FIG. 6 further illustrates that the shroud  110  does not bridge a first apex  325  of a first skirt included in the insulator  15  and a second apex  330  or a second skirt included in the insulator  15 .  
         [0041]    [0041]FIGS. 7 and 8 are pictorial representations that depict one example of a derivative method of the present invention for shrouding a conductor. Once a shroud assembly  110  is positioned over a cutout  10 , this variation of the present method provides for shrouding the conductor  55  connected to the upper contact assembly  25 . According to this variation of the method, a flexible insulator  180  comprising a longitudinal slot  185  is spread apart about the slot  185  and positioned  187  over the conductor  55 . Once so positioned, the flexible insulator  180  envelopes the conductor  55  as shown in FIG. 8. The flexible insulator  180  may then be drawn partially into an internal cavity  190  of the shroud  110  or may be abutted to a top surface  200  of the shroud  110 . The flexible insulator may be formed of any suitable isolative material.  
         [0042]    [0042]FIG. 9 is a pictorial diagram that depicts one example embodiment of a cutout cover according to the present invention. According to this example embodiment, a cutout cover comprises a first section  220 , a second section  225  and a third section  230 . It should be noted that the definition of these sections is made here for the purposes of illustrating the formation of a cutout cover  110  according to the present invention and should not be used to exclude from the scope of the appended claims any alternative embodiments that may become apparent upon the reading of this specification.  
         [0043]    According to this illustrative embodiment of a cutout cover  110 , the first section  220  is formed to envelope a portion of the perimeter of the insulator  15  comprising the cutout  10 , said portion being substantially in opposition to the direction in which the upper contact assembly  25  protrudes outward from the insulator  15 . Accordingly, any appropriate perimeter shape may be used in fashioning the first section  220  of the cutout cover  110 . Generally, the perimeter of the insulator is followed to a point where a second section  225  begins. This, according to at least one embodiment of the invention, is a point where a wall comprising the insulator perimeter envelope may be extended tangentially in a direction substantially parallel to the upper contact assembly  25 . The perimeter wall  222  envelope in the insulator  15  has an upper edge  223 . The cutout cover  110  further comprises a first section top surface  224 . According to one alternative embodiment of the present invention, the first section  220  of the cutout cover  110  may further comprise a conductor slot  221  that breaches the insulator perimeter wall  222  and extends inward toward the center of the first section top surface  224  to a location where a conductor may be connected to the upper connector  20  of the cutout  10 .  
         [0044]    The second section  225  of the cutout cover  110  begins where the first section leaves off. Two perimeter walls, substantially opposing each other, straddle the upper contact assembly  25  and are bridged by a second section top surface  226 . The second section top surface  226  flows from the first section top surface  224 . According to one alternative embodiment of the present invention, the second section may expand in width about the upper contact assembly in order to provide clearance for a hook assembly  30  included in a fuse holder assembly  35 . The second section perimeter walls may further comprise pin-holes, said pin holes being placed in substantial opposition to each other in opposing walls and further placed either below the upper contact assembly  25  or below the hook assembly  30 .  
         [0045]    Third section  230  of the cutout cover  110  continues from the second section  225 . The third section  230  comprises a third section top surface  232 . Envelope walls blend downward way from the third section top surface  232  outward away from the upper contact assembly  25 . The purpose for this is to provide an additional containment volume for a hooks  30  included in one embodiment of a cutout  10 . Further, this outward slope forms a funnel-shape that is wider at the bottom of the cutout cover  110 . This funnel-shape enables attachment of a load-breaking tool to the hooks  30  and to a pull-ring  40  included in a fuse holder assembly  35 , wherein attachment can be accomplished at various angles relative to an axis defined by the fuse holder assembly  35 .  
         [0046]    The height (H) of the various sections of a cutout cover  110  may be adjusted to accommodate various types of cutouts. The height (H) of the first section  220  is adjusted so as to prevent excessive encroachment over the insulator  15 . This height is selected empirically in order to minimize any possible reduction in electrical isolation to the mounting bracket  50  provided by the insulator  15 . The height of the second and third sections ( 225 , 230 ) is varied in order to accommodate the vertical placement of the hook assembly  30  relative to the upper contact assembly  25  and the vertical placement of the pull-ring  40  included in the fuse holder assembly  35 . Hence, where the height of the first section  220  is selected to minimize its impact on the isolative characteristics of the insulator  15 , the height of the second and third sections ( 225 , 230 ) are selected to provide a minimum volume about the upper end of the fuse receptacle so as to shield the hooks  30 , the upper end of the fuse holder assembly  35  and its associated pull-ring  40 .  
         [0047]    According to one alternative embodiment of the present invention, a single piece cutout cover  110  may be constructed by molding a dialect material into the shapes described for the first, second and third sections. Such a molded part may be constructed using any suitable dialect material that provides sufficient electrical isolation and is resilient to the ultraviolet radiation present in ordinary sunlight. Various materials suitable for such molding of a cutout cover include, but are not necessarily limited to high-density polyethylene. It should be noted that the claims appended hereto are not to limited to any particular material listed herein.  
         [0048]    The invention further comprises a flexible insulator conductor shroud  180  that is fabricated from dielectric material. The conductor shroud comprises a slot and is pliable to the extent that the slot may be spread apart in order to cover a conductor. The dielectric material is selected in order to provide the resilience necessary to return to its original shape so as to envelope the conductor. According to one example embodiment of the present invention, the flexible insulator conductor shroud  180  is fashioned from high-density polyethylene. It should be noted that the claims appended hereto are not to limited to any particular material listed herein.  
         [0049]    [0049]FIGS. 10 and 11 are, respectively, a perspective and profile pictorial diagrams that depict one alternative method for shrouding a lower contact assembly of a cutout  10 . According to one alternative method, the lower contact assembly is shrouded by a second  355 . This is an optional step to a first example method wherein the upper contact assembly of a cutout  10  is shrouded by a first shroud  350 .  
         [0050]    Alternative Embodiments  
         [0051]    While this invention has been described in terms of several preferred embodiments, it is contemplated that alternatives, modifications, permutations, and equivalents thereof will become apparent to those skilled in the art upon a reading of the specification and study of the drawings. It is therefore intended that the true spirit and scope of the present invention include all such alternatives, modifications, permutations, and equivalents.