Wildlife guard assemblies and methods for using the same

A wildlife guard assembly for use with an electrical insulator body includes first and second guard members and an actuator member. The first and second guard members define a seat to receive the insulator body and are connected to one another to permit relative movement between an open position. The first and second guard members define a sideward opening to laterally receive the insulator body into the seat, and a closed position, wherein the first and second guard members at least partially encircle the insulator body to capture the insulator body in the seat. The actuator member is configured to be inserted between the first and second guard members in the open position and, when forcibly displaced radially to an installed position, to force the first and second guard members to move from the open position to the closed position.

FIELD OF THE INVENTION

The present invention relates to protective guards and, more particularly, to wildlife guards for power distribution lines and associated insulators.

BACKGROUND OF THE INVENTION

Electrical equipment, such as power transmission lines, insulators, surge arrestors, switchgear and transformers (e.g., operating at voltages in excess of 1 kV and particularly in excess of 10 kV, such voltages hereinafter being referred to as “high voltage”), often have parts thereof or parts associated therewith that are not insulated from the surrounding air. Thus, an exposed portion of such equipment can be at high voltage and be longitudinally separated from another portion at low voltage, for example at earth potential. The exposed high voltage portion may be physically supported by an insulator, for example when an overhead power line is mounted on an insulator that spaces it from a supporting tower that is itself at earth potential, or for example when a high voltage cable is terminated at a bushing or switchgear whose metal housing is at earth potential. In such instances outdoors, larger wildlife such as squirrels and birds with large wingspans may be big enough to form a direct bridge (i.e., an electrical short circuit) between the high voltage equipment and earth potential, with serious, usually fatal, consequences for themselves and often with serious consequences for the electrical equipment and the supply of electrical power—usually at least a fuse is actuated or a circuit breaker triggered such that the power supply is interrupted.

One known solution to the foregoing problem is to install a wildlife guard that may be referred to as a “squirrel guard”. Typically, a wildlife guard includes one or more parts forming a disk with an aperture. The wildlife guard is mounted on an insulator (e.g., between sheds) such that the disc extends radially outwardly from the insulator beyond the sheds. The wildlife guard substantially increases the distance from earth potential to the high voltage equipment so that wildlife are prevented from simultaneously making contact with each of, and thereby bridging, earth potential and the high voltage equipment.

Wildlife guards of known design may be difficult or cumbersome to install on elevated insulators by an installer situated on the ground using a hotstick, for example. It is desirable that a wildlife guard be securely mounted on an insulator once installed.

SUMMARY OF THE INVENTION

According to embodiments of the present invention, a wildlife guard assembly for use with an electrical insulator body includes first and second guard members and an actuator member. The first and second guard members define a seat to receive the insulator body and are connected to one another to permit relative movement between an open position. The first and second guard members define a sideward opening to laterally receive the insulator body into the seat, and a closed position, wherein the first and second guard members at least partially encircle the insulator body to capture the insulator body in the seat. The actuator member is configured to be inserted between the first and second guard members in the open position and, when forcibly displaced radially to an installed position, to force the first and second guard members to move from the open position to the closed position.

According to method embodiments of the present invention, a method for installing a wildlife guard assembly on an electrical insulator body includes providing a wildlife guard assembly. The wildlife guard assembly includes first and second guard members and an actuator member. The first and second guard members define a seat to receive the insulator body and are connected to one another to permit relative movement between an open position, wherein the first and second guard members define a sideward opening to laterally receive the insulator body into the seat, and a closed position, wherein the first and second guard members at least partially encircle the insulator body to capture the insulator body in the seat. The method further includes: with the first and second guard members in the open position, placing the first and second guard members on the insulator body such that the insulator body is received laterally through the sideward opening into the seat; and thereafter, with the first and second guard members guard members mounted on the insulator body in the open position and the actuator member inserted between the first and second guard members, forcing the actuator member radially to an installed position and thereby forcing the first and second guard members to move from the open position to the closed position.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

With reference toFIGS. 1-9, a wildlife guard assembly100according to embodiments of the present invention is shown therein. The wildlife guard assembly100may be used with an electrical insulator body such as the electrical insulator bushing10as shown inFIG. 6to form protected electrical equipment5(FIG. 8). In the illustrated embodiment, an energized electrical conductor20extends from the bushing10and the bushing10is mounted on a support22. The bushing10, which is typically formed of porcelain or other electrically insulative material, electrically shields the conductor20from the support22and/or other electrically conductive components (e.g., which may be at earth potential). When installed on the bushing10, the wildlife guard assembly100extends radially outwardly from the bushing10and serves to enlarge or extend the shortest distance between the components at significantly different electrical potential (i.e., the conductor20and the support22) that can be bridged by wildlife such as squirrels or large birds. That is, the wildlife guard assembly100has a diameter greater than the bushing10so that the wildlife guard assembly100provides an effective barrier or obstacle to wildlife prostrating themselves from earth to high voltage.

As discussed in more detail below, the wildlife guard assembly100can be applied to the bushing10using one or more manipulator tools (such as hotsticks or the like) while the conductor20is energized. According to some embodiments, the wildlife guard assembly100can be mounted and secured on the bushing10by a single operator using only a single hotstick.

Turning to the wildlife guard assembly100in more detail and with reference toFIG. 1, the wildlife guard assembly100includes a first guard member110, a second guard member130, a pivot pin104and an actuator member160(forming a part of an actuator mechanism150). Generally, the guard members110,130can be pivoted or rotated about the pivot pin104about an axis A-A (FIG. 7) from an open position (as shown inFIGS. 1 and 7) to a closed position (as shown inFIG. 8) by forcing the actuator member160in an installation direction I from a ready position (as shown inFIGS. 1,2and7) to an installed position (as shown inFIG. 8). The guard members110,130may remain coplanar or in substantially parallel planes as they pivot from the open position to the closed position.

The guard member110includes a guard body112, a hinge feature114(FIG. 3), an outer peripheral edge116A, a front terminal edge116B, an inner peripheral edge116C and a rear terminal edge116D (FIG. 3). The guard body112may take the form of an interconnected network of legs forming a grate as illustrated, for example. Removable or trimmable sections or features117(FIG. 2) are provided along the inner peripheral edge116C. Alignment or stabilizer features118extend from the front terminal edge. A rail120(FIG. 3) extends along the rear terminal edge116D. A plurality of grooves122A (FIG. 4) are defined in crossbars123of the guard body110and collectively define a groove122. A series of integral barbs124(FIG. 4) are positioned along the length of the rail120.

With reference toFIGS. 1-3, the guard member130includes elements132,134,136A,136B,136C,136D,137,138,140,142,142A,143, and144corresponding to elements112,114,116A,116B,116C,116D,117,118,120,122,122A,123and124, respectively, of the guard member110. The guard member130may be identical to the guard member110or a mirror image thereof. The guard member130is coupled or fastened to the guard member110by the pivot pin104and the hinge features114,134.

With reference toFIG. 3, the actuator member160includes an actuator body162having a leading end164A, a trailing end164B, and opposed side walls164C and164D. Guide rails166are joined to the body162by crossbars168and extend along the side walls164C and164D in spaced apart relation. A series of tabs170also extend from each of the side walls164C,164D and are spaced apart above or below the adjacent rail166and crossbars168to define respective channels172(FIG. 5). According to some embodiments and as illustrated, the side walls164C,164D and the side rails166are curvilinear and, according to some embodiments, define a substantially uniform arc. Retention features or projections174(FIG. 5) are provided on the sides of forward tabs170facing the corresponding rails166. A handling feature176is provided on the trailing end of the actuator member160. A further handling feature179(e.g., in the form of a loop or eyelet) depends from the actuator member160as well (FIG. 3).

The actuator member160is mounted on the guard members110,130such that a leading portion of the actuator member160is interlocked with the features adjacent the rear terminal edges116D,136D. More particularly, the rails120,140of the guard members110,130are slidably captured in the channels172(defined by the tabs170and the crossbars168and rails166), the rails166are seated in the channels122,142, and the side walls164C and164D are positioned adjacent (and may abut) the rear terminal edges116D and136D, respectively. As shown inFIG. 1, the actuator member160is in the ready position and releasably secured in this position by the retention features174(FIG. 5), which capture a crossbar123,143of each guard member110,130. Additionally or alternatively, a frangible or cuttable tie wrap152(FIG. 1) may secure the actuator member160in place.

In the closed position, the guard member110, the guard member130and the actuator member160form a substantially planar structure. As illustrated, the wildlife guard assembly100is generally disc-shaped. However, it will be appreciated that other shapes may be employed for the guard member110, the guard member130or the wildlife guard assembly100overall.

The inner peripheral edges116C,136C of the guard members110,130collectively define a seat182. With the actuator member160mounted in the ready position, the guard members110,130are retained in the open position (FIG. 1) such that a sideward opening180is defined between the spaced apart edges116B,136B and communicates with the seat182.

The wildlife guard assembly100has a central axis E-E (FIG. 7), which may be substantially centered in the seat182when the wildlife guard assembly100is in the closed position. The installation direction I (FIG. 7) is transverse to and may be radial to the axis E-E. In some embodiments and as illustrated, the installation direction I is substantially perpendicular to the axis E-E. The actuator160is located on the same side of the seat182as the pivot axis A-A.

The guard member110, the guard member130and the actuator member160may be formed of any suitable electrically insulative material. The material may be weather resistant. According to some embodiments, the guard member110, the guard member130and the actuator member160are formed of a polymeric material. According to some embodiments, the guard members110,130and the actuator160are formed of a track resistant, insulating grade, UV stable polymer. The guard members110,130and the actuator160may be formed of the same or different materials. The components110,130,160may be formed of a rigid or semi-rigid material. In some embodiments, the material has a secant modulus of at least 25,000 psi and/or a tensile strength of from about 1200 to 2500 psi. According to some embodiments, the guard member110, the guard member130and the actuator member160are each integrally formed and, according to some embodiments, each are unitarily molded (e.g., injection molded).

With reference toFIGS. 6-8, the wildlife guard assembly100may be mounted on the bushing10in the following manner in accordance with embodiments of the present invention. The removable sections117,137(FIG. 2) may be removed or trimmed as needed depending on the size of the bushing10. The actuator160may be premounted on the guard members110,130as shown and described.

The insulator bushing10(FIG. 6) is merely exemplary and includes an elongated core12having a core axis B-B (FIG. 7). The core12may be substantially cylindrical. A plurality of axially spaced apart skirts or sheds14extend radially outwardly from the core12and define slots or gaps16therebetween. While the insulator body is shown and described as an insulator bushing, the wildlife guard assembly100may be used with other types of insulator bodies such as surge arrestors, switch insulators, or support insulators.

As shown inFIG. 7, the wildlife guard assembly100may be lifted and positioned on the bushing10using a hotstick30having a selectively operable gripper mechanism32. Suitable hotsticks may include the Model 8112 Shotgun Stick available from Hastings Fiber Glass Products, Inc. of Hastings, Mich. The installer can grip the handling feature176, lift the wildlife guard assembly100and laterally push (i.e., in the direction I) the wildlife guard assembly100between the selected skirts14of the bushing10until the core12is in the seat182. More particularly, the bushing10is received through the opening180and into the seat182.

Once the wildlife guard assembly100is so positioned, the installer continues to force the actuator member160radially inwardly in the direction I. Because the guard members110,130abut the bushing core112, the actuator member160(after overcoming the resistance of the retention features174and the tie wrap152, if present) will push laterally into the space between the guard members110,130. In this manner, the side walls164C,164D progressively bear against the edges116D,136D of the guard members110,130to force the guard members110,130to rotate about the pivot axis A-A of the pivot pin104and the core12in opposed, convergent directions C1, C2until the actuator member160achieves the installed position (FIG. 8), whereupon the front edges116B,136B of the guard members110,120are in close proximity to close the opening180and secure the core12in the seat182. The inner portions of the guard members110,130reside in the selected slot16between the skirts14to prevent vertical removal of the wildlife guard assembly100from the bushing10. According to some embodiments, the installed wildlife guard assembly100is substantially coaxial with the bushing10. The wildlife guard assembly100may snugly fit about the core12. The hotstick30can then be removed.

In some embodiments and as shown, the guard members110,130and the actuator160collectively form a disc that fully or substantially fully encircles the core12. The actuator160can extend at least to or proximate the outer perimeter of the guard members110,130to fill the gap therebetween.

The actuator member160is secured in the installed position by the barbs124,144, which interlock with the crossbars168of the actuator member160to resist detachment. According to some embodiments, the wildlife guard assembly100can be removed from the bushing10by twisting and/or drawing back on the actuator member160to defeat the interlock.

As shown inFIG. 8, the stabilizer features118,138may assist in aligning the guard members110,130as they come together and to torsionally stabilize the guard members110,130against warping. The engagements between the rails120,140, the tabs170, the crossbars168and the rails166can prevent or resist torsion or warping of the wildlife guard assembly100at the junctions between the actuator160and the guard members110,130.

Notably, the wildlife guard assembly100may be installed by a single installer using a single hotstick.

FIG. 9illustrates installation of the wildlife guard assembly100using a hotstick30from a different orientation or installer location. In this case, the installer can engage the handling feature179(FIG. 3) of the actuator member160with a hook of the gripper mechanism32, for example.

According to some embodiments, the width W2(FIG. 2) between the side walls164C,164D at the trailing end164B is greater than the width W1between the side walls164C,164D at the leading end164A. According to some embodiments, the width W2is at least 700 percent greater than the width W1.

According to some embodiments, the outer diameter of the wildlife guard assembly100when closed is between about 200 and 600 percent greater than the outer diameter of the skirts14. According to some embodiments, the outer diameter of the wildlife guard assembly100when closed is in the range of from about 59 to 62 cm.

With reference toFIG. 10, a wildlife guard assembly201according to further embodiments of the present invention is shown therein. The wildlife guard assembly201includes a base assembly200corresponding to the wildlife guard assembly100and having a guard member210, a guard member230, and an actuator member260corresponding to guard member110, the guard member130, and the actuator member160, respectively. The wildlife guard assembly201further includes shell bodies226and246secured to or integrally formed with the guard members210and230, respectively, hinge features227,247, and displaceable conductor port walls229,249. When closed, the shell bodies226,246define an interior chamber203C to hold a portion of the insulator body and conductor ports203A,203B for the passthrough of electrical conductors to the enclosed insulator body. The wildlife guard assembly201may be installed in the same manner as discussed above with regard to the wildlife guard assembly100.

Integral or separate latch structures may be provided on the front end of the guard members110,130in addition to or in place of the stabilizer features118,138.