Abstract:
An elbow arrester with a T-body is disclosed capable of coupling with an apparatus for protection from transient over voltage, and coupling with additional cable accessories, without having to loosen the initial connection with the coupled apparatus. The elbow body of the T-body arrester has a first portion, and a second portion protruding from an intermediate section of the first portion to define a T-body. A receiving feature is located within the first portion extending towards a first end, while a male feature is coupled to a second end of the first portion, opposite from the receiving feature. A coupling fastener is integrally molded into the first portion, providing for an apparatus coupled to the coupling fastener to be decoupled without loosening the connection of another apparatus connected to the T-Body elbow. Further, decoupling the other apparatus does not loosen the apparatus coupled to the coupling fastener.

Description:
FIELD OF INVENTION 
       [0001]    The present invention generally relates to the field of surge arrester and, more particularly, to a T-body arrester used for underground and overhead electrical systems. 
       BACKGROUND OF INVENTION 
       [0002]    Conventional surge arresters protect electrical systems from transient over-voltage surges from lightning, switching, and the like. Traditionally, a 200 Ampere (200 A) elbow arrester configuration is used to address the surges. In this configuration, the bushing of the desired apparatus designed to protect against the surges is connected to a first portion of the elbow connection. An arrester, typically consisting of metal oxide varistor (MOV) elements, is positioned in the second portion of the elbow connector. The MOV elements and bushing are electrically connected in an intermediate portion of the first part of the elbow connection. A ground connecter—which is positioned at an end of the second portion of the elbow connector—is electrically connected to the MOV on a first end and coupled to an external ground on a second end. Therefore, a voltage is applied across the MOV elements from the bushing connection of the apparatus and ground. At steady state, the MOV elements have a relatively high impedance, however as the voltage applied across the elements increases, such as from a lightning surge, the impedance of the MOV elements decreases until a breakdown voltage, wherein the impedance rapidly decreases towards zero. As a result, the MOV elements become highly conductive and serve to conduct transient current from the surge voltage to ground, thereby protecting the apparatus. 
         [0003]    In applications of higher loads than 200 A, the resulting 600 A connector system requires an adapter known as a load break reducing tap plug (LRTP), which, in conjunction with an extender is coupled to the first portion of the 200 A elbow arrester. The inherent disadvantages of using such a system is that the additional parts introduce installation complexities and fault points for the system. 
         [0004]    Such inherent disadvantages in known systems has not been entirely ignored in the industry. In response a T-Body surge arrester with an integrated 600 ampere (600 A) bushing was developed, thereby removing the need for the 600 A/200 A LRTP, and extender. An example of a T-body surge arrester configuration can be found in issued patent Yaworski et al. U.S. Pat. No. 8,018,707 entitled “High Amperage Surge Arrestors.” As discussed in the Yaworski et al. disclosure, a T-body elbow arrester comprises an elbow body having a first portion and a second portion extending from an intermediate section of the first portion in a generally perpendicular direction to define the T-shape. A surge arrester is position in the second portion and an end cap assembly—positioned at an end of the second portion—is electrically connected to the surge arrester. A bushing receiving portion region is positioned on a first end of the first portion of the elbow body, while an insulating plug extends from the intermediate portion of the first portion to a second end of the first portion of the elbow body. An end of the insulating plug is located in the intermediate portion of the elbow body to be coupled to secure the T-body elbow arrester in the assembly. 
         [0005]    A disadvantage of the configuration disclosed in Yaworski et al. is that the initial connection of an arrester connected to the bushing receiving area must be removed in order to connect a power cable via a T-body elbow to the same connection point. Another method of installing a power cable via a 600 A elbow to the arrester of Yaworski would be to remove the insulating plug (thereby loosening the connection to the bushing), install another accessory device known as a connecting plug, and then install the new 600 A elbow and power cable. 
         [0006]    Therefore, there is a need in the art for an arrester configuration, with a receiving feature that can be mounted directly to an apparatus, such as a bushing or connector accessory. It is preferred that such an apparatus further include a built in male feature designed to allow connection to another accessory. 
         [0007]    In addition, there is a need for a coupling fastener positioned in the arrester that allows an apparatus coupled to the coupling fastener to be decoupled without loosening the connection of another apparatus coupled to the elbow body. 
         [0008]    Furthermore, there is a need for an insulating cap that couples with the male feature. When the insulating cap is removed the male feature can then be coupled to another accessory, without loosening the connection of an apparatus coupled to the receiving feature. 
       SUMMARY 
       [0009]    According to various embodiments the present invention, an elbow arrester with a T-body is disclosed capable of coupling with an apparatus for protection from transient over voltage, and coupling with additional cable accessories, without having to loosen the initial connection with the coupled apparatus. The elbow body of the T-body arrester has a first longitudinally extending portion and a second longitudinally extending portion. The second portion protrudes in a substantially perpendicular direction from an intermediate section of the first portion to define a T-body. A surge arrester portion is located within the second portion of the elbow body. Further, an end cap assembly is coupled to an end of the second portion, and is electrically connected to the surge arrester. A receiving feature is located within the first portion of the elbow body extending from the intermediate section towards a first end of the first portion of the elbow body. Further, a male feature is coupled to a second end of the first portion of the elbow body, opposite from the receiving feature. 
         [0010]    In one embodiment, a coupling fastener is integrally molded into the intermediate portion of the elbow body extending towards the male feature. In yet another embodiment, the coupling fastener is integrally molded onto an end of the male feature. As a result, an apparatus coupled to the coupling fastener can be decoupled without loosening the connection of another apparatus connected to the T-Body elbow. 
         [0011]    In one embodiment, the receiving feature is configured to conformably receive a 600 A standard shaped male bushing, and the surge arrester is a metal oxide varistor (MOV) arrester block stack. The end cap assembly can include an end cap in the second portion and a ground connector. The ground connector has a first end that is electrically connected to a first end of the surge arrester, and a second end that is configured to be connected to an external ground. 
         [0012]    In another embodiment, a second, opposite end of the surge arrester is positioned in the intermediate portion of the first portion of the elbow body. The surge arrester is electrically connected to an apparatus that is coupled to the receiving portion of the elbow body. Further, a second apparatus coupled to the male feature of the elbow body is electrically connected to the surge arrester when an apparatus is coupled to the receiving portion of the elbow body. The electrical connection defines an electric path from the apparatus to the ground connector through the surge arrester. 
         [0013]    In an embodiment where the coupling fastener is positioned in the intermediate section of the first portion of the elbow body, the electrical connection is created when the apparatus is coupled to the coupling fastener through the receiving portion. The apparatus can include a screw threaded section. The screw threaded section can be a male thread and a second end of the coupling fastener can include a female thread section configured to threadably receive the male thread of the apparatus. A first end of the coupling fastener is connected to a conductive core extending towards the male feature. When an apparatus is coupled to the male feature and another apparatus—such as an insulating plug—is coupled to the receiving portion, the conductive core electrically connects both apparatuses to the arrester. 
         [0014]    In another embodiment the coupling fastener is located on an end of the male feature. Coupling an apparatus to the coupling fastener defines an electrical connection, when another apparatus is coupled to the receiving portion of the elbow body. 
         [0015]    In further embodiments, an insulating cap can be attached to an end of the male feature. The insulating cap comprises of a receiving portion, pulling eye, and grounding eye. The receiving portion is configured to couple with the male feature of the T-body elbow arrester, while the pulling eye is positioned substantially in line with the longitudinal-axis of the insulating cap. When the insulating cap is coupled to the male feature the pulling eye provides a location to connect a hotstick or other device for engaging or disengaging the insulating cap. Further, the grounding eye can be used to ground the semi-conductive outer surface of the insulating cap. 
         [0016]    In further embodiments, the elbow body is an elastomer, such as EPDM rubber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    A further understanding of the present invention and the objectives other than those set forth above can be obtained by reference to the various implementations set forth in the illustrations of the accompanying figures. Although the implementations illustrate certain aspects of the present invention, including the apparatus and method of use of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings, examples, and the following description. One skilled in the art will recognize that the examples and figures are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention. The detailed description makes reference to the accompanying figures wherein: 
           [0018]      FIG. 1  is a side view of a 600 A (Ampere) T-body elbow arrester according to an embodiment of the present invention. 
           [0019]      FIG. 2  is a cross-sectional side view of an insulating cap according to an embodiment of the present invention. 
           [0020]      FIG. 3  is a side view illustrating the coupling of a 200 A (Ampere) elbow to a load break reducing tap plug. 
           [0021]      FIG. 4A  and  FIG. 4B  are side views that depict coupling an embodiment of the present invention to a bushing at the receiving feature, and to an insulating cap at the male feature. 
           [0022]      FIG. 5A ,  FIG. 5B , and  FIG. 5C  are side views that depict coupling an embodiment of the present invention to a bushing at the receiving feature and to a cable accessory at the male feature. 
           [0023]      FIG. 6A  and  FIG. 6B  are side views that depict coupling an embodiment of the present inventor to a cable accessory at the male feature and to an insulating plug at the female feature. 
           [0024]      FIG. 7  is a cross-sectional side view of an embodiment of the present invention for the configuration in  FIG. 4  and  FIG. 5 . 
           [0025]      FIG. 8  is a cross-sectional side view of an embodiment of the present invention for the configuration in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0026]      FIG. 1  is a side view of a 600 A (Ampere) T-body embodiment of the present invention, which includes an elbow body  102 . The elbow body  102  has a first longitudinally extending portion  104  and a second longitudinally extending portion  106  extending substantially perpendicular from an intermediate section  112  of the first portion  104 , to form the T-body. In one embodiment first portion  104  and second portion  106  are integrally formed to create elbow body  102 . In an additional embodiment, first portion  104  and second portion  106  are separable and connected at intermediate section  112  of first portion  104 . 
         [0027]    The elbow body  102  can be an electrically shielded elbow body, wherein the outer surface is an elastomer, such as EPDM rubber or the like. 
         [0028]    A surge arrester, shown in  FIG. 7  and  FIG. 8  as a metal oxide varistor (MOV) arrester block stack  126 , is located in the second portion  106  of elbow body  102 . 
         [0029]    An end cap assembly  120  is attached to an end  118  of second portion  106 . The end cap assembly  120  includes, but is not limited to, an end cap  122 , and ground connector  124 . The ground connector  124  is electrically connected to surge arrester  126  (shown in  FIG. 7  and  FIG. 8 ) located in the second portion  106  of elbow body  102 . The ground connector  124  is configured to be connected to an external ground, and its composition can consist of various materials such as brass, stainless steel, and the like. 
         [0030]    Further, a coupling fastener  130  is located in intermediate section  112  of first portion  104 , as shown in FIG.  7 , or end  116  of male feature  114 , as shown in  FIG. 8 . 
         [0031]    A receiving feature  110  is located in the first portion  104  of elbow body  102  extending from intermediate section  112  towards a first end  109  of first portion  104 . Receiving feature  110  can be configured to comformably receive a bushing, such as a 600 A standard bushing, or other connector accessories. A male feature  114  is coupled to a second end  108  of the first portion  104  of elbow body  102 . 
         [0032]    Male feature  114  and first portion  104  of elbow body  102  can be molded using techniques known to one skilled in the art. For example, a single molding can be made whereby male feature  114  and first portion  104  of elbow body  102  are injected into their respective sections. The sections can also be molded separately using known molding techniques and the male feature  114  mold can be affixed to the first portion  104  mold of elbow body  102 . In another example, the first portion  104  of elbow body  102  can be placed in a second mold, so that male feature  114  is overmolded onto first portion  104  of elbow body  102 , thereby bonding male feature  114  to first portion  104  of elbow body  102 . Coupling fastener  130  (shown in  FIG. 7  and  FIG. 8 ) is integrally molded into the mold of elbow  102 , using molding procedures commonly performed in the art. 
         [0033]    In one embodiment the male feature  114  is a 600 A deadbreak tap, that can be coupled to an apparatus. 
         [0034]    An end  116  is located on an end of male feature  114 . An insulating cap  200  (shown in  FIG. 2 ) can be attached to male feature end  116  when male feature  114  is not coupled to another apparatus or accessory. 
         [0035]      FIG. 2  is a cross-sectional side view of an insulating cap  200  according to some embodiments of the present invention. Insulating cap  200  comprises of a pulling eye  202 , grounding eye  204 , coupling component  206 , and receiving portion  208 . In the present embodiment, receiving feature  208  is configured to couple with male feature  114  (as shown in  FIG. 1 ) of T-body elbow arrester  100 , while pulling eye  202  is positioned substantially in line with the longitudinal-axis of insulating cap  200 . When insulating cap  200  is coupled to male feature  114 , pulling eye  202  provides a location to connect a hotstick or other device for engaging or disengaging insulating cap  200 . Further, grounding eye  204  can be used to ground the semi-conductive outer surface of insulating cap  200 . In the present embodiment, coupling component  206  consists of a male threaded section that is configured to threadably insert into male feature  114 . One skilled in the art would understand that coupling component  206  can utilize other configurations such as a female threaded section. 
         [0036]      FIG. 3  is a side view illustrating the coupling of a 200 Ampere (A) elbow to a load break reducing tap plug. In the configuration, elbow  500  is rated for 200 A loads. In applications of higher loads than 200 A, a load break reducing tap plug (LRTP)  502  is coupled to elbow  500 . Further LRTP  502  is coupled to an extender  504 . Finally, the assembly consisting of elbow  500 , LRTP  502 , and extender  504 , is coupled to the bushing  506  of the apparatus to protect the connection. The inherent disadvantage of using such a system is that the additional parts introduce installation complexities and fault points for the system. 
         [0037]      FIG. 4A  and  FIG. 4B  are side views that depict a configuration, wherein T-body elbow arrester  100  of  FIG. 1  is coupled to a bushing  300  and insulating cap  200 . Bushing  300  includes an integrally molded male feature  302 . In the present embodiment, receiving feature  110  of elbow arrester  100  is configured to slidably receive male feature  302 . Receiving feature  208  of insulating cap  200  is configured to couple with male feature  114  of T-body elbow arrester  100 . 
         [0038]      FIG. 5A ,  FIG. 5B , and  FIG. 5C  are side views that depict a configuration, wherein the T-body elbow arrester of  FIG. 1  is coupled to a bushing  300 , cable accessory  400 , and insulating plug  402 . In  FIG. 5A , insulating cap  200 —which was coupled in FIG.  4 B—has been decoupled from T-body elbow arrester  100 . An advantage of the present invention over the prior art is that the connection between elbow arrester  100  and bushing  300  is not loosened as a result of decoupling insulating cap  200 . Therefore, elbow arrester  100  remains securely coupled to bushing  300 . Next, in  FIG. 5B  a first end of connector accessory  400  is positioned to be coupled with male feature  114  of elbow arrester  100 . An insulating plug  402  is positioned to couple with a second end of connector accessory  400 . Insulating plug  402  can include a plug component and coupling component, wherein the end of the insulating plug can be configured to be coupled to a receiving feature. In the present embodiment, the second end of connector accessory  400  is configured to receive insulating plug  402 . Further, the first end of connector accessory  400  is configured to receive male feature  114  of T-body elbow arrester  100 . 
         [0039]    An inherit disadvantage of connector accessory  400  is that male feature  114  is not securely coupled to connector accessory  400 , until both male feature  114  and insulating plug  402  are coupled within cable accessory  400 . Further, decoupling insulating plug  402  to attach another accessory results in male feature  114  no longer remaining securely coupled to cable accessory  400 . Although connector accessory  400  is depicted as a T-body elbow, it would be apparent to one skilled in the art that other connector accessories, including, but not limited to an elbow arrester  100  could be utilized. 
         [0040]      FIG. 6A  and  FIG. 6B  are side views that depict a configuration, wherein the T-body elbow arrester of  FIG. 1  is coupled to a cable accessory  400 , and insulating plug  402 . Cable accessory  400  is coupled to bushing  300  at a first end. This coupling is not secure until male feature  114  of elbow arrester  100  is coupled to a second end of cable accessory  400 . This assembly thereby electrically connects elbow arrester  100  to bushing  300 . Further, an insulating plug  402  is coupled to receiving portion  110  of elbow arrester  100 . An advantage of the present invention over the prior art in this configuration is that the connection between elbow arrester  100  and bushing  300  is not loosened as a result of decoupling insulating cap  402 . Therefore, elbow arrester  100  remains securely coupled to bushing  300  and another accessory can be quickly coupled to receiving portion  110 . 
         [0041]      FIG. 7  is a cross-sectional side view of an embodiment of the present invention for the configuration in  FIG. 4  and  FIG. 5 . As shown, a conductive contact  128  is positioned in intermediate portion  112 . Conductive contact  128  is electrically connected to MOV arrester block stack  126 . When elbow arrester  100  is coupled to an apparatus on receiving portion  110 , the apparatus is electrically connected to MOV arrester block stack  126 . In the present embodiment, coupling fastener  130  is integrally molded in intermediate section  112  extending towards male feature  114 . A first end  130   a  is connected to conducting core  132 , which extends to end  116  of male feature  114 . Conducting core  132  electrically connects the apparatus coupled to male feature  114 , to MOV arrester stack  126 , through conductive contact  128 , when another apparatus is coupled to receiving feature  110 . End  116  of male feature  114  can consist of a female threaded section that is configured to threadably receive a male threaded section of an apparatus coupled to male feature  114 . Further, a second end  130   b  of coupling fastener  130  can include a female threaded section that is configured to threadably receive a male threaded section of an apparatus coupled to receiving feature  110 . 
         [0042]      FIG. 8  is a cross-sectional side view of an embodiment of the present invention for the configuration in  FIG. 6 . As shown, a conductive contact  128  is positioned in intermediate portion  112 . Conductive contact  128  is electrically connected to MOV arrester block stack  126 . In the present embodiment, coupling fastener  130  is integrally molded into an end  116  of male feature  114 , compared to the configuration in  FIG. 7 , wherein coupling fastener  130  is integrally molded into intermediate section  112 . A first end  130   a  of coupling fastener  130  is connected to a conducting core  132  that extends to intermediate portion  112 . The end of conducting core  132  positioned in intermediate portion  112  includes a female threaded section that is configured to threadably receive a male threaded section of an apparatus coupled to receiving feature  110 . When an apparatus is coupled to male feature  114 , the apparatus is electrically connected to MOV arrester block stack  126 , when a threaded section, such as a male thread, is coupled to a second end  130   b  of coupling fastener  130 . In the present embodiment the second end  130   b  can include a female threaded section that is configured to threadably receive a male threaded section of an apparatus coupled to receiving feature  110 . 
         [0043]    Referring now to  FIG. 7  and  FIG. 8 , the outer surface of elbow body  102  can be electrically shielded, and consist of an elastomer such as EPDM rubber or the like. As shown in the present embodiment, elbow body  102  includes an inner portion  102   b  that can be an insulating EPDM and an outer portion  102   a  that can be conductive. 
         [0044]    Thus, there has been summarized and outlined, generally in broad form, a plurality of the most important features of the present invention. While this summary is presented so that the novelty of the present contribution to the related art may be better appreciated, it will further be apparent that additional features of the invention described hereinafter (which will form the subject matter of the claims appended hereto) will further define the scope, novelty, and in certain instances the improvements upon any existing art. The following description provides specific details for a thorough understanding of, and enabling description for, various examples of the technology. One skilled in the art will understand that the technology may be practiced without many of these details and it is to be readily understood that the invention presented herein is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the various figures integrated and categorized herein. For example, in some instances, well known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the examples of the technology. It is intended that the terminology used in the description presented below be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain examples of the technology. Although certain terms may be emphasized below, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Those skilled in the art will appreciate that the disclosure of the present invention may readily be utilized as a basis for forming other similar structures, methods and systems for carrying out the various purposes and objectives of the present invention. Thus, the claims as set forth shall allow for such equivalent constructions insofar as they do not depart.