United States Patent [191 Sankey et al. I
[111 3,883,208 [451 May 13, 1975 VISIBLE BREAK TEE-CONNECTOR {73] Assignee: RTE Corporation, Waukesha. Wis' [22] Filed: Oct. 25, 1973 [2]] App]. No: 409,764
[52] U.S. Cl 339/92 R; 339/l l l; 339/60 R [51] Int. Cl H0lr l3/54 [58] Field of Search 339/75, 92, Ill, [12, 143.
Primary ExaminerMarion Parsons, Jr. Assistant E.\'aminerR0bert A. Hafer Attorney, Agent, or Firm-Ronald Er Barry 5 71 ABSTRACT A visible break tee connector for electrically connecting a high voltage cable to a bushing for an electrical apparatus, ,said connector including a T-shaped resilient dielectric housing, a primary cable connecting cl ement in said housing electrically connected to the primary cable abushing connecting member positioned in said housing in electrical communication with said cable connecting element. said housing being mounted on the bushing with the connecting member electrically connected to the bushing, a contact assembly is mounted in the housing in electrical contact with the connecting member to provide a ground contact on disconnection, the connecting member. connecting element and contact assembly being disconnectable from the bushing without disconnecting the connecting member from the cable connecting element.
16 Claims, 9 Drawing Figures mm om m SHEU 18F 4 NENTEU W l 3195 VISIBLE BREAK TEE-CONNECTOR BACKGROUND OF THE INVENTION In high voltage apparatus operating at lKV or higher it is esssential on disconnection for repair or mainte nance to have a visible break and provisions for grounding the apparatus bushing or terminating point of the high voltage cable.
The visible break precludes any possibility of a lineman getting injured during repair or maintenance of the cable and/or apparatus. The visible disconnect isolates the section of cable and/or apparatus that is under repair and eliminates the possibility of the cable becoming accidentally energized due to error in switching or cross tying.
This visible disconnect must be performed using standard hot line operating tools and the electrical apparatus must be able to be tested to determine if the apparatus is energized.
SUMMARY OF THE INVENTION The tee-connector of the present invention provides a visible break for the lineman on disconnection of the primary cable from the terminating bushing of the electrical apparatus while maintaining a ground connection to the primary cable. The primary cable is connected to the bushing in such a way that a connection to ground can be maintained to the primary cable on dis connection. The visible break is thereby provided be tween the primary cable and the bushing without disturbing the ground connection. This has been achieved by maintaining electrical communication between a bushing connecting member, cable connecting element and a grounded contact assembly during disconnection.
. DRAWINGS FIG. I is a view in section of the visible break teeconnector of this invention showing the parts prior to assembly;
FIG. 2 is a view in section of the tee-connector mounted on the bushing and capped for use;
FIG. 3 is a view in section of the tee-connector showing the ground connection prior to disconnection;
FIG. 4 is a view in section showing the grounded teeconnector disconnected from the bushing;
FIG. 5 is an enlarged view ofthe connecting member, connecting element and contact assembly shown as scmbled in the housing;
FIG. 6 is a view in section of an alternate form of the invention;
FIG. 7 is a view of one form of the electrically conductive ring used to maintain electrical communication between the connecting member and connecting element;
FIG. 8 is a view similar to FIG. 6 showing another form of the tec-conncctor; and
FIG. 9 is a view of another form ol'tec-connector according to the invention.
DESCRIPTION OF THE INVENTION The visible break tee-connector 10 of the present invention, as seen in FIG. 1, is used to connect a high voltage primary cable 12 to a bushing 16 for an electrical apparatus such as a transformer. The primary cable 12 is connected to a cable connecting element 18 which is positioned within a T-shaped resilient dielectric housing 30. A bushing connecting pin or member 20 is positioned in the dielectric housing 30 in electrical communication with element 18 and is retained therein by means of a contact assembly 22. The open end of the housing 30 can be closed by means of a cap 25 and the bushing 16 can be closed by means ofa protective cap 27.
On assembly. as seen in FIG. 2, the cap 27 is removed and the housing 30 is mounted on the bushing 16 in sealing engagement with the outer surface of the bushing. The connector member 20 is electrically connected to an electrical conductor 14 in the bushing 16 which is connected to the electrical apparatus. The cap 25 is mounted on the housing 30 to close the open end of the contact assembly 22.
The visible break between the primary cable 12 and the bushing 16 is achieved by grounding the teeconnector 10 and removing the bushing connecting member 20, cable connecting element l8. contact assembly 22 and housing 30 from the bushing l6 a single unit. As seen in FIG. 3, the tee-connector 10 is pre' pared for disconnection by removing cap 25 and grounding the contact assembly 22 by means of a grounded disconnect tool 29. The disconnect tool 29 in this embodiment is used to manually disengage the member 20 from the conductor 14 as more particularly described hereinafter.
Upon disconnection as seen in FIG. 4, the end of the bushing 16 will be exposed. The primary cable 12 is grounded by tool 29. The cap 27 can be placed on the bushing 16 to protect the open end of the bushing during repair of the electrical apparatus.
More particularly. and referring to FIGS. 2 and 5. the bushing 16 includes a body or housing 24 formed from a dielectric material. and having a tapered outer surface 23. The electrical conductor 14 is embedded within the body 24 and is connected at its inner end to the electrical apparatus. Means are provided at the outer end of the electrical conductor 14 for receiving the connecting member 20. Such means is in the form of a tapered bore 26 having a threaded section 28 at its inner end.
The primary cable 12 includes a high voltage conductor 40 enclosed within a cable insulation 42 and a semiconductive layer 38. The cable 12 is normally prepared for termination by stripping the layer 38 from the end of the cable to expose the insulation 42. A portion of the insulation 42 is then removed to expose the end of the conductor 40.
CABLE CONNECTING ELEMENT 18 Cable termination is achieved by means of the cable connecting element 18 which includes a blind bore 44 and an extension or flange 46 having an opening 48. The exposed end of the conductor 40 is inserted into the blind bore 44 in the cable connector and is secured therein by crimping the connector 18 as shown at 43 to the conductor 40. The connecting element [8 is electrieally connected to the conductor 14 in the bushing 16 by means of the bushing pin or connecting member 20.
The cable connecting element l8 after assembly to the cable 12 is initially positioned within the T-shaped housing 30. The housing 30 is formed from a resilient insulating material such as rubber and includes a first or open ended passage 32 having a tapered section 33 at one end to sealingly engage the outer tapered surface 23 of the bushing 16. A secondary cable passage 36 is provided in the housing 30 and intersects the passage 32. An electrically conductive elastomeric lining is pro vided on the surface of the passage 36 to equalize the voltage gradient around the electrical connection be tween the connecting element 18 and connecting mem ber 20. The connecting element 18 is inserted into passage 36 far enough for the opening 48 on the extension 46 to be axially aligned with the first passage 32.
Connecting Member In this regard, the connecting member 20 is formed from a solid cylindrical conductive material such as copper and includes a center section 58, tapered sections 59 and 61 and threaded sections 50 and S2 at each end. Hexagonal openings 54 and 55 of the same size are provided at each end of the member 20. An annular flange 56 is provided on the outer surface of the center section 58 of the pin 20. The flange 56 is spaced a distance from the intersection of section 59 with section 58 slightly greater than the width W of connector extension 46. The diameter of the center section 58 of the connecting member 20 should be slightly smaller than the diameter of the opening 48 in the cable connecting element 18. Electrical communication can be provided between the member or pin 20 and element 18 by means of a conductive ring 45 provided in a groove 47 in element 18. The conductive ring 45 has an inner diameter slightly smaller than the outer diame ter of the center section 58 of member 20.
Contact Assembly The cable connecting element 18 is retained on the bushing connecting member or pin 20 by means of the contact assembly 22. In this regard, the contact assem bly 22 includes a conductive sleeve 60 having a threaded section 62 at its inner end and a threaded section 64 at its outer end A tubular nut 66 having a first outer threaded section 68 and a second outer threaded section 69 is threadedly received in the threaded section 62 of sleeve 60. A flange 67 is provided at the end of the threaded section 68. A hexagonal opening 70, which is larger than hexagonal opening 54 in member 20, is provided in the nut 66 and an inner threaded section 72 is provided in the center of the nut 66. The inner threaded section 72 is adapted to be received on the threaded section 52 of member 20. The nut 66 can be positively located on the member 20 by means of a tapered section 73 provided at the end of the threaded section 72 which corresponds with tapered section 59 on the member 20. When the nut 66 is mounted on the member 20, the flange 67 should terminate at the end of tapered section 59 to provide a fixed space slightly larger than the width of extension 46 to allow member 20 to rotate freely in opening 48.
An electrically conductive receptacle 74 having a threaded section 76 at the inner end is mounted on the second outer threaded section 69 of nut 66. An are extinguishing sleeve 78 having an inner bore 80 and an outer threaded section 82 is threadedly received in the threaded section 64.
The open end of the contact assembly 22 is closed by means of the cap 25. The cap includes a body 35 formed from an elastomeric material and a conductive coating 37 on the outer surface made of electrically conductive elastomeric material. A conductive liner 39 having a plug or extension 41 in electrical contact with receptacle 74 is provided on the inner surface to equalize the voltage gradient across the body 35.
Assembly On assembly, the bushing connecting member 20 is turned into the opening 28 in the electrical conductor 14 until flange 56 seats against the end of conductor 14. The contact element 18, which has been previously mounted on cable conductor 14, is inserted into pas sage 36 far enough for opening 48 to be aligned with passage 32 in housing 30. The housing 30 is then mounted on the bushing 16 with the member 20 extending through opening 48. The housing 30 is pushed onto the bushing 16 until the tapered opening 33 of housing 30 sealingly engages the tapered section 23 of the bushing 16. The contact assembly 22 is inserted into passage 32 until the threaded section 72 is aligned with threaded section 52 on member 20. The contact assembly 22 is rotated by means of a tool such as grounding tool 29 having a hexagonal male section at the inner end to engage opening on the threaded end 52 of member 20.
The contact assembly 22 is turned until the tapered section 73 seats tightly against section 59. The flange 67 will then be spaced from flange 56 on the connecting member 20 a distance sufficient to allow member 20 to rotate freely in opening 48. The member 20 must be free to turn in order to connect and disconnect the primary cable to and from the bushing 16 as described hereinafter.
Disassembly in order to achieve a visible break on disconnection while maintaining ground contact, the member 20 is turned out of the threaded section 28 in the conductor 14 by means of the grounding tool 29 which includes a male hexagonal end 31 corresponding to the hexagonal opening 54 in the member 20. The member 20 is free to rotate within the opening 48 in the cable connecting element 18 so that it can be disconnected from the conductor 14. The contact assembly 22 will rotate with the connecting member 20 to maintain electrical contact between the element 18 and the contact assembly 22. As the grounding tool 29 is rotated counterclockwise to remove the connecting member 20 from the conductor 14, positive ground is maintained with element 18 through electrical recepticle 74. Once the connecting member 20 has been unscrewed from the threaded section 28, the housing 30 can be pulled from the bushing 16 using a gripper stick to engage the pull ring or eye 28 with the pin 20, cable connector 18 and contact assembly 22 still assembled as a single unit within housing 30 and grounded through the grounding tool 29.
The contact assembly 22 can be removed from the member 20 by inserting the tool having the hexagonal end corresponding to the hexagonal opening 70 into the sleeve 60 and inserting the tool having the hexagonal end corresponding to the opening 55 into the member 20. The tools are rotated in opposite directions to disengage the contact assembly 22 from the member 20. The member 20 can then be removed from the element 18 to release the primary cable from the housing 30.
Accidental disassembly of the contact assembly 22 from the member 20 is prevented by means of the smaller hexagonal opening 54 in member 20. The hexagonal tool used to remove the member 20 will only engage the hexagonal opening 54 in the member since it is too small to engage the hexagonal opening 70.
FIG. 6
In the alternate embodiment of the invention shown in FIG. 6, a multiple connector arrangement is disclosed wherein an intermediate bushing member 84 is provided in the housing for connection to conductor 14. The connecting member 20 and contact assembly 22 have been replaced by the bushing member 84. Although only one intermediate housing 30 is shown, a number of such units can be mounted in series on the bushing 16, if desired.
The electrically conductive connecting member 84 includes a threaded section 85 at one end corresponding to threaded opening 28, a cylindrical body portion 86 having a diameter substantially equal to opening 48 in extension 46 and a flange 88 at one end of the body portion 86. A blind bore 87 having a threaded section 90 is provided in the other end of member 84. A hexagonal recess 92 is provided at the open end of bore 87.
Electrical communication can be provided between member 84 and element 18 by means of a conductive ring 94 as seen in FIG. 7. The ring 94 is positioned between the cylindrical portion 86 and the opening 48. The ring 94 is provided with a plurality of twisted sections 95 which are bowed slightly to provide a tight tit.
The primary cable 12 is connected to the bushing 16 in this embodiment, by inserting the connecting member 84 into passage 32 through opening 48 in element 18. The housing 30 is then pushed onto the bushing 16 until the threaded section 85 is aligned with threaded section 28. The member 84 is then rotated by inserting a hexagonal tool into opening 92 to draw the housing 30 into sealing engagement with surface 23 on bushing 16.
On disassembly, the member 84 is merely turned out of threaded section 28 by inserting the grounded hexagonal tool into hexagonal opening 92. The member 84 will turn freely in opening 48. The housing 30, primary cable element 18 and member 84 can then be removed as a single unit from bushing 16. The element 18 can be removed from housing 30 by pulling member 84 out of passage 32.
FIG. 8
In the embodiment of the invention shown in FIG. 8, an alternate form of connecting member is disclosed which can be used in place of member 84. In this embodiment, the connecting element 18 is modified by providing a threaded opening 112 in extension 46 and a tapered recess 114 in conductor 14.
The electrically conductive connecting member 110 includes a cylindrical body 116 having an axial bore 117 which tapers at the inner end to a small opening 118. A counterbore 120 is provided at the other end which has a hexagonal recess 121 at the open end.
The member 110 is secured to the conductor 14 by means of a tapered section 122 provided at the inner end of the member 110 which is slotted at 126. The tapered section 122 is expanded into frictional engagement with the tapered recess 114 by means ofa rod 128 positioned in bore 117. The end of the rod 128 abuts against the small opening 118 and has a threaded section 130 at the other end which is threadedly received in a threaded section 133 in bore 117. When the rod 128 is turned into threaded section 130, the end of the rod 128 will force the slotted end of the member 110 outwardly into engagement with recess 114. The member 110 is secured to the element 18 by means of a threaded section 132 provided on the body 116 which is threadedly received in threaded opening 112.
On assembly, the element 18 is inserted into the passage 36 in the housing 30 until threaded opening 112 is axially aligned with passage 32. The member 110 is inserted into passage 32 and the threaded section 132 turned into threaded opening 112. The housing 30 is then mounted on bushing 16 with the tapered section 122 inserted into recess 114. The rod 128 is turned into threaded section 133 to force the end of the rod 128 into the small opening 118. The rod 128 will force the slotted end of the member 110 outwardly into engagement with the recess 114.
FIG. 9
In the alternate embodiment shown in FIG. 9, an alternate form of connecting member is shown positioned within the housing 30. The connecting member 150 includes a cylindrical body portion 152 which is positioned within the opening 48 in the element 18. A threaded extension 154 is provided on one end of the member 150 and an electrical contact section 164 is provided on the other end. The member 150 is free to rotate with respect to the element 18. The contact assembly 22 is mounted on the member 150 by rotating the threaded section 52 onto extension 154.
Electrical connection between member 150 and the bushing is made by means of the contact section 164 on member 150 and a pin provided on the conductor 14. In this regard, the pin 160 includes a threaded section 162 which corresponds to the threaded section 28 provided at the end of the conductor 14. The housing 30 is mounted on the bushing 16 by pushing the section 164 into frictional engagement with pin 160 until the housing 30 sealingly engages the outer surface 23 of the bushing 16.
The housing 30 is retained on the bushing by means of a bale 166. In this regard, the bale 166 is mounted in a groove or opening 168 provided on the housing 30. A pair of inwardly directed sections 170 are provided at the end of the bale to engage connector 172 provided on the bushing 16.
On disassembly the cap 25 is removed from the housing 30 and the grounding tool 29 inserted into the contact assembly 22 to electrically engage the member 74 and opening 54. The bale 166 is released from the bushing 16 by pulling connector 172 off of bushing 16 and a hook stick inserted into the pull ring or eye 28. The housing 30 and member 150 are pulled from the bushing 16 to provide the visible break between the primary cable and the bushing 16 as described above.
We claim:
1. A visible break tee-connector for electrically connecting a high voltage cable to a bushing for an electrical device, said connector comprising:
a housing formed from a resilient insulating material,
an electrically conductive primary cable connecting element positioned in said housing, said element being electrically connected to said primary cable, and
a bushing connecting member positioned in said housing and including a body portion electrically engaging said element,
means at one end for electrically connecting said member to said bushing,
means at the other end for electrically connecting said element to ground and mechanical means for holding said bushing connecting member onto said element on disconnection from said bushing whereby said bushing con necting member can be grounded prior to disconnection from said bushing without disconnecting said member from said cable connecting element 2. The connector according to claim I wherein said primary cable connecting element includes an opening and said bushing connecting member includes a section on said body portion conforming to the opening in said cable connecting element. said member being rotatable with respect to said element.
3. The connector according to claim I wherein said first electrically connecting means comprises a threaded section on one end of said member for secur ing said bushing connecting member to the bushing, and said second ground connecting means at the other end of said member includes first means for turning said bushing connecting member into and out of said bushing.
4. The connector according to claim 3 wherein said ground connecting means includes a second threaded section at the other end and including a ground contact assembly including a nut having a threaded opening corresponding to said second threaded section for threadedly engaging said second threaded section and a second turning means in said nut larger than said first turning means in said bushing connecting member. said contact assembly including a hollow sleeve mounted on said nut for connecting said bushing connecting member to ground potential whereby said bushing connect ing member can be removed from said bushing without disconnecting said contact assembly from said bushing connecting member.
5. The connector according to claim 4 wherein said nut includes means for locating said nut on said connecting member to allow said member to rotate with respect to said element.
6. The connector according to claim 5 wherein said member includes an external tapered section and said locating means comprises an internal tapered section to matingly engage said tapered section on said member,
7. The connector according to claim 2 wherein said bushing connecting member includes an annular shoulder having a diameter greater than the diameter of said opening. said shoulder being located between said bushing and said cable connecting element.
8. The connector according to claim I wherein said cable connecting element includes a circular opening and said bushing connecting member includes a cylindrical section having an outer diameter substantially equal to the diameter of said opening. said first means comprising a threaded section at one end of said memher for securing said bushing connecting member to said bushing. and an annular shoulder on said member having a diameter greater than said opening and located between said bushing and said cable connecting element.
9. The connector according to claim I wherein said connecting member includes means for friction-ally engaging said bushing.
10. The connector according to claim 1 wherein said cable connecting element includes a threaded opening and said bushing connecting member comprises a cylindrical shaft having a slotted tapered section at one end and an axial passage tapering at said one end to a small opening.
a threaded section for connecting said bushing connecting member to the threaded opening in said primary cable connecting element.
and means positioned in said small opening in said bushing connecting member passage to expand said tapered section into locking engagement with said bushing.
1]. A visible break teeconnector for electrically connecting a high voltage cable to a bushing for an electrical apparatus, said connector comprising:
a housing formed from a resilient insulating material. said housing includes a first passage having one end formed to sealingly engage said bushing and a sec- 0nd passage intersecting said first passage.
an electrically conductive primary cable connecting element positioned in said second passage and extending partially into said first passage. said element being electrically connected to said primary cable and having an opening axially aligned with said first passage.
and a bushing connecting member including a body portion positioned in said opening in said element and being in electrical communication with said element and including threaded means for electrically connecting said member to said bushing. and ground connecting means for electrically connecting said member to ground. said bushing connecting member being disconnectable from said bushing without disconnecting said member from said cable connecting element and from ground whereby a visible break will be formed on disconnection of said bushing connecting member from said element.
[2. The connector according to claim ll including an annular shoulder on said member and a contact as sembly for holding said member on said element with said shoulder located between said bushing and said element.
13. The connector according to claim 12 wherein said contact assembly includes means for locating said assembly on said member to allow said member to to tate freely in said element.
[4. The connector according to claim it wherein said opening is threaded and said member includes a threaded section on said body portion corresponding to said threaded opening.
15. The connector according to claim 14 wherein said bushing includes a tapered opening and said member includes an axial bore, said bore tapering to a small bore at the inner end of said member. the inner end of said member being tapered and slotted to [it in said tapered opening in said bushing and rod means in said bore mounted for movement into engagement with said taper to force the slotted end of said member outward.
16. A visible break tee-connector for connecting a primary cable to the electrical conductor in a bushing for an electrical apparatus. said connector comprising:
a resilient dielectric housing for sealingly engaging the bushing.
an electrical connector assembly housed within said housing, said assembly including a connecting element for terminating the primary cable. a manually disconnectable member electrically bridging the remaining in electrical communication with said element and grounding means to maintain said member and element at ground potential on disconnection from said brushing.