US3122658A - Means for controlling the connection between underground high voltage conductors - Google Patents

Description

Feb. 25, 1964 H. J. BARTA 3,122,658

MEANS FOR CONTROLLING THE CONNECTION BETWEEN UNDERGROUND HIGH VOLTAGE CONDUCTORS Filed June 22, 1961 3 Sheets-Sheet 1 Emu/2d Lead INVENTOR. flrzcy Jfiarza, BY

H. J. BARTA Feb. 25, 1964 3,122,658 MEANS FOR CONTROLLING THE CONNECTION BETWEEN UNDERGROUND HIGH VOLTAGE CONDUCTORS 3 Sheets-Sheet 2 Filed June 22, 1961 d m m WW w Y M W m N m H Y N B W m a a ,E 7 ww 1 I w 6 7 wwwmwmwww m my 3 wk 6 1 w? I 3,122,658 MEANS FOR CONTROLLING THE coNNEcTI0N BETWEEN UNDERGROUND HIGH VOLTAGE CONDUCTORS Filed June 22, 1961 H. J. BARTA Feb. 25, 1964 5 Sheets-Sheet 3 I!!! alf rlflf fllllIlll'llllilllll'll r INVENTOR. Hazy 1.73am W W E T a w m a w w m w mw/r. m E EH United States Patent 3,122,653 MEANS FOR CQNTRGLLING THE CGNNECTHON BETWEEN UNDERGRGUND HEGH VOLTAGE C(DNDUCTORS Henry .1. Barter, Broolriield, 113., assignor to S & C Electric Company, Chicago, 111., a corporation of Delaware Fiietl June 22, 1961, Ser. No. 118,967 17 Claims. (Cl. sin-94) This invention relates, generally, to circuit connecting means and it has particular relation to disconnecting fuses and disconnecting switches for interconnecting underground insulated conductors.

Among the objects of this invention are: To provide new and improved means for interconnecting sections of buried insulated conductors employed for the distribution of relatively high voltage alternating current; to provide for the direct burial of disconnecting fuses and switches for use in protecting and sectionalizing underground electric power distribution circuits; to interconnect adjacent ends of a pair of buried insulated conductors with vertically spaced terminals in a buried insulating housing and to detachably interconnect these terminals with removable connecting conductor means; to employ for the connecting conductor means either a fuse of the expulsion or current limiting type or a disconnecting blade, these devices being interchangeable and capable of application to and removal from the spaced terminals; to provide at the lower end of the insulating housing a metallic exhaust chamber for receiving the are products incident to blowing of the fuse; to prevent the return of the arc products to the use once they have been discharged into the exhaust chamber; to seal the exhaust chamber to the insulating housing and prevent the entrance of ground moisture; to locate the insulating housing at the lower end of an access tube that extends to the ground surface and through which an operator, such as a live line stick, can be inserted to apply or remove the connecting conductor means; to seal the insulating housing to the access tube and prevent the entrance of ground water; to provide a ground rod extending through the access tube and along the insulating housing and metallic exhaust chamber and embedded in the adjacent ground; and to interconnect the ground rod with metallic shields surrounding the spliced connections between the insulated conductors and terminal members extending from the terminals in the insulating housing or metallic shields forming part of the cable.

Other objects of this invention will, in part, be obvious and in part appear hereinafter.

in the drawings:

FIG. 1 is a view, somewhat schematic in character and partially in vertical section, showing a typical application of the present invention.

FIGS. 2A-2B taken together with the former positioned above the latter show a longitudinal vertical sectional view of one embodiment of the connecting means constructed in accordance with this invention.

FIG. 3 is a horizontal sectional view taken generally along the line 3-3 of FIG. 2B.

FIGS. 4A-4B taken together with the former positioned above the latter show a vertical sectional view of another embodiment of the connecting means constructed in accordance with this invention.

FIG. 5 is a horizontal sectional view taken generally along the line 5-5 of FIG. 48.

Referring now particularly to FIG. 1 it will be observed that the reference characters and 11 designate, generally, insulated high voltage conductors comprising, respectively, conductors 12 and 13, either solid or stranded, and overlying insulation sheaths 14 and 15.

ice

The insulated high voltage conductors 10 and 11 are of conventional construction and are employed for the distribution of high voltage alternating current, principally for use in residential areas to energize distribution transformers that reduce the high voltage to lower voltage suitable for residential use. They may operate at voltages of the order of 2300 volts andhigher and may form a part of a distribution circuit of the ring type. Usually the insulated high voltage conductors 10 and 11 constitute one phase of a polyphase distribution system having a grounded neutral. In accordance with present conventional practice the insulated high voltage conductors 10 and 11 are located well beneath the surface of the ground which is indicated at 16. Ordinarily, a trench is excavated for receipt of the insulated high voltage conductors 10 and 11 and the equipment associated therewith to be described presently.

It is desirable to provide connecting means, shown generally at 17, for interconnecting the insulated high voltage conductors 10 and 11 in order to sectionalize them and to provide for protection against the occurrence of a fault. The connecting means 17 includes an insulating housing 18 that may be :formed of molded plastic material such as a phenolic condensation product. Also, the insulating housing 18 can be formed of fiber glass or various combinations of it with other plastic insulating materials as may be desired. Extending laterally from the insulating housing 18 and formed integrally therewith are a lower insulating arm 20 and an upper insulating arm 21. It will be observed that the lower and upper insulating arms 20 and 21 extend toward the insulated high voltage conductors 10 and 11, respectively, and that each of them includes a conductor in the form of a lower terminal member 22 and an upper terminal member 23. As shown more clearly in FIGS. 2A2B and FIG. 3 of the drawings the terminal members 22 and 23 are rod shaped. As indicated in FIG. 3 a metallic connecter 24 is provided on the outer end of each of the terminal members 22 and 23 for receiving the corresponding end of the conductor 12 or 13 in order to provide a circuit connection thereto. It will be understood that the ends of the conductors 12 and 13 are spliced to the respective terminal members 22 and 23 by the metallic connecters 24 in conventional manner and that the resulting splices are surrounded by insulation 2525 that, in turn, are surrounded by metallic shields 26-46. The splices thus provided are con-ventional cable splices and the insulating arms 20 and 21 are provided to facilitate such splices.

The metallic shields 262 6 are connected by ground conductors '27-27 to a metallic ground rod 218 which is embedded in the ground in the vicinity of the connecting means 17 and which extends along the insulating housing 18 and upwardly to ground level 16 as indicated in FIG. 1.

Since the connecting means 17 together with the insulated high voltage conductors 10 and 11 is permanently buried beneath ground level 16, it is desirable that provision be made for entrance to the connecting means 17. Accordingly, an access tube 31 is provided which may be either of metallic construction or of insulating material. Its lower end telescopes over the upper end of the insulating housing 18 and a sealing gasket 32 is provided therebetween to exclude ground Water. It will be observed that the ground rod 28 extends through the sealing gasket 32 and upwardly inside the access tube 31. If the latter is formed of metal, it is connected at 33 to the ground rod 28. At its upper end the access tube 31 is provided with a suitable closure 34 that can be arranged so that a lock 35 must be removed by authorized personnel before the access tube 31 can be opened.

3 Referring now particularly to FIGS. 2A-2B of the drawings, it will be observed that the lower and upper terminal members 22 and 23 are connected interiorly of the insulating housing 18 to lower and upper terminals 36 and 37 respectively. These terminals are generally cylindrical in configuration and conform to the inner periphery of the insulating housing 18, being held in place therein by the terminal members 22 and 23 which extend therethrough and are headed over on the inner sides thereof.

The lower terminal 36 is of special construction. It includes a lower radially inwardly extending flange 38 and an upper radially inwardly extending flange 39, the latter being provided with slots 48-48 as shown more clearly in FIG. 3 of the drawings. The upper terminal 37 is similar to the lower terminal 36 except that it is only provided with an upper radially inwardly extending flange 41 that has slots 42-42 which are aligned with slots 48-40 in the flange 39 of the lower terminal 36.

The slots 40 48 in the flange 39 and the slots 42-42 in the flange 41 are provided for receiving outstanding flanges 43-43 which are positioned at the upper and lower ends of terminal assemblies 44-44 which are mounted at the upper and lower ends of a tubular liner 45 of a suitable insulating material such as nylon or the like which gives off an arc extinguishing medium when it is subjected to the heat of an arc. Each of the terminal assemblies 44 includes a pair of L-shaped brackets 46 46 the longer portions of which are secured by rivets 47-47 to the outer sides of the respective end of the liner 45. The short portions of the L-shaped brackets 46-46 are secured by rivets 48-48 to lateral flanges 49-49 of cylindrical contacts 58-50 which have contact fingers 51-51 formed integrally therewith and extending upwardly and downwardly as the case may be. Garter springs 52-52 serve to bias the contact lingers 51-51 inwardly.

The tubular liner 45 is inserted through the upper end of the insulating housing 18 in such position that the outstanding flanges 43-43 on the lower terminal assembly 44 are in alignment with the slots 42-42 in the flange 41 on the upper terminal 37. These slots also permit the passage of the outstanding flanges 43-43 of the upper terminal assembly 44 when the tubular liner 4-5 has been inserted to such an extent that the outstanding flanges 43-43 on the lower terminal assembly 44 have passed through the slots 40-48 in the upper flange 39 on the lower terminal 36. Now the tubular liner 45 is turned through about 90 from the position shown in FIG. 3 and the outer ends of the flanges 43-43 engage contact fingers 53-53 which are secured by rivets 54-54 to the inner side of the respective terminals 36 and 37. Because of the rotation of the tubular liner 45, the respective ends of the flanges 43-43 load the associated contact fingers 53-53, which are resilient in character, with the result that good contact engagement is provided therewith and the circuits are completed from the lower and upper terminal members 22 and 23 through the terminal assemblies 44-44 to the contact fingers 51-51 thereof. In order to hold the tubular liner 45 in the rotated position an annular fitting 55 is located within the lower terminal 36 and it is biased upwardly by a coil compression spring 56 which reacts between the under side of it and the upper side of the lower flange 38 as will be understood more clearly from a consideration of FIG. 2B. The arrangement is such that, when the tubular liner 45 is rotated through the proper extent, the spring 56 urges the flanges 53-53 into detents requiring that an endwise downward force be applied to the tubular liner 45 against the force exerted by the coil compression spring 56 to remove the flanges 43-43 on the lower terminal assembly 44 before it can be rotated to the released position where the flanges 43-43 are in alignment with the slots 40-40 and the slots 42-4-2.

Provision is made in accordance with this invention for interconnecting the upper and lower terminal assemblies 44-44 at the upper and lower ends of the tubular liner 45 for, in turn, interconnecting or disconnecting the lower and upper terminal members 22 and 23. For this purpose connecting conductor means, shown generally at 59, is provided. This means may be in the form of a disconnecting blade or rod, such as shown in U.S. Patent No. 2,316,470, issued April 13, 194-3, or it may be in the form of an expulsion fuse constructed generally as disclosed in copending application Serial No. 39,885, filed June 30, 1960, now Patent 3,094,597. The present invention is disclosed as embodying for the connecting conductor means 59 an expulsion fuse certain details of the construction of which will now be set forth.

Referring particularly to FIGS. ZA-ZB, it will be observed that the connecting conductor means 59 in the form of an expulsion fuse includes a lower fuse terminal 68 which constitutes a discharge terminal and an upper fuse terminal 61, these terminals being located at the ends of a fuse tube 62 of insulating material and being arranged to engage the contact fingers 51-51 of the terminal assemblies 44-44 previously described. Within the fuse tube 62 is a liner 63 of boric acid cakes or similar material having a common bore 64 therethrough in which a movable rod-like terminal 65 extends. The lower end of the rod-like terminal is connected by a fusible element 66 and a strain Wire 67 to a terminal 68 that extends radially inwardly from the lower fuse terminal 60. At its upper end, FIG. 2A, a coiled flexible cable 69 interconnects the rod-like terminal 65 to the lower end of a metallic tube 70 which extends upwardly through the fuse tube 62 and has a metallic bushing 71 secured to its upper end that is threaded into the lower end of the upper fuse terminal 61. A coil tension spring 72 strained between the upper end of the metallic tube 70 and the upper end of the rod-like terminal 65 serves to bias the latter upwardly for moving the rod-like terminal 65 upwardly through the bore 64 when the fusible element 66 and strain wire 67 blow upon the occurrence of predetermined overload. It is desirable that provision be made for receiving the products of the are discharged through the lower fuse terminal 60 on blowing of the fusible element 66 and strain wire 67. For this purpose a metallic exhaust chamber 75 is located at the lower end of the insulating housing 18 and has a sealed connection therewith at 76. At its lower end the metallic exhaust chamber 75 has a closure 77 which is held in place and sealed against the entrance of ground water by the inturned lower end 78 of the metallic exhaust chamber 75. Any suitable cooling and condensing means, indicated generally at 79, can be provided within the metallic exhaust chamber 75. For example, the cooling and condensing means may bein the form of plates of metal or wire screen or combinations of these elements or similar elements suitable for cooling and condensing the are products quickly and limiting the pressure developed incident to blowing of the fusible element 66 and strain wire 67.

it is desirable to use the connecting conductor means 59 as a disconnecting switch in order to disconnect the insulated high voltage conductor 16 from the insulated high voltageconductor 11. In addition it is desirable that the are products be prevented from reentering the fuse tube 62 once they have been discharged therefrom. Accordingly, a trailer 82 of insulation is provided. The trailer 82 is formed of suitable material, such as methylmethacrylate resin or other insulating material capable of evolving an arc extinguishing medium when subjected to the heat of an arc. The trailer 82 is mounted at the lower end of the lower fuse terminal 66 and is arranged to be moved upwardly along with the fuse tube 62 when the connecting conductor means 59 is withdrawn for circuit isolating purposes. The are drawn between the lower end of the lower fuse terminal 6% and the contact fingers 51-51 of the lower terminal assembly 44 is quickly extinguished since it is drawn over the outer surface of the trailer 82 and the inner surface of the tubular liner 45. The trailer 82 not only functions as an arc extinguishing device but also it functions as a check valve to prevent the reentry of the are products into the fuse tube 62 once they have been discharged therefrom. For this purpose a stem 83 is provided on which the trailer 82 is slidably mounted. The upper end of the stem i5? is anchored to a transverse spider or bridge 84 within the lower fuse terminal 60. It will be understood that the s ider or bridge 84 is so constructed that it presents a minimum of obstruction to the flow of the are products downwardly through the lower fuse terminal dd. At its lower end the stem 83 has a head 85 and between it and the upper end of the trailer 82 a coil compression spring 86 is strained and it acts to bias the trailer 82 upwardly. The upper end of the trailer 82 is protected from the are products by an overlying metallic washer 37 which is of suitable dish shape to overlie the conically shaped upper end of the trailer 82. It will be understood that the pressure incident to the blowing of the fusible element 66 and strain wire 67 is usually sufiicient to move the trailer 82 downwardly against the biasing action of the coil compression spring 86 a suiiicient distance to permit the discharge of the are products. However, when the pressure ceases, the spring 86 immediately returns the trailer 32 to the closed position shown in FIG. 23 with the result that the are products, and particularly the gas incident thereto, once discharged into the lower end of the insulating housing 18 and into the metallic exhaust chamber '75 cannot return to the interior of the fuse tube 62.

Since the insulating housing 18 is permanently buried below the ground level 16 it is desirable to provide for the application and removal of the connecting conductor means 59 through the access tube 31 by inserting a suit able live line stick downwardly through the access tube 31 after opening of the closure 34-. The construction shown in FIG. 2A is particularly adapted for this purpose. Here it will be observed that an insulating link 89 is threaded at t ll to the upper end of the upper fuse terminal m. The upper end of the insulating link $9 is threaded at 91 to a metallic stud M which is welded or brazed at @3 to a lower compression plate Q4 which extends transversely of the upper end of the insulating housing 18 and bears against the upper side of a radially inwardly extending annular rib 5. The upper end of the metallic stud )2 is threaded at 96 for receiving the lower end of attachment means, shown generally at 97. The attachment means 97' includes a metallic rod 98 the lower end of which is threaded at 99 for receiving the threaded upper end lid of the stud 92. At its upper end the metallic rod 98 is provided with an operating ring or eye liltl for receiving a book of a live line tool which can be rotated axially of the access tube 31 and also withdrawn therethrough. lt will be understood that an endwise pull applied to the operating ring or eye 1% of the attachment means d7 causes the withdrawal of the connecting conductor means 59.

Preferably the upper end of the insulating housing 18 is sealed to prevent the entrance of moisture. The seal is arranged and constructed to the end that it can be applied when the connecting conducting means 59 is inserted downwardly through the access tube 31 into operative position. Also it is arranged to become unsealed prior to the removal of the connecting conductor means 59 from the insulating housing 18. For these purposes a bellows M93 of rubber like material such as neoprene and indicated, generally, at W3 is provided. The bellows lit? has a bottom res that is bonded at 195 to the upper side of the lower compression plate 94. Also the bellows 1% has a top 1636 which is bonded at M7 to the under side of an upper compression plate 108. Overlying the upper side of the upper compression plate res is an annular flange 10? that is formed integrally with or is secured to the metallic rod 98.

When the connecting conductor means 59 is applied in operative position downwardly through the access tube 31 and into the insulating housing 18, the arrangement is such that the corrugated annular side Wall fill of the bellows M33 moves readily into the upper end of the insulating housing 18. After the connecting conductor means has been properly located as determined by the engagement of the under side of the lower compression plate 94 with the upper side of the annular rib 95, the operator or live line stick in engagement with the operatring or eye and is rotated to screw the metallic rod onto the threaded upper end 96 of the metallic stud $2. This causes the upper compression plate 198 to be moved toward the lower compression plate 94 and to expand the corrugated annular side wall 11% of the bellows 1% against the juxtaposed inner surface of the upper end of the insulating housing 18 and against a cylindrical back up tube lliti. This provides a sealed connection which can be removed by rotating the metallic rod 98 in the reverse direction.

The construction shown in FIGS. 4A4B of the drawings is generally similar to that illustrated in FIGS. 2A- 2B and described hereinbefore. The insulating housing l8 shown in FIGS. 4A-4B is slightly smaller than the insulating housing 18 shown in FlGS. 2A2B. Accordingly, the bellows M93 and some of the associated parts are correspondingly reduced in size.

In the construction shown in FIGS. 4A4B lower and upper terminals lid and 117 are provided and they have integrally formed upstanding and depending contact fingers 13 .8 and 119 for engaging the lower fuse terminal se and the upper fuse terminal til, respectively. Garter springs 120 and 121 serve to bias the contact fingers 118 and 15.9 inwardly. The terminals lllfi and 117 are pro vided with radially inwardly extending annular flange portions 122 and 123 between which a liner 124 of nylon or other similar insulating material is located. Once the assembly has been made it is not intended that the liner 124 will be removed. Since the removable feature is not provided in the construction shown in FIGS. 4A-4B, it is possible to use a smaller diameter of insulating housing ill.

It will be understood that a connecting bar or blade can be provided between the lower fuse terminal 69 and the upper fuse terminal 61 when the connecting conductor means 5'9 is to be employed solely for disconnecting purposes. in such case provision is made for securing the trailer to the lower end of the modified construction to serve for are extinguishing purposes in the manner described.

What is claimed as new is:

1. In an underground. high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, and attachment means at the upper end of said connecting conductor means for receivhig an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

2. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end or" each in close proximity, in combination, an access tube for extending upwardly irom the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably inconnecting said upper and lowe terminals, attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube, and a metallic chamber extending from the lower end of said insulating housing and completely sealing oil the same.

3. in an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending u iwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interterconnecting said upper and lower terminals, attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube, and expansible and contractible sealing means at said upper end of said insulating housing operated by said attachment means under the control of said operating member for sealing off said upper end of said insulating housing.

4. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of verticallyspaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube, a metallic chamber extending from the lower end of said insulating housing and completely sealing oil the same, and expansible and contractible sealing means at said upper end of said insulating housing operated by said attachment means under the control of said operating member for sealing oil said upper end of said insulating housing.

5. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebe veen, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member Wl 11 each arm for connection at its outer end to the respe "ve conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecking conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube, said attachment means including an eye member to receive said operating member and thereadably mounted on the upper end of said connecting conductor means, upper and lower compression plates extending in parallel spaced relation with said upper end of said insulating housing, said lower compression plate being movable with said connecting conductor means and said upper compression plate movable with said eye member whereby said compression plates are movable relatively toward and away from each other, and a bellows of rubber-like material interposed between said compression plates and expandable into sealing relation with the inner wall of said upper end of said housing on predetermined relative movement of said compression plates toward each other as a result of rotation of said eye member by said operating member.

6. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulatin arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, said connecting conductor means being in the form of an expulsion type fuse having a discharge terminal at its lower end, a metallic exhaust chamber extending from the lower end of said insulating housing and completely sealing oil the same for receiving the are products from said fuse on blowing thereof, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

7. In an underground hi h voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, said connecting conductor means being in the form of an expulsion type fuse having a discharge terminal at its lower end, a trailer of insulating material at the lower end of said discharge terminal, means slidably mounting said trailer relative to said discharge terminal, means biasing said trailer into a position closing off st id discharge terminal to prevent are products discharged therethrough from returning, a metallic exhaust chamber extending from the lower end of said insulating housing and completely sealing off the same for receiving the are products from said fuse on blowing thereof, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

8. In an underground high voltage electric power dis tribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, an insulating liner within said insulating housing extending between said upper and lower terminals and surrounding said connecting conductor means and acting to protect said insulating housing from the heat of an are drawn from said lower terminal on withdrawal of said connecting conductor means under load, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

9. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescopcd with the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, an insulating liner within said insulating housing extending between said upper and lower terminals and surrounding said connecting conductor means and acting to protect said insulating housing from the heat of an are drawn from said lower terminal on withdrawal of said connecting conductor means under load, means removably mounting said liner between said terminals, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

10. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, an insulating housing having its upper end telescoped within the lower end of said access tube and a sealed connection therebetween, a pair of vertically spaced insulating arms extending laterally from said insulating housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, insulation surrounding each connection between a terminal member and the respective insulated conductor, a metallic shield around said insulation for each connection, a ground rod extending downwardly through said access tube past said insulating housing and connected to said metallic shields, upper and lower terminals in said insulating housing connected to the respective inner ends of said terminal members, connecting conductor means within said insulating housing for detachably interconnecting said upper and lower terminals, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

ll. In combination, a tubular insulating housing having a terminal at one end, an expulsion fuse slidably mounted within said housing and having a discharge terminal at one end normally in contact engagement with said terminal on said insulating housing and movable with said expulsion fuse into said housing, a tubular trailer of insulating material slidably mounted relative to said dis charge terminal and arranged when drawn into said housing with said expulsion fuse to have its outer surface juxtaposed to the inner surface of said housing, and a coil compression spring within said tubular trailer biasing it into a position closing off said discharge terminal to prevent are products discharged therethrough from returnmg.

12. The invention, as set forth in claim 11, wherein a metallic shield is mounted on the end of the trailer upon which the are products impinge.

13. The invention, as set forth in claim 11, wherein an exhaust chamber closed to the atmosphere is connected to the one end of the tubular insulating housing and constitutes an endwise extension thereof for receiving the are products from the discharge terminal on blowing of the expulsion fuse.

14. In combination, a tubular insulating housing carrying internal terminals in spaced relation therealong, an expulsion fuse having terminals engaging said terminals on said housing and movable endwise within said housing into and out of contact engagement therewith, one of said terminals of said expulsion fuse being a discharge terminal through which are products incident to blowing of the fuse flow, a trailer of insulation slidably mounted relative to said discharge terminal, and means biasing said trailer into a position closing off said discharge terminal to prevent said are products from returning into said expulsion fuse, movement of said expulsion fuse out of engagement with said terminals within said housing under load drawing an arc between said discharge terminal and the associated terminal within said housing which is confined between the inner surface of said housing and the outer surface of said trailer.

15. In combination, a tubular insulating housing carrying internal terminals in spaced relation therealong, an expulsion fuse having terminals engaging said terminals on said housing and movable endwise within said housing into and out of contact engagement therewith, one of said terminals of said expulsion fuse being a discharge terminal through which are products incident to blowing of the fuse flow, an exhaust chamber forming an extension of said housing to receive said are products, a trailer of insulation slidably mounted relative to said discharge terminal, and means biasing said trailer into a position clos ing off said discharge terminal to prevent said arc products discharged into said exhaust chamber from returning into 3. l c said expulsion fuse, movement of said expulsion fuse out of engagement with said terminals within said housing under load drawing an are between said discharge terminal and the associated terminal within said housing which is confined between the inner surface of said housing and the outer surface of said trailer.

16. in an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination, an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, a housing having its upper end joining with the lower end of said access tube and a sealed connection thereoetween, a pair of vertically spaced insulating arms extending laterally from said housing toward said insulated conductors having a terminal member within each arm for connection at its outer end to the respective conductor, upper and lower terminals in said housing connected to the respective inner ends of said terminal members, connecting conductor means within said housing for detachably interconnecting said upper and lower terminals, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through 25 said access tube.

17. In an underground high voltage electric power distribution system including a pair of buried insulated conductors having one end of each in close proximity, in combination; an access tube for extending upwardly from the vicinity of said ends of said conductors to ground level, a housing having a sealed connection to the lower end of said access tube, upper and lower terminals in said housing in insulated spaced relation and aligned with said access tube, means for electrically connecting said upper and lower terminals to said ends respectively of said buried insulated conductors, connecting conductor means having electrically connected upper and lower ferrules for detachable engagement respectively with said upper and lower terminals, and attachment means at the upper end of said connecting conductor means for receiving an operating member inserted in said access tube from its upper end to apply and remove said connecting conductor means through said access tube.

References Cited in the file of this patent

Claims (1)

17. IN AN UNDERGROUND HIGH VOLTAGE ELECTRIC POWER DISTRIBUTION SYSTEM INCLUDING A PAIR OF BURIED INSULATED CONDUCTORS HAVING ONE END OF EACH IN CLOSE PROXIMITY, IN COMBINATION; AN ACCESS TUBE FOR EXTENDING UPWARDLY FROM THE VICINITY OF SAID ENDS OF SAID CONDUCTORS TO GROUND LEVEL, A HOUSING HAVING A SEALED CONNECTION TO THE LOWER END OF SAID ACCESS TUBE, UPPER AND LOWER TERMINALS IN SAID HOUSING IN INSULATED SPACED RELATION AND ALIGNED WITH SAID ACCESS TUBE, MEANS FOR ELECTRICALLY CONNECTING SAID UPPER AND LOWER TERMINALS TO SAID ENDS RESPECTIVELY OF SAID BURIED INSULATED CONDUCTORS, CONNECTING CONDUCTOR MEANS HAVING ELECTRICALLY CONNECTED UPPER AND LOWER FERRULES FOR DETACHABLE ENGAGEMENT RESPECTIVELY WITH SAID UPPER AND LOWER TERMINALS, AND ATTACHMENT MEANS AT THE UPPER END OF SAID CONNECTING CONDUCTOR MEANS FOR RECEIVING AN OPERATING MEMBER INSERTED IN SAID ACCESS TUBE FROM ITS UPPER END TO APPLY AND REMOVE SAID CONNECTING CONDUCTOR MEANS THROUGH SAID ACCESS TUBE.

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