US2374048A - Apparatus for installing and removing electric-power lines - Google Patents

Description

April 17, 1945.

- APPARATUS FOR P. S-TAHELI I 2,374,048

INSTALLING AND REMOVING ELECTRIC-POWER LINES Filed April 19, 1944 4 ShGetS -Sheet 1 \NVENTOR PAUL STAHEU Wm J22 ATTO R N EYS P. STAHELI April 17, 1945.

APPARATUS FOR INSTALLING AND REMOVING ELECTRIC-POWER LINES Filed April 19, 1944 4 Sheets-Sheet 2 INVENTOR PAULSTAHE ATTURNEYS April 17, 1945. I P. STAHELI 2,374,043

APPARATUS FOR INSTALLING AND REMOVING ELECTRIC-POWER LINES Filed April 19, 1944 4 Sheets-Sheet 3 \NVENTOR 10$, PAUL sTAHEu mflw m ATTORNEYS April 17, 1945. P. STAHELI ,048

I APPARATUS FOR INSTALLING AND REMOVING ELECTRIC-POWER LINES Filed April 19, 1944 4 Sheets-Sheet 4 3 b .nm) 0 o O 27 E6 E4 I 51 \NVENTOR 51 PAUL STAH L F167 MMM ATTORNEYS Patented Apr. 17, 1945 APPARATUS FOR INSTALLING AND REMOV- ING ELECTRIC-POWER LINES Paul Staheli, Arvida, Quebec, Canada Application- April 19, 1944, SerialNo. 531,836 I In Canada March 4, 1944 8 Claims.

This invention; relates to the installation and removal of-v electric-power. lines andhas particular reference totransmission and distribution lines which. are suspended from their supports by suspension insulators commonly known as strain insulators. The object of the invention is to simplify the procedure of installing and removing such power lines, and to lessen danger of injury to the conducting cable by the apparatus employedfor raising and lowering saidcable during, installation and removal thereof.

The apparatus heretofore employed for installing and removing the electric power lines mentioned herein involves the use of a cable grip which is. applied directly to the conducting cable and forms part of the cable raisingv and lowering means. When: the power line is being installed it is raised by a hoisting line having one end attached to the cable grip and the other end attached to tractor or winch, the intermediate portion of the hoisting line being trained over a pulley block positioned, adjacent the point on one of the supporting structures from which the power line is to be strained by strain insulators attached thereto. The strain insulators are usually coupled together to form what is commonly termed the insulator string, the cable being attached. to the insulator at one end of the string by means of: a strain clamp and the insulator at the other end of. the string being attached to the pole, tower, or other supporting structure after the power line has been suitably raised by the cable grip and the hoisting line. The cable grip is usually attached to the power line immediately adjacent the clamp connection between the power line andthe insulator string.

In removing the power line the cable grip of the hoisting line is first attached to the power line to raise the same slightly to thereby relax the cable string and facilitate detachment of said stringfrom the supporting structure to which it is anchored. The released portion of the cable is then lowered toward the groundby the cable grip and the hoisting line.

In using the foregoing conventional apparatus it is necessary, during installation of the cable, to provide an additional pulling line for raising the relatively heavy insulator string to bring the insulator at the free end of the stringclose to its point of attachment to the supporting structure from which the cable is being strained. It is also necessary to provide a strain seat to enable the linemen to reach and. detach the cable grip from the power line afterthe latter has been supported in place by anchorage of the cable string to the supporting structure.

It will be understood that the foregoing operations are repeated in connection with the raising and lowering of each portion of the cable to which an insulator string is attached for the purpose of straining said portion of the cable from a cable supporting pole, tower, or other supporting structure.

It may also be pointed out that, particularly in the case ofpower lines in which the conducting cable is made of aluminum, injury to the cable sometimes results from the direct attachment of the cable grip thereto.

The present invention eliminates the necessity of using the above mentioned insulator pulling line and strain seat and thereby simplifies the procedure by reducing both the amount of apparatus and the number of operations required for installing and removing the power lines. These advantages, as well as the elimination of injury to the conducting cable, are realized by providing an insulator clamp through the agency of which a single hoisting and lowering line is attached to an insulator located at or adjacent the free end of one of the insulator strings associated with the cable. When the cable is raised with this arrangement the insulator string is brought into convenient reach of the lineman by the single hoisting line and he has no difiiculty in raising the fewinsulators located above the point of attachment of the pick-up and is therefore enabled to fasten the insulator string to the tower or other support without resorting to the use of the extra insulator pulling line heretofore required. The same advantage obtains in releasing the cable from its support since the lineman needs no strain seat for reaching the insulator to which the insulator grip is attached prior to releasing the string from its support.

Proceeding now to a more detailed description of this invention reference will be had to the accompanying drawings, wherein- Fig; l is a View of a typical power line installation wherein the. cable is strained from dead end or anchor towers.

Fig. 2 is a, View illustrating the application of my invention in connection with the installation shown in Fig. 1.

Fig. 1a is a view of a typical power line installation wherein the cable is held by strings of suspension insulators hanging vertically from their points of support on the tower.

Fig. 2a is a view illustrating the application of my invention in connection with the installation shown in Fig. la.

Fig. 3 is a perspective view showing my improved insulator grip clamped in place about the cap portion of one of the insulators of a conventional insulator string.

Fig. 4 is a perspective view showing the manher in which the two halves of the insulator grip are fitted around the cap portion of an insulator prior to being bolted together and equipped with suspension shackles.

Fig. 5 is a perspective view of the insulator grip per se showing the two half sections of the grip in slightly separated relation, the suspension shackles being omitted.

Fig. 6 is a perspective view of that half section of the insulator grip which carries the bolts for fastening the grip in place about an insulator.

Fig. '7 is a perspective view of the half section of the insulator which is provided with threaded sockets to receive the clamping bolts shown in Fig. 6.

Fig. 8 is a top plan view of the insulator grip per se showing the two half sections bolted 'together, the suspension shackles being omitted.

Fig. 9 is a sectional view along the line 9.9 of Fig. 8.

Fig. 10 is a sectional view along the line lD lll of Fig. 8. I

That portion of a typical power line installation which is shown in'Fig. 1 comprises a conducting cable 5, supporting towers 6 and I, and insulator strings 8 and 9 straining the cable from said towers. Each insulator string comprises a series of conventional insulators l coupled together in conventional fashion, one end of the string being clamped to the cable and the other end being anchored to one of said towers.

In Fig. 21 have shown how my invention is applied for raising or lowering a portion of the cable to which one of the insulator strings is attached. In this instance an insulator pickup, generally indicated at 12, is shown clamped in place about the cap portion I 0a of an insulator forming part of the insulator string 8 which is shown detached from the tower 6 to which it is anchored in the installed condition of the power line. The pick-up I2 i preferably applied to an intermediate insulator of the string which is not too far distant from the terminal insulator which is to be anchored to the tower. For example, the pick-up may be applied to the second, third,

or fourth insulator from'the tower end of the string.

The pick-up I2 is attached, by the shackles l3 and sling M, to one end of a hoisting line !5 which is passed over a pulley block l5 and has its other end attached to a tractor, winch, or other suitable hoist line operating means (not shown). The pulley block l6 may be mounted .in any conventional manner but should be located relatively close to the point where the tower end of the insulator string 8 is anchored to the tower 6 when the power line is installed.

Assuming that the power line shown in Fig. 2

isbeing installed the hoist line i5 is operated from the bolt hole 40.

in releasing the power line from each of its supporting towers is equally simple. The lineman on the tower from which the line is to be released and lowered attaches the insulator pick-up I2 to an insulator l0 within convenient reach and the hoist line I5 is then operated to lower the released portion of the line toward the ground.

The specific construction of the insulator pick-up constitutes an important feature of my invention and is clearly illustrated in Figs. 3

to 10 inclusive.

In its preferred form the insulator pick-up l2 comprises two half sections respectively indicated at 20 and 2 I. Each half section includes an intermediate substantially circular insulatorcap gripping portion 22 and two terminal wing extensions 23. Each semi-circular portion is formed with an inwardly directed and substantially horizontal seat-forming flange 24 and with two vertically disposed inwardly directed lugs 25. The flange 24 is located at the lower edge of the semi-circular portion 22 and has its inner edgeportion bevelled or curved as indicated at 26. The lugs 25 are located at opposite ends of the semi-circular portion 22 in substantial alignment with the wing extensions 23. Each Wing extension 23 is provided, near its outer end, with a bolt hole 21 and a shackle stop 28. A fibre guard 29 is fitted over the upper edge of each wing extension 23 a slight distance inwardly from the shackle stop 28 and is riveted or otherwise secured in place.

The wing extensions 23 of grip section 20 are provided with bolt holes 3| in line with internally threaded bosses 32 projecting from the outer sides of said wing extensions.

The wing extensions 23 of grip section 2| carry two threaded clamping bolts by means of which the two halves of the grip are fastened together. As shown more particularly'in Figs. 5 and 10, each bolt comprises a head 35, a relatively large shank portion 36, a relatively small shank .por tion 31 and a threaded portion 38. The relatively small shank portion 31 connects the relatively large shank portion 36 and the threaded portion 38 and is slidable in a bolt hole 40. The relatively small shank portion 31 is also slidable in the slot 4| of a keeper plate 42 which partially covers the outer end of bolt hole 40. The threaded portion 38 of the bolt is slightly larger than the shank portion 31 and affords a shoulder 44 which engages thep-late 42 to prevent the threaded portion being completely withdrawn The shank portion 36 also provides a shoulder 45 which engages the outer side of the plate 42 when the bolt is screwed home during the fastening together of the two parts of the pick-up.

The pick-up described herein is applied in the following manner: The semi-circular portions of the two half sections 20 and 2| are fitted to the cap Illa of the insulator I0 so that the inner edges of the seat-forming flanges 24 fit against and support the lower curved surface 48 of the can (see Fig. 9) which lies below the cap ridge t9, the oppositely disposed lugs 25 of each cap section being fitted against the curved upper por tion 50 of the cap which .lies above said ridge. It is important to note here that the seat-forming flanges 24 engage and support the lower curved surface of the cap Illa above the point where the cap meets the porcelaindisc 10b. After being thus engaged with the cap portion of the insulator the two semi-circular portions 22 of the grip are clamped iii-place by the previously mentioned clamping bolts, the threaded ends of which are passed through the bolt holes 3! or" section 25) and into the internally threaded bosses 32. The bolts are screwed into the bosses until the Shoulders 45 provided by the relatively large shank portions 36 of the bolts are clamped tight-' 13 against the flanges 23'of pick-up section 2|.

After the pick-up member has thus been secured to the-insulator cap itis fastened to the sling H} by" means of the shackles l3 which are secured to the wing extensions 23 by bolts 52 which are passed through the bolt holes 2': provided for this purpose and are secured in place by cotter pins or other fastenin means.

' The lugs 25 of the insulator pick-up serve to prevent or limittilting movement of the picl -up relative to the insulator cap to which it applies and thus reduces the danger of the pick-up being tilted into damaging contact with the'porcelain disc lb of the insulator located above the one to'which the grip is fastened. The lugs 25 also serve as alignment members for the pick-up and ensure correct distribution of stress from the semi-circular portions 22 to the Wing extensions 23.

The fibre guards 29 attached to the wing extensions of the grip serve to prevent damage to the porcelain disc Illb of .the insulator located above the pick-up in the event of tilting movement of the pick-up relative to said disc. These guards prevent the metal of the pick-up from coming in direct contact with the overlying porcelain insulating disc.

The two half sections of the pick-up described herein may be made of steel, iron, aluminur magnesium or any other material having the strength and other requisite properties.

In the case of the installation shown in Figs. 1a and 2a the pick-up device may be used in the following way: In the event of the necessity of replacing a defective insulator in one of the insulator strings, the pick-up device is attached to the insulator immediately below the defective one with the hoisting line running from the pickup sling l4 through a pulley block on the tower. The whole assembly is then raised to relieve the tension sulnciently to enable easy removal and replacement of the defective insulator. The pick-up device may also be used in all cases for lowering the cable to the ground.

Having thus described what I now consider to be the preferred embodiments of this invention it will be understood that various modifications may be resorted to within the scope and spirit of the invention as defined by the appended claims.

Iclaim:

1. Cable raising and lowering apparatus for use in connection with the installation and re moval of electric-power cables which are su pended or strained from their supports by suspension or strain insulators attached to said cables, each said insulator comprising a metal can portion surmounting a disc made of insulating material, said apparatus comprising an insulator pick-up device composed of two sections shaped to lit around the cap portion of one of said in sulators in supporting engagement therewith, each of said sections including an intermediate semi-circular portion and terminal wing extensions, said semi-circular portion being provided with an inwardly directed seatforming ledge adapted to underlie and support the lower portion of the cap part of the insulator to which said device is applied, said semi-circular portion of each of said sections being also provided with inwardly directed vertically disposed lugs shaped to fit against the upper portion of the cap part e of the insulator to prevent tilting of the pick-11p device with respect to said insulator, means, including the wing extensions of said sections, for securing said sections together in grippin and supporting engagement with the interposed cap portion of the insulator to which the gripping device is applied.

2. An insulator supporting pick-up of the character described comprising two half sections, each comprising an intermediate and substantially 15 semi-circular gripping portion and terminal portions extending in opposite directions from the ends of said semi-circular portion, means for securing together the terminal portions of the two sections with the intermediate portions of said sections disposed opposite each other to jointly provide a substantially circular insulator gripping clamp and non-metallic guards fitted over the upper edges of the terminal portions of each of said sections.

3. An insulator pick-up of the character described comprising a pair of insulator clamping sections adapted to be secured together in gripping and supporting engagement with a, portion of an insulator interposed therebetween and a :m pair of bolts slidably and rotatably secured to one of said sections so that said bolts are free to slide and turn relative to said section but are prevented from being completely detached therefrom, the other of said sections being provided with threaded openings into which said bolts are threaded to secure said sections together in clamping engagement with the interposed insulator.

4. An insulator pick-up device for use in raising or lowering a string of insulators attached to an electric-power cable comprising a pair of insulator gripping sections adapted to be fitted around a portion of one of the component insulators of said string, means for fastening said sections together in gripping and supporting engagement with the insulator interposed therebetween, a pair of shackles, means for pivotally securing said shackles to said sections, shackle stops carried by said sections and arranged to prevent the shackles swinging into contact with and insulator located above the one to which the picl-11p device is attached and a hoisting line attached to said shackles.

5. An insulator pick-up device of the character described comprising a pair of sections each including a semi-circular intermediate portion shaped to fitaround a portion of an insulator in supporting engagement therewith and terminal portions extending in opposite directions from the ends of said semi-circular portion, the terminal portions of one section being provided with threaded bolt holes and the terminal portions of the companion section being provided with nonthreaded bolt holes adapted to be aligned with said threaded holes, bolts passing through the non-threaded bolt holes of the last mentioned section and into threaded engagement with said threaded bolt holes, said bolts being capable of bothsliding and rotary movement in said nonthreaded bolt holes and means for securing said bolts against complete separation from the section in which the non-threaded bolt holes are provided.

6. An insulator pick-up device of the character described comprising two half sections adaptill ed to be fastened together in supporting and gripping engagement with a portion of an insulator interposed therebetween, each half section including a semi-circular portion shaped to fit around the interposed portion of the insulator and provided with (a) an inwardly directed ledge providing a supporting seat adapted to underlie the said interposed portion of the insulator in supporting engagement therewith and (b) inwardly directed vertically extending lugs adapted to bear against portions of the insulator extending upwardly above said seat-forming ledge and means for securing said sections together in gripping and supporting engagement with the portion of the insulator interposed therebetween.

'7. An insulator supporting pick-up of the character described comprising two half sections, each comprising an intermediate and substantially semi-circular gripping portion and terminal portions extending outwardly in opposite directions from the ends of said semi-circular portion, vertically disposed lugs extending inwardly from the opposite ends of the semi-circular portion of each section, and means for securing together the terminal portions of the two sections with the intermediate portions of said sections disposed opposite each other to jointly provide a substantially circular insulator gripping clamp.

8. An insulator supporting pick-up of the character described comprising two half sections, each comprising an intermediate and substantially semi-circular gripping portion and terminal portions extending in opposite directions from the ends of said semi-circular portion, a seat-forming ledge extending inwardly from the lower edge of the semi-circular portion of each of said sections, a pair of vertically disposed lugs extending inwardly from the opposite ends of each of said semi-circular portions and means for secur ing together the terminal portions of the two sections with the intermediate portions of said sections disposed opposite each other to jointly provide a substantially circular insulator gripping clamp.

PAUL STAHELI.

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