DE2308864A1 - HIGH VOLTAGE LINE - Google Patents

Description

CIBA-GEIGY AG. CH-4002 Bas «* i WiS ^ / A Vj ti VJI Y

AnwaObsakte 23 588 Feb. 22, 1973

Case 37-8633 / E

GERMANY

High voltage overhead line

The invention relates to a high-voltage overhead line in which the electrical conductor carrying Isolators are pivotably mounted on the masts or the like.

In the case of the known high-voltage lines, the conductors are suspended from the arms of the pylons using suspension insulators. These suspension insulators are practically only subjected to tensile loads. The ladder's suspension points are not stationary, but these suspension points move depending on the length of the suspension insulator from the vertical starting position, if, for example, an air flow is effective transversely to the direction of the conductor. The consequence of this shift is that the ladder is moving towards or away from the mast,

409832/0262

2308854

depending on the strength of the wind, the cause of the air flow is. A minimum distance between the ladders and the supporting masts despite the possible displacement of the suspension points to ensure it is necessary to extend the boom by the said displacement. The width of the route is wider to widen the double displacement path so that the minimum safety distance between the ladders and any Buildings, trees or other high-voltage lines are preserved. During the swinging out of the suspension insulators is disadvantageous across the course of the ladder, the possibility of swinging out in the direction of the ladder has a favorable effect on the Stress on the ladder itself and the masts.

So-called Isolation swing applied. Such an isolating rocker comprises two inclined suspension isolators, the lower ends of which are connected to one another are connected. The conductor is attached to the connection point. The top ends of the two hanging insulators are attached to the boom of the pylon so that they can be pivoted at a distance from each other, so that the two suspension insulators form a V. Such isolating swing prevents a shift of the suspension point in the direction transverse to the conductor run, during a Movement of the suspension point in the direction of the ladder is retained. The problem of the isolating rocker arises Therefore, in the case of a very strong crosswind, the force resulting from the weight and wind loads strongly against the vertical can be inclined, e.g. up to about 45 °. When the two

409832/0262

the isolators forming the isolating rocker are less inclined to the vertical than the resulting force occurs an axial compressive load in one of the two isolators. In the case of long insulators, relatively low axial Pressure loads lead to buckling.

To reduce the line width and to save the metal brackets (trusses) of the support masts further proposed so-called pivotable insulating crossbars. A swiveling insulating cross-member comes from an insulating rocker characterized in that the connecting line of the two insulator ends which are attached to the support mast so as to be pivotable at a distance the horizontal in the vertical or in a direction slightly inclined to the vertical. The metallic one As a result, the boom is either completely superfluous or shrinks at least to a very short jib. Such a one The insulating cross member has a tension insulator and a pressure insulator. During tensile isolators according to a permissible tensile stress of their material are to be dimensioned, one must dimension pressure insulators so that they are under the occurring Do not buckle the maximum axial compressive force. The resistance to buckling is not determined by the strength of the material, rather, it is determined by the modulus of elasticity of the material. Pressure isolators are therefore essential larger cross-sections than tension insulators. Train isolators generally endure compared to their portable ones Tensile loads only low compressive forces. One end of the mostly horizontal

409832/0262

zontally arranged pressure isolator and ι 1 of the horizontal inclined train insulators are connected to each other, and at this connection point is the conductor or a Ladder blind attached. The other ends of the tension or pressure isolator are usually 10 ° to 25 ° from the vertical inclined axis pivotably connected to the support mast.

This allows the suspension point to move in the direction of the

ι Ladder can move, but there is no significant approach of the suspension point to the pylons. If the pressure insulator and the tension insulator are of the same length, which makes sense for electrical reasons, the result of a horizontal arrangement of the pressure insulator is:

Pan,

that the axis is inclined at an angle to the vertical which is half the size of the angle formed between the pressure insulator and the tension insulator. The angle between Swivel «

the 'axis and the vertical is responsible for the behavior of the Insulating traverse under the forces acting at the connection point between the pressure insulator and the tension insulator, which be exercised by the ladder on the suspension point, determining. A major disadvantage of a pressure isolator and a The insulating crossbeam formed by a tensile isolator is its instability against high wind loads. This is expressed in the fact that the boom formed from the two insulators can fold down towards the mast if the relationship between the one directed towards the mast horizontal wind load and the vertical weight load of the conductor exceeds a certain limit. Around an impermissibly wide folding down of the insulating crossbars when

409832/0262

prevent this instability from occurring as a result of high wind loads, every third, fourth or fifth mast is necessarily guided with fixed ladder suspension points the end. In order to maintain a certain uniformity of the entire line, these fixed ladder suspension points are formed mostly in the form of a rigid tripod insulated rail. Such an insulating crossbar either includes a horizontal one running pressure insulator and two tension insulators or one tension insulator and two approximately horizontally running pressure insulators, which insulators represent a three-legged support. However, this results in a greater need for insulators and higher bending and twisting loads on the masts with rigid insulating crossbars, which means the 3au of a high-voltage line expensive.

The invention aims to create an overhead line which has the advantages of being equipped with insulating crossbars Has overhead lines, but avoids their disadvantages.

The high-voltage overhead line according to the invention is characterized in that when the insulator is unloaded a) the pivot axis and the longitudinal axis lie in a vertical plane perpendicular to the route, b) the pivot axis is inclined at an angle α ^ 30 to the vertical, c) the longitudinal axis around a larger angle α + β is inclined to the vertical, and d) the angle α + β has the relation \

4098 3 2/0262

45 '* ^ α + ρ <180 ° c.-flUJt, where e *> όοΐ attachment point of the Conductor on the insulator on a vertical running through it has a smaller distance from the ground than "the point of intersection this vertical with the pivot axis.

The new type of swivel mounting of the isolators behaves kinematically in the same way or at least similarly to the known isolating rocker, but this advantageous kinematics is achieved with significantly less constructive effort. In the overhead line according to the invention, no or only very small brackets and only a single insulator per conductor or conductor bundle are required to hold or support the conductors on the support mast. Further advantages of the subject matter of the invention are explained below.

In the following the invention is explained in more detail with reference to the drawings, for example; show it:

Fig. 1 to 3 three exemplary embodiments of the bei.der invented

according to the overhead line used novel pivot bearings of the insulators in part on average,

Fig. 4 shows a section along the line IV-IV of Fig. 3, Fig. 5 and 6 each one exemplary embodiment of a complete

Support mast in view in the direction of the route.

The insulator shown in Fig. 1 for trimming a non-shown conductor on an only partially drawn T :. mast 1 has a core 2 acting as a flexible beam

409832/0262

a unidirectional glass fiber reinforced plastic. With the exception of its edge areas, the core has a jacket 3 surrounded, which has a sufficiently long creepage path due to the formation of insulator screens 4. The coat 3 will preferably obtained by casting the core 2 with a casting resin which is flexible enough to allow the core to be able to endure certain elongations without cracking.

One end of the core 2 is surrounded by an end cap 5 which has a bore 6 for attaching the not shown Has conductor. The end cap 5 is firmly connected to the core 2 with a binding agent 7 and is the separation point between the jacket 3 and the end cap 5 is closed with a sealant 8 so that no moisture to Core 2 can get.

The other end of the core 2 is in a metal sleeve 9 embedded, in which it is held rigid with the binder 7. The separation point between the metal sleeve 9 and the jacket 3 is closed with the sealant 8 in a moisture-proof manner. On the side facing away from the jacket 3 is the Metal sleeve 9 closed and provided with a pivot pin 10 inclined to the longitudinal axis of the core 2.

A bearing bush 11 is arranged on the support mast 1, via a flange 12 welded to it and is rigidly connected to the support mast 1 by means of screws 13. The axis 14 of the bearing bush 11 closes with the vertical

409832/0262

2108864

kalen V has an effect} c *, which can amount to CO, for example can. The end of the pivot pin 10 is provided with a thread 15, so that a nut 16 and a lock nut 17 on the 'thread 15 can be screwed so that the The pivot pin 10 is freely rotatably mounted in the bearing bush 11. The free end of essentially the pivot pin 10, the metal sleeve 9, the core 2, the jacket 3 and the end cap 5 comprehensive isolator protrudes downwards. The longitudinal axis L of the core 2 encloses an acute angle # ', for example 15 °, with the horizontal H, and is about the axis 14 of the bearing bush 11 or the pivot pin 10 can be pivoted. Between the angle ST and that also shown in the figure Angle / between the vertical V and the longitudinal axis L of the isolator there is the relationship γ = α + β - 90.

The insulator shown in FIG. 1 is for use for lines; whose operating voltage is less than 110 kV. This isolator can therefore be made relatively short, so that one need not be very concerned because of the axial pressure load on the shaft 2 which occasionally occurs when there is wind load, because the tendency of short isolators to buckle is low. According to this execution ?. For example, the angle tf "between the horizontal and the longitudinal axis of the insulator was chosen to be 15 ° in order to save on the height of the support mast 1. In order that a sufficiently large swivel radius r results, the axis of rotation is at an angle c <65 ° from the vertical inclined so that one is still

409832/0262

gives sufficient stability against high wind loads.

Fig. 2 shows a second exemplary embodiment an isolator mounting according to the invention. In this figure

! St ZUy

/ note that the part represented by the support mast 1 in Reality practically vertical and that the pivot axis 14 runs horizontally. The pivot axis 14 is arranged horizontally, although an inclination of the pivot axis relative to the horizontal of up to 20 ° is sufficient Would ensure stability against very high wind loads.

When choosing the angle of inclination Sf between the longitudinal axis of the insulator with respect to the horizontal, it should be noted that the more the insulator is inclined, the lower its bending stress, which is dependent on the weight of the conductor and the ice load. At an angle ίΓ = 45 °, the limit is usually reached at which the safety distance between the ladder and the support mast would be too small. The smaller you choose the angle of inclination £, the more mast height can be saved, but the smaller the * pivotability of the isolator with a one-sided conductor run, because the radius r of the pivoting movement is reduced (see also Fig. 1). The most important aspect for the choice of the angle of inclination if is the following: It must be ensured that in addition to the bending stress, no or only relatively small axial compressive loads can occur on the core 22, which acts as a bending beam, and these compressive loads should never act for a long time. A bending stress with

409832/0262

an additional axial compressive load can lead to kink-bending to lead.

In the isolator arrangement according to the invention, the fact,
The fact that the insulator is pendulous and not rigidly connected to the mast, the possibility to influence the cost of materials and the electrical functionality favorably through sensible shaping. Since the isolator is pivotably connected to the support mast, all forces acting on this isolator lie in a plane running through the pivot axis 14 and the longitudinal axis of the isolator. If a unilateral conductor run occurs, the isolator follows this force by pivoting until the resulting force acting on the isolator is again in the plane formed by the longitudinal axis of the isolator and the pivot axis 14. The reason for this is as follows: The load application point, ie the point at which the conductor (not shown) is attached to the insulator, lies in the plane formed by the pivot axis 14 and the longitudinal axis of the insulator. As long as the resulting force is not also in this plane, it exerts a torque on the isolator with respect to its pivot axis and therefore pivots the same. This means that the swivel movement not only significantly reduces the one-sided conductor run, but that the insulator also inevitably adjusts itself so that the bending forces always occur in one and the same plane of the insulator.

409832/0262

This affects the dimensioning of the isolator extraordinarily favorable because of the fact Use can be made of the fact that with bending beams that are only ever stressed in one plane, the minimum amount of material required can achieve a relatively narrow but high cross-sectional profile. The core acting as a bending beam is accordingly the Auflihrungsbeispieles according to Fig. 2 is conical, the support mast 1, the thicker end and not shown Head the thinner end facing. The cross section of the core 22 is based on an approximately circular shape on the outside End into a cross-section composed of a rectangle and two semicircles at the other end, whereby the radius of the circular cross-section is equal to the radius of the two semicircles. So the width of the core is The same over its entire length while its height increases linearly.

The bending moment acting on the end of the core 22 associated with the support mast 1 is controlled by the metal sleeve 29 added because the end of the core 22 is embedded in the metal sleeve 29. In this end piece of the core 22 arise very high lateral support forces directed transversely to the beam axis, which make a dimensioning of this end piece necessary for permissible interlaminar shear stresses. The core 22 becomes preferably made of predominantly unidirectional glass fiber reinforced Epoxy resin made with a glass fiber volume fraction of about 60%.

409832/0262

2305364

On one side, the metal sleeve 29 is through a Bearing bush 21 completed, which is used to hold a on the pylon 1 rigidly attached pivot pin 20 is used. This can extend transversely through the mast 1, which is advantageous be designed as a conical steel or light metal tubular mast can, wherein at the end of the pivot pin 20, not shown, a further insulator, not shown, is pivotally mounted can be. The end of the pivot pin 20 protruding into the bearing sleeve 21 is partially conical and has two cylindrical parts 18, which are arranged in the bearing bushing 21 maintenance-free plain bearings from a self-lubricating Bearing metal alloy are surrounded. The end of the pivot pin 20 is threaded onto which a castle nut 26 is screwed on, which prevents the bearing bush 21 from separating from the pivot pin 20. That The thread and the castle nut 26 are covered by a cap 19 to protect them from the effects of the weather. This in the metal sleeve 29 protruding end of the core 22 is supported by two rings made of high-strength potting compound or filled binder 7 held and the remaining space is filled with a soft casting compound 8.

Particular care is taken in the training of the transition point Dedicated from the metal sleeve 29 to the elastic jacket 23 made of cast resin. The one facing this connection point The end of the metal sleeve 29 is provided with an inner and an outer bead 27. The first insulator screen 28 of the

409832/0262

2303864

Jacket 23 is adapted to the shape of the outer bead 27 and glued to the outer bead. This design creates the elastic jacket 23 the possibility of radial deformation and bending without excessive stresses to adapt to the rigid metal sleeve for every temperature and load condition. Furthermore, the large collar-like effect Conclusion of the metal sleeve 29 favorably on the electrical stress on the insulating jacket 23, because the from Leakage currents flowing from the metal sleeve onto the insulating jacket onto a large plastic surface from the outset are distributed and from the outer bead 27 of the metal sleeve 29 emanating glow discharges into the air away from the jacket 23 being held. The bounded by the inner and the outer bead 27 and the first insulator screen 28 of the jacket 23 Space is filled with a fine-pored foam 30.

The end cap 25 is placed on the other end of the core 22. The diameter of this end of the core 22 increases towards the outside, so that together with the conical design of the interior of the end cap 25 and the high-strength potting compound 7 a form-fitting connection is created. The end cap 25 is the last insulator screen of the jacket 23 encompassing bead 31 is provided, and the space enclosed by these two parts is made of fine-pored foam 30 filled up. On the end face of the end cap 25, two tabs 32, each with a bore 33, are arranged. These tabs 32 are used to attach a clamping device, not shown, for the conductor, also not shown.

409832/0262

The isolator described with reference to FIG. 2 is suitable

for the construction of a high-voltage line with an operating voltage of 110 kV.

In Figs. 3 and 4 is a further Ausihrungsbeispiel an insulator to support a two-wire blind ISY a high-voltage pylon, which insulator is suitable for the construction of a 380 kV high-voltage line suitable. If one would for this isolator a similar design of the bearing on the support mast as for the one above Choosing an isolator described with reference to Fig. 2 would make it very heavy and cumbersome for assembly Formations drove. The thicker end of the likewise conical core 34 is anchored in the metal sleeve 35, the one side is closed with a lid. The part of the located between the metal sleeve 35 and the end cap 36 Core 34 is surrounded by a jacket 37 with insulating screens 38. On a small, only partially drawn boom

39 of the support mast, not shown, are two pivot bolts

40 arranged, the pivot axis 14 defined by these pivot bolts extending horizontally in the assembled state of the isolator. Each pivot pin 40 is from a bearing sleeve 41 surrounded. These bearing sleeves are connected to a fork-shaped coupling device 43 via connecting links 42 rigidly connected so that the bearing bushes 41, the coupling device 43 and the connecting links 42 form a bearing block 44 which is detachably connected to the metal sleeve 35.

409832/0262

At the closed end of the metal sleeve 35 is a Metal sleeve-encompassing ring with a tab 45 welded on, which extends into the fork of the coupling device 43 and is connected to it via a bolt 46. At A bracket 47 is attached to the bearing bushing 41 adjacent to the metal sleeve 35, through which the open end of the metal sleeve 35 is supported. The angled ends of the Bligel 47 are attached to further straps attached to the metal sleeve screwed on, whereby the metal sleeve 35 is rigidly but detachably connected to the bearing block 44, so that the insulator only is pivotable about the pivot axis 14.

During assembly, the boom 39 is first attached to the mast, followed by the bearing block 44 the pivot pin 40 is placed, then the tab 45 of the metal sleeve 35 is inserted into the fork of the coupling device 43 and secured with the bolt 46, and finally the metal sleeve 35 is pivoted so that part of it is attached to the Bail 47 rests and can be screwed to this.

The releasable connection between the bearing block 44 and the metal sleeve 35 not only allows assembly facilitate, but also simplifies the manufacture and transport of the isolator, because during embedding of the core 34 in the metal sleeve 35 and the transport of the heavy and bulky bearing block 44 not yet with the metal sleeve 35 is connected.

409832/0262

In the case of large insulators, the core 34 is preferably reinforced by glass fiber reinforced by layered and glued together Plates formed. The core 34 is then to a certain extent laminated, the glue joints being arranged parallel to the plane of the drawing in FIG. 3. With this type of Manufacturing the core means there is no additional effort between the glass fiber reinforced plastic sheets to insert a plate reinforced with high tensile organic fibers in order to make it possible for an overly large one Stress on the insulator, the core may break partially but cannot fall off.

In the case of the insulators described above, the loads caused by the conductors, the dead weight, become a possible ice load and a wind load, not exclusively as with the insulators customary on high-voltage line support masts up to now as axial forces, but mainly transmitted to the mast by bending the insulator. For insulator lengths, which are required for voltages of 110 kV, 220 kV or 380 kV, and large mast spacings result on the insulator Bending moments so high that these insulators are not made of the usual insulator materials such as porcelain and glass, can be produced. By using high-strength, unidirectional glass fiber reinforced plastic as the core of the Isolators, however, isolators up to voltages of at least 400 kV can be implemented. But above all, the Isolator described above the serious disadvantage so-called insulating traverse, i.e. its kinematically determined

409832/0262

- 17 - 2308364

Instability at high wind loads, completely overcome. if If you arrange the isolator with a horizontal swivel axis on the support mast, you get a completely wind-stable suspension the ladder achieved as it was previously only suspended from a very large metal bracket Isolating rocker has been reached. The unconditional stability against high wind loads is ensured by energy supply companies Great importance is attached, since in unusual storms wind loads can certainly occur that are greater are than the weight loads of the ladder resulting from its own weight. When using the isolators described above with a horizontally running swivel axis, from the point of view of stability, with straight line routing, any Many masts can be lined up without interruption by masts with fixed ladder suspension points.

The inclined arrangement of the isolators described above is advantageous for self-cleaning by rain and wind. With regard to this self-cleaning, the angle of inclination (Γ of the insulator against the horizontal) should not be made larger than necessary Are insulating crossbars.

If the bending load is excessive, the

Lever arm of the bending force due to the deflection of the core

Y> 30 ° / f

y Y

noticeable, especially when the load is directed vertically

409832/0262

2303364

is what is the case with its own weight and fiisload. Any breakage of the isolator is essentially due to the pressure zone limited and here, too, there is no brittle fracture, but rather a fibrous brush fracture with delamination occurs a lot of work is done. Therefore it is practically impossible that an isolator described above is completely breaks off, especially if the core of the core contains highly stretchable organic fibers, as mentioned above.

In FIG. 5, a high-voltage line support mast 49 is shown, which has been described above with reference to FIG Is equipped with isolators. The bearing bushes 21 of the insulators are on the invisible ends of the masts

49 traversing trunnions symmetrically on both sides of the mast arranged. The lines leading down from the outer ends of the insulators indicate the slack in the conductors

50 at. The middle isolators are arranged on a relatively short cantilever 51, whereby the vertical distance between the middle ladders and the ladders above and below it. This allows to reduce the overall height of the mast 49. The route required for such a high-voltage line is extreme narrow, which leads to a significant cost saving in the construction of such a high-voltage line.

6 shows a further exemplary embodiment of a line pole 52 which, in addition to the above-described Insulators additionally with known insulating

409832/0262

- 19 - 230S86A

swing 53 is provided. Such a combination of diverse Insulators stacked a shorter line pole to use. However, this advantage can only be achieved with the disadvantage of a somewhat wider route, which is The disadvantage, however, is not so important in open terrain.

409832/0262

Claims (20)

'- 20 OBLIGATION Γ 1. J high-voltage overhead line, in which the insulators carrying the electrical conductors can pivot on the / loads or the like. are stored, characterized in that when the isolator is unloaded: a) the pivot axis (14) and the longitudinal axis (L) of the isolator in a perpendicular to the route
Lie vertical plane, b) the pivot axis at an angle
α > 50 ° to the vertical (V) is inclined, c) the longitudinal axis is inclined by a larger angle α + β to the vertical, and d) the angle α + β has the relationship 45 ° <α "+ ß <180 ° met, where e) the attachment point (6) of the conductor on
Insulator on a vertical running through it
has a smaller distance from the ground than the intersection of this vertical with the pivot axis. 2. Overhead line according to claim 1, characterized in that the angle α is in the range of approximately 45 to 90 °. 3. Overhead line according to claim 1 or 2, characterized in that the angle β in the range of about 30 ° to 60 ° lies. 4. Overhead line according to claim 1, characterized in that that the angle α = 90. 5. Overhead line according to claim 4, characterized in that the angle β is in the range from approximately JO ⁰ to 50 °. 409832/0262 2308854 ~ 21 - 6. Overhead line according to claim 4, characterized in that that the angle β = 40. 7. Overhead line according to one of the preceding .Ansprüche, thereby characterized in that the shank of the insulator has a cross section which is symmetrical to that through the longitudinal axis of the isolator and the pivot axis (14) extending plane and parallel to this plane a greater extent has than in the planes which are perpendicular to the plane extending through the longitudinal axis and the pivot axis. 8. Overhead line according to one of the preceding claims, characterized in that the insulator has a core (2) glass fiber reinforced plastic has that this core is surrounded by a jacket made of flexible, electrically insulating plastic and is firmly connected to this, and that the jacket (3) is provided with screens (4). 9. Overhead line according to claim 8, characterized in that that the core (2) acting as a bending beam is made of uniairectional glass fiber reinforced epoxy resin with a glass fiber voluxer share from 50 to 70; S consists. 10. Overhead line according to dependent claim 3, characterized in that that the core (2) of the insulator consists of a number of glass fiber reinforced plastic sheets stacked on top of one another is glued together, the glue joints parallel to that through the longitudinal axis of the isolator and the pivot axis 409832/0262 2308964 • - 22 - running plane. 11. Overhead line according to claim 10, characterized in that to avoid the complete Abreche-ns "one Part of the insulator in the event of an overload, the innermost plate contains plastic-bound, highly stretchable organic fibers. 12. Overhead line according to one of the preceding claims, characterized in that the insulator or its core is conical, that the cross section of the core of an approximate circular shape merges at one end into a cross-section of a rectangle and two semicircles, and that the radius of the circle and the semicircles are equal. 13. Overhead line according to one of the preceding claims, characterized in that the mast-side insulator end is encapsulated in a metal sleeve (29) that the cross-section of the part of the insulator or core embedded in the metal sleeve is constant that the line-side insulator end is provided with an end cap (25), and that the cross section of the part of the insulator or end cap protruding into this end cap Kernes to obtain a positive connection against the end of the insulator or core increases. 14. Overhead line according to claim 8, characterized in that the jacket (23) provided with insulator screens (24) between the metal sleeve (29) and the end cap (25) extends that the metal sleeve at the end facing the jacket a 409832/0262 Has bead (27) which protrudes radially outward beyond the insulator shields, so that the insulator shield bena .ibarte the bead a Has annular groove into which the bead partially protrudes and on the contact surface thus formed with the adjacent Insulator screen is glued, and that one of the bead and the adjacent insulator screen delimited annular The cavity is filled with a fine-pored foam (8). 15. Overhead line according to claim 14, characterized in that the end cap (25) has an insulator screen adjacent to the same has comprehensive bead (31). 16. Overhead line according to one of claims 13 to 15, characterized in that the metal sleeve (29) in a bearing bush (21) opens out, and that within this bearing bush two plain bearings (18) with different inner diameters are arranged at a distance for receiving a pivot pin (20) attached to the support mast. 17. Overhead line according to claim 16, characterized in that that the bearing bush (41) is detachably connected to the metal sleeve (35) is. 18. Overhead line according to one of the preceding claims, characterized in that two bearing bushes (41) with common Axle for receiving two pivot pins (40) mounted on a boom (39) and a coupling device (43) for releasable fastening of the bearing bushes to the metal sleeve 409832/0262 (35) are provided, and that the bearing bushes and the plucking device via one or more connecting links Connecting links (42) are kept at a distance and form a bearing block (44). 19. Overhead line according to claim 18, characterized in that that the coupling device has a fork for receiving a bracket (45) rigidly connected to the metal tube (35) and a bolt (46) extending through bores in the fork and the bracket, and that on that of the metal sleeve A bracket (47) for screwing on the metal sleeve is arranged in the adjacent bearing bush. 20. Overhead line according to one of the preceding claims, characterized in that an insulator is pivotably arranged at each end of a pivot pin passing through the high-voltage line sma st. 409832/0262 Blank page