United States Patent [72] Inventors Akira Otsuki;

Kimikazu Numata, both of Tokyo, Japan [21] Appl. No. 64,735 [22] Filed Aug. 18, 1970 [45] Patented Nov. 30, 1971 [73] Assignee The Fujikura Cable Works, Ltd. Tokyo, Japan [32] Priorities Aug. 27, 1969 [33] Japan [31] 44/80782;

Aug. 28, 1969, Japan, No. 44/81225 [54] JUMPER ARRANGEMENT FOR OVERHEAD TRANSMISSION LINES 10 Claims, I 1 Drawing Figs.

[52] US. Cl 174/43 [51] Int. Cl 02g 7/00 [50] Field of Search 174/40 R, 43,45 R, 126 CP, 131 R; 191/40, 41;248/58,63; 339/222 [56] References Cited UNITED STATES PATENTS Stone t.

Primary Examiner Laramie E. Askin AltomeyFlynn & F rishauf ABSTRACT: In a jumper arrangement for an overhead electric power transmission line wherein conductors of the transmission line are secured to a power transmission tower through strain insulator string assemblies and conductors on the opposite sides of the tower are electrically interconnected by a jumper conductor, main parts of the jumper conductor are formed by a rigid jumper rod and each end of the jumper rod is connected with a supporting fixture interposed between the conductor of the transmission line and the strain insulator string assembly through a pivotally connected supporting means. The jumper rod is further connected to the conductor of the transmission line through at least one electroconductive flexible connecting wire.

PATENTED "W30 [9" SHEET 1 BF 4 FIG.

FIG.

PATENTED nuvao i9?! SHEET 2 BF 4 F|G.4 FIGS FIG. 6

PATENTED NOV30 l97| SHEET 3 BF 4 FIG. 7

FIGiO FIGH JUMPER ARRANGEMENT FOR OVERHEAD TRANSMISSION LINES This invention relates to a jumper arrangement for overhead electric power transmission lines.

Prior jumper arrangements for a single or multibundle conductor overhead electric power transmission line are usually made of a wire of the same type as the conductors strung in spans and are mounted on a power transmission tower to have a desired insulation distance from the tower. For example, a predetermined length of a jumper wire is cut at the construction site, jumper sockets are fitted under pressure to the op posite ends of the jumper wire, and the jumper sockets are connected to anchor clamps secured to the ends of the line conductors. However, this method of mounting involves many problems regarding the workability, saving of the cost, accuracy of the dimension, etc.

Although the clearances or spaces between the jumper wire and the tower or its arms are determined by considering the sag length of the jumper wire, the swinging movement of the jumper wire or the other movements of the power transmission line, it is essential to decrease as far as possible these clearances in order to decrease the size of the jumper device and the tower itself.

To this end, it is desirable to firmly secure the jumper wire or to construct it as a perfectly rigid body so as to prevent swinging movement or other movements from occurring. However, it is not permissible to firmly secure the jumper wire to the conductors or to construct the jumper wire as the perfect rigid body merely for the purpose of preventing the swinging movement or other movements, because the jumper wire is required to move in response to the variation in the catenary angle of the conductor and insulator string caused by temperature variations and various movements of conductor and insulator strings such as sleet-jump and galloping.

For this reason, it has been considered to manufacture the jumper arrangement in a factory, thus eliminating the field work of cutting the jumper wire to desired length as well as securing the jumper sockets. Such a prefabricated jumper arrangement can be fitted to the transmission conductors supported by the tower by means of bolts and nuts. Furthennore, it is highly desirable to provide an economical but efficient jumper arrangement capable of efficiently preventing the swinging movement of the jumper wire as well as the movement thereof due to uplift wind load and which in addition is readily capable of following the variation in the catenary angle of the conductor and insulator string, while maintaining a small clearance between the jumper wire and the tower.

It is an object of this invention to provide an improved jumper arrangement including a rigid jumper rod which can be cut and manufactured in a factory to have a desired length determined by the line angle or catenary angle thus simplifying the mounting operation at the construction site.

Another object of this invention is to provide an improved jumper arrangement capable of withstanding swinging movement as well as the movement of the conductor of the transmission line caused by uplift wind load, icing and so on.

A further object of this invention is to provide an improved jumper arrangement capable of following variations in the catenary angle of the conductor and insulator string caused by temperature variations and various movements of the conductor and insulator strings.

Another object of this invention is to provide an improved jumper arrangement including means to adjust the length of the connecting wire thus facilitating the mounting work of the jumper arrangement.

According to this invention there is provided a jumper arrangement for an overhead electric power transmission line of the type wherein conductors of the transmission line are secured to a power transmission tower through strain insulator string assemblies and the ends of the conductors on the opposite sides of the tower are electrically interconnected by a jumper conductor, said jumper arrangement being characterized in that the jumper conductor takes the form of a rigid jumper rod, and that each end of the jumper rod is connected with a supporting fixture interposed between the conductor of the transmission line and the strain insulator string assembly through a pivotally connected supporting means and to the conductor of the transmission line through at least one electroconductive flexible jointing wire.

In the drawings:

FIG. 1 is a side view of the jumper arrangement after it has been secured to a power transmission tower and conductors of an electric power transmission line;

FIG. 2 is an enlarged side view of a portion of the jumper arrangement shown in FIG. 1;

FIG. 3 shows a cross section of one example of a jumper rod utilized in the jumper arrangement;

FIG. 4 shows a cross section of a modified jumper rod;

FIG. 5 shows a cross section of another example of jumper rod;

FIG. 6 is a side view of a modified jumper arrangement after it has been secured in position;

FIG. 7 is an enlarged view to show the construction of the joints between the jumper rod, supporting means and connecting wires shown in FIG. 6;

FIG. 8 is a side view of another embodiment of this invention;

FIG. 9 is an enlarged side view of a portion of the embodiment shown in FIG. 8;

FIG. 10 is an enlarged side view, partly in section, of an adjusting fixture for adjusting the length of the supporting means adapted to support the jumper rod shown in FIG. 8; and

FIG. 11 is a sectional view taken along the line XI-XI in FIGS. 8 and 9 and viewed in the direction of arrows.

With reference now to the drawings, in the embodiment shown in FIGS. 1 and 2, there is provided a horizontal jumper rod 1 consisting of an aluminum pipe, for example. The jumper rod is cut into a predetermined length in a factory by taking into consideration various factors encountered in the construction site. The opposite ends of the jumper rod are supported by yoke plates or fittings 3 through supporting means 2. As best shown in FIG. 2, each end of the jumper rod 1 is connected with the lower end of a supporting means 2 through a link 4 pivotally connected to these means. One end of each fitting 3 is connected with an arm 7 secured to a tower 6 through a strain insulator string assembly 5 while the other end of the fitting 3 is connected with one end of main conductors ll successively through a yoke 8, sector shaped yoke plates 9 and anchor clamps 10. Further, each end of the jumper rod 1 is connected to the ends of the main conductors 11 through flexible connecting wires 12. The lower ends of flexible connecting wires 12 are connected to one end of the jumper rod 1 by connecting element 13 while the upper ends are connected to anchor clamps 10. Two connecting wires 12 are held spaced apart by means of a spacer 14.

As shown in FIG. 3, the jumper rod 1 may be comprised by a hollow tubular rod of rigid conductive material such as aluminum for example. Alternatively the jumper rod 1 may be comprised by a composite conductor including an outer aluminum pipe 1 and an inner iron pipe 40 as shown in FIG. 4 or a modified composite conductor including an aluminum pipe I, a helical core 30 of an iron strip contained in aluminum pipe 1 and an outer layer of stranded aluminum conductors 31.

Since the jumper rod 1 has sufficient rigidity it will not sag and can prevent swinging movement or other movements. For this reason, it is possible to always maintain constant clearances between the jumper rod and the tower as well as between said rod and the tower arm. In other words, even with a relatively small clearance between the jumper rod and the tower or its arm, there is no fear of shortening between the tower and the jumper rod thus enabling to reduce the size of the tower and jumper rod. Longitudinal movement of the jumper rod 1 permitted by the use of pivotally connected link 4 and flexible connecting wires 12 permits the connection between the jumper rod and main conductors to follow the variation in the catenary angle of the strain insulator string assembly 5 and main conductors 11 caused by temperature variation and the aforementioned movements of conductor and insulator strings such as sleet-jump and galloping, thus preventing excessive impulsive shock from being applied to the jumper rod 1.

Since connecting wires 12 connected between main conductors l1 and jumper rod 1 are flexible, a slight difference in the length of the jumper rod is permissible, thus enabling cutting of the jumper rod in the factory without regarding the accurate length of the jumper rod. This greatly saves work in the construction site.

FIG. 6 shows a modified embodiment of this invention wherein the length of the jumper rod is especially made small for the convenience of transportation. In this case supporting means are mounted at inclined positions, and two spacers 14 are used to reinforce connecting wires 12. Other component parts are designated by the same reference numerals as in FIG. I so that their description is believed unnecessary.

FIG. 7 illustrates a modified branched socket 13' including a socket arm 15 on one side for receiving the jumper rod 1 and a pair socket arms 16 on the opposite side for receiving connecting wires I2. The upper end of the socket 13' is pivotally connected to the lower end of the supporting means 2 through link 4.

FIGS. 8 and 9 show still another modification of this invention which is substantially identical to the previous embodiments except that a vernier-type length adjuster 17 is inserted at an intermediate point of each supporting means 2.

As shown in FIG. the length adjuster 17 comprises a strip-shaped connecting member 19 provided with a number of equally spaced-apart openings 18, a U-shaped connecting member 21 having two legs sandwiching the connecting member 19 and provided with a plurality of openings 20 of a pitch different from that of openings 18, a bolt 22 extending through a selected pair of openings 18 and 20 and a nut 23.

The jumper rod 1 and connecting wires 12 are interconnected in the following manner. A flange 25 with a plurality of openings 24, as shown in FIG. 11 is secured to one end of the jumper rod 1, and a cylindrical sleeve 26 is press-fitted about the gathered ends of two connecting wires 12. The sleeve 26 is integrally formed with flange 27 having a plurality of openings 28 aligned with openings 24 in flange 25, and these flanges 25 and 27 are connected by bolts 29 extending through aligned openings 24 and 28.

The embodiment shown in FIGS. 8 and 9 provides the same advantages as those of the embodiment shown in FIGS. 1 and 2. Further, according to the embodiment shown in FIGS. 8 and 9 it is possible to adjust the length of the supporting means so as to adjust the horizontality and the level of the jumper rod, thus correctly maintaining it in the desired position.

What we claim is:

I. In a jumper arrangement for an overhead electric power transmission line wherein conductors of the transmission line are secured to a power transmission tower through strain insulator string assemblies and the ends of said conductors on opposite sides of said tower are electrically interconnected by a jumper conductor, the improvement which comprises a rigid jumper rod forming said jumper conductor, supporting fixtures interposed between said conductors of the transmission line and said strain insulator string assemblies, a pair of supporting means, each including a rigid element connecting respective ends of said rigid jumper rod to one of said supporting fixtures for suspending said rigid jumper rod from said transmission line, and an electroconductive flexible connecting wire connecting each end of said rigid jumper rod to its respective conductor of the transmission line.

2. The jumper arrangement according to claim 1 wherein a link mechanism pivotally connects each end of said rigid jumper rod and said respective supporting means to enable said jumper rod to be displaced.

3. The jumper arrangement according to claim 2 wherein said rigid elements of said supporting means are arranged substantially vertical.

4. The umper arrangement according to claim 2 wherein said rigid elements of said supporting means are arranged on an inclined plane.

5. The jumper arrangement according to claim 1 wherein at least one of said supporting means includes adjusting means for adjusting the horizontality and the level of said rigid jumper rod.

6. The jumper arrangement according to claim 5 wherein said at least one supporting means includes a rigid member having an adjustable length for adjusting the horizontality and level of said rigid jumper rod.

7. The jumper arrangement according to claim 5 wherein said adjusting means comprises a strip-shaped connecting member having a number of equally spaced-apart openings therein, a U-shaped connecting member having two legs sand: wiching said strip-shaped connecting member and being provided with a plurality of openings spaced differently from said spaced openings in said strip-shaped connecting member, and a locking member for selectively locking one of said openings of said strip-shaped connecting member and one of said openings of said U-shaped connecting member.

8. The jumper arrangement according to claim 5 wherein a link mechanism pivotally connects each end of said rigid jumper rod and said respective supporting means to enable said jumper rod to be displaced.

9. The jumper arrangement according to claim 8 wherein said at least one supporting means includes a pair of rigid elements, each pivotally connected to an end of said rigid jumper rod and each pivotally connected to one of said supporting fixtures, each of said rigid supporting elements including means for adjusting the length thereof for adjusting the horizontality and level of said rigid jumper rod.

10. The jumper arrangement according to claim 1 wherein said supporting fixtures include means for pivotally connecting said conductors of said transmission line to said strain insulator string assemblies.