US3250852A

US3250852A - Suspension plate assembly for bundle conductor

Info

Publication number: US3250852A
Application number: US399576A
Authority: US
Inventors: William L Hollander
Original assignee: AB Chance Co
Current assignee: AB Chance Co
Priority date: 1964-09-28
Filing date: 1964-09-28
Publication date: 1966-05-10
Anticipated expiration: 1983-05-10

Description

y 0, 1966 w. L. HOLLANDER 3,250,852

SUSPENSION PLATE ASSEMBLY FOR BUNDLE CONDUCTOR 2 Sheets-Sheet 1 Filed Sept. 28, 1964 INVENTOR. William L. Hollander" flTTOR/VEYS.

y 10, 1966 w. L. HOLLANDER 3,250,852

SUSPENSION PLATE ASSEMBLY FOR BUNDLE CONDUCTOR Filed Sept. 28, 1964 2 Sheets-Sheet 2 INVENTOR. William L. Hollander ATTORNEYS?" United States Patent Chance Company, Centralia, Mo., a corporation of Missouri Filed Sept. 28, 1964, Ser. No. 399,576 4 Claims. (Cl. 174144) This invention relates to an improved assembly for suspending bundled conductors of a high voltage transmission line from a supporting tower and, more specifically, to such an assembly which prevents corona discharge between the conductors and the tower without the necessity of providing corona shield attachments,

Corona discharge with attendant radio interference is a problem inherent in the transmission of high voltage electrical energy. This problem becomes increasingly acute as the voltage is raised. Presently, extra high voltages on the order of 345 to 500 kilovolts are utilized in the transmission of alternating current electrical energy, and shields must be utilized with the transmitting con ductors employed to suppress the corona.

When voltages of this magnitude are employed for transmitting electrical energy, each phase of the transmitted energy is commonly carried by a series of conductors presenting a bundle rather than a single, larger conductor because of the necessity of providing a conductor of substantial cross-sectional area to handle the heavy currents encountered. A single conductor of this size has not been found to be economically practical. Thus, a number of conductors must be individually shielded against corona discharge. It is commonly the practice to utilize shields which are attached to the suspension plates that suspend the conductors from the supporting tower; however, such shields interfere with the stringing of the conductors during installation of the transmission line and normally must be attached to the suspension plates after the conductors are in place. Furthermore, these shields are costly and increase the number of man-hours required to install a transmission line.

It is therefore, the primary object of this invention to provide a suspension assembly for an electrical conductor of a high voltage transmission line which overcomes corona discharge problems without resorting to the use ,of costly and inconvenient corona shields.

It is another object of the instant invention to provide a suspension assembly for a high voltage conductor which is constructed of a minimum number of elements.

Still another object of this invention is to provide such a suspension assembly which will decrease installation time of a transmission line and suppress corona discharge.

Yet another object of the instant invention is to provide a suspension assembly as aforesaid in which the supporting yoke and the corona shield or shields is integrally constructed.

Other objects will become apparent as the detailed description proceeds.

In the drawings:

FIGURE 1 is a front elevational view showing one embodiment of the suspension assembly of the instant invention;

FIG. 2 is an end view of the assembly shown in FIG. 1;

FIG. 3 is a front elevational view of a second embodiment of the instant invention;

3,250,852 Patented May 10, 1966 FIG. 4 is a vertical, sectional view taken along line 4-4 of FIG. 3 showing only the yoke and clevis portions of the assembly? FIG. 5 is a front elevational view of a third embodiment of the instant invention;

FIG. 6 is an end view of the assembly shown in FIG. 5, showing only the yoke and clevis portions of the assembly;

FIG. 7 is an enlarged, detailed view of the shielding clevis common to the three embodiments, the interconnection of the clevis with these embodiments being illustrated in broken lines; and

FIG. 8 is a cross-sectional view taken along line 88 of FIG. 7.

Referring to FIGS. 1, 2, 7 and 8, the numeral 10 designates the suspension plate assembly of the instant invention which includes a yoke 12 and a pair of U-shaped members or clevises 14 integral with respective ends of yoke 12. Each clevis 14 has a pair of normally downwardly extending ends 16 which are apertured at 18 to receive a pin 20.. The latter is held in apertures 18 by a cotter key 22. Each of the pins 20 is utilized to secure a clamp 24 to the associated clevis 14, each clamp 24 being employed to grip a corresponding conductor 26. Clamp 24 comprises an upper jaw 28 secured to a lower jaw 30 by a pair of threaded bolts 32, pin 20 being received by a downwardly extending portion 34 of the lower jaw 30.

The configuration of the clevises 14 is shown in detail in FIGS. 7 and 8. The spaced-apart ends 16 of each clevis are interconnected by an umbrella 36 provided with an outwardly facing surface comprising three

regions

38, 40 and 42. The three regions are arcuate as viewed in cross section, as illustrated in FIG. 8 for region 40, and are longitudinally arcuate as shown most clearly in FIG. 7. Thus, the three regions are outwardly convex in configuration, region 40 normally facing upwardly, while

regions

38 and 42 are opposed and face in lateral directions.

It may be noted that the curvatures of the three regions all follow the arc of a circle, whether viewed in cross section, as in FIG. 8, or in front elevation as in FIG. 7. The radius of the cross-sectional curvature is the same for all three regions; however, as shown in, FIG. 7, the radius of curvature of region 40 as viewed in front elevation is greater than the radii of curvature of

regions

38 and 42, which are equal. Thus, the three regions blend together to form an umbrella-like structure of generally elliptical coinfiguration having a normally horizontali, semi-major axis. An integral internal web 44 merges with the outersurface of umbrella 36 and is utilized to increase the structural strength of the unit.

Referring particularly to FIG. 1, it may be seen that each clevis 14 is provided with an upstanding ear 46 which receives a pin 48, connecting the clevis to a link 50 extending from an insulator 52. The insulators 52 illustrated in FIG. 1 represent the lowermost insulators of two strings thereof utilized to suspend assembly 10 from a supporting tower (not shown) or other supporting structure. The ear 46 is not shown in FIGS. 7 and 8 so that the configuration of the outer surface of clevis 14 is more clearly illustrated. It may be noted that yoke 12 is provided with four openings 54 through the central portion thereof for use in temporarily attaching stringing blocks to the yoke during installation of conductors 26.

The embodiment of FIGS. 3 and 4 is similar in con 64 is utilized for attachment of stringing blocks.

, tween the conductors and the supporting tower.

struction to that as described hereinabove. Ears 46 are omitted from clevises 14 and yoke 61 is longitudinally straight rather than arcuate as in the embodiment of FIG. 1. Instead of being suspended from two. strings of insulators, the embodiment of FIGS. 3 and 4 is adapted for suspension from a single string of insulators, the lower insulator 56 thereof being shown provided with a link 58 which is interconnected with a central, upstanding ear 60 on yoke 61 by a pin 62. A single opening Otherwise, this embodiment is identical in structure to that as shown in FIGS. 1 and 2.

Referring to FIGS. and 6, the third embodiment of the instant invention is shown. The clevises 14 are identical in construction to that as described hereinabove, with the exception that each clevis 14 is provided with upstanding stanchions 66 which receive pivot pin 68 and swingably mount the clevis on yoke 70. Yoke 70 is an elongated, generally triangularly-shaped plate for use in suspending conductors 26 during bends in the run of the line. Links 72 are associated with respective strings of supporting insulators (not shown) and are attached to two apexes of yoke-70 by pins 74. It may be seen that the remaining apex of the yoke carries one of the clevises 14, while the other clevis is mounted adjacent the apex remote therefrom. A single, central opening 76 in the yoke may be utilized to temporarily attach stringing blocks thereto during installation.

It is important to take note of the fact that all surfaces of the bundle conductor supports which present end edges, are of cross-sectionally curved configuration to avoid any sharp edges or points which could increase current density at a point on the yoke assemblies sufficient as to cause corona discharge.

In operation, the various embodiments of the instant invention are employed in the conventional manner to suspend bundled conductors 26 from a tower or other support. The umbrellas 36 of clevises 14 serve as shields to suppress corona discharge between the conductors and the supporting tower, which is the closest ground. Be- 1 cause of their particular configurations, the umbrellas 36 are especially adapted to prevent excessive voltage density on the conductor supports at the areas thereof in facing relationship to the tower cross arms, thereby preventing ionization of the air between the conductor support and the tower arm to an extent to prevent corona discharge therebetween.

This voltage density reducing effect, and attendant corona suppression, is attributable to the fact that the outer surface of each clevis is arcuate and has no abrupt bends or discontinuities. Since this surface is disposed between each conductor and the supporting tower, the clevises may be mounted in closely spaced relationship to the links which form the lowermost extremity of the insulator string or strings used to suspend the assembly. In this manner, the ends 16 of the clevises extend downwardly in, operation, permitting easy insertion of the conductors during installation of the line, and yet are positioned adjacent the suspension point or points on the yoke since umbrellas 36 will at all times be be- This is advanta-geous not only in that it facilitates mounting of the conductors within the clevises by insertion of the clamps thereinto, but also forms a more rigid suspension assembly sincespacing of the conductors from the suspension point or points on the yoke is reduced.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is: 1. An assembly for suspending a pair of conductors from a support in spaced, bundle-defining configuration comprising:

a yoke having opposed extremities; means connected to said yoke at one of said extremities and at a point between said extremities forsuspending the yoke from said support;

a pair of U-shaped members carried by said yoke and pivotally coupled thereto adjacent said one extremity and at the other of said extremities, respectively, in positions where an imaginary line extending between the members is proximal to said suspension means, each of said members having a pair of normally downwardly extending, spaced-apart ends;

a clamp for gripping each of said conductors respectively; and

means attaching each of said clamps to the ends of a corresponding member and positioning the clamps between such ends, each of said members presenting an elongated, longitudinally arcuate umbrella interconnecting the ends thereof for shielding the associated conductor from corona discharge between the conductor and the support,

each umbrella being provided with an outwardly facing surface having a normally upwardly facing, longitudinally convex region, and a pair of opposed, longitudinally convex, normally laterally facing regions merging with said upwardly facing region to provide said surface with an uninterrupted, corona resistant contour.

2. In an assembly for suspending bundle conductors:

a suspension element of unitary, one-piece construction comprising a yoke provided with a pair of spaced, U-shaped members each having a pair of normally downwardly extending, spaced-apart ends;

a pair of conductor-gripping clamps; and

means attaching said clamps to respeotive members between said ends thereof,

each of said members presenting an elongated, longitudinally arcuate umbrella interconnecting the ends thereof in overhead, shielding relationship to the associated clamp,

3. The invention of claim 2, each umbrella having an arcuate cross-sectional configuration providing said regions with arcuate transverse contours. 4. An assembly for suspending a plurality of conductors from a support structure therefor and in spaced, bundle-defining configuration for transmission of high voltage electrical current, said assembly comprising:

a generally U-shaped support member for each conductor and each having opposed legs interconnected by a central portion cooperable to define a slot for receiving a respective conductor;

a suspension plate adapted to be suspended from said structure and joined to and supporting said members in inverted relationship with the legs thereof all extending downwardly and the conductor receiving slots of the same all being upright and open at the bottom thereof, said plate being configured'and the members being joined to and supported by the latter in disposition causing the conductors received in said slots to define said bundle presenting configuration; and

conductor clamp means pivotally and removably mounted between each pair of legs of each support member and disposed to receive a respective conductor therein in clamping relationship thereto, each of said support members having a generally semicircular umbrella defining rib section integral with the legs and central portion thereof in overlying, protecting relationship to the conductor and conductor clamp receiving slot therein, each of the umbrella rib sections having an upwardly facing, transversely and longitudinally convex uppermost 5 6 surface which merges smoothly with opposed, trans- References Cited by the Examiner versely concave and longitudinally convex, essen- UNITED STATES PATENTS tially downwardly facing undersurfaces which join at an arcuate zone located at thelcentral portion of 2O8615O 7/1937 Austin the respective support member to thereby cause each 5 3O76863 2/1963 Lantz et 174-149 X support member to be resistant to corona discharge F REIGN PATENTS thereof, the umbrella defining rib section of each 53 027 11 19 2 Canada support member being of sufficient length and dis- 843 710 7 1952 Germany posed to project outwardly from all areas of the plate in direct adjacent relationship thereto. 10 LARAMIE ASKIN, Primary Examiner-

Claims

2. IN AN ASSEMBLY FOR SUSPENDING BUNDLE CONDUCTORS; A SUSPENSION ELEMENT OF UNITARY, ONE-PIECE CONSTRUCTION COMPRISING A YOKE PROVIDED WITH A PAIR OF SPACED, U-SHAPED MEMBERS EACH HAVING A PAIR OF NORMALLY DOWNWARDLY EXTENDING, SPACED-APART ENDS; A PAIR OF CONDUCTOR-GRIPPING CLAMPS; AND MEANS ATTACHING SAID CLAMPS TO RESPECTIVE MEMBERS BETWEEN SAID ENDS THEREOF, EACH OF SAID MEMBERS PRESENTING AN ELONGATED, LONGITUDINALLY ARCUATE UMBRELLA INTERCONNECTING THE ENDS THEREROF IN OVERHEAD, SHIELDING RELATIONSHIP TO THE ASSOCIATED CLAMP, EACH UMBRELLA BEING PROVIDED WITH AN OUTWARDLY FACING SURFACE HAVING A NORMALLY UPWARDLY FACING, LONGITUDINALLY CONVEX REGION, AND A PAIR OF OPPOSED, LONGITUDINALLY CONVEX, NORMALLY LATERALLY FACING REGIONS MERGING WITH SAID UPWARDLY FACING REGIONS TO PROVIDE SAID SURFACE WITH AN UNINTERRUPTED, CORONA RESISTANT CONTOUR.