US1282481A - Multiple-section suspension-insulator. - Google Patents

Description

$.18. SONNEBORN.

MULTIPLE SECTIQN SUSPENSION INSULATOR.

' v APPLICATION HLED FEB. 10. 1917.

1382381. Patented Oct. 22, 1918 2 SHEETS-SHEET Susp crease; This is due to the fact that under sor; s,

soun'anoautlor BRooKnYN, new YORK.

' MULTIPLE-SECTIGN sUsrEN sIo -msULAToR;

To all whomz't may concern Be it known that I, SOL S. SONNEBORN, a citizen ofthe. United States, and a resident of Brooklyn, county of Kings, and State of New York, have invented certain new. and useful Improvements in Multiple-Section ension-Insulators, set forth in the following specification. I This invention relates to insulators for high-potential transmission lines and particularlyto insulators ofthe suspension type.

All practical problems in transmission line -1sulation involve a combination ofefi'ects resulting from the employment, through necessity, of atleast two cinds of dielectric,air and the solid insulating material employed for structural purposes. Unfortunately the air is not always dry and the insulat-or design must take into consideration protection against the precipitation of moisture in the form of rain. The protection against rain through the medium of 'petticoats to a large extent prevents designing an insulator in a manner to give greatest efficiency to the solid insulating material, were the airalways dry. Nevertheless it is desirable that the insulating material be so formed that its contour lines correspond as nearly as practicable to the flow lines of dielectric stress. This is to give maximum efficiency to the air path over the surface of the insulating material.

In a perfectly 'designedinsulator of single section construction the cost is approximatel'y'proportional to the cube of the electric stress for which the insulator is, designed.- It has been found, however, that by constructing an insulator out of a number of sections in series, theoretically atleast the cost can be made approximately proportional directlyto the voltage instead-of to the cube There are certain practical v of the voltage. difficulties, however, whichmake it impracticable indefinitely tions in series so that each added section will give its proirata increase in potential inoperating conditions there is pracno leakage current over the surfaces normal tically of the each insulator section is therefore subjected is dependent upon the charging currents of Specification of Letters Patent.

would be subjected.

- with a view to the the conducting to employ insulator secs insulators .and the potential to which.

Patented Oct. 22, 1918,

I Applicationflled February 10, 1917. Serial No. 147,734.

all insulator sections are identical, must sustain the maximum voltage, and that nearest the tower arm or ground is required to sustain the least. Therefore, for'equal distribution of voltage between the various insulator sections, grading must be resorted to. Grading is not tions would be required, thus doing away with interchangeability of parts. .Heretofore, when interchangeability'of parts has tov be favored on account of-the fact that so many various styles of insulator secbeen adhered to, the maximum electric stress to which the lowest insulator section in a series was to be subjected determined the size of all the insulator sections and, obviously, every insulator section above the lowest became inefficient or more costly than was necessary, to withstand .One objectof the present inventionis to strain to which it divide as equally as possible the largest? amountof electric stressbetween the two I" lowest insulator sulator sections. A further object of the in vention is to design the insulator sections capability of coupling in pairs so that a symmetrical disposition of parts of each pair, will result and the relative shaping and disposition of the. conducting parts and of the solid'insulat sections in a series and so on between each superposed couple or pair of ining material so that the contour lines of the a v insulating material will conform as nearly as possible to the flow lines stress while, at the same time, protection against rain and consequent surface leakage will be provided. A still further object in connection with the symmetrical positioning parts Illa/p311 of insuof the conducting lator sectlonsjls the creation of a condenser arrangement capable of equalizing the elecof electro-static tric stress as nearly as practicable between two insulators so that-themaximum size for the insulator section in accordance with this made much smaller and invention may be, cheaper than has heretofore been possible.

Further objects tions in accordance with this invention.

The above and further elements of the invention will better be understood from the accompanying claims and the following specification which is drawnin connection with an illustrative embodiment of the inof the invention are to 7 provide accessory parts tending to correlate" and simplify the combining of insulator secform a part hereof and in which like characters designate corresponding parts .in the I tion of the section several figures. v y

In the drawings Figure 1 is a front elevation of a suspension insulator comprising two units each of each; Fig. 2 is a vertical section of-the lower insulator unit of Fig. 1 but drawn tov an enlarged scale; Fig. 3 is a detail enlarged sectional elevation of the coupling for use between insulator unit's; tical section with partsbroken away showing a coupling pin or bolt; and Fig. 5 is a top plan view with parts broken away an shown in section of one of the cup-shaped metallic members of the insulator construction. p

In the insulator illustrated the unit A comprises two similar yet radically different individual sections 1) and c. The insulator section 1) comprises an inverted metallic cup 1 providing a suitable terminal which may be in the form of the perforated lug 2. The

'cup 1 is a uniform body of revolution.

Axially positioned within the metalliccup'l but depending downwardly is the terminal 3 of substantially eye-bolt construction, but having its eye-portion 4 so shaped and positioned relatively to the interior surface of the cup 1 that the bounding surfaces of the intermediate insulating'material 5 conforms substantially to the flow lines of dielectric stress. This is approximated in the mechanical construction by having the boundaries of the eye-portion parallel to the inner surface of the cup 1. (See Figs. 2 and 5). The stem of the eye-bolt 4 is preferably enlarged into a collar 6 the contour lines of which are free from sharp angles and below which is formed any suitable connector such as the perforated lug Y The eye-portion 4 of thebolt 3 is fitted with overlapping cylinders 8 and 9 of some insulating material of high dielectric strength such, for example, as mica-board. The tie-bolt 10 passes through the inner insulating bushing 9 and engages the walls of the cup 1 in suitable perforations where it may be fixed in position in any suitable manner, as by center punches 11 in the ends- In assembling the structure the cup and the eye-bolt are preferably mechanically united first, and the insulating material 5 is thereafter molded about the previously assembled parts. It is preferable that the cup 1 be formed with a headin 12 about its terminal edge and with an undercut portion 13 providing a ledge 14. The insulating material molded about the metallic parts is preferably formed into a petticoat 15 which terminates under the ledge 14 against the cup 1 and flares outwardly to form the usual rainshedding surface, its under portion 16 being two. insulator sections Fig. 4 is a detail yer- The lower insulating section 0 of the unit' A is substantially a symmetrical reproducb. In this construction the eye-bolt 300 is axially positioned within the upright cup-shaped terminal 100 but exdownwardly. 1500 terminates against the and againstg tends upwardly instead of The petticoat beading 600 on its top surface, the ledge M00 on its lower face. In other words, the parts for the lower section, characterized by the same numbers as characterize the similar parts in section 0 with the addition of two additional ciphers, are in all respects the same as those for the top section b, except that the idea of symmetry is carried out for the metallic or terminal parts. It is preferred that the top and bottom sections b and c of insulator unit A be connected by a flexible coupling cl, prefera' ably of a type to increase the electro-static capacity. Such a coupling is illustrated, comprising a central disk-shaped portion 17, which extends outwardly about the axis. The disk portion 17 is provided with top and bottom connecting lugs 18 and 19, which may be connected with the lugs 7 through the medium of bolts 20, it being preferred that-the type of bolt illustrated be employed. This bolt comprises a major portion 21 having an internally threaded bore 23. It also comprises a locking bolt 24 having external threads 25, fitting into the threaded bore 23. In the insulator construction illustrated,

and 700 external threads 22 and instead of having the terminal of an eye-bolt 1 adapted to connect with the line wire, the present invention contemplates connecting the line wire to the cup-shaped terminal 100, so that the first insulator unit connected to the line, provides within itself two condensers in series, that is, the condenser provided between the cup 100 and the bolt 400, and the condenser between the bolt 4 and the cup 1 and, in addition, a condenser in parallel to the two in series, condenser provided between the plate '100 and the plate 1. Another advantage is'the uniform distribution of electrostatic stress namely, the

as it is taken directly from the line wire.

This is provided by the cup 100, In Fig. 1 two exactly similar insulator units A and Bare shown connected in-;series, the coupling between each unitbeing preferably accomplished by the special yoke D. This yoke or coupling D comprises two exactly identical sections 30, each of which consists of an elongated metal strap 31 having near one end a perforation 32 and near the other end a laterally extending threaded stem 33, symmetrically positioned relatively to the perforation 32. The stem of one portion 30 is thrust through the perforation of the opposite portion, whereupon nuts 34 complete the assemblement. The advantage is to keep in stock a number of identical parts, any'two of complete a yoke.

The purpose of the conducting disk17 between insulator sections may be considered as two-fold. It serves to distribute the dielectric stress more uniformly and also is a protection in the case of flash-over, tending to prevent local disruption of the insulator at the mechanical surface of demarcation between dielectric and conducting material.

\Vhat is claimed and what is desired to be secured by United States Letters Patent is:

l. A high potential chain insulator for sustaining and insulating a conductor from an anchorage between which conductor and anchorage there is adapted to exist a high potential difference comprising one or more insulation units, each said unit comprising two insulator-sections having each two separated metal parts one of which is laterally extensive and a body of insulatioubetween each of said two separated metal parts, all said metal parts of each said unit being substantially symmetrical about a plane central which make a couple and to said unit and at right angles to the axis of said chain, whereby plural insulation plus more uniform distribution of electrostatic stresses is obtained for each said unit.

2. A sectional high-potential insulatorstructure of the strain type comprising laterally extensive substantially symmetrically shaped and positioned metal end members; a metallic tension means extending axially between said endmembers and having a disk-like metal port-ion intermediate its ends; and insulation interposed between the ends of said tension means and said end members. all whereby electrostatic stresses are favorably distributed.

3. A high-potential insulator of the suspension type comprising at the bottom an upwardly concave metallic cup provided with means for conductively connecting and securing a line-conductor; an upwardly extending bolt for attachment to an anchorage; and a body of insulating material insulating said bolt from said cup and providing an upper water-shed, all whereby the necessary metal parts are positioned to give more favorable distribution of electrostatic stresses originatingfrom a nether positioned conductor.

4-. In a high potential insulator in combination two separated insulator sections having metal terminal parts, all of Which are relatively substantially symmetrically shaped and positioned; and a conducting plate electrically connected with a terminal part of each of said sections and positioned between said sections and located in a plane substantially at right angles to the axis of each, said section.

A capacity increasing coupling for suspension insulator sect-ions comprising in a unitary structure a central disk of conducting material and metallic attaching lugs cent'ally positioned on opposite sides of said disk. a

6. In high-potential insulators an in verted metallic cup; a similar upright metallic cup beneath said inverted metallic cup; a metallic tension structure substantially swmnetrically positioned between the concavities of said cups; and a body of insulating material located between each said cup and the respective ends of said tension structure,

In witness whereof I have signed my name to this specification, this 26th'day of Jan, 1917.

SOL S. SONNEBORN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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