US1730232A - Insulator structure - Google Patents

Description

Get. 1, 1929. E. s. NEWILL INSULA'IOR STRUCTURE Filed April 28. 1927 INVENTOR Edward 5. New/71' BY v ATTORNEY i atented it, r9231 EDWARD B. NEWILL, 0F WILKINSBURG,

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

rnsrrnaron Application filed April 28,

My invention relates to insulator structures and particularly to insulator structures adapted for high-voltage service.

ployed.

Another object similar units.

A further object of my invention is to provide a high-voltage insulator structure that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In co-pending application, Serial No. 818, insulator, filed April 1, 1922 by H. B. Smith and assigned to the )Vestinghouse Electric & Manufacturing Company, is disclosed an insulator structure embodying an insulating rod and electrostatic-stress-distributing terminals of particular form and purpose.

In the device of the copending application, shields or terminals, adjacent to the ends of an insulating rod, are so shaped relative to each other as to Widely distribute the electro static held and prevent its concentration a any position, as Well as to form What may be called a hollow field, or zone oi? extremely weak electrostatic stresses, through which the insulating member extends.

This construction, by preventing the coucentration of the field and maintaining the surface of the insulating member free from dangerous stresses, is a material improvement in the high-voltage insulator art and, so far as 1 am aware provides a single lllSlllll tor unit of higher voltagercslstiug f my invention is to provide an electrostatic-stress-distributing or directing unit that Shall so differently affect the electrostatic field at its sides, facing oppositely along the longitudinal axis of an insulator, as to permit its use at either end, or at an intermediate portion of, the insulator, for proper cooperation with one or more s'rnuornnn 1927. Serial No. 187,127.

than any other single unit for similar service and of comparable amount and kind of material.

To accomplish the purposes of the abovementioned insulator, its terminals are provided with toroidal or annular conducting surfaces that are very Widely or gradually rounded, at all places thereon, and that are of considerably greater area, and differently related, than the surfaces of similarly-disposed terminals heretofore suggested. I

For outdoor service, the terminals are constructed as a'hood and a ring at the upper and lower ends o1 the insulator, respectively, and are, therefore, separate and distinct parts. There are also, holding or securing terminal portions outside the stress-distribut= ing hood and ring, which add somewhat to the total length of the insulator.

It has been suggested to place two or more insulators, of the above mcutioned type, in series relation, as is done With insulators 01": the Wellhnovvn cap-and-pin type and with insulators oi other forms. Thus, there would be as many more hoods and rings employed as there were insulators joined in series, in addition to increased length in accordance With the number of insulators so joined.

It is my aim to permit insulator units, of

sis,-

series relation by the use of fewer parts, to thereby, conserve storage and handling expense, to provide a series-section insulator of shorter overall length than is obtained by merely connecting a plurality of the above mentioned insulators, and to provide a single stress-distributing or directing unit which may be used intermediate the ends of the insulator or in the place of either the hood or the ring, above-mentioned.

Accordingly, in practicing my invention, I provide an electrostatic-stressdistributing unit, incorporating both a ring portion and a hood portion, and an insulating member or red of such construction that one red may be employed with two of such units at its ends, two or more rods may be employed With the units at the ends, or between the sections, of the compounded rod, and other combinations value may be made and a shorter structure obtained.

4 the above-mentnimed type, .to be placed in U ion The single figure of the accompanying drawing is a view, partially in elevation and partially in section, of an insulator structure embodying my invention.

The device comprises, in general, an insulating rod or member 2 embodying sections 8 and 4, a top member 6 for mounting the insulator, abottom member or clamp I for supporting a conductor 8, a top electrostaticstress-distributing unit 10 and similar units 11 and 12 disposed intermediate the ends of the structure and at the bottom end, respectively.

The rod sections 3 and 1, which may be of any suitable construction and material, are shown as constructed as substantially solid cylindrical bars of porcelain or similar material having cylindrical end recesses in which internally-screw-threaded metal cups or sleeves 14 are secured, as by cementing, for the reception of screw-threaded studs 15.

The top and bottom insulator-mounting and conductor-supporting members 6 and-7, respectively, are of usual types and need no particular description except that they are adapted for mounting on the top and bottom studs 15, respectively.

The units 10, 11 and 12 are preferably alike and each comprises a hood portion 17 having a rounded outer perimetral or water-drip portion 18, an annular portion 20 of maximum-potential gradient disposed intermediatethe water-drip portion 18 and the center thereof, and an upper ring or toroidal portion 21.

These units may be variously constituted, so long as the outer surfaces thereof are conducting, as by constructing them of insulating material with a foil or other metal coating thereon, or by pressing or spinning them" of sheet metal, such as copper or aluminum.

As here shown, the upper unit 10 is made of spun sheet-metal, with the parts 17 and 21 spun integrally from one sheet and an annular sheet-metal ring 23 inserted flush with the lower surface of the hood across a space at the base of the portion 21.

The unit 11 is constructed by spinning the parts 17 and 21 from separate sheets and suitably securing them to each other.

In any form, the units 10, 11 and 12 are each provided with one or more openings 25 to provide drainage for the center of the portion 21.

Dotted lines X indicate the zones of ma;xi'

at eit'lier sides of the lines X, the field be- "comes gradually weaker laterally therefrom I until, at positions adjacent to the surfaces oi the rod sections 3 and 4 and at the outer water-drip portions 18, itbecomes almost negligible.

Thus, at positions where surface current tends to build up and where water may cause a conducting path, the field is so reduced as to prevent breakdown from these causes. This feature protects the sections 3 and 4 against damage by corona and arcs and causes the ultimate fiashover value to be substantially the same under wet, as under dry, conditions.

A separate toroidal member, similar to the portion 21 without the hood portion 17, may be used at the bottom of the structure, as may a separate hood member without the toroidal portion be employed at the top thereof but the combined unit shown is preferably of such construction as to serve for either or both and to render the carrying of separate hood and toroids unnecessary.

The combined unit is of particular advantage intcrn'iediate the ends of the insulator in conserving space and simplifying the construction theriof and, since it embodies longitudinally offset toroidal and hood portions of different shapes and dimensions, it constitutes a single means for ditterently atfecting the field at opposite sides thereof facing the ends of the insulator.

The device is extremely easy to assemble by simple. screwing operations and is, in general, an improvement in the field of service to which it relates.

While I have shown and described a particular form of my invention, changes may be effected therein without departing from the spiritand scope thereof, as set forth in the appended claims.

1 claim as my invention: 1

1. An insulator comprising an elongated insulating structure, a hood thereon having an intermediate annular, arc-assuming portion and an outer annular water-drip portion, a member having a toroidal conducting surface longitudinally spaced from said hood and an element on said structure intermediate said hood and said member having a toroidal portion similar to said first toroidal portion and a hood portion similar to said first hood.

2. An insulator comprising an elongated insulating structure and a plurality of electrostaticstress-distributing units disposed thereon in longitudinally-spaced relation to each other, each unit embodying a lower hood poition and an upper toroidal portion inte grally united to each other,

8. An insulator comprising an elongated insulating structure andafplurality of end and intermediate electrostatic-stress-distributing units. therefor, the top I unit having a'hood portion, thebottomunit having a to .rcad'al portion and an intermediate unit hai inghood and toroidal portions.

4.. An insulator comprising an elongated EDWARD B. NEWILL.

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