US1693380A - Insulator - Google Patents

Description

Nov. 27, 1928.

G. I GILCHREST INSULATOR Filed. Oct. 1 8, i919 INVENTOR @eoryf. 63/02/2 52 IA'IITORNEY Patented Nov. 27, 1928.

I UNITED STATES GEQBGE I. GILCHREST, 0F WILKINSBUBG, PENNSYLVANIA, ASSIGNOR T0 WESTING- 7 HOUSE ELECTRIC 8c MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

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Application filed October 18, 1919. Serial No. 331,548.

My invention relates to insulators and particularly to insulators of the pillar type.

One object of my invention is to provide a built-up pillar-type insulator of ready assembly and of reduced overall length.

Another object of my invention is to provide connecting members for disposition between the insulating members of a built-up pillar-type insulator that shall be symmetrically formed and related to the insulator and the electrostatic field thereof to ofier a minimum of disturbance to said field.

Another object of my invention is to provide connecting means for an insulator whereby the latter is subjected to compressive stresses only, in response to temperature changes.

Heretofore, it has been usual to construct built-up pillar-type, and other series or endto-end connected, insulators with various forms of complicated connecting devices between the insulatingshells or members.

These have usually employed projecting lugs,

bosses, nuts, bolts and other irregularlyformed portions or members that disturbed the electrostatic field of the insulator. Gertain other insulators have been so constructed as to subject the insulating material to expansion stresses of the metal connecting members thereof.

In practising my invention, I provide an insulator, preferably of the pillar type, although certain features thereof may readily be adapted to insulatorsof other types, that shall be so provided with metal members dis-' of the insulating members asposed outside to prevent damage to the latter by expansion of the metal members and that shall be so symmetrically formed of metal and insulating parts as to improve the electrostatic field thereof.

I further provide relatively-simple caplike connecting members which, with the insulating members, constitute a series of snugly and symmetrically fitting units that may be assembled and taken apart with substantially the same facility as in certain wellknown plug-and-socket connectors.

The single figure of the accompanying drawings is a brokenside View, partially in elevation and partially in section, of an in sulator embodying my invention.

that shall be extremely simple and durable in construction,

In general, my improved insulator embodies a plurality of units 1 each comprising an insulating member 2 and end members 3 and 4.

Each insulating member 2, preferably of porcelain, is of'substantially cup-shape or of tubular form having a transverse wall 5 at one end and a petticoat portion 6 intermediate its ends.

I The end members 3 and 4:, preferably of relatively thin malleable iron, are similar in that they both comprise flanges 7 embracing the ends of the member 2. The member 3 is provided with an exteriorly-threaded, outwardly-projecting portion 8 for co-operative engagement with an interiorly-threaded, inwardly-projecting portion 9 on the member a, the threads of the members 3 and 4 being preferably formed to facilitate the ready and rapid engagement thereof. It will be understood, of course, that the portions 3 and 4, at the extremities of the insulator, are adapted for co-operative engagement with conductor and insulator-supporting members (not shown).

The flanges 7 are somewhat larger in interior diameter than the members 2 and have serrated 0r roughened inner surface between which and similar surfaces on the ends of the members 2 bodies of cement are disposed to lloiold the members 3 and 4 securely to the memers 2.

Co-operating raised annular ring portions 10 on the members 3 and 4; serve as seats by which the respective units 1 are held in binding relation to each other.

The base member 4 may be provided with angularly displaced perforate lugs or bosses 11 through which screws or bolts (not shown) may be placed to prevent the insulator from turning about its axis.

The arrangement eliminates cement and metal-from adjacent the inside surfaces of the porcelain members, thereby preventing fracture of the insulating material by the expansion of the metal parts under temperature changes.

In accordance withthe principles set forth in Patent No. 1,129,520, issued Feb. 23, 1915, to K. C. Randall, S. WV. Farnsworth and C. LeG. Fortescue, insulating body for elec-.. tric apparatus, and assigned to the Westinghouse Electric &.Manufacturing Company, the elimination of bolts and other projecting bodies, on the exterior surface of the insulator, and the symmetrical construction and relation of the metal and insulating parts," render the electrostatic field more uniform and reduce the number of positions at which electrostatic stresses may concentrate.

lhe electrostatic capacity of the insulator shown is relatively low butmay be increased,

as by increasing the area of the metal inside the units, or by varying the distance between the members 3 and 4. I

The structure is mechanically very comact, of ready assembly and, by reason of the fact that the metal connecting portions occupy a relatively-small portion-of the axial distance of the insulator, may be of substantially a minimum overall length for a given potential between its ends.

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

I claim as my invention 1. In an insulator, the combination with a pair of insulating members each having a portion entirely thereacross of insulation and embodying a cylindrical portion having a flat transverse end surface disposed in close proximity to the flat-end surface of the other,

of a metal member secured to each of said ends embodying a transverse discoidal portion'in relatively close flat-surface relation to and contacting with the metal member of the other insulating member, each metal member having a uniform relatively smooth outermost perimeter and a central portion for connection to the members having discoidal portions disposed b other, one of said central portions being disposed within the plane of the outer surface of its discoidal portion.

2. An insulator comprising two metal in contacting flat-surface-to-surface relation and portions projecting oppositely in the direction of the longitudinal axis of the insulator, said members also having central connecting elements, and insulating members secured to said oppositely-projecting portions and projecting beyond the outer ends thereof to provide portions entirely across the insulating members of insulation, one of said central elements being disposed within the plane of-the outer surface of its discoidal member.

3. A built-up insulating pillar comprising a plurality of insulating members having main body portions of substantially cylindrical flat-endcup-shape, flat discoidal connecting members embodying relatively short uniform cylindrical flanges embracing the closed ends of the insulating members and holding portions projecting therefrom, and similar connecting members embracing the open ends of said insulating members having holding portions projecting into said insulating members for cooperation with said first holding portions, said insulating members having portions entirely thereacross of insulation.

4. A built-up insulator comprising a plurality of hollow insulating members, a relatively-flat transverse connecting member disposed at one end of each of said insulating members and having a holding portion projecting outwardly therefrom and a similar connecting member disposed at the other end of each of said insulating members and having a holding portion projecting into the insulating member and cooperating with the outwardly projecting holding portion of the next adjacent insulating member.

5. A built-up insulating pillar comprising a plurality of substantially cylindrical insulating members having petticoat portions intermediate the ends thereof and recesses therein, a metal connecting member embracing one end of each of said insulating members having an exteriorly-threaded portion projecting therefrom, and a metal connecting member embracing the other end of each of said insulating members having an interiorly-threaded portion projecting into one of said recesses for cooperation with the outwardly projecting portion of the next adjacent member.

6. An insulator comprising an insulating member of substantially cup-shape, a connecting member of substantially cup-shape embracing the closed end of the insulating member and having an exteriorly-threaded centrally-projecting portion and a connecting member of substantially cup-shape embracing the open end of the insulating member and having an interiorly-threaded centrally-disposed portion projecting into the insulating member.

7. An insulator of the pillar type comprising a plurality of superposed insulating memers having flat cylindrical ends, and relatively fiat substantially discoidal metal connecting members therefor disposed therebetween, said metal members having unobstructed longitudinal outer perimetral holding flanges secured to adjacent longitudinal surfaces of the insulating members and integral inner-end portions for connection to each other in an end recess of one of the hollow insulating members of each adjacent pair of insulating members.

8. An insulator comprising an insulating member having cylindrical ends, one of which is recessed, a metal terminal member having a discoidal portion over the recessed end and cylindrical longitudinal flanges, one of which'embraces and is secured to the re- -cessed end and the other of which, constituting a holding portion, extends into the recess, and a similar terminal member having a dis coidal portion over the other end of the insulating member and cylindrical longitudinal flanges, one of which embraces and is secured to said other-end of the insulating memv ber and the other of which, constituting a holding portion, proj ects outwardly from the insulating member.

9. An insulator comprising an insulating member having a recessed cylindrical end and a metal terminal member having a discoidal portion disposed in flat transverse relation to the longitudinal axis of the insulator over said end and cylindrical longitudinal flanges, oneof which embraces and is secured to said end and the other of which, constituting a holding portion for attaching the'insulator to an exterior member, extends into the recess.

10. An insulator comprising an insulating member having cylindrical ends, one of which is recessed, a metal terminal member having a discoidal portion disposed in flat transverse relation to the longitudinal axis of the insulator over the recessed end thereof and cylindrical longitudinal flanges, one of which embraces and is secured to the recessed end and the other of which is internally screw threaded and extends into the recess, and a similar terminal member having a discoidal portion in flat transverse position over the other end of the insulating member and cylindrical longitudinal flanges, one of which embraces and is secured to said other end of the insulating member and the other of which is externally screw threaded and projects out Wardly from the insulating member.

11. An insulator comprising an insulating member having cylindrical ends, one of which is recessed, a metal terminal member having a discoidal portion disposed in flat transverse relation to the longitudinal axis of the and the other of whichis internally screw threaded and extends into the recess, and a similar terminal member having a discoidal portion in flat transverse position over the other end of the insulating member and cylindrical longitudinal flanges, one of which embraces and is secured to said other end of the insulating member and the other of-which is externally screw-threaded and projects outwardly from the insulating member, said terminal members each having an annular raised seat portion on the outer surface thereof intermediate the said flanges thereon.

12. An in'sulatorcomprising a pair of insulating members having adjacent end portions, a substantially discoidal terminal member secured to one of said end portions and having a connector portion between the plane of its outer surface and theinsulating member to which it is secured, and a similar terminal member secured to the other end portion in relatively close substantially parallellane relation to said first-discoidal member aving an outwardly-extending connector portion for cooperation with said connector portion of the first discoidal member.

In testimony whereof, I have hereunto subscribed my name this 8th day of Oct, 1919.

GEORGE I. o LoHREsT.

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