US1657341A - Insulator pin - Google Patents

Description

- Jan. 24, 1928.

A. o. AUSTIN INSULATOR PIN Original Filed May" 12. 1920 INVENT E' M A? M 5 44 Patented Jan. 24, 1928.

UNITED, STATES PATE O E:

ARTHUR o. AUSTIN, or Bummer. OHIO, 'assreuoafsv Mam lassrenmnurs, To

THE OHIO BRASS compan or MANSFIELD, ion c, A eoaronarrou or NEW JEB- SEY.

Q'INSULATOR rm.

on application filed Kay 12, 1920, Serial 110380.826. Divided-andthis application filed September 4, 1925. Serial No.54,430.

This invention relates .to pins for supporting insulators for various electrical conductors; and has for its object'the provision of a device which shall be of improved-construction and operation, and Whichshall be economical to manufacture and provide ef' licient distribution of the material -withoutinterfering with the electrical propertiesof the insulator. a The invention is exemplifiedin the combina-tion and arrangementof parts shown in the accompanying drawing and described in the following specification, and-it is more particularly pointed out in the appended claims. I

In the drawing Fig. 1 is an elevation of a pin showing one embodiment of the present invention with the separately formed base in section;

Fig. 2 is a horizontal section on line 2--2 ofFig. 1.

This application is a division of appli'ca tion,Serial No. 380,826, filed May 12, 1920.

Insulators for electrical conductors are supported in a variety of Ways, one of the common means being by the use of pins carried by the supporting structure and bearing the insulator fitted over theend thereoi Such pins are used for supporting insulator: on metal and wooden arms and pole tops and also on various constructions other than regular line Wire supports. A pin to meet the requirements to which it is subjected must have the necessarymechanical strength to Withstand the stressesbrought upon "it and should not materially lower the fiasliover voltage of the insulator or otherwise diminish the electrical efficiency of the insulator. The cost of manufacture should be kept as low as possible and the pin should provide the required strength Without setting up undue stress in the fragile material of the insulator which it carries. The pin should also be adaptableto various conditions which arise in line construction and other electrical installations Where insulators are used,.an'd it is also desirable that the pins should be so designed that a large variety can be made from as small a variety of stock as pomible.

From the embodiment of the invention shownin thedrawing, it will beapparent that the small body diameter of pins 0011- structed inaccordance with this invention permitsdeveloping the maximumflashover 5 voltage value of the insulator since the small diameterofthe pin body keeps the outer surfaceotf the body" at. a maximum distance from the lower edge of the' insulator itself.

It Will also be seen that the supportingbase 00 and the body portionof the insulator pin are made: in separate parts which permits the use of a. base having sufficient area so that tliexcross-arm upon Which the base rests will not :be crushed under bending moment. The 05 construction permits of a. balanced arrange ment and at the same timedoes not sacrifice the electricalproperties of the insulator. In pins having a small base formed integrally with the pin, the bending moment upon 10 the pinforces the edge ioftheibase into con tact with theupper face of the summit ing structure so that where the structure is made of Wood, thefibresare crushed at the edge of: the base. permitting the pin to lean I to onesideand loosening the connection with the support. It isiinpractical to form apin 'With an integral base of sufficient area to overcome this difli'culty, tor the reason that I if the'pin is cut from apiece of stock of large diaineterithe Waste is too great to justify a sufficient expanse of base, and if it is undertaken to upset or savage a smaller piece of stoclcto form the base, it is impossible to expand the material a sull' cient amount to give abase ofthe required extent. Such operation also tends to form laps or flaws in the metal. Where the base is formed separately from the pin andisprovidedwith meansto hold the two rigidlytogethen when the pin is installed, the base maybe made of any'desired' extent and shape and pins may be standardized so that the same pinsmay be used with a large variety of supporting bases. pin may be secured to the base by means of a tapered end fittingin atapered socket and the taper may beso proportioned that thepins may be readily made With a sWaging-machine from straight-bar stock I without the loss of material. No finishing when a bending moment is applied, and at the same time the taper should preferably be such that the pin will not bend in the smallsections, the smaller portion of the pin being reinforced by the. base. When the base and body are assembled they are held together so that they will work as a unitary struetureand the main body of the pin may be made in straight section or given a taper,

which will give uniform strength for the bending moment, or it may be made in stepped diameters, if desired.

The insulator may be secured to the pin in a large variety of ways, depending upon conditions. .In some cases a lead tip may be cast or pressed on'the pin which will form a cushion between the hard metal and the porcelain. pin may, under some conditions, be provided with a roughened surface, or with resilient flanges or projections, to reduce the danger of cracking the insulator under expansion and contraction of temperature changes. Another method of securing the insulator to the top of thepin is to provide the end of the pin with large or small threads which can be adapted to a thimble of sheet material threaded into the insulator.

In thisconstruction the threaded parts may be. cone-shaped and the insulator may be tightened downfirmly and afterwards the wire groove in the insulator may be properly alined by turning the pin relative to its supporting base. *The thimbles, however, instead of being cone-shaped may be cylindrical so that they can be turned upon the pins to aline the wire grooves without loossuing the insulator on the pin. Where this arrangement is made, the pin can be rigidly attached to the supporting base. Under most conditions, however, the pin and base will be separable which will permit-combinations of various forms of pin with dif ferent kinds of bases so that the proper arrangement maybe secured for alarge variety of conditions. i i

V In the form of the invention shown in the drawing, the numeral 1 designates the elongated'body portion of a pin which may be formed from stockmaterial by swagingor forging to produce the elongated tapered body portion of the pin and a tapered lower end, indicated at 2 in the drawing. Below the tapered portion 2 there is provided a cylindrical extension 3 of reduced size being threaded at its lower end for receiving a nut 4 which engages. a washer 5 disposed be-v neath the cross-arm or supporting structure. The pin is provided with a base member 6 having a conical-shaped socket which is cut away, as shown at 7 to provide ribs 8 for The upper portion of the engaging the tapered portion 2 of the pin. This enables the socket member to grip the pin and hold it more firmly against rotation. It also makes it possible toeasily it the individual pins and socketswhere necessary. It When the parts are assembled there is foundany irregularity a drift tool may be driven into the tapered socket to bring the socket to proper taper, or, the socket. maybe easilyreamcd to true shape. I claim 1. The combination with an insulator pin,

of abase for supporting-said pin, said base having a -socket for receiving said pin, the wall of said socket being recessed to provide contact between said socket and pin for a portion only of the surface of said pin while the portion of said pin disposed in said socket has a continuously curved circular outer surface.

2. The combination with aninsulator pin, a

of aseparately formed base having a socket:

for receiving said pin, said soeket'having longitudinally extending narrow ribson the inner facethereo'f for engaging the surface of said pin, said ribsbeing of less than degrees extent circumferentially. of said socket. 3 y i i 3. The combinationwith an insulatorpin, of a base having a socket for receiving the lower end of said pin, said 'pin being enlarged 'at the upper end of said socket to limit the movement of said" pin into said socket, and an extension on said pin below said socket for attaching said pin to a supporting structure, said socket having more than two. longitudinally extending narrow ribs for engaging the surface of said pin.

,4. An insulator support comprisinga pin having an elongated body member, and a tapered portion at the lower end of said body member, and a separately formed base for said pin. said base having a tapered socket provided with more than two longitudinally extending inwardly projecting narrow ribs each of less than 90 degrees extent circumferentially for engaging the tapered portion of said pin; y I

5. Ali-insulator support comprising a pin having an elongated body member, a tapered portion at the lower end of said bodymember. anda cylindrical extensionbelow said.

socket provided with more than two inwardsocket of said base member and for clamply projecting longitudinally extending naring said pin and base member on a supportrow ribs of less than 90 degrees extent cirin structure. 10 cumferentiallynf said socket for engaging in testimony whereof I have signed my 5 the tapered base portion of said in, and a name to this specification on this 26th day threaded member on said cylindrical extenof Aug, A. D. 1925. sion for drawing said pin into the tapered ARTHUR O. AUSTIN.

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