US1702237A - Process of manufacturing insulator pins - Google Patents

Description

Feb. 12,, 1929.

A. o. AUSTIN -PROCESS OF MANUFACTURING INSULATOR PINS Filed March 1. 192's 2 Sheets-Sheet 1 INVENTOR By M 8% 1 A TITORNE rs Feb. 12, 1929.

. A. O. AUSTIN PROCESS OF MANUFACTURING YINSULA'I'OR PINS Filed March 1, 1923 2 Sheets-Sheet 2 fl/NVENTOR BY 7 A TTORNE V ARTHUR O. AUSTIN, OF BARBERTON, OHIO, ASSIGNOR, BY MESFTE ASSI(3N111715151"!S, TO

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Patented Feb. 12, 1929.

UNITED STATES PATENT. OFF'ICE.- V

THE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEY.

rnoon'ss' or MANUFACTURING INsULA'roR rms.

Application filed March I, 1923. Serial No. 621,966. I

This .invention relates to supports for electrical insulators having a pin on which the insulator is mounted and means for securing the p n to a cross arm or ber'. 'Ihe invention has for its object the provislon of an economical and simple method of manufacturing insulator pins whichmay be easily assembled in place on their supports and which are efficient 'in operation both from a mechanical and an electrical The invention also contemplates simplification and lmprovement of the pin itself so,

' as to facilitate the process of manufacture mem and provide a pin of maximum eifi'ciency. The invention is exemplified in the combinat10n and arrangement of parts shown in the accompanying drawings and described in the following specification and it is more particularly pointed out in the appended claims.

In the drawings Fig. 1 is an elevation of one form of insulator pin manufactured according to the present invention.

Fig. 2 shows a base member.

slightly modified form pf Fig. 3 illustratesone step ofthe process ofmanufacturing the base member.

Fig. 4 illustrates another step in the process.

Figs. 5 and 6 illustrate two steps of the process as performed with slightly different tools from those illustrated in Figs. 3 and 4.

Fig. 7 shows another form of tool that may be used.

' Fig. 8 is a punching and before the final finishing operation.

Fig. 9 is a top plan view of another form of base member.

Fig. 10 is a vertical section of the base member shown in Fig.- 9 and illustrates the finishing operation therefor.

Fig. 11 is a section on line 1111 of Fig. 10. Fi 12 is a top plan of another form of base Fig. 13 is a vertical section of the member shown in Fig. 12 and illustrates the finishing operation therefor.

As shown in Fig. 1', the numeral 10 designates the body portion of an insulator pin which may be forged or otherwise formed of iron or steel and is preferably galvanized,

other supporting mem "greatest section of the base member after i drawn tightly to teriaL A thimble of lead for other similar materlal is formed on the upper end of the p1n forthe purpose of providing a suitable connection with the insulator.

In order to support the pin upon the cross arm it is desirable to have a base member 12 having a considerable bearing surface 13 to rest upon the upper face ofthe support. It 1s mpractical from a manufacturing standpoint to'form this supporting flange integrally with the main body of the pin 10 for thereason that such a method of manufacture would either require very great amount of metal to reduce the other parts to their proper size or else the expansion by upsetting or other processes of the cutting away of a Y the portion of the metal to form the flange. Both of these methods of manufacture are diflicult and expensive. Where a separate base is provided it is desirable that the strength of the pin shall not be reduced at thepoint where it enters the support, for this is the portion of the pin subjected to the bending moments. It is also desirable that the parts may be readily assembled and easily attached to the support and that a firm connection shall be established between the pin and base member so that they will act substantially as one piece both as to rotary and laterally acting forces. It has been found that a plain taper 14 in the base member 12 which fits a corresponding taper,

on the pin is well adapted to secure these results. This permits the base member to reinforce the portion of the pin where it is reduced to pass thru the cross arm and also insures a tight fit between the base and pin, since the pin is drawn tightly into the taper by the nut 15 threaded to the pin beneath the cross arni. The perforation thru the base 12 is preferably provided with a straight por-' tion 16 at the bottom thereof to insure proper bearing of the tapered surfaces on the pm and base. When the two fitting tapers are gether the friction between the surfaces will resist relative rotation of the pin and base and will cause the two to act substantially as one piece. Where it is desired to hold the pin against rotation on the cross arm while screwing the insulator on the pin the base may be provided with teeth or projections 17 as shown in Fig. 2 of the drawing. In that figure the supportmg base is curved as shown at 18 to fit the upper curved surface of the rounded cross arm. It will be understood that the teeth 17 may be formed on a fiat base such as that shown in Fig. 1 as well as upona curved supporting surface illustrated in Fig. 2.

In manufacturingthe base member 12, ithas been found impractical to accurately form the perforation for receiving the pin by the ordinary forging process for the reason that it is difficult to maintain the forging tools sufliciently accurate to provide an accurate fit for the pin and base. Forging deep recesses is also a diflicult operation. To overcome these difficulties, according to the present invention the base member 12 is first forged into a shape similar to that illustrated in Figs. 3 and 5 in which the central perforation is formed part way thru the base from both of the opposite sides. This avoids the necessity of forming excessively deep recesses by the forging process and at the same time makes perforation sufiiciently deep that the remaining metal 17 may be severed from the base member by drilling or punching to complete the perforation. In finishing the base from the forging as shown in Fig. 5 the metal 17 may first be drilled from the center of the forging and the tapered open-' ing may then be completed by means of a reamer of proper size and taper. Another method of completing the base is to insert a cylindrical punch into the upper tapered opening as illustrated in Fig. 5v and force the material 17 downwardly completing the perforation, the forging being held by a suitable supporting die 18 (Fig. 3) having a stripper 19 connected therewith. After the punching operation a tapered drift tool 20, Fig. 7, is forced into the tapered opening, the drift tool 20 being of proper size and taper to correspond to the tapered portion of the pin 10. The finishing operations may be performed with the metal either hot or cold. A single tool may be employed as illustrated in Figs. 3 and 4 for both punching and shaping the interior of the perforation, but if separate tools are used it is found that in some cases less difficulty will be experienced in maintaining the tools in proper condition. The drift tool may in some cases be pro vided with a guiding boss or pilot 21, as shown in Fig. 7, or this guide may be omitted as shown in Fig. 6. After punching, the base member will have the form illustrated in Fig. 8 and the metal inside the broken lines 22 will be forced back by the finishing tool to give the correct taper shown by these lines.

In Figs. 9, 10 and 11 there is shown a base member having a tapered socket with angular sectional shape. This can be finished from the form of forging shown in Figs. 3 and 5 by a punch like that shown at 22', Fig. 10.' The base may be provided with ears 23 to hold it from turning on the base while an insulator is screwed to the top of the pin,

Which will of course be provided with an angulartaper portion to fit the socket 1n the base member. The base member is also pro 'vided with an outer angular portion 27, upon 24 through which bolts or cap screws may be passed for securing it to its support. In this form the underside of the base is recessed at 25 to receive a nut 26 for holding the pin to a the base. This form is especially. valuable for use with bus bars and other installations where the base is anchored on the support.

I claim: i

1. The process of manufacturing an insulator pin wherein a pin body and base are separately formed the base being shaped and partially perforated by forging after which the perforation is completed by a severing operation the interior of said perforation being given a predetermined taper to correspond to a tapered portion of said pin body the shape of said tapered perforation being produced by a tool of corresponding shape and size which is forced into said perforathe interior thereof is given a tapered formation to fit a tapered portion of a pin to be supported thereby said tapered formation being imparted to said perforation by a drift tool forced into said perforation.

3. The process of manufacturing an insulator support wherein a pin body and a base member are separately formed said base member being roughly formed by forging and being finished to provide a perforation therethru, having a tapered portion of predetermined size and shape to correspond to a similar tapered portion on said pin body, the pin body being inserted in said base member and secured in place in said base member by an attaching means arranged to draw the tapered portion of said pin body and base member tightly together.

4. The process of manufacturing an insulator support comprising the steps of forming a pin body having portions of different diameters connected by an intermediatetapered portion, separately forming a base member to support said pin body and having a socket to fit said intermediate tapered portion, and forming the socket in said base member in separate steps including a combined punching and shaping operation.

In testimony whereof I have signed In name to this specification on this 24th day of February, A. D. 1923.

" ARTHUR O. AUSTIN.

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