US806717A - High-voltage insulator. - Google Patents

Description

PATENTED DEC. 5, 1905.

G. W. THOMAS.

HIGH VOLTAGE INSULATOR.

APPLICATION FILED SEPT. 7. 1904.

WITNESSES ATTORNEYS UNITED STATES PATENT OFFICE.

GEORGE W. THOMAS, OF EAST LIVERPOOL, OHIO, ASSIGNOR TO THE R.

THOMAS AND SONS COMPANY, OF EAST LIVERPOOL, OHIO, A CORPO- RATION OF OHIO.

HIGH-VOLTAGE INSULATOR.

Specification of Letters Patent.

Patented Dec. 5, 1905.

To all whom, it may concern.-

Be it known that I, GEORGE W. THOMAS, a citizen of the United States of America, residing in East Liverpool, in the county of O0- lumbiana, State of Ohio, have invented an Improved High-Voltage Insulator, of which the following is a specification.

The object of my invention is to so construct an insulator especially adapted for high-voltage electric-transmission lines that it will re sist tendency to deterioration from arcing or other electrical accidents and at the same time will be able to stand the great mechanical strains to which it is subjected.

In general practice high-tension petticoated insulators, whether of porcelain or glass, are mounted on wooden pins, which with or without central ironbolts are fixed in cross-arms on the supporting-poles. One serious trouble eX- perienced with these Wooden pins is that when an arc forms across from the insulatorpetticoat it almost always jumps across to the point where the wooden pin joins upon the cross-arm and the wooden pin at that point becomes burned and loses both its mechanical strength and its electrical insulating power.

It is the main object of my invention to provide a construction which will enable me to dispense with this wooden pin and provide a non-combustible substitute which will at the same time have at least equal mechanical strength.

In the accompanying drawings, Figure 1 is a vertical section of an insulator constructed in accordance with my invention, and Fig. 2 is a view of a modification.

The main body of the insulator may vary considerably in construction and may have any suitable number of petticoats without departing from my invention. In Fig. 1, by Way of example, I have shown the body of the insulator as made with two petticoats A and A and preferably in two parts accordingly. These parts may be of porcelain or glass and may be united by any suitable means, as by cement a, or, if of porcelain, by means of slip or glaze during the process of manufacture, as is well known.

Instead of constructing the central lower part of the insulator with a female screwthread, as is common, for the reception of a corresponding male thread upon the upper end of a wooden supporting-pin I provide a supporting pin or post B, of porcelain or glass or like vitreous material, which I cement into the body of the insulator by suitable cementing material I).

One of the troublesome features in the manufacture of insulators is the formation of the usual carefully-formed female screw to receive the correspondingly-threaded wooden pin. This requires special forming-tools and special skill on the part of the operator. By my invention the formation of this screwthread is avoided, for the central hole into which the supporting-post is to be cemented may be made plain or may have any roughlyformed projections, so that the manufacture is materially simplified. On the upper end of the supporting-post annular grooves or screw-threads or other suitable projections I) may be formed, as indicated in Fig. 1, to give the needed holding-surface for the securingbody of cement.

The vitreous pin B is tubular and has passing through it a headed iron or other metallic bolt O, the head 0 of the bolt bearing upon the upper end of the vitreous post, while the other end of the iron bolt is threaded and receives a nut and washer n, by means of which the insulator, with its attached post, maybe secured to the usual cross-arm D. (Indicated by dotted lines.) The head of the iron bolt may be of any convenient shape to form a shoulder and, if preferred, may be formed as at c, Fig. 2, by simply bending the upper end of the bolt over. Between the shouldered head of the bolt and the top of the vitreous post B, I prefer to provide acushion-washer c, which may be conveniently of fiber. The lower end of the vitreous post should be of sufficient diameter to give a broad bearingface where it rests upon the cross-arm. It does not enter into the cross-arm, and accordingly sidewise mechanical strains are taken by the iron bolt and not by the post, as would be the case were the vitreous post to pass down into a hole in the cross-arm.

In putting the parts together it is preferable to so apply the cement that it -will also fill up crevices between the bolt and post.

I claim as my invention An insulator, comprising a petticoated body portion and a supporting-post, all of Vitreous I In testimony whereof I have signed my materiahthe supporting-post beingcemented name to this specification in the presence of to the body portion and having its lower end two subscribing Witnesses. a broad base adapted to rest on the cross-arm,

5 a metallic bolt assing through the post, and Witnesses:

having a shoul ered head bearing on the up- A. R. HOLMES, per end of the post. B. D. KENNEY.

GEORGE W. THOMAS.

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