To all whom it may concern:

Be it known that I, FRED M. LOCKE, a citizen of the United States, and resident of Victor, in the county of Ontario, in the State of New York, have invented new and useful improvements in the Manufacture of Insulators for high-Potential Electric Conductors, of which the following is a full, clear, and exact description.

This invention relates to certain improvements in the manufacture of insulators for high potential electric conductors, and is a division of my co-pending application Serial No.482,382, filed March 9, 1909, which has matured into Pat. No.1127042, Feb. 2, 1915, and refers more particularly to a composition electrical insulation as a new article of manufacture, the essential ingredients of which are boron or boron compound and porcelain or glass thoroughly mixed by trituration or levigation and then molded and fired in the usual manner for porcelain or glass insulators.

The use of glass as an insulator for high potential electric conductors is recognized by manufacturers and users as being impracticable owing to its brittleness and susceptibility to breakage by varying temperatures or climatic conditions, and also from the dielectric stresses and resultant heat to which it is subjected.  For this reason porcelain, which appears to have a greater dielectric strength and is less susceptible to breakage by variations in temperature or climatic conditions, is generally employed.

The primary object of my present invention is to increase the inductive capacity, dielectric strength and heat-resisting properties of this class of insulators to more effectively resist puncture or disintegration by an electric current or static charges therefrom, or from temperature of climatic changes.

I have discovered that by incorporating a suitable quantity of boron or boron compound, such as boracic acid, with the body of porcelain or glass usually employed for insulators, the inductive capacity, dielectric strength and resistance to puncture or disintegration by the electric current and sudden temperature or climatic changes, are increased approximately 20% over the same size and form of the base of porcelain insulators. For example, in the experiments which I have made to determine the relative specific inductive capacity of air, glass, porcelain and my improved insulator composition, I find that the specific inductive capacity of this composition is three times as great as that of the commercial porcelain insulators of the same size and form; six times as great as glass, and twelve times as great as air.

In the tests which I have made to determine the resistance to puncture by high voltage, I find that where a porcelain or glass insulator of the best quality was capable of resisting

 80,000 volts, an insulator made of my improved composition and of the same size and form as the porcelain or glass insulator, withstood 100,000 volts, or 20,000 volts more than the porcelain or glass insulator, which was due solely to the increased specific inductive capacity and dielectric strength produced by the boron or boron in some of its compound forms.  This high inductive capacity and dielectric strength which gives great toughness to the insulator, is probably due to the fact that boron and hydrogen form no compound or compounds under fusion and except in one or two special instances and under special circumstances, boron forms no compound whatsoever with hydrogen, thereby more effectively excluding moisture from the composition, which is believed to account for the high inductive capacity, dielectric strength, as well as non-puncturability and resistance to heat.

The manufacture of high potential porcelain and glass insulators is well understood, and in the formation of my improved composition the boron or boron compound, such as boracic acid, and porcelain or glass ingredients, are thoroughly mixed in suitable proportions.  The composition is then molded while in a plastic condition into the desired form of insulator and finished in the usual manner for making high potential porcelain or glass insulators.

The invention herein relates to a structure adapted to serve as an insulator in the technical meaning of the term as applied to an article of manufacture, and the terms "insulating support for line conductors" and "insulator for high potential electric conductors" are used in the claims herein to clearly define such structure as an article of manufacture to serve as an insulator in the technical meaning of the term and the claims herein are drawn to the process of producing the insulator described herein, and the term boron material as used in the claims hereof is deemed to include boron in elemental form as well as boron compounds and derivatives.

What I claim is:

1. An insulator for line conductors formed by fusing a vitrifiable base and boron material into a homogeneous body.

2. An insulator for line conductors formed by fusing a glass base and boron material into a homogeneous body.

3. An insulator for high voltage current formed by fusing a vitrifiable base and boron material into a homogeneous body, and shaping the fused mass to desired form.

In witness whereof I have hereunto set my hand this 12th day of January, 1915.

     FRED M. LOCKE.

Witnesses:

L. F. LOOMIS,

C. A. MOORE.