Improvements in Insulating Material for Electric Purposes
Year: 1895

page_text: Date of Application, 30th Apr, 1895-Accepted, 22nd June, 1895
COMPLETE SPECIFICATION
Improvements in Insulating Material for Electric Purposes
A communication from THE VIRGINIA PHOSI HATE AND PAINT COMPANY,
a corporation organized under the Laws of the State of Virginia, United
States of Amenca said Company having an office in Washington, DC
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement
-
It has been found that a composition of matter consisting of titanic mineral and
a hydrocarbon, such as asphaltum, makes a fair insulator of electricity By adding
to this composition however, even a small percentage of a silicious material, such
as rice hulls or other organic material rich in silicic acid, it is found that it
becomes a most excellent insulator, capable of re-isting succe sfully electic currents
of very high tension
The titanic minerals which it is preferred to employ are found in a phosphate
ore of Nelson County, Virginia, USA and constitute about seventy per cent of
the same
They are known as menace unite, rutile, anatase and brookite, the first
mentioned being present in the largest proportion Either of these minerals may
be used exclusively, but as they are all usually found together in the ore referred
to they are conveniently so used
Any suitable hydro carbon may be employed, such as asphaltum, pitch or coal
tar, but it is preferred to use asphaltum
The silicious materials that may be employed are numerous Most any material
rich in silicic acid may answer, but it is preferred to use rice hulls, both on account of
their containing a large proportion of silicic acid and because of their cheapness-
no use for them having been heretofore discovered
In forming this improved insulating compound, it is preferable, in producing a
hundred pound, to use from seventy five to eighty five pounds of the titanic
mineral, fiom ten to twenty pounds of asphaltum and about five pounds of rice
hulls
The mineral, is preferably ground to a fine powder and mixed intimately with
the asphaltum by heat and stirring, adding the rice hulls either during or after the
mixing of the other ingredients
The insulating properties of this composition are remarkable, small masses of it,
not greater than an eighth of an inch in thickness, having been found capable of
resisting a cui rent of 24,000 volts
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondents and in what manner the
same is to be performed, I declare that what I claim is
1 An insulating compound composed of titanic mineral, such as de cribed,
hydro-cubon material, such as asphaltum, and a silicious material in substantially
the proportions set forth
hydio-carbon
2 An insulating compound composed of tita nc mineral a
material, such as asphaltum and rice hulls, in about the proportions set forth
Dated this 30th day of April 1895
BOULT & WADE,
Agents for the Applicant