Improvements in the Method of Frosting or Obscuring Glass Globes.
Year: 1890

page_text: Date of Application, 12th Feb., 1890
Complete Specification Left, 29th Mar., 1890-Accepted, 31st Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Method of Frosting or Obscuring Glass Globes.
I, WILLIAM HOPKIN AKESTER, of No. 15, Munster Road, Fulham, in the
County of Middlesex, Electrician, do hereby declare the nature of this invention to
be as follows:-
This invention relates to improvements in the method of frosting or obscuring
glass globes, such as those employed in incandescent electric lamps, whereby the
desired object is effected in a simple, economical, and effectual manner.
The glass surface to be frosted or obscured, after having been thoroughly cleansed,
is dipped into a bath of nitro-cellulose dissolved in acetate of amyl, and is afterwards
allowed to remain exposed to a dry atmosphere at a suitable temperature until the
solvent has evaporated.
Any coloring or other desired material for producing the frosting or other effect
is added to the above mentioned solution. By adding clear coloring material only
to the solution, the obscuring film on the glass will be comparatively clear and
transparent.
The frosting or obscuring medium on the surfaces of glass globes as hereinbefore
described will be found to offer a greater resistance to the action of heat and
moisture than is the case when the frosting or obscuring effect is produced by the
means ordinarily employed.
Noted this 10th day
1800
VAUGHAN & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Method of Frosting or Obscuring Glass Globes.
I, WILLIAM HOPKIN AKESTER, of No. 15, Munster Road, Fulham, in the
County of Middlesex, Electrician, 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 :-
This invention relates to improvements in the method of frosting or obscuring
articles or surfaces of glass and such as the exterior surfaces of the globes of
incandescent electric lamps whereby the desired object is attained in a more simple,
economic, and effective manner than heretofore.
For this purpose, the surface of the article to be frosted or obscured is first
thoroughly cleansed by any suitable means which will render it chemically clean
and such as methylated spirits, and the article is then dipped into a bath consisting
of nitro-cellulose dissolved in any suitable volatile solvent, such as acetate of amyl.
In preparing the bath, and when using acetate of amyl as the solvent, I take a
quantity of that form of nitro-cellulose known as the ordinary gun cotton of
commerce and place it in a closed vessel, and I add thereto a quantity of acetate of
amyl so that the consistency of the solution will be such that it will run freely.
To ensure the intimate combination of the nitro-cellulose with the acetate of
amyl, the vessel containing the solution is agitated, or the latter is stirred from time
to time.
When treating articles which are of such form or dimensions as to render the
dipping operation impracticable or inconvenient, I apply the bath solution to the
surface of the article by the aid of a brush, or other suitable means, or, I may cause
the solution to flow on to, and over such surface, and then permit any excess to
drain off.

page_text: The article which has been coated with the solution in the manner above
described, now place in a drying chamber, which is heated to a temperature of
about 100° Fahrenheit by means of steam or hot water circulating through suitable
pipes and through which chamber, a current of air is caused to pass, and I allow
it to remain in the chamber until the solvent of the solution has completely
evaporated; or, in lieu of employing the steam or hot water circulation pipes to
furnish the necessary heat to carry off the solvent, I may cause the current of air
to be heated to a temperature of about the same degree before passing into the
drying chamber.
In order to give to the article to be treated the appearance of ground glass, I
add to the bath solution hereinbefore described, from about 5 to 15 per cent. by
weight of finely divided kaolin, or, I may employ any like silicate of alumina or
white lead or other finely divided matter in suitable proportions.
When it is desired that the article should be coated with a colored film, I add to
either of the bath solutions hereinbefore described, any suitable coloring matter, such
as colored earth, but preferably the aniline series of dyes; or, when combining
pigment with the bath solution, I may dispense with the aniline, or other like
coloring matter; and employ colored earth in place of kaolin or other colorless
material.
By adding a clear coloring material, such as aniline, to the bath solution herein
first described, I am enabled to obtain a comparatively clear and transparent film
upon the article.
I would here remark that I do not confine myself to the precise proportions of
the ingredients hereinbefore given, as the same will admit of considerable modifi-
cation without departing from the peculiar character of my invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
1. The method of frosting or obscuring articles of glass consisting in applying
thereto a solution of nitro-cellulose dissolved in any suitable solvent, substantially
as herein described.
2. The method of frosting or obscuring articles of glass, consisting in applying
thereto a solution of nitro-cellulose dissolved in any suitable solvent, and combined
with aniline, or other suitable coloring matter, substantially as herein described.
Dated this 29th day of March 1890.
VAUGHAN & SON,
Agents for the Applicant.