An Improvement in the Manufacture of Glass Articles.
Year: 1897

page_text: Date of Application, 5th Jan., 1897-Accepted, 20th Mar., 1897.
An Improvement in the Manufacture of Glass Articles.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the
City of London, Civil Engineer and Chartered Patent Agent, do hereby declare
the nature of this invention (a communication to me from George Washington
Blair, of Pittsburg, in the County of Allegheny and State of Pennsylvania,
United States of America, Manufacturer), 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 chimneys, globes, shades, electric light bulbs, and like
articles (hereinafter termed chimney or globe) employed with sources of artificial
illumination; the diffusion of the light passing through the same being greatly
increased.
In the accompanying drawings, Fig. 1 is a side elevation, partly broken away,
of a mould adapted for use in the production of a lantern globe according to this
invention; Fig. 2 being a cross section of the globe blown therein.
In experimenting upon glass articles of the kind above referred to, it has been
found that by providing the same with a series of adjacent inwardly extending
projections, there being on the outside a series of registering angular indentations,
the diffusion of light afforded is enhanced, and much better and more ornamental
results are obtained than when plain chimneys are employed.
The invention therefore consists in the manufacture of blown glass articles for
the purposes specified having their outer surfaces provided with series of adjacent
angular indentations while corresponding and registering projections are formed in
their inner surfaces.
In the drawings, a, a represent the parts of a blow-mould for lantern globes,
these parts being hinged together in the usual way, and having upon their inner
faces, which form the mould-cavity, contiguous series of inwardly extending
angular and adjacent projections b, which, when the glass is blown in the mould,
form upon the outer surface of the globe contiguous series of sharply defined
prismatic angular indentations, and, on the inner face, corresponding series of
registering projections which are the reverse of the indentations.
The advantages of the invention result from the fact that when the article is in
use the light striking the faces of the inwardly extending projections is broken up
and diffused, thus greatly increasing the illuminating power and giving a much
softer and more pleasing effect.
It will be apparent that the mould may be varied and that the shape of the
articles and. of the projections, may be changed in many ways without departing
from the principle of the invention.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I claim :-
1. As a new article of manufacture, a lamp chimney or globe having upon its
inner surface contiguous series of inwardly extending adjacent projections,
substantially as described.

page_text: 2. As a new article of manufacture, a lamp chimney or globe having upon its
inner face contiguous series of adjacent projections, and upon its outer face
corresponding series of recesses, substantially as described.
Dated this 5th day of January 1897
G. G. M. HARDINGHAM.