Improvements in Incandescent Electric Lamps.
Year: 1894

page_text: Date of Application, 21st July, 1894
Complete Specification Left, 22nd. Apr., 1895-Accepted, 24th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Incandescent Electric Lamps.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern.& Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by Carl Schwabe, of 70, Blumenstrasse, Berlin, in the German Empire,
Manufacturer) to be as follows::-
This invention relates to improvements in incandescent electric lamps.
In that class of incandescent lamps which are. provided with a metallic covering
which serves as a reflector there is a disadvantage which interferes with their
usefulness, arising from the fact that the image of the incandescent carbon filament
is reflected from the metallic covering. This disadvantage is especially evident
when white surfaces are to be illuminated, the result being that reading or writing
by the aid of this illumination is found to be injurious.
In the present lamp this disadvantage is avoided by roughening the free portion
of the bulb.
According to my invention the upper part of the lamp is furnished with a
metallic casing which serves as a reflector, whilst the lower part of the bulb is
made dull by any suitable means. By this means the reflection of the incandescent
carbon filament is prevented.
Dated the 21st day of July 1894
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Incandescent Electric Lamps.
I, GEORGE FREderick Redfern, of the Firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by Carl Schwabe, of 70, Blumenstrasse, Berlin, in the German Empire,
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 improvements in incandescent electric lamps.
In that class of incandescent lamps which are provided with a metallic covering
which serves as a reflector there is a disadvantage which interferes with their
usefulness, arising from the fact that the image of the incandescent carbɔn filament
is reflected from the metallic covering. This disadvantage is especially evident
when white surfaces are to be illuminated, the result being that reading or writing
by the aid of this illumination is found to be injurious.
In the present lamp this disadvantage is avoided by partially or entirely frosting,
grinding or otherwise roughening or making dull the uncovered portion of the
bulb.
The accompanying drawing represents in elevation an incandescent electric lamp
embodying this invention.

page_text: The upper part of the lamp is furnished with a metallic casing A which serves
as a reflector, whilst the lower part B of the bulb is made dull by any suitable
means. By this means the reflection of the incandescent carbon filament is
prevented.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
An incandescent electric lamp having a metallic casing serving as a reflector and
a bulb which is partially or entirely frosted, ground or otherwise roughened or
rendered dull, substantially as hereinbefore described.
Dated the 22nd day of April 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.