Improvements in Electric Incandescent Lamps.
Year: 1897

page_text: Date of Application, 16th Feb., 1897-Accepted, 16th Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Electric Incandescent Lamps.
We CHARLES SUMNER DOLLEY, RUSSELL HAWKINS, THOMAS MONTGOMERY
LIGHTFOOT, and HOWARD TOWNSEND GOODWIN, all of 683 Bourse Building,
Philadelphia, in the County of Philadelphia, and State of Pennsylvania, United
States of America, Gentlemen, 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 certain new and useful improvements in electric,
incandescent lamps.
An incandescent lamp constructed in accordance with this invention consists
essentially of a carbon conductor enclosed between plates or sheets of mica, or
other non-conducting substance, having a like resistance to the action of heat.
The carbon conductor may consist of an ordinary filament, or it may be cut to
any suitable or desired shape from paper or any other suitable material, or it may
be composed of suitable carbon paste which is placed in plastic condition upon the
face of a plate or sheet of mica, and hardened in situ.
An incandescent electric lamp, constructed in accordance with this invention
is shown in the accompanying drawings which form a part of this Specification,
and we have also shown in the drawings the application of the invention in its
relation to the production of words or characters in illuminated signs, etc.
In said drawings :-
-
Fig. 1 is a perspective view of an incandescent electric lamp embodying this
invention.
Fig. 2 is a central, longitudinal section of the same.
Fig. 3 is a side elevation of the lamp in which the carbon conductor is shown
as fashioned into a word.
In making this lamp, the carbon which we decide to employ in the construction
of the lamp is placed upon the face of a mica plate or sheet, and if desired the
carbon may be saturated with the salts of such metals as exhibit a high degree of
incandescence when heated. The mica plates may have any desired shape or
outline and may be of any suitable or preferred size, the two plates being so
intimately approximated as to expel and exclude the air when subjected to heat
which is applied simultaneously with heavy pressure within a chamber from which
the air has been exhausted.
The mica plates are held together and the air is excluded by a coating of any
suitable cement, (adapted to withstand a moderately high temperature) before the
application of pressure and exhaustion. A suitable cement is that known as
Liquid Glass, manufactured by Lawton Bros., of New York City, or the cement
used may be composed of chromatised gelatine.
The carbon conductor B thus enclosed between the non-conducting plates A A,
of mica or other substance adapted to the purpose, is furnished with connections
as shown at C, whereby the electric current is conveyed to it. These connections
preferably consist of wires of platinum or other metal, or of thin strips of metal such
as platinum foil or other similar foil,

page_text: The mica sheets thus prepared are preferably mounted within a suitable
boundary frame.
The mica sheets with their enclosed carbon conductor and metallic connections
and frame or glass cover, are furnished with a suitable base in which the metallic
connections are attached to metallic contact posts or rods C which extend into said
base in such a manner as to allow the lamp to be attached to a bracket or electrolier
bringing the contact posts or rods into' connection with the wires which supply the
electric current.
The carbon conductor may be cut, stamped or otherwise shaped into any desired
design, thus rendering it possible to produce artistic designs, ornamental signs,
numbers, letters and the like.
It is evident that this invention is capable of modifications without departing
from the spirit of the invention, as for instance, instead of using two transparent
plates of mica, one transparent plate might be used in connection. with a plate
of some opaque substance, thus producing a shaded light, which in some instances
might be desirable.
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+
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In an incandescent electric lamp, an incandescent filament compressed
between two non-conducting plates, one or both of which plates is either
transparent or translucent and from between which plates 'the' air las licen
exhausted, and a hermetically sealed boundary frame for said plates, substantially
as described and for the purpose specified.
11
2. The combination with two non-conducting plates, one or both of which is
either transparent or translucent, and from between which plates the air has been
exhausted, a filament compressed between said plates, a hermetically sealed
frame extending around the outer edges of the plates, and connection's for electric
wires, substantially as described.
3. The combination with two plates of mica or their equivalent, of an
incandescent filament compressed between said plates, a hermetically sealed frame
extending around the outer edges of the plates, and wire connections with the
filament thus compressed between the plates, 'substantially as describeu and for the
purpose specified.
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BOULT & WADE,
Agents for the 'Applicants.