IMPROVEMENTS IN AND RELATING TO INCANDESCENCE ELECTRIC LAMPS
Year: 1884

page_text: I HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co Patent Agents,
uthampton Buildings in the County of Middlesex do hereby declare the nature
my Invention for "IMPROVEMENTS IN AND RELATING TO INCANDESCENCE
ELECTRIC LAMPS" 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 incandescence electric lamps, and especially to a burner
comprising a carbon and earths, metals, minerals, or other material used in
connection with the carbon, whereby certain advantages hereinafter enumerated
are obtained; to the manner of uniting the carbon with the platinum or other
conducting wires; to the shape and form of the glass globe or bulb, forming the
shell of the vacuum chamber; to the use in connection with the said lamp of a
reflector; and to a wire gauze protector all as hereinafter described.
The advantages of the composite burner may be obtained in two ways, first, by
uniting the light-diffusing particles or surfacing of metal or other substances
directly with the carbon, and, second by supporting the said metal or other
substance for producing light in such close proximity to the carbon that it shall be
heated thereby.
I consider that three principal advantages are obtained by the use of this
composite burner and the first arises from the fact that by using metals or other
substances which diffuse light at a temperature less than the light-giving
temperature of a carbon, less electric force is required to run the light; for it is
only necessary to heat the carbon sufficiently to cause it in turu to heat the inetal
or other substance carried thereby, or in close contact therewith or relation thereto
sufficiently to diffuse light; and as the light-diffusing temperature of many metals
and other substances is much less than that of the ordinary carbon, it is obvious
that this advantage is of considerable value.
The second advantage arises from the fact that a much brighter or whiter light
can be obtained by the use of certain metals and other substances than can be
obtained from the carbon alone. And this result may arise when metals or
substances which diffuse an intense light at a lower temperature than the light-
diffusing temperature of the carbon are used; or when the same, or even a greater

page_text: temperature is employed; and the economy which arises from this use is in the
greater intensity and power of the light.
The third advantage relates especially to the durability of the burner, as the life
of a burner of the construction which I am describing will be greater than that of
the ordinary carbon.
In the accompanying Drawing,
Figure 1 represents in elevation and vertical section an incandescence electric
lamp fitted with a reflector and gauze screen.
Figures 2, 3, 4 and 5 illustrate the manner of uniting the carbon filament to
platinum or other conducting wires bereinafter inore fully described.
Figures 6, 7, 8, 9, 10 and 11 refer to a burner for incandescence electric lights in
which a carbon filament is employed for heating superposed metal, mineral or
earthy matter.
Figures 12 and 13 illustrate the application to an incandescent electric light of
a gauze protector.
I prefer to make the carbon filament of silk, flax, cotton or linen fibre or thread,
but I do not wish to be understood as confining myself thereto. And to illustrate
one method of treating the fibre to produce the composite burner I will describe
the process which I prefer to employ, when silver is used as the light-diffusing
material.
I first make an ammoniacal solution of silver, and into this solution the fibre is
placed, and allowed to soak therein for from two to ten or twelve hours, when it is
largely covered or saturated with ammoniacal oxide of silver. The fibre thus
treated is stretched or dried, then coated with an adhesive solution, and then
covered with fine plumbago or gas-house retort carbon, or a mixture of both, the
adhesive solution holding to the fibre. It is then cut into suitable lengths and is
placed in grooves formed in a carbon plate and covered with a thin layer of
plumbago, gas-house retort carbon, or a mixture of both, and is then carbonized in
a muffle. After carbonization the carbon filaments are placed in the silver solution
and allowed to remain therein from three to eight hours. This fills the interstices
and covers the surface of the carbon with silver, so that, it may be said, the carbon
is charged on its surface with silver. Each carbon is then placed in a vacuum and
a current of electricity passed through it. It is then taken out, and in some
instances heated again, when it is ready for use.
When other metals or substances are used in lieu of the silver the fibre and
carbon are treated by substantially the process herein described, that is to say, if a
metal is used it is preferably reduced to a solution and precipitated upon the
carbon, but it may be attached thereto by an adhesive composition, or in any other
desirable manner; and the same may be said of such other substances as may be
employed. As there are many such substances it will be impossible for me to name
them all, and I shall simply refer to a few of the most obvious, namely, brass, iron,
zinc, lead, tin, nickel, platinum and aluminium.
This form of composite carbon is well represented in Figures 1, 12 and 13.
In Figures 6 to 11 inclusive I represent another form of my Invention in which
the light-diffusing material instead of being attached directly to the carbon filament
is not supported thereby but is placed in close relation thereto. Any suitable
carbon filament may be used in this modification, and I prefer to use one that is
made of silk, flax, cotton, linen, or other similar fibre, coated by means of an
adhesive solution of fine plumbago, gas-house retort carbon, magnesia, silex or
ground glass, or either, or any combination, of these materials, and placed in grooves
in a carbon plate and covered with plumbago, gas-house retort carbon, magnesia, silex
or ground glass, or either or any combination of these materials, and then carbonized
in a mulle. Each carbon before use should be placed in a vacuum and a current of
electricity passed through it. The carbon is then arranged within the vacuum
chamber of the glass bulb or globe, in close proximity and auxiliary to the burner
or light. And the auxiliary burner or, light may be made of any suitable light-
diffusing material, and may be arranged in any form in relation to the carbon. It

page_text: may be made in the form of a light sleeve which shall enclose the carbon, as
represented in Figure 8, or as a perforated sleeve, as represented in Figure 9, or
as a spiral wire, as shown in Figure 6, or in detached or separate sections as
represented in Figure 11.
This auxiliary burner is suspended from glass or other insulators within the
chamber, and must bear such relation to the carbon and wires connected therewith
as not to connect the platinum wires.
Before placing the carbon burner within the vacuum chamber of the lamp, I
prefer to heat the carbon or auxiliary burner in a vacuum one or more times, as
by so.doing I find that with certain metals or materials a more desirable result is
obtained.
In the Drawings A is the glass bulb, B the carbon filament, C the auxiliary
burner.
The globes or bulbs are preferably made slightly concave upon their under sides
as shown in Figures 6 and 8. The object of shaping the bulbs or globes in this
manner is to reduce the thickness of the under sides thereof and make them of
uniform thickness with the side portions, thereby facilitating the downward
diffusion of light. When the globe has a thick mass of glass at its bottom it
interferes materially with the downward diffusion of light, but by making the
globe as described if there is a defect in the device it is overcome.
.
I prefer to connect the carbon with the platiuum wires by a joint substantially
like that shown in Figures 2 to 5 inclusive that is, upon each end of the platinum
wires there is formed a tube a, through which I pass the ends 6 of the carbon, and
I then flatten the tubes thereon and clamp the ends of the carbon to the wire, and
cover the joints with cement composed, substantially of the following elements:
Plumbago 40 parts gas-house retort carbon 35 parts, clay 20 parts, borax 4 parts
sal ammoniac 1 part. The clay and sal ammoniac are placed in a copper pan and
heated to a red heat, fused, and pulverized when cold, and are then mixed with
the other ingredients and with water. The cement thus prepared is applied with
a brush about the joint (see Figures 4 and 5) and then placed in a gas jet and
heated until red hot and then cooled. The cement should entirely cover the joint
and extend well into the platinum wire.
When lamps are used in factories employing naphtha or other inflammable
vapors it is desirable to protect them with a wire gauze, and in Figures 1, 12
and 13 I have shown the light thus protected. By placing the gauze at a distance
from the lamp beyond the radiating point of an igniting temperature no danger of
inflaming the atmosphere of the factory would occur even if the globe or bulb were
broken, in the short time which elapses before the filament is burned.
For certain purposes it is desirable to use in connection with the gauze a
reflector attached to the neck or holder of the globe or bulb, and I have represented
such a construction in Figure 1 where it is also shown in connection with a gauze
envelope. By plating the wire gauze with white metals, such as silver, tin or
nickel the wire gauze refiector will utilize most of the light.
The principal advantages of the Invention, however, arise from the use of the
burner described, as it provides for a great diffusion of light with a less expenditure
of electro-motive force than any incandescent lamp which the communicator of
this Invention has knowledge of and therefore greatly cheapens the cost of the
light.
Having now particularly described and ascertained the nature of my said
Invention and the manner of performing the same I declare that what I claim
is:-
First. An incandescence electric lamp having a glass bulb or vacuum chamber
and a composite or compound burner of the character specified, all substantially as
described.
Second. A carbon for incandescence electric lamps, consisting of a carbon
filament bearing or supporting a surfacing or particles of metal or other material

page_text: for diffusing light when heated by the carbon, all substantially as, and for the
purposes, described.
Third. In an incandescence electric lamp the combination of a carbon, a separate
burner of metal or other suitable material disposed and supported. within the
vacuum chamber, and adapted to be heated by the carbon, all substantially as, and
for the purposes, described.
Fourth. The combination of a glass globe. or bulb forming a vacuum chamber,
the carbon connected at each end with electric conductors, and an auxiliary burner
of metal or other material supported within the vacuum chamber, and in close
proximity to the carbon, all substantially as, and for the purposes, described.
Fifth. In an incandescence lamp, as a means of uniting the carbon filament with
the platinum or other electric conductors, the joint herein described.
Sixth. In an incandescence electric lamp a glass globe or bulb having the shape
described.
Seventh. In an incandescence electric lamp, the combination of the transparent
vacuum bulb and the enclosed filament, with a wire gauze envelope, substantially
as, and for the purposes, described.
Eighth. The combination in an incandescence lamp, of the transparent vacuum
bulb, its enclosed filament, a reflector, and a gauze envelope, all substantially as,
and for the purposes, described.