IMPROVEMENTS IN THE CONSTRUCTION OF INCANDESCENT ELECTRIC LAMPS
Year: 1883

page_text: LETTERS PATENT to Emilius Müller 79 Leadenhall Street in the City of
London for an Invention of IMPROVEMENTS IN THE CONSTRUCTION OF
INCANDESCENT ELECTRIC LAMPS
PROVISIONAL SPECIFICATION left by the said Emilius Müller at the Office
of the Commissioners of Patents on the 9th April 1883.
EMILIUS MÜLLER of No. 79. Leadenhall Street in the City of London
IMPROVEMENTS IN THE CONSTRUCTION OF INCANDESCENT ELECTRIC LAMPS
1st The interior Glass tubes or Carbon-holders of the present lamps are dispensed
with and merely a glass bar is fixed across the Platinum wires so as to secure
them and prevent their touching one another
2nd The horse-shoe filiament is made of Box-wood (boxus sempervirens)
carbonized in the ordinary furnace (or by the usual process of carbonization and
the Filiament is connected inside the two Carbon blocks with the platinum wires,
these wires conveying the Electric Current through sealed orifices on the outside of
the bulb of the Lamp instead of being connected through a special tube at the base
of the lamp as in existing lamps.
3rd The Carbon filiament which consists of Boxwood (boxus sempervirens) is
fixed by a much more simple method. By inserting the connecting wires in an
aperture bored in each end of the Carbon blocks into which the filiaments are inserted,
so that the Platinum fits quite tightly in the blocks: the horse-shoe filiament is
fixed into the Carbon blocks in the same manner being secured by Cement so as to
produce a good Conductor, the two conducting platinum wires then pass out of the
bulb where they are hermetically sealed into the glass.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Emilius Müller in the Great Seal Patent Office on the
9th October 1883.
EMILIUS MÜLLER of 79 Leadenhall Street in the City of London
IMPROVEMENTS IN THE CONSTRUCTION OF INCANDESCENT ELECTRIC LAMPS
The said Invention has for its object the production of Electric Incandescent
Lamps of greater durability and simplicity and the avoidance of fine and delicate
workmanship-In order to obtain the desired results the lamps are constructed in
the following manner and in order to render the said Invention and construction
more easily understood and carried into effect, reference is made to the accompanying
sheet of drawings in which the figures indicate the various parts of the Lamp.
Figure 1. shows glass bulb before Carbon filament has been fixed. Figure 2. The
Carbon filament fixed in glass bulb ready for exhausting Figure 3. Lamp complete,
the Air having been exhausted and the bulb hermetically sealed, Figure. 4.
represents the Pump by which the lamps are exhausted. The Chamber or drying
tube A contains Sulphuric Acid, for the purpose of drying the Atmosphere in the
Lamps. C is a glass bulb in which the Mercury rises to the taps (B¹ and B²).
B¹ is closed so as to prevent air returning to Lamps, B being opened in order to
allow the Air to escape-D. is the lifting Bottle containing the Mercury—this
process is continued several times in order to produce a perfect vacuum, the
Electric Current being applied at the same time in order that all gases given off
from the Carbon filament by the Action of the Current may be removed with the
Air. Figure 5. represents the Carbon filament which consists of Box-wood (boxus
sempervirens) which wood I prefer for my filament-Figure 6. shows the platinum
wires drawn in the form of a tube into which the Carbon filament is inserted.
Figure 7. is the same two platinum wires held in position by passing through the
glass bar A. Figure 8. represents the platinum wires connected to the Carbon
tilament, my method of doing which, I now describe---
At the end of the Platinum wire a Carbon block is connected by means of the
wire being inserted in an aperture bored in the same, at the other end of the
Carbon block; the Carbon filament which consists of Boxwood (boxus sempervirens)
is inserted in exactly the same manner the whole being cemented so as to produce
good conductor, or in the following manner; one end of the Platinum wire being
flattened and twisted into the form of a tube, the Carbon filament being then
inserted in the same and cemented as before described; the two conducting wires
and the filament are then hermetically scaled into the top of the glass bulb as
shewn in figure 2. The lamp is then subjected to the exhausting process and
hermetically sealed as slewn in figure 3.
Having now described the nature of the said invention and the manner of
carrying into effect I would have it understood that modifications may be made in
the details without departing from the essential features of the invention but I
claim and therefore desire to have secured to me by the Grant of Letters Patent-
First The substance from which my filament is made. Second. The general
simplicity of the process of construction and exhaustion. Third. The improvements
in Incandescent Lamps, substantially and hereinbefore set forth described and
illustrated by the accompanying sheet of drawings.
In witness whereof I, the said Emilius Müller have hereunto set my hand
and seal this Ninth day of October One thousand Eight hundred and Eighty
three..