IMPROVEMENTS IN INCANDESCENCE ELECTRIC LAMPS AND IN APPARATUS EMPLOYED IN THE MANUFACTURE OF THE CARBON FILAMENTS THEREFOR
Year: 1882

page_text: LETTERS PATENT to Jules Wauthier, of Clerkenwell in the County of
Middlesex Glass Blower for an Invention of IMPROVEMENTS IN INCANDESCENCE
ELECTRIC LAMPS AND IN APPARATUS EMPLOYED IN THE MANUFACTURE OF
THE CARBON FILAMENTS THEREFOR
PROVISIONAL SPECIFICATION left by the said Jules Wauthier at the
Office of the Commissioners of Patents on the 10th March 1882.
JULES WAUTHIER of Clerkenwell in the County of Middlesex Glass Blower.
"IMPROVEMENTS IN INCANDESCENCE ELECTRIC LAMPS AND IN APPARATUS
EMPLOYED IN THE MANUFACTURE OF THE CARBON FILAMENTS THEREFOR
"
My Invention relates to improvements in incandescence electric lamps and has
for its object first to obtain a greater body of light in a small compass by making
the carbon filament of peculiar form so as to get a greater length of filament than
usual.
The Invention has for its object secondly to lessen the number of joints in the
conducting wires and to more effectually protect the said wires and to avoid twice
sealing the exhaustion tube and more effectually protect the same and reduce the
labor and cost of manufacture.
My Invention consists first in making the carbon filament with one limb straight
or nearly so and the other coiled in the form of one or more turns of an open hèlix
encircling the straight or nearly straight limb at a distance therefrom so as to
occupy comparatively little space in the bulb with a relatively considerable length
of filament. The carbon filament is made of this peculiar shape by means of a
mould constructed as hereafter described.
My Invention consists secondly in an improved construction of the bulb and
head piece whereby there is only one piece of platinum and consequently only one
joint in each conducting wire instead of two pieces of platinum and three joints as
usual and only one sealing of the exhaustion tube instead of two and there is less
liability of accident to the lamp in sealing the exhaustion tube and the said tube
and wires are more effectually protected when the lamp is mounted. The platinum
1

page_text: conducting wires pass through the inner end of an inverted cup or tube of glass
inserted in the neck of the bulb and sealed thereto around the edge of the cup by
a double joint.
The inner end through which the wires pass into the bulb is closed but has a
central aperture into which the exhaustion tube is sealed by a "double joint " this
being done before the cup is inserted in the neck of the bulb. This cup or tube
extends inwards towards the bulb and forms a sort of inner neck closed at the
innermost end and sealed to the neck of the bulb around its outer end which is
open and accessible to the operator. The wires and exhaustion tube pass out
through this inner neck or cup and after the bulb has been exhausted the tube is
sealed up at a point just opposite or within the open end of this neck and at a
sufficient distance from the rest of the neck to avoid risk of accident to the latter
in sealing the exhaustion tube. It is well known that the usual method is to seal
the exhaustion tube a first time after exhausting, at a point distant from the neck
leaving a long length of tube attached thereto and afterwards to seal it a second
time close up to the neck and remove the excess so as to leave as little tube
projecting as possible, but in this second sealing there is great liability of fracturing
the neck or bulb and the projection however small is apt to be broken off in
mounting the lamp in its holder, whereas by my Invention the exhaustion tube is
central, it is sealed only once and that at a point distant from its junction with the
neck and yet it is wholly contained within the neck or nearly so and is therefore
protected from injury.
The moulds in which the filaments are brought to the desired shape and
carbonized consist of a central cylinder having a longitudinal perforation with or
without circumferential grooves, and outer segments enveloping said cylinder
grooved internally which are clamped around the cylinder.
The mould is capable of holding a large number of filaments which are passed
through the longitudinal perforation of the central cylinder and wound spirally
round its circumference and enveloped by the outer segment. The process of
moulding and carbonizing is much as usual.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jules Wauthier in the Great Seal Patent Office on the 9th September
1882.
JULES WAUTHIER of Clerkenwell in the County of Middlesex, Glass Blower.
"IMPROVEMENTS
IN INCANDESCENCE ELECTRIC LAMPS AND IN APPARATUS
EMPLOYED IN THE MANUFACTURE OF THE CARBON FILAMENTS THEREFOR."
My Invention has for its object to lessen the number of joints in the conducting
wires of electric incandescence lamps, and to more effectually protect the said wires
and avoid twice sealing the exhaustion tube, and more effectually protect said tube
and reduce the labor and cost of making the lamp.
My Invention consists in an improved construction of the neck or head piece of
the bulb whereby there is only one piece of platinum and consequently only one
joint in each conducting wire instead of two pieces of platinum and three joints as
usual in some kinds of lamps, and only one sealing of the exhaustion tube instead
of two as usual in all lamps, and there is less liability of accident to the lamp in
sealing the exhaustion tube, and the said tube and wires are more effectually
protected when the lamp is mounted in its holder.
In order that the Invention may be more readily understood, I have illustrated
an example thereof in the accompanying drawings and will proceed to describe it
with reference thereto. Figure 1 represents the lamp complete, and Figure 2
illustrates the different stages in the manufacture of the part through which the
wires pass.
The Invention consists in constructing the neck b of the bulb with a cup or
tube a of glass inserted therein and sealed thereto around its edge c, thus forming
a sort of inner neck closed at its inner end with the exception of a central aperture
at d; and in sealing the exhaustion tube e into this central aperture d so that the
said tube e extends centrally through the said inner neck a and projects from the
open mouth thereof. By this construction the tube can, after the bulb has been
exhausted, be sealed up at a point e¹ just opposite or within the open end of the
neck, which point is thus situated at a sufficient distance from the junction of
the tube with the neck or bulb to avoid risk of accident to the latter in sealing the
tube, and yet the neck or head piece of the bulb is not increased in length and the
exhaustion tube does not when sealed off, project so as to be liable to breakage, but
is protected by its central position within the neck. It is well known that the
usual method is to seal the exhaustion tube a first time after exhausting the bulb,
at a point distant from the neck, leaving a long length of tube attached to the
bulb, and afterwards to seal it a second time close up to the neck and break off
the excess of the tube so as to leave as little of the tube projecting as possible, but
in this second sealing there is great danger of fracturing the neck or the bulb and
the projection however small is apt to be broken off, thus destroying the lamp in
mounting the bulb in its holder whereas by my Invention the exhaustion tube is
central, it is sealed only once for all, and that at a point distant from its junction
with the neck and yet it is wholly contained within the neck or nearly so and is
therefore protected from injury.
The process of making the lamp is as follows:-I take a tube of glass a Figure 2
and draw it down as represented by dotted lines at a¹ a². The portion a¹ is then
removed leaving a central aperture d. The platinum wires fleach with a small
drop of glass adherent to it is inserted through a small hole made in the shoulder
of the tube a and sealed into the teats g thus formed in the usual manner, and the
end of the exhaustion tube e is then sealed into the aperture d by what is known

page_text: "
by glassblowers as a "double joint as shown. The glass is then severed at a³
and the portion a² represented in dotted lines is removed and the inner neck is
then inserted some distance within the outer neck b of the bulb and is sealed
thereto at c as shewn (i.e. by a "double joint ") the portion b' of the neck outside
of this joint being afterwards removed. The lamp is then exhausted in the usual
way and the tube e is afterwards sealed once for all at e¹ as above mentioned and
the superfluous portion e' of the tube is broken off and the lamp is then complete.
The parts of the wires where they pass through the teats g, only are of platinum,
the remainder being of copper.
Figure 3 represents the form of carbon filament, and Figure 4 the construction
of moulds for making it referred to in the title of my Letters Patent and in my
Provisional Specification but to which I do not now desire to lay any claim as part
of the Invention for which the aforesaid Letters Patent were granted. The form
of the carbon is sufficiently evident from the figure and the mould for producing it
consists of a central cylinder A of carbon and two segments B of the same material
fitting closely to and enclosing about two-thirds of the cylinder A. The latter has
a longitudinal perforation represented by the dotted lines and an end cavity as
shown, and the segments have grooves on their inner surface to receive the fibres
to be carbonised, a number of which are passed together through the longitudinal
perforation and wound spirally round the cylinder A and held in form by the
segments B applied against cylinder A and secured thereto by any suitable means.
The process of moulding and carbonising is the same as usual.
Having described the nature of the said Invention and the manner of performing
the same, I hereby expressly disclaim as part of my Invention the form of the
carbon and the moulds for making the same shown in Figures 3 and 4 and
described in reference thereto, and I declare that what I claim as the Invention to
be protected by the hereinbefore in part recited Letters Patent is.
The construction of the neck or head piece of the bulb of an incandescence lamp
substantially in the manner and for the purpose herein described and illustrated in
Figures 1 and 2 of the drawings, that is to say, with an inner tube or neck sealed
into the outer neck and extending inwards and closed at its inner end and with
the exhaustion tube sealed into an aperture in the said inner closed end of the
inner neck, the said tube extending outwards through the inner neck, substantially
as set forth.
In witness whereof I the said Jules Wauthier have hereunto set my hand
and seal this eighth day of September. A.D. 1882.