Improvements in Incandescent Electric Lamps, and the Method of Making the same.
Year: 1895

page_text: Date of Application, 15th Oct., 1895-Accepted, 11th Jan., 1896
COMPLETE SPECIFICATION.
Improvements in Incandescent Electric Lamps, and the Method
of Making the same.
I, SAMUEL EDWARD Cox, of 47 E. Prospect Street, Cleveland, in the County
of Cuyahoga, and State of Ohio United States of America, Electrician do
hereby declare the nature of my invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
My invention relates to an improvement in incandescent electric lamps and the
method of making the same.
In the manufacture of incandescent electric lamps it has been the usual custom to
use a number of pieces of glass in forming the mount or support for the filament;
the tubular extensions to enable the application of a vacuum pump and seals for
the bulb.
It is apparent that if one piece of glass only can be treated in such manner and
utilized for the bulb itself; tubular extension for attachment of a vacuum pump
and seal, considerable advancement will be made in the manufacture of incan-
descent electric lamps and it is the object of my invention to produce a lamp
constructed in this manner.
A further object is to so construct an incandescent electric lamp that the
complete lamp, including a metallic sleeve or ferrule, can be made at one operation
and so that the lamp will be adapted for the reception of a cap of any description,
which cap can be mechanically fitted thereon easily and quickly.
A further object is to construct an incandescent electric lamp in such manner
that the expense of material and the amount of time consumed in its manufacture,
will be reduced to a minimum.
A further object is to produce an incandescent electric lamp which shall be
simple in construction; avoid the tit or enlargement on the larger end of the
bulb, and which shall be efficient, in all respects, in the performance of its
functions.
With these objects in view the invention consists in an incandescent electric
lamp having the bulb, filament support and seal made of a single piece of glass.
The invention also consists in an incandescent electric lamp having the bulb,
filament support, seal and tubular extension for the attachment of exhausting
apparatus, made from a single piece of glass.
The invention also consists in the method of making an incandescent electric
lamp consisting in passing leading-in wires through holes in the walls of the neck
of the bulb, sealing said holes on the leading-in wires, exhausting the air from the
bulb and then sealing the butt or neck end of the bulb.
And the invention also consists in certain novel features of construction and
certain novel steps in the method of making incandescent electric lamps as herein-
after set forth and pointed out in the claims.
In the accompanying drawings,
Figures 1, 2, 3, 4, 5, 6 and 7 are views illustrating the various stages during
the manufacture of a lamp in accordance with my invention.
Figure 8 is a view of the finished lamp.
Figure 9 is a detail view of the ferrule, and
Figures 10 and 11 are separate views illustrating the leading-in wires and
filament.

page_text: In the drawing I have shown the conventional form of bulb, A, although any
other desired fort may be adopted, and in Figure 1 the bulb is represented as it
comes from the glass manufacturer.
In carrying my improved method of making an incandescent electric lamp into
effect, I first forin two small tubular protuberances 1, 1, Figure 2), which project
of the
outwardly about one-half to three-fourths of an inch, from the neck
bulb and practically at right angles thereto. These protuberances may be con-
veniently made by means of a fine needle carried by a suitable holder (at right
angles to the latter) and inserted into the neck of the bulb, the needle being pressed
against the inner face of the glass while a jet of flame is made to play against the
outer face. When the glass becomes soft or plastic, the pressure of the needle
against it will cause it to be forced outwardly to form one of the protuberances 1.
the same operation being repeated at a diametrically opposite point on the neck of
the bulb to form the other protuberance.
The tubular protuberances are then cut off to the desired length, preferably
about one eighth of an inch from the neck of the bulb, by means of any convenient
device, such, for instance as the ordinary glass knife. There will now bo two
holes 3, 3, in the neck of the bulb, as shown in Figure 3, for the reception of the
leading-in wires 4, the holes being of such size that the wires can be easily
threaded through them, as shown in Figure 4. The platinum leading-in wires 4
are preferably about three-eighths of an inch in length from a to 6 (Figure 10) aml
may be bent into L-shape, the ends of the filament 5 being secured to them at h
in any suitable manner.
The leading-in wires 4 may be entirely of platinum as shown in Figure 10, but
in order to reduce the expense of the lamp, it will probably be more desirable to
make each leading-in wire in two parts, c, d, as shown in Figure 11, the upper
part c to which the ends of the slament are attached, being of copper and the
lower
part d which passes through the wall of the bulb, being of platinum.
In Figure 4 the free ends of the leading-in wires are shown as projecting loosely
through the tubular protuberances on the bulb and the filament so disposed that
its upright portions will be parallel with each other. A small flame applied to
the outer ends of the protuberances will cause them to grasp and hold the leading-
in wires in position. The flame is next applied for sealing the leading-in wires to
the protuberances 1, 1,-the bulb being held at right angles to the flame.
When the glass surrounding the platinum wires becomes heated it will fall onto
said wires, effectually closing the bulb at these points and forming perfect sents.
While the glass is still in a plastic state, the leading-in wires will be caught by a
pair of small pliers from inside the bulb and pulled inwardly to any desired extent
or the wires may be grasped by the pliers from outside the bulb and pressed
inwardly. When the leading-in wires are thus forced inwardly, the glass which
previously formed the protuberances 1, 1, will be carried with them and made to
project into the bulb, as shown at e, Figure 5.
It will be observed that the labor and skill required to make the seals for the
leading-in wires are very much reduced over the ordinary methods employed for
accomplishing this purpose and that there is no combination or multiplicity of pieces
of glass with their attendant losses incident to the employment of the usual mounts
and bridges,
In order to form a channel for the external wires G, which must be connected to
the exposed ends of the leading-in wires, I heat the glass wall for a convenient
distance in a straight line directly under the points where the lending-in wires are
senled in the bulb. Then, by means of a carbon wedge or similar instrument, the
walls of the bulb are pressed in to form channels or recesses 12, which are
preferably made deeper at their upper than at their lower ends, or in other words,
anid channels or recesses are made tapering. The joints between the external
wires 6 and the outer ends of the leading-in wires are disposed in these channels
or recesses. Another function of the tapering channels or recesses is to receive
plaster Paris or similar sealing material which forms an anchor for a metallic sleeve

page_text: or ferrule 13 placed on the neck of the bulb and prevent the detachment of said
sleeve or ferrule. The sleeve or ferrule 13 is also made with an annular enlarge-
ment which forms an internal annular groove 14 for the reception of plaster or-
other sealing material. The joints between the external and leading-in wires are
preferably located in the channels or recessed at the junction of the latter with
the groove 14 in the sleeve or ferrule.
The bulb is now placed in a suitable device and rotated, while at the same time.
a flame is allowed to play on the neck of the bulb as 15, Figure 6. The walls of
the bulb are thus softened at 15 and the portion below said point will descend.
In order to prevent the wall of the bulb from thickening too much at 1, 1, the end
of the neck of the bulb will be drawn out so as to form a tube at 16 of proper
length. The end 17 will then be cut off at 18 and a convenient meaus will thus -
be provided for the attachment of an exhaust pump. When a vacuum shall have
been formed in the bulb, the tube 16 will be cut off and the neck of the bulb sealed
as at 19, Figure 8. The sealing of the bulb at the neck end thereof gets rid of
the small protuberance on the top of the bulb, which protuberance is not only
unsightly but cuts off some of the light.
It will be observed that only one piece of glass is used in the entire method of
making an incandescent electric lamp as herein described, thus avoiding the
necessity for the use of a separate glass mount or other separate part for
supporting the filament and leading-in wires, as well as a special tube for outside
purposes.
"
The metallic sleeve or ferrule 13 above referred to is an important feature of
my invention, for by its employment I am enabled to accomplish an object of much
intrinsic value, at least from a commercial standpoint. In manufacturing lamps for
"stock" it is the usual custom to make up a quantity of lamps and place them in
stock, without "capping or basing." After an order is received to be filled,
the lamps are provided with special caps specified in the order. As this capping
is done by the use of plaster Paris, a considerable time is required for drying and
setting, thus necessitating much delay in shipping. It would be impractical to cap
lamps as they are usually made, for stock, as there are a great many different
caps on the market. By means of my sleeve or ferrule 13, I can cap (provide
them with ferrules) the lamps as soon as they are made and place them in stock
with the plaster dry and set. The ferrule, being of metal, can be easily and
quickly mechanically fitted to any cap in the market.
My improved lamp is simple in construction, cheap to manufacture and effectual,
in all respects, in the performance of its functions.
Having now particularly described and ascertained the nature of my said inven--
tion and in what manner the same is to be performed, 1 declare that what [
claim is :-
1st. In au incandescent electric lamp, the combination with a bulb, of leading-in
wires passing through and sealed in the walls thereof and channels or recesses made
in the wall of the bulb, in which channels or recesses the outer ends of the leading-in
wires are disposed, substantially as set forth.
2nd. In an incandescent electric lamp, the combination with a bulb having
channels or recesses in its neck, of a metallic sleeve or ferrule on said neck, and
sealing material between said ferrule and neck of the bulb, said sealing material
being made to enter said channels or recesses, substantially as set forth.
3rd. In an incandescent electric lamp, the combination with a bulb having
tapering channels or recesses in its walls, of a sleeve or ferrule in said neck and
sealing material between said sleeve or ferrule and neck and in said tapering
channels or recesses, substantially as set forth.
4th. In an incandescent electric lamp, the combination with a bulb having:
channels or recesses in its neck, of a sleeve or ferrule having an internal groove,
on said neck, and sealing material between said neck and ferrule, aud in said.
channels or recesses and groove, substantially as set forth.

page_text: 5th. The method of making an incandescent electric lamp, consisting in forming
tubular protuberances on the neck of the bulb, cutting off the ends of said tubular
protuberances, passing lending-in wires through said protuberances, sealing the
glass on the leading-in wires, forcing the protuberances inwardly so that they will
project into the neck of the bulb, and exhausting and sealing the bulb, substantially
as set forth.
6th. The method of making an incandescent electric lamp, consisting in scaling
the leading-in wires with the filament attached thereto, in the walls of the bulb,
making channels or recesses in the wall of the bulb, in which the outer ends of
the leading-in wires enter, exhausting the bulb, placing a metallic ferrule on the
neck of the bulb and inserting sealing material between said neck and ferrule,
substantially as set forth.
D1 Sion 1805
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicant.