IMPROVEMENTS RELATING TO THE MANUFACTURE OF INCANDESCING ELECTRIC LAMPS
Year: 1884

page_text: 'I BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris & Mills of 23 South-
ampton Buildings in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for IMPROVEMENTS RELATING TO THE MANUFACTURE
OF INCANDESCING ELECTRIC LAMPS, a communication to me from abroad by
William Holzer of the town of Harrison, in the County of Hudson and State of
New Jersey in the United States of America, glass blower, to be as follows:—
The flexible carbon conductors or loops of incandescing electric lamps, frequently
become bent and irregular in shape during the process of carbonization, and
sometimes when raised to high incandescence during the operation of exhausting
the globes.
This difficulty increases as the loops are increased in length and decreased in
cross sectional area, and forms a serious obstacle in the way of making high
resistance loops of regular and uniform shape.
The object of the invention is to overcome this difficulty which is accomplished
by subjecting the loops to strain while raised to incandescence in a vacuum.
This is accomplished while the lamps are being exhausted.
A weight is attached to the end of each loop and keeps it under constant strain.
When the loop is raised to a high incandescence, as it is at the end of the process
of exhaustion, the carbon becomes somewhat plastic and the weight draws the loop
into regular shape, or prevents it from assuming an irregular form. This weight
may be a wire with a hook end, and if not heavy enough itself, may have any
suitable body attached to it to increase its weight The wire is passed into the
exhaust tube of the lamp and hooked on to the loop, hanging down into such
exhaust tube.
The exhaust tube is made of sufficient length so that when the lamp is ready for
sealing off from the pump a seal can be made in the tube which will leave a tube

page_text: attached to the lamp as long as the weight. By manipulation the weight is then
unhooked from the loop and drops into the tube when the lamp is sealed off from
the tube carrying the weight.
The weight can then be removed from the tube and used with other lamps.
The weight may be just sufficient to straighten the loop or prevent it from
bending without materially changing its form, or it may be heavy enough to
change the shape of the loop by drawing it into a wedge form.
This process may be applied to lamps in the course of construction, or lamps
already constructed and having irregular loops may be opened, and have exhaust
tubes attached to them, and then be re-exhausted and have their loops straightened
by this process.
The removal of the weight from the lamp'may be simplified, by making such
weight partly or wholly of iron, steel or other magnetic material, and by using a
magnet or a solenoid externally applied for releasing the weight from the loop.
The weight can then be dropped out of the lamp into the drying chamber of the
pump while the lamp is still in connection with the pump, and the lamp can be
sealed off directly, without using the double sealing before described.
The magnetic weight may be attached to the loop as well as detached from it by
a magnet or solenoid and if desired a magnet or solenoid could be used to increase
the pull or strain of the weight on the loop and could be mounted in position to be
applied constantly during the exhausting operation, or could be brought into action
when desired...
After the carbon loop has been straightened by the process described, the weight
need not be removed from the globe at all, but may be sealed therein.
B. J. B. MILLS.
By Harris & Mills,
23, Southampton Buildings,
Agents.

page_text: I BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of 23 South-
ampton Buildings in the County of Middlesex, Patent Agent do hereby declare the
nature of the said Invention for IMPROVEMENTS RELATING TO THE MANUFACTURE
OF INCANDESCING ELECTRIC LAMPS a communication to me from abroad by
William Holzer, of the Town of Harrison in the County of Hudson and State of
New Jersey in the United States of America, Glass Blower and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The flexible carbon conductors or loops of incandescing electric lamps frequently
become bent and irregular in shape during the process of carbonization and some-
times when raised to high incandescence during the operation of exhausting the
globes.
This difficulty increases as the loops are increased in length and decreased in
cross-sectional area, and forms a serious obstacle in the way of making high
resistance loops of regular and uniform shape.
The object I have in view is to overcome this difficulty which I do by subjecting
the loops to strain while raised to incandescence in a vacuum.
This I do while the lamps are being exhausted.
A weight is attached to the end of each loop and keeps it under constant strain.
When the loop is raised to a high incandescence, as it is at the end of the process
of exhaustion, the carbon becomes somewhat plastic and the weight draws the loop
into regular shape or prevents it from assuming an irregular form. This weight
may be a wire with a hook end and if not heavy enough itself may have any
suitable body attached to it to increase its weight. The wire is passed into the
exhaust tube of the lamp and hooked on to the loop, hanging down into such
exhaust tube.
The exhaust tube is made of sufficient length so that when the lamp is ready for
sealing off from the pump, a seal can be made in the tube which will leave a tube
attached to the lamp as long as the weight. By manipulation the weight is then
unhooked from the loop and drops into the tube, when the lamp is sealed off from
the tube carrying the weight.
The weight can then be removed from the tube and used with other lamps.
The weight may be just sufficient to straighten the loop or prevent it from
bending without materially changing its form, or it may be heavy enough to
change the shape of the loop by drawing it into a wedge form.
This process may be applied to lamps in the course of construction, or lamps
already constructed and having irregular loops may be opened and have exhaust
tubes attached to them and then be re-exhausted and have their loops straightened
by this process.

page_text: The removal of the weight from the lamp may be simplified by making such
weight partly or wholly of iron, steel or other magnetic material, and by using a
magnet or solenoid, externally applied for releasing the weight from the loop.
The weight can then be dropped out of the lamp into the drying chamber of the
pump while the lamp is still in connection with the pump, and the lamp can be
sealed off directly without using the double sealing before described.
The magnetic weight may be attached to the loop as well as detached from it by
a magnet or solenoid, and if desired the magnet or solenoid could be used to
increase the pull or strain of the weight on the loop and could be mounted in
position to be applied constantly during the exhausting operation, or could be
brought into action when desired.
After the weight has performed its office of straightening the carbon loop, or
preventing it from assuming an irregular form, it need not be removed from the
lamp globe but may be sealed therein, by the fusion of the glass upon it inclosing
the lamp globe.
In the accompanying drawing forming a part of the present specification.
Figure 1 is an elevation of a lamp with exhaust tube attached as it appears
before exhaustion, the weight hanging on the loop; Figure 2 is an elevation of the
lamp after the first sealing, the weight being detached from loop; Figure 3 is an
elevation of the lamp after final sealing. Figure 4 is an elevation illustrating the
method when a magnetic weight and external magnet are used, and Figure 5
shows the use of an externally applied solenoid.
With reference to figures 1, 2 and 3:-A is a lamp bulb sealed to stem a and
inclosing a carbon loop B, secured to leading in wires 1, 2, passing through and
sealed into the glass as usual.
The bulb has attached to it an exhaust tube C into which is passed the wire
weight D with a hook end for hanging the weight on the loop as shown in figure 1.
A wire of copper or platinum has been found suitable. A piece of glass is shown
as fused to the end of the wire to increase its weight.
The weight is hooked on to the loop by inserting a suitable tool in tube C, and
the lamp is then put on the pump in the position shown in figure 1, the weight
banging downwardly. After the operation of exhaustion is completed, which
includes the heating of the loop to high incandescence by an electric current, the
tube C is sealed off at the point indicated by the dotted line 6 in figure 1,
producing the construction shown in figure 2.
By manipulating the lamp the wire is unhooked from the loop and dropped into
the closed tube C when this tube carrying the weight is sealed off from the lamp
at the point c and the lamp is given its final sealing producing the construction
shown in figure 3.
With reference to figure 4:-A is the drying chamber of the pump, and a b c the
mercury drop tubes. The chamber A has a tapering tube d receiving the exhaust
tube B from the lamp globe or bulb C;-D is the carbon loop of the lamp, to
which is hung the magnetic weight.
This is composed of a hook end wire e of copper or platinum, and a body ƒ of
iron, steel, or other magnetic material, or the entire weight including the wire may
be of magnetic material.
E is a permanent or electro-magnet, which may be used to unhook the weight
from the loop or to hook it thereon, or to increase the pull of the weight on
the loop.
By the preferred method after the operation of exhausting the lamp is completed,
during which operation the weight is hung on the loop, as shown in full lines in
the drawing the magnet E is brought close to tube B and the weight is raised and
turned to unhook it from the loop, and is then allowed to drop into the chamber A
as shown in dotted lines; or the hook on the end of the weight may be straight or
nearly so, to permit the hook to be drawn laterally off the loop without raising the
weight.

page_text: After the weight is dropped into the chamber A the lamp is sealed off at the
point g.
In figure 5, the solenoid F is shown as acting upon the magnetic weight.
It is evident that the weight or a portion of it, may be left in the lamp by
sealing the lamp directly upon the weight wire which should in that case be of
platinum.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The method of straightening a loop-form conductor for incandescing electric
lamps or of changing its shape or of maintaining it straight which consists in
subjecting the conductor to strain while raised to incandescence in a vacuum, as
herein specified.
2. The removal of the weight from the lamp by means of the double sealing as
herein specified.
3. The magnetic weight used in conjunction with an external magnet or solenoid
as herein specified.
4. The sealing of the weight, or a portion of it, directly into the lamp, after it
has performed its office of straightening the carbon loop as herein specified.
wawe way of apri
B. J. B. MILLS.
By Harris & Mills,
23, Southampton Buildings,
Patent Agents.