Year: 1899

page_text: We, GERALD CARLYLE ALLINGHAM and WILLIAM FENNELL, both of Harrow
Green, Leytonstone Road, in the County of Essex, Electrical Engineers, do here-
by declare the nature of this invention to be as follows:-
Our invention relates to that form of electric incandescence lamp, in which
the incandescent filament or body is a non-conductor of electricity when cold, and
therefore has to be subjected to a preliminary heating before it will conduct an
electric current sufficient to maintain it in a state of incandescence. It has
hitherto been customary to carry out this preliminary heating by applying a
Hame to the filament; it has also been carried out by means of platinum wire
heated electrically, an automatic device being provided for cutting the platimun
wire out of circuit when the current is passing through the incandescent filament.
Heating devices of this form have however not hitherto been practically satis-
factory.
According to our invention, we effect the preliminary heating of the filament
by means of an electric arc. In general, we connect this are in parallel with
the filament, and cause it to be automatically extinguished when sufficient electric
current passes through the filament to incandesce it, either by separating the
electrodes of the arc or otherwise. Carbon electrodes may be employed for the
arc, but in some instances we prefer to form one or both of the electrodes of
the arc of some metal or other substance, in order to produce an arc of lower
temperature, which will be less likely to damage the filament.
According to one form of our invention, we construct the incandescent fila-
ment or body in the form of a rod, tube or wire, which is mounted between two
terminals. One electrode of the arc is fixed close to one of the terminals of the
filament and is electrically connected to it, or one of the terminals of the filament
may be employed as the fixed electrode of the arc.
The other electrode of the arc is made movable in a direction parallel to the
length of the filament, and in close proximity to it; it is electrically connected
to the other terminal of the filament, and is coupled to the iron core or armature
of a solenoid or electric magnet, the winding of which is generally connected
to the same electrical circuit as the filament and arc. This solenoid or electro
magnet is connected in series with the filament and are:-
1. It is found necessary in practice, when incandescent filaments of the des-
cription herein referred to are run in parallel on a constant potential circuit, to
connect a steadying resistance in series with each. The winding of our solenoid
or electro magnet will serve as a steadying resistance, additional resistance being
connected in series with it if necessary, and there is no loss of electrical energy
beyond that necessary for maintaining a state of stable equilibrium.
We usually connect each electrode of the arc directly to one of the terminals
of the filament, so that the same steadying resistance is in series with both arc
and filament, but we may so connect up the are and the filament that different

page_text: resistances are in series with each. The movable electrode of the arc is so
arranged that when there is no current flowing through the solenoid or electro
magnet, it rests in contact with the fixed electrode, by its own weight and that
of the core or armature, or by means of a spring or otherwise When the electric
current is switched on, it passes through the electrodes of the arc, and through
the solenoid or electro magnet, which immediately attracts its core or armature,
and strikes the arc. At first, no appreciable current passes through the filament,
but when the arc is struck, it heats the end of the filament, and some of the cur-
rent flows through the heated portion, and arcs across from it to the moveable
electrode. As the moveable electrode travels along in a direction parallel to the
filament, the arc from the filament follows it as the filament heats, until the
moveable electrode is drawn beyond the terminal of the filament, when, as there
is then no potential difference between. the moveable electrode and the filament,
the arc goes out.
So long as the electric current is flowing through the lamp, the core or armature
and the moveable electrode of the are are held up by the solenoid or electro magnet
and when the current is switched off, the moveable electrode returns to its origi-
nal position in contact with the fixed electrode, ready to strike an are and heat the
filament next time it is desired to light the lamp.
We so adjust the winding of the solenoid or electro magnet, and the shape of
the core or cores, or armature, that the moveable electrode of the arc is drawn
along parallel to the filament at just the right speed to heat it to the temperature
at which it conducts electricity. If the electrode is moved too slowly the filament
may be overheated by the arc, and damaged; if it is moved too quickly the fila-
ment will not be heated sufficiently and the circuit will be broken, which will
cause the arc to "pump." The motion of the electrode may be steadied by means
of dashpots or the like.
We also prefer to construct the core or cores, or armature of such a form that
when the filament is glowing, the magnetic circuit of the solenoid or eléctro
magnet is as perfect as possible, so that it will attract and hold up the core or
armature, and the electrode attached thereto, with considerable force.
When continuous current is used, we prefer to connect the moveable electrode
of the arc to the positive pole, in order to minimise any possible damage to the
filament, which will then form the negative pole of the are, and will be burnt
less by it than if it formed the positive pole. We may also so fix the filament
that it may be reversed end for end at intervals, automatically or by hand, in
order to equalise the wear of the filament caused by the arc, which would tend
to be greatest at the end nearest to the fixed electrode of the are. Or we may
cause the are to move along the filament alternately in opposite directions, which
may be effected as follows:-
The arc is provided with two fixed electrodes, one at, or adjacent to, each end
of the filament, and its moveable electrode is coupled to the core or armaturé, not
rigidly, but by means of a cam or the like, such that, when the core or armature
is attracted by the solenoid or electro magnet, the moveable electrodes is moved
along the filament in one direction, but when the core or armature is released the
moveable electrodes does not return its original position, but remains in contact
with the other fixed terminal. The next time the current is switched on, and the
core or armature is attracted by the solenoid or electro magnet, the cam moves the
moveable electrode along the filament in the direction opposite to that in which
it moved previously, until it returns to its original position.
The core or armature is also coupled by a similar device to a reversing switch,
which is operated when the said core or armature is released. When the move-
able electrode has just been moved along the filament. by the attraction of the
core or armature as before described, it is in electrical connection with the ter-
minal of the filament to which it is adjacent. and remains so as long as the lamp
is alight when the current is switched off, the core or armature is released, and
throws over the reversing switch, which connects the moveable "electrode. to the

page_text: opposite end of the filament so that it is ready to strike an arc when the current
is switched on again. It is preferable when using continuous current to keep the
movable electrode always connected to the positive pole, and to reverse the
polarity of the terminals of the filament; this is also advantageous on account.
of the electrolytic action of the electric current on filaments of this class.
The electrodes of the arc may be made adjustable or replaceable by any of the
ordinary methods, so as to compensate for the burning away of the electrodes.
The moveable electrode may be made to move parallel to one side of the fila-
ment, or helically round it, or in any way so that the are travels along the fila-
ment or sufficiently near it to heat it to the conducting temperature. When the.
arc travels along. one side of the filament, the filament may be revolved continu-
ously or at intervals, about an axis parallel to its length, automatically or by
hand, in order to expose all sides of the filament equally to the arc.
This revolution may be effected by the motion of the core or armature by means
of a ratchet wheel or the like.
"
"
The filament may be either straight or curved, and may be fixed either hori-
zontally vertically, or obliquely.
A convenient arrangement is to make it in the form of an arc of a circle, the
moveable electrode being pivoted at the centre of the circle.
Instead of employing one fixed and one moveable electrode, both electrodes
of the are may be caused to move, or the filament may be caused to move.
Dated this Thirteenth day of March 1899.
G. C. ALLINGHAM.
W. FENNELL.
We, GERALD CARLYLE ALLINGHAM and WILLIAM FENNELL, both of Harrow
Green, Leytonstone Road, in the County of Essex, Electrical Engineers, do here-
by declare the nature of this invention 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 that kind of electric incandescence lamp in which
the filament or incandescence body is a non-conductor of electricity when cold
and therefore has to be subjected to a preliminary heating before it will conduct
sufficient electric current to maintain it in a state of incandescence. It has
hitherto been usual to effect this preliminary heating by means of a flame, or by
means of platinum wire heated electrically.
Now according to this invention, the preliminary heating of the filament or in-
candescence body (hereinafter called the incandescence body), is effected by means
of an electric arc which is set up between electrodes connected in parallel with the
incandescence body and is automatically extinguished when sufficient electric
current passes through the body to maintain it in an incandescent state. Carbon
electrodes may be employed for producing the arc, but in some instances it is
preferred to form one or both of the electrodes of a substance, for example iron,
which will enable an arc to be produced having a lower temperature than that
which would be produced with carbon electrodes, so that there may be less liability
of fusing or volatilising the incandescence body.
The incandescence body may be of any desired shape and is mounted between
suitable clamps, holders or terminals.
It may be either straight or curved, and may be fixed either horizontally, verti

page_text: cally or obliquely. A convenient arrangement is to make it in the form of an arc
of a circle, the movable electrode being pivoted at the centre of the circle. In
one arrangement, one electrode is fixed close to one of the terminals of the inean-
descence body and is electrically connected to it, or, as an alternative, one of the
terminals of the said incandescence body may be employed as the fixed electrode
of the arc. The other electrode is made movable in a direction approximately
parallel to the length of the incandescence body and in close proximity thereto
so as to allow of an arc being formed between the two, and it is electrically con-
nected to the other terminal of the incandescence body, and when automatic action
is desired; is mechanically connected to the iron core or-armature of a solenoid
or other electro-magnetic device the winding of which may be part of the circuit
in which the incandescence body and arc are included. Each electrode may in
such an arrangement be connected directly to one of the terminals of the incan-
descence body so that the same steadying resistance, of which the winding of the
electro magnetic device may constitute the whole or part, is in series with both
the arc and the incandescence body, but the arc and body may have different
steadying resistances if desired.
Fig. 1 of the accompanying drawing shows diagrammatically one arrangement
of electric incandescence lamp according to this invention.
In this arrangement is the incandescence body of the kind referred to, made
in the form of a straight rod held at its ends in clamps or holders 2 and 3. 4 is
the fixed electrode in clectric connection with the clamp or holder 2 which is
connected to the lamp terminal 5. 6 is the movable electrode carried by one arm
of a lever 7 pivoted at S and the other arm of which is connected to the movable
core or armature 9 of an electro-magnet the winding 10 of which is connected at
one end to the said lever and to the clamp or holder 3 and at the other end to
the lamp terminal 11, the movable electrode being arranged to travel in close
proximity to the incandescence body 1 so that an arc can be formed between
them. The winding 10 may, of course, form simply a solenoid instead of con-
stituting the winding of an electro-magnet. In each case, the arrangement is such
that when no current is flowing through the winding 10 the movable electrode 6
will be kept in contact with the fixed electrode 4 by gravity, or by spring force.
When however the electric current is switched on, it will pass through the two
electrodes 4 and 6 and through the winding 10 which being thus energised will
immediately attract the core 9 and strike the are between the two electrodes. At
first, no appreciable current will pass through the incandescence body I but when
the arc is struck it will heat the end of the incandescence body and some of the
current will flow through the heated portion and arc across from it to the mov-
able electrode G. As the movable electrode travels along in a direction parallel
to the incandescence body, the arc established between the movable electrode and
the said body will travel along the latter as the same becomes heated, until the
movable electrode is moved beyond or against the clamp or holder 3 of the said
body whereupon, as there is then but a small or no potential difference between
the movable electrode and the incandescence body the arc is automatically
extinguished.
So long as the electric current is flowing through the lamp, the core or arma-
ture 9 and the movable electrode 6 are held up by the action of the winding 10.
and when the current is switched off, the movable electrode will return to its
original position in contact with the fixed electrode 4 ready to again strike an arc
and heat the incandescence body when it is again desired to light the lamp.
The winding 10 of the solenoid or electro-magnet, and the shape of the core 9
(or cores) or armature are so arranged that the movable electrode 6 will be moved
along parallel to the incandescence body at the right speed to enable the body to
he heated to the temperature at which it will conduct electricity. If the elec-
trode were moved too slowly the incandescence body would be overheated by the are
and damaged if on the other hand it were moved too quickly, the body would
not be heated sufficiently and the circuit would be broken. The speed of the

page_text: movable electrode may be regulated by means of a dash pot or equivalent device.
In Fig. 1, the core 9 is adapted to so fit the interior of a hollow fixed core 9*
that it also acts as a dash pot in a manner that will be readily understood from
the drawings.
When a continuous current is used, the movable electrode 6 is preferably made
the positive pole of the arc in order to minimise any possible damage to the in-
candescence body which will, during the travel of the movable electrode, form
the negative pole of the arc. By this means the said body will be heated to a less
degree than if it formed the positive pole.
The incandescence body may be reversed end for end at intervals, either auto-
matically or by hand, in order to equalise the wear thereof caused by the arc,
and which will be greatest at the end nearest to the fixed electrode. Or, in.
order to equalize the wear of the incandescence body the arc may be caused to
move along the same alternately in opposite directions. This may be effected
automatically.
It is preferable when using a continuous current to keep the movable elec-
trode 6 always connected to the positive pole or terminal of the lamp and to
reverse the polarity of the terminals of the incandescence body 1; this is also
advantageous on account of the electrolytic action of the electric current on an
incandescence body of the kind to which this invention relates.
Figs. 2 and 3 are elevations at right angles to one another showing, more or
less diagrammatically, an arrangement of lamp whereby the arc can be caused
to travel alternately in opposite directions, and the polarity of the terminals of
the incandescence body can be reversed, at successive operations of the lamp.
Each of the clamps or holders 2 and 3 of the incandescence body 1, which is
shown bent to the form of a circular arc, is provided with a fixed electrode 4 or 4*
and the lever 7* carrying the movable electrode G is fixed to a cam-like device 12
which is in the form of a plate pivoted to a support 13 and formed on its under-
side with a central tooth or projection 14 and on opposite sides thereof with
notches 15 and 15. 16 is a link the upper end of which is pivoted to the lower
side of the armature 9* of an electro-magnet and the lower end of which is pro-
vided with a pin 16 adapted to enter one or other of the notches 15 or 15 in the
plate 12. 17 is a metal reversing switch bar pivotted to the support 13 and
formed at its upper side with two notches 18 and IS.
19 is a second link the
upper end of which is pivoted to the armature 9 and the lower end of which is
provided with a pin 19 adapted to enter one or other of the notches 18 or 18*
in the bar 17.
The switch bar 17 carries two insulated movable contacts 21 and 21* arranged
to work between two pairs of fixed contacts riz. 22 and 22 and 23 and 23. The
movable contacts 21 and 21 are connected to the holders 2 and 3 respectively
by flexible connections 24 and 24. The fixed contacts 22 and 23 are connected
together and to the positive terminal 5 of the lamp and also to the support 13
to which the lever 7 with plate 12 is pivoted, so that the movable electrode G
will always be in connection with the positive terminal 5 of the lamp and con-
sequently forms the positive pole of the are formed between it and the fixed elec-
trode 4 and incandescence body 1. The fixed contacts 22 and 23 are connected
together and to one end of the winding 10 the other end of which is connected
to the negative terminal 11 of the lamp.
Assuming the parts to be in the position shown, then if current be switched
onto the lamp, it will pass from the positive terminal 5 to the contact 22, sup-
port 13, lever arm 7ª, movable and fixed electrodes 6 and 4, holder 2, connec-
tion 24 and fixed contact 22 to the winding 10 whence it will pass to the negative
terminal 11. The armature 9 will consequently be raised and by the pull of the
link 16 on the plate 12 will cause the movable electrode to move slowly along
the incandescence body and away from the right hand electrode 4, thereby set-
ting up an arc that will first pass between the two electrodes and afterwards
from the positive electrode 6 to incandescence body 1 when the same is rendered

page_text: sufficiently.conductive by heat. The positive electrode gradually moves to the left
moving the are with it, and finally comes to rest against the left hand elec
trode 4 where it remains during the operation of the lamp and whereby the are
is automatically extinguished. When the lamp is switched out of circuit and the
armature. 9. falls, the pin 16 on the link will leave the notch 16 in the
plate 12, and come below the notch 15 in the said plate. Also the pin 19 on the
link 19, which will have been raised from the notch 18 in the switch bar 17
by the previous rising of the armature, will fall into the notch 18 and by the
weight of the armature and attached parts will move the said switch bar with
contacts 21 and 21ª into the position indicated by the dotted line r so, that the
holders 2 and 3 which were previously connected to the negative and positive
terminals 11 and 5 respectively of the lamp will now be connected to the positive
and negative terminals respectively, of the lamp, thus reversing the polarity of the
holders or, terminals to which the incandescence body is connected. When the
current is next switched on, the rising of the armature 9 will, through the link 16
and plate 12, cause the movable electrode 6 to turn in the opposite direction, i.e.,
to the left, along the incandescence body and again produce an arc to heat the
said body finally coming to rest against the fixed contact 4 and causing the arc
to, become extinguished.
The electrodes may be made adjustable or replacable by any of the ordinary
methods, so as to compensate for the burning away of such electrodes.,
The movable electrode may be moved parallel to one side of the incandescence
body, as in the arrangements hereinbefore described, or helically around such
body, or in any other way, so long as the arc is caused to travel along the incan-
descence body or sufficiently near it to heat it to the conducting temperature.
When the are travels along one side of the incandescence body the latter may be
rotated continuously or at intervals about an axis parallel to its length, and
either automatically or by hand, in order to expose all sides of the body equally
to the arc. This rotation may be effected by the motion of the core or armature
of the electromagnetic device used to operate the movable electrode or electrodes
such motion acting through a ratchet wheel or equivalent device to rotate the
incandescence body.
Figs. 4 and 4 shows an arrangement of lamp of this kind wherein the incan-
descence body 1 is fixed in holders 2 and 3 that are mounted to rotate in the lamp
frame and are provided with toothed wheels 2 and 3 in gear with toothed
wheel 25 and 26 that are fixed upon but insulated from a shaft 27 provided with
a ratchet wheel 28. Engaging this ratchet wheel is a pawl 29 carried by a rod 30
connected to one end of a lever 31 the other end of which is jointed to. the link 8
by which the core 9 of the electromagnet 10 is connected to the bent lever arm 7*
carrying the movable electrode 6. The arrangement is such that each time the
core 9 is raised to move the movable electrode 6 from left to right, the pawl 29
will be depressed and the holders 2 and 3 with incandescence body 1 partly
rotated.
Instead of employing one fixed and one movable electrode, both electrodes may
be caused to move, or the incandescence body may be caused to move, and this
motion may take place in any way that will cause the arc to automatically pass
to the incandescence body and travel along the same.
Fig. 5 shows diagrammatically an arrangement wherein both electrodes 4. and
6 are made movable, being carried by a pair of spring arms 4* and G* that are
connected to opposite terminals of the lamp and are moved apart, upon switching
on the current, by a separating device such as an insulated block 32 connected to
the movable core 9 of the electromagnet 10.
T
In each of the arrangements shown the movable electrode 6 is of material, for
example iron, producing an arc of less temperature than that produced between
two carbon electrodes. The fixed electrode or electrodes may be of carbon.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed we declare that what we claim
is:-
1. In an incandescence electric lamp having an incandescence body of the kind
herein referred to, effecting the preliminary heating of such incandescence body
by means of an electric arc that is established between the incandescence body
and an electrode and is caused to travel along the incandescence body from one
end thereof to the other, substantially as described.
2. In an incandescence electric lamp wherein the preliminary heating of the
incandescence body is effected by an electric are the combination with the incan-
descence body of one or more movable electrodes and means whereby on the lamp
being switched into circuit the said movable electrode or electrodes will be auto-
matically caused to travel along or in proximity to the incandescence body and
produce an electric arc or arcs that will heat such body until the same conducts
the electric current and will then be automatically extinguished, substantially
as described.
3. In an incandescence electric lamp having an incandescence body of the kind
herein referred to, the combination with a movable electrode for striking the
are used for heating the said body, of an electromagnetic device the movable part
of which is connected to the movable electrode and is controlled by a dash pot
or equivalent device adapted to cause the said movable part of the electromagnetic
device to move slowly, substantially as described.
4. In an incandescence electric lamp of the kind referred to in Claim 1, means
whereby the direction of travel of the arc relatively to the incandescence body
can be reversed at each operation of the lamp, substantially as set forth.
5. In an incandescence electric lamp of the kind herein referred to, the combi-
nation with the incandescence body of means whereby the polarity of the holders
or terminals to which the body is connected is automatically reversed from time
to time, substantially as described.
6. In an electric incandescence lamp wherein the preliminary heating of the
incandescence body is effected by an electric are, the use for forming the arc of an
electrode or electrodes composed of or containing a substance that will furnish
an are of a lower temperature than is obtained when both electrodes are of carbon.
7. Incandescence electric lamps constructed, arranged and operating substan-
tially as herein before described with reference to Fig. 1 to Figs. 2 and 3; to
Fig. 4 and 4 and to Fig. 5 of the drawings annexed
Dated this 14th day of December 1899
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.