Improvements in Electric Lamps.
Year: 1887

page_text: Date of Application, 13th June, 1887
Complete Left, 13th Mar., 1888
Complete Accepted, 11th May, 1888
Improvements in Electric Lamps.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention a communication to me from
abroad by Camille Bertou of 92 Avenue d'Jéna Paris France Gentleman to be as
follows:-
This Invention relates to incandescence arc lamps or incandescence electric lamps
burning in the open air in which the carbons are fed mechanically and automatically.
The lamps are of the type in which a carbon pencil is caused to abut against an
infusible block and one of the distinctive features of the invention is that the pressure
of the carbon against this block is regulated automatically by the effect which the
pressure itself exerts upon the feed mechanism.
When two carbons in contact with each other, are traversed by a current of suffi-
cient intensity the point or points at which they touch are rendered incandescent, and
the more the carbons are pressed together, the greater will be the quantity of
electricity traversing them, and the less brilliant will be the points of incandescence and
conversely. The maximum of useful effect will therefore be obtained with the
minimum of pressure between the carbons inasmuch as the incandescence is then at
its maximum and the quantity of electricity expended, at its minimum. The same
results are obtained if, instead of two carbons a single carbon is in contact with a
metal abutment, provided the latter be relatively inoxidizable.
This Invention enables the lamp to be regulated in such manner that the
predetermined minimum limit of pressure of the carbon upon its abutment shall never
be exceeded.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation which shew two arrangements of lamp by way of illustration of the invention.
Figure 1 represents a lamp intended for suspension in which A is a metal plate
traversed by a central metallic or other rod B and upon which the whole of the
regulating mechanism is carried. The rod B. has a longitudinal V groove, as shewn
in cross section in figure 2 to serve as a guide for a carbon pencil C of suitable
diameter, forming one of the electrodes of the lamp. The carbon pencil is retained

page_text: in the groove at its lower end beneath the base plate A by a hinged metal clamping
jaw D which is pressed by a spring against the carbon so as to ensure perfect
electrical contact of the carbon with the metal clamp and frame of the lamp, without
however preventing the carbon from receiving a continuous downward movement
from the feed mechanism. This mechanism is actuated by a weight E sliding upon
the rod B and pressing at its lower end upon the upper end of the carbon pencil, so
as to push it continually downwards.
It will be evident that the motion of the carbon may be reversed, and the weight E
may be replaced by a spring which will force the carbon pencil upwards, when the
arrangement of the lamp is to be inverted, as for instance when it is to stand upon a
table instead of being suspended, the luminous focus being then at the upper instead
of at the lower part of the lamp.
In order to regulate the feed motion and bring it into operation at the proper
times the weight is attached to the end of a flexible steel ribbon F which passes
around a supporting and guide roller G and is attached to a drum H upon which it is
wound a sufficient number of turns to allow of the necessary movement of weight E.
The drum H is fast with a toothed wheel I which gears with a train of wheels and
pinions whereby the descent of the weight and consequently of the carbon pencil will
be considerably retarded, and a slight pressure upon the last wheel I of the train is
sufficient to altogether arrest the motion.
The rate of descent is so calculated as to be a little greater than that of the
combustion of the carbon, when the lamp is working at its maximum rate of
consumption.
K is the terminal connecting the carbon with any source of electricity through the
lamp frame.
The lower end of the carbon pencil rests upon a block L of carbon or metal of
as inoxidizable a nature as possible. The block is let into a tube M of refractory
material, traversed by a metal wire N which is soldered to the bottom of block L
and serves to connect the latter to one of the poles of the source of electricity. The
tube M serves to isolate the block L calorifically from the other parts of the lamp,
and consequently diminish the conduction of heat away from the point of the carbon
pencil it being desirable to maintain the temperature of this point, as high as possible,
in order to increase its luminosity.
O is a bracket fixed to the underside of the base plate A and insulated therefrom,
which communicates metallically, by means of a rod not shewn, with the other
terminal X, which is also insulated from the metal frame of the lamp. A levor P is
pivoted at O' to bracket O, the curved arın P¹ of which terminates in a metal
socket P3 in axial alignment with the carbon pencil. This socket P3 is of larger
diameter than the tube M which is held centrally therein, by means of three binding
screws, as shewn in figure 3, the intervening space being filled with asbestos or other
poor conductor of heat. The straight arm P2 of the lever P extends upwards and
terminates in a detent Q of insulating material which is caused by the oscillation of
the arm P to engage with the last wheel I' of the train, and arrest the movement.
Below the detent is also attached an arm R, at right angles to arm P2 and insulated
therefrom said arm torminating in a weight R¹ which balances the combination of
parts L, M, N, P, P₁, P², P³, Q, and R, upon the centre of oscillation 0', in order
that the same may in all positions be in a state of indifferent equilibrium. To the
arm R at R2 are attached two antagonistic spiral springs, one of which S is hooked
to plate A, while the other S' is connected to the end of an elbow lever T pivoted
at T to a lug T, on the underside of a plate U forming the top plate of the casing
which encloses the mechanism betore described.
An aperture is provided in one side of the casing through which is inserted the
shank of the adjusting screw V which screws into part T2 and bears against the tail
end of lever T, to regulate the tension of spring St.
Supposing the apparatus to be in position of rest, the carbon Û being pressed down
by the weight E on to the abutment L, and the lever P being thereby oscillated
sufficiently to cause detent Q to bear against the last wheel l' of the train, so as to

page_text: arrest its movement and consequently that of weight E. If now the current is
supplied to the lamp the point of the carbon C which presents at its point of contact
with the abutment L an obstacle to the passage of the current becomes incandescent
and in presence of the surrounding air becomes consumed away in a continuous
manner whereby the lever P is oscillated in the reverse direction so as to release the
wheel 1 permitting the weight E to feed the carbon to an extent equal to the quantity
which has been consumed. The lever is thereby again oscillated and the feed
mechanism arrested until by the continued consumption of the carbon, the same action
is repeated, and so on.
The mechanism will continue to act so long as the carbon is not entirely consumed
and the weight has not arrived at the end of its course.
It will be seen by referring to figure 1 that the relative length of the lever
arins L O and O'Q is such, that a very slight consumption or descent of the carbon
pencil suffices to release or arrest the wheel 1'.
It is also evident that the pressure of the point of the carbon pencil upon the
abutment L is proportionate to the tension of spring S₁ which can be regulated by
means of the adjusting screw V. The pressure of the electrodes the one upon. the
other may thus be so regulated as to obtain the greatest luminous effect, as after: the
springs S, S¹ have been once regulated, the pressure of the carbon Cupon
abutment L cannot exceed a certain amount, without the weight E immediately
ceasing to operate.
By acting directly in this manner upon the feed motion a perfectly automatic
regulation is obtained which is impossible in those lamps wherein instead of acting
directly on the motor a brake is cumployed whose action cannot be always relied on to
counteract the power of the motor, and is in any case irregular. It will however be
understood that the combination and arrangement of the various parts constituting
the improved lamp may be varied without departing from the invention.
In order to illustrate such modification, I have represented in figure 4 a lamp
actuated by a spring barrel and provided with a supply of carbon which are brought
automatically and successively into use as fast as the preceding ones are consumed.
This lamp is intended by its construction and dimensions to be mounted upon an
ordinary lamp pedestal, or upon a bracket arm in lieu of a gas burner or to be
supported in a pendant.
In this lamp the actuating weight described in reference to figure 1 is replaced by
a spring barrel A driving a train of wheels similar to that described in figure 1.
The spring barrel also drives through pinions B and C, a feed wheel D having a
roughened and grooved periphery and which is shewn separately in figure 5. E is
an electro magnet of which only one coil is visible on the drawing. A lever F
pivoted at F carries at its upper end an armature G which is at right angles to the
lever and opposite the poles of the electro magnet. At the middle of its length, the
lever F carries a roller H free to turn upon its axis, which is carried by the lever F
and is situated in the same horizontal plane as the axis of tho feed roller D. The
lever F carries at its lower end a spring terminating in a metal jaw I which enters a
slot in the guide I' for the carbon which is fixed to the underside of the lower
plate M of the lamp. Above the pair of rollers D and H is fixed a reservoir K in
which are placed a number of carbon sticks of suitable length. The bottom of this
reservoir is formed by a plate of hardened steel R burnished on its upper surface,
and is fixed at such an angle as to form an inclined plane down which the reserve of
carbon pencils which rest thereon by their lower ends, can slide. Between the lower
end of this inclined plane and the adjacent side of the .reservoir a slot is left of
sufficient width to allow the foremost one of the carbon pencils to pass through freely
for the purpose of feeding the lamp, this slot being situated exactly over the line of
bite of the rollers C & H. The carbon pencil passing through this aperture and
between the feed rollers, is fed downwards with a constant motion derived from the
feed roller D which, as before mentioned, is continuously rotated by the barrel A¹.
The carbon pencil passes through the guide 11 and forces back the jaw 1 by which it
is nipped sufficiently to ensure the perfect electrical contact with the mechanism of

page_text: the lamp. The carbon pencil continuing its descent, meets the block L supported by
the system of levers P P1 P2 similar in every respect to that before described with
reference to figure 1.
It will be seen therefore that, as soon as by the consumption of the carbon pencil
its length becomes less than the distance between the block Land the rollers H it
will be immediately succeeded by the next following carbon pencil which will pass
out of the reservoir and enter between the rollers and will continue to feed forward
the remnant of the preceding carbon and will ultimately take the place of the latter
and so on.
The arrangement of the conductors for supplying the electric current having been
already described in reference to figure 1 and being capable of variation, it will be
unnecessary to again describe it here. The lower plate M supporting the whole
mechanism of the lamp above described, is itself supported by three hollow glass
pillars N each traversed by a steel rod secured to the base Z which is provided with
à screw socket for mounting it upon a suitable support.
The operation of the lamp is as follows:-Supposing an electric current to traverse
the circuit formed by the electro-magnet E, the block L, and the carbon pencil which
is in operative position in the lamp, the electro-magnet E becoming energized attracts
its armature G, thereby oscillating the lever F carrying the roller H, whereby the
carbon pencil is nipped between the two rollers and is fed downwards by the revolu-
tion of the feed roller D). At the moment when the roller H pressed against
the carbon pencil, the metal jaw I entered the notch in the guide I and ensured the
electrical contact of the carbon pencil in course of combustion with the mass of the
lamp. The regulating mechanism then continues to work as previously described in
reference to Figure 1, that is to say, should the pressure of the carbon upon
block L become excessive, the lever P P P which is equilibrated by the springs S S¹
regulated by the screw V, rocks upon. its axis so that the detent carried by the
arm P engages with the last wheel X of the train actuated by the barrel and arrests
the latter so that the feed motion of the carbon is interrupted and it no longer con-
tinues to descend. The lamp continues to work in this manner until the length of
the carbon pencil becomes less than the distance between the extremity of the guide I
and the block L whereupon the remnant of the carbon being no longer supported by
the guide I falls into the globe. The electrical circuit being thereby interrupted the
electro-magnet becomes inactive and releases its armature, thereby allowing the
lever F to move back, and with it the roller and jaw I. The next succeeding
carbon pencil, which, as above mentioned, has become entered between the feed
rollers, being no longer nipped against the feed roller D, slips past the latter and
falls by its own weight until it niects the block I wherefrom the remnant of the
preceding carbon has just fallen, and thus re-established the circuit. The electro-
imagnet again becomes active and the different parts of the mechanism resume their
former position and the working of the lamp continues as before.
:-
In this manner the automatic relighting of the lamp takes place within an inappre-
ciable period of time, viz. that necessary for the second carbon to fall froin a
height of 15 millimetres. In order therefore to keep the lamp burning continuously,
it is only necessary to wind up the barrel and keep the reservoir filled with carbon
pencils, the internal mechanism of the lamp requiring no attention.
L
1
1
T
1002
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Lamps.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents,
do hereby declare the nature of this invention (a communication to me from abroad
by Camille Bertou, of 92, Avenue d'Jéna, Paris, France, Gentleman), 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 incandescence are lamps or incandescence electric lamps
burning in air and in which the carbons are fed mechanically and automatically. The
lamps are of the type in which a carbon pencil is caused to abut against an infusible
block, and one of the distinctive features of the invention is that the pressure of the
carbon against this block is regulated automatically by the effect which the pressure
itself exerts upon the feed mechanism.
When two carbons in contact with each other, are traversed by a current of suffi-
cient intensity the point or points at which they touch are rendered incandescent, and
the more the carbons are pressed together, the greater will be the quantity of
electricity traversing them, and the less brilliant will be the points of incandescence and
conversely. The maximum of useful effect will therefore be obtained with the
minimum of pressure between the carbons inasmuch as the incandescence is then at
its maximum and the quantity of electricity expended, at its minimum. The same
results are obtained if, instead of two carbons a single carbon is in contact with a
metallic abutment, provided the latter be relatively inoxidizable.
This Invention enables the lamp to be regulated in such manner that the pre-
determined minimum limit of pressure of the carbon upon its abutment shall never be
exceeded.
Reference is to be had to the drawings filed with my provisional specification and
also to the accompanying additional drawings forming part of this specification which
shew several arrangements of lamp by way of illustration of the invention. Figure 1
represents a lamp intended for suspension in which A is a metal plate traversed by a
central metallic or other rod B and upon which the whole of the regulating mechanism
is carried. The rod B has a longitudinal V groove, as shewn in cross section in figure 2
to serve as a guide for a carbon pencil of suitable diameter, forming one of the
electrodes of the lamp. The carbon pencil is retained in the groove at its lower and

page_text: beneath the base plate A by a hinged metal clamping jaw D which is pressed by a
spring against the carbon so as to ensure perfect electrical contact of the carbon with
the metal clamp and frame of the lamp, without however preventing the carbon from
receiving a continuous downward movement from the feed mechanism. This mechanism
is actuated by a weight E sliding upon the rod B and pressing upon the upper end of
the carbon pencil, so as to push it continually downwards.
It will be evident that the motion of the carbon may be reversed, and the weight E
may be replaced by a spring which will force the carbon pencil upwards, when the
arrangement of the lamp is to be inverted, as for instance when it is to stand upon a
table instead of being suspended, the luminous focus being then at the upper instead
of at the lower part of the lamp.
In order to regulate the feed motion and bring it into operation at the proper times
the weight is attached to the end of a flexible steel ribbon F which passes around a
supporting guide roller G and is attached to a drum H upon which it is wound a
sufficient number of turns to allow of the necessary movement of weight E. The
drum His fast with a toothed wheel I which gears with a train of wheels and pinions
whereby the descent of the weight and consequently of the carbon pencil will be con-
siderably retarded; a slight pressure upon the last wheel I' of the train being sufficient
to altogether arrest the motion.
The rate of descent is so calculated as to be a little greater than that of the com-
bustion of the carbon, when the lamp is working at its maximum rate of consumption.
K is the terminal connecting the carbon with any source of electricity through the
lamp frame.
The lower end of the carbon pencil rests upon a block L of carbon or metal of as
inoxidizable a nature as possible. The block is let into a tube M of refractory
material, traversed by a metal wire N which is soldered or otherwise connected to the
bottom of block L, so as to place the latter in electrical communication through lever P
and bracket O with the other terminal X. The tube M serves to isolate the block L
calorifically from the other parts of the lamp, and consequently diminish the con-
duction of heat away from the point of the carbon pencil it being desirable to maintain
the temperature of this point, as high as possible, in order to increase its luminosity.
O is a bracket fixed to the underside of the base plate A and insulated therefrom,
which communicates metallically, by means of a rod not shewn, with the terminal X,
which is also insulated from the metal frame of the lamp. A lever P is pivoted at O¹
to bracket O, the curved arm P¹ of which lever terminates in a metal socket P³ in
axial alignment with the carbon pencil. This socket P³ is of larger diameter than the
tube M which is held centrally therein, by means of three binding screws, as shown in
figure 3, the intervening space being filled with asbestos or other poor conductor of
heat. The straight arm P2 of the lever P extends upwards and terminates in a detent Q
of insulating material which is caused by the oscillation of the arm P to engage
with the last wheel I¹ of the train, and arrest the movement. Below the detent Q is
also attached an arm R, at right angles to arm P2 and insulated therefrom said arm
terminating in a weight R' which balances the combination of parts L, M, N, P, P¹,
P², P, Q, and R, upon the centre of oscillation O', in order that the same may in all
positions be in a state of indifferent equilibrium. To the arm R at R are attached two
antagonistic spiral springs, one of which S is hooked to plate A, while the other S' is
connected to the end of an elbow lever T pivoted at T' to a lug 12, on the underside of
a plate U forming the top plate of the casing which encloses the mechanism before
described.
An aperture is provided in one side of the casing through which is inserted the
shank of the adjusting screw V which screws into part T2 and bears against the tail
end of lever T, to regulate the tension of spring S¹.
Supposing the apparatus to be in position of rest, the carbon being pressed down
by the weight E on to the abutment L, and the lever P being thereby oscillated
sufficiently to cause detent Q to bear against the last wheel I' of the train, so as to
arrest its movement and consequently that of weight E. If now the current is sup-
plied to the lamp the point of the carbon C which presents at its point of contact with

page_text: the abutment L an obstacle to the passage of the current becomes incandescent and m
presence of the surrounding air. becomes consumed away in a continuous manner
whereby the lever P is oscillated in the reverse direction so as to release the wheel I'
permitting the weight E to feed the carbon to an extent equal to the quantity which
has been consumed. The lever is thereby again oscillated and the feed mechanism
arrested until by the continued consumption of the carbon, the same action is repeated,
and so on.
The mechanism will continue to act so long as the carbon is not entirely consumed
and the weight has not arrived at the end of its course.
It will be seen by referring to figure 1 that the relative length of the lever arms LO¹
and O'Q is such that a very slight consumption or descent of the carbon pencil
suffices to release or arrest the wheel I'.
It is also evident that the pressure of the point of the carbon pencil upon the abut-
ment L is proportionate to the tension of spring S¹ which can be regulated by means
of the adjusting screw V. The pressure of the electrodes the one upon the other may
thus be so regulated as to obtain the greatest luminous effect, as after the springs S, S¹
have been once regulated, the pressure of the carbon C upon abutment L cannot
exceed a certain amount, without the weight E immediately ceasing to operate.
By acting directly in this manner upon the feed motion a perfectly automatic regn-
lation is obtained which is impossible in those lamps wherein instead of acting directly
on the motor a brake is employed whose action cannot be always relied on to counteract
the power of the motor, and is in any case irregular. It will however be understood that
the combination and arrangement of the various parts constituting the improved lamp
may be varied without departing from the invention.
In order to illustrate such modification, I have represented in figure 4 a lamp
actuated by a spring barrel and provided with a supply of carbons which are brought
automatically and successively into uso as fast as the preceding ones are consumed.
This lamp is intended by its construction and dimensions to be mounted upon an
ordinary lamp pedestal, or upon a bracket arm in lieu of a gas burner or to be sup-
ported in a pendant.
In this lamp.the actuating weight described in reference to figure 1 is replaced by
a spring barrel A driving a train of wheels similar to that described in said figure.
The spring barrel also drives through pinions B and C, a feed wheel D having a
roughened and grooved periphery and which is shewn separately in figure 5. E is an
electro magnet of which only one coil is visible on the drawing. A lever F pivoted
at F carries at its upper end an armature G which is at right angles to the lever and
opposite the poles of the electro magnet. At the middle of its length, the lever F
carries a roller H free to turn upon its axis, which is carried by the lever F and is
situated in the same horizontal plane as the axis of the feed roller D. The lever F
carries at its lower end a spring terminating in a metal jaw I which enters a slot in
the guide for the carbon which is fixed to the underside of the lower plate M of the
lamp. Above the pair of rollers D and H is fixed a reservoir K in which are placed
a number of carbon sticks of suitable length. The bottom of this reservoir is formed.
by a plate of hardened steel R burnished on its upper surface, and fixed at such an
angle as to form an inclined plane down which the reserve of carbon pencils which
rest thereon by their lower ends, can slide. Between the lower end of this inclined
plane and the adjacent side of the reservoir a slot is left of sufficient width. to allow
the foremost one of the carbon pencils to pass through freely for the purpose of feed-
ing the lamp, this slot being situated exactly over the line of bite of the rollers D
and H. The carbon pencil passing through this aperture and between the feed rollers, is
fed downwards with a constant motion derived from the feed roller D which, as before
mentioned, is continuously rotated by the barrel A. The carbon pencil passes through
the guide and forces back the jaw I by which it is nipped sufficiently to ensure
perfect electrical contact with the mechanism of the lamp. The carbon pencil continuing
its descent, meets the block L supported by the system of levers PP1 P2 similar in
every respect to that before described with reference to figure 1.

page_text: It will be seen therefore that, as soon as by the consumption of the carbon pencil
its length becomes less than the distance between the block L and the rollers D H it
will be immediately succeeded by the next following carbon pencil which will pass out
of the reservoir and enter between the rollers and will continue to feed forward the
remnant of the preceding carbon and will ultimately take the place of the latter and
so on.
The arraugement of the conductors for supplying the electric current having been
already described in reference to figure i and being capable of variation it will be
unnecessary to again describe it here. The lower plate M supporting the whole
mechanism of the lamp above described, is itself supported by three hollow glass
pillars N each traversed by a steel rod secured to the base Z which is provided with a
screw socket for mounting it upon a suitable support.
The operation of the lamp is as follows:-Supposing an electric current to traverse
the circuit formed by the electro-magnet E, the block L, and the carbon pencil which
is in operative position in the lamp, the electro-magnet E becoming energized
attracts its armature G, thus oscillating the lever F, whereby the carbon pencil is
nipped between the two rollers D H and is fed downwards by the revolution of the
feed roller D. At the moment when the roller H pressed against the carbon pencil,
the metal jaw I entered the notch in the guide [¹ and ensured the electrical contact of
the carbon pencil in course of combustion with the mass of the lamp. The regulating
mechanism then continues to work as previously described in reference to Figure 1,
that is to say, should the pressure of the carbon upon block L become excessive,
the lever P P P which is equilibrated by the springs S S¹ regulated by the screw V
rocks upon its axis so that the detent carried by the arm P engages with the last
wheel of the train actuated by the barrel and arrests the latter so that the feed
motion of the carbon is interrupted and it no longer continues to descond. The
lamp continues to work in this manner until the length of the carbon pencil becomes
less than the distance between the extremity of the guide I and the block L
whereupon the remnant of the carbon being no longer supported by the guide 1' falls
into the globe. The electrical circuit being thereby interrupted the electro-magnet
becomes inactive and releases its armature, thereby allowing the lever F to move back,
and with it the roller H and jaw I. The next succeeding carbon pencil, which as
above mentioned, has become entered between the feed rollers, being no longer
nipped against the feed roller D, slips past the latter and falls by its own weight
until it meets the block L wherefrom the remnant of the preceding carbon has just
fallen, and thus re-establishes the circuit. The electro-magnet again becomes active
and the different parts of the mechanism resume their former position and the
working of the lamp continues as before. In this manner the automatic relighting of
the lamp takes place within an inappreciable period of time, viz :-that necessary for
the second carbon to fall from a height of 15 millimetres. In order therefore to
keep the lamp burning continuously, it is only necessary to wind up the barrel and
keep the reservoir filled with carbon pencils, the internal mechanism of the lamp
requiring no attention.
Figures 6 to 11 represent another form of the lamp containing modifications of the
motor, feed mechanism, relighting, and automatic supply arrangements. Figure 6 is
a front elevation and figure 7 a side elevation of the lamp. Figure 8 is a vertical
section taken through the reservoir of carbons. Each figure is shewn as divided
into two parts which unite at the dotted lines x, y, to form the complete figure.
Figure is a detail of the relighting electro magnet. Figures 10 and 11 show
details hereinafter referred to. The same letters of reference denote like parts in
figures 6 to 11.
The first modification relates to the motor, and consists in replacing some of the
wheels of the train by a tangent screw or worm which economizes space and also
reduces the noise of working. a is the spring barrel, the wheel train, c the worm,
and d the worm wheel. e is the lever carrying the abutment electrode and a
brako g in frictional contact with a disc h on the worm spindle c in order to maintain

page_text: constant the desired contact between the carbon and its abutment f. The carbons i
are fed downwards by the pair of grooved rollers kk (figures 8 and 10) both of which
are geared directly with the motor so as to act in unison upon the carbon pencil.
The supply of carbons i are contained in a reservoir and rest on an incline m
pivoted at m¹ and oscillated by inclined teeth n on one of the feed rollers k which
act on a corresponding inclined tooth on the under side of the inclined plate m so as
to raise it slightly and let it fall suddenly, this action assisting the carbons i to
gravitate towards the point where they are delivered in succession to the nip of feed
rollers k. The carbons are pressed together at their upper ends by a metal rod o
bent at its lower end and pivoted at o' to the framing so as to rest against the
carbons.
r
The improvement in the automatic relighting mechanism has for its object to
considerably accelerate the motion of the feed rollers when a fresh carbon comes into
use, in order to render almost nil the period of extinction of the light which occurs
whenever a fresh carbon is brought into use. This arrangement is illustrated in
detail in figure 11 in which p is a toothed wheel geared by its axis with one of the
feed rollers through a pinion and a friction clutch with the worm wheel d
which is controlled by the worm and brake gh, as before mentioned. The male
and female cones forming the friction clutch are each carried by a half of the
spindle, which is divided as shewn, and they are normally pressed into contact by a
springs which also forms the armature of an electro-magnet t. Under normal
conditions the two parts of the spindle turn together as one and the feed wheel k is
controlled by the worm gear and brake, but when the magnet t attracts its armature
the clutch is slackened- sufficiently to render the feed wheels independent and so
that they will allow the carbon to descend freely, the normal working being resumed,
immediately the lamp is relighted.
The arrangement for exciting the electro-magnet t at the proper moment is
represented in top view detached in figure 9 and also in figure 6, and consists of a
contact u mounted upon the lever e. So long as the carbon i rests upon abutment f
the pallet is held out of contact with screw v, but immediately the pressure ceases,
the lever e swings backward in the direction of the arrow z (figure 7) and closes the
circuit of the electro-magnet t.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. The herein described system of incandescent arc lamp in which the pressure
of the carbon pencil upon the abutment is automatically regulated by arresting the
motor mechanism by the direct action thereon of a balanced lever carrying the
abutment electrode upon which the carbon bears, substantially as described.
2. The means of calorifically insulating the abutment electrode supporting the
point of the carbon pencil, substantially as shewn and described.
3. In an incandescent arc lamp, the combination of an actuating weight and
regulating wheel train as described and represented in figures 1, 2, 3, of the
drawings.
4. In an incandescent arc lamp, the combination of the spring motor barrel,
regulating train, feed rollers, abutment electrode, balanced lever carrying the same,
electro-magnet operating the balanced lever and the reservoir of carbon pencils
having an inclined bottom whereby the reserve of carbons are brought successively
into operation and the automatic relighting effected, substantially as herein described
and represented in figures 4 and 5.
5. In an incandescent are lamp, the combination of the motor barrel, feed rollers,
worin gear, and brake, substantially as described and represented in figures 6, 8,
and 10.

page_text: 6. In an incandescent arc lamp, the means for imparting a vibrating movement to
the inclined bottom of the carbon reservoir, substantially as described and represented
in figures 8 and 10 for the purpose specified.
7. In an incandescent arc lamp, the automatic relighting arrangement, consisting
of an electro magnet, spring armature, and friction clutch for disconnecting the feed
wheels from the brake which normally controls them and allowing the carbons to be
fed rapidly, substantially as described with reference to figures 6, 7, and 11 of the
drawings.
Total thi. 19th
1 1000