IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1885

page_text: We, ERNEST alias CHARLES STREET and FREDERIC VICTOR MAQUAIRE, Engineers,
of N° 8 Rue Saint-Didier, Paris in the Republic of France do hereby declare the
nature of our invention for IMPROVEMENTS IN ELECTRIC ARC LAMPS and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :—
This apparatus is intended for the production of electric illumination by means
of an arc lamp possessed of the following characteristics:
The resistance of the arc is constant;
The luminous focus may be fixed or variable;
The kindling and rekindly are spontaneously effected;
The lamp may be lighted either singly or in groups, in series or in multiple arc;
It can be used for the production of very small as well as of very powerful
lights;
It is automatically shunted out of the circuit in case of accident to the lamp or
of complete wear of the carbon pencils.
Fig. I is a detailed view of the lamp and illustrates the feeding and regulating
mechanisms and the carbon points shunt.
Fig. II is a diagram of the same, illustrating the lamp safety shunt.
Fig. III is a diagram of the lamp safety shunt.
Fig. IV is an elevation of the lamp as actually manufactured.
Fig. V is a diagram of the same.
In Figs. I & II of the annexed drawing
A is a disk of soft iron fixed on a rotating axle O.
B and C are two electro-magnets the cores of which are composed of soft iron
wires or strips.
b and c are two soft iron armatures made of either one massive or of more pieces,
and fixed on the springs e e; the latter are secured on the rigid blocks E E E in
such a manner that the extremities of the armatures b and c are tangential to the
disk A.
If in these conditions an alternating, an ondulatory or an intermittent current is
caused to circulate through the wires of the electromagnets B and C, each of the
armatures b and c, under the influence of the two antagonistic actions of the
magnetic attraction of the electro-magnets and to the elasticity of the flexible
springs upon which they are mounted, become possessed of a vibratory motion.
Price S/1

page_text: The shape given to the armatures b and c is that of a bar the central line of
which is parallel to the direction of the vibratory motion of the springs c.
A polarity is, under the influence of the poles of B and C developed at each end
of the bars b and c. The said polarities partake of all the fluctuations, resulting
from the variations, the successions or the changes in the direction of the currents
circulating through the electro-magnets B and C.
The polarities thus developed in the bars b and c simultaneously produce the
following effects:
1° The magnetic adherence to the disk A, and tangentially to the said disk, of
the free ends of the armatures.
2° The motion of the said armatures towards the poles of the electro-magnets.
A backward motion of the armature succeeds that of attraction during the period
of decrease or of cessation of polarity in the electro-magnets. The adherence of
the armatures to the disk then ceasing, the springs e bring them back to their
initial position without causing any motion of the disk.
The result of these effects is an action the tendency of which is to actuate the
disk A. in the direction of the arrows shown in the diagram.
It will thus be seen that the variations, the successions, or the changes of
polarity of the electro-magnets determine a series of motions of the armature which
motions are transmitted by the said armatures to the disk.
The direction and speed of rotation of the disk are two functions of the
proportion existing between the effects of the two antagonistic electro-motors.
This system of electro-motors constitute an electro-dynamic balance the motion
of which expresses the variations of proportions between the values of the two
combined electrical systems.
In Figs. I & II the actions of the two armatures are opposed. If they were
equal the disk A would remain motionless. If on the contrary one of the two
actions exceeds the other, the disk A rotates in the direction of the greatest action,
following also the variations in the actions of the armatures as regards to value as
well as direction.
If it was desired to actuate the revolving disk in only one direction, this could
be effected by attaching a single system of electro-magnet and armature to the
disk A, as it is illustrated in Figs. IV and V or a series of systems set in the same
direction and operating upon one or several disks.
The armatures may also be arranged so as to act upon the plane surfaces of a
disk, or upon the surface of a cylinder or of a sphere, or upon some conical-surfaces
provided the motion of the armatures is rendered circular and concentrical with
the axle of the disk, the sphere, or the rotating magnetic cone.
The adhesion instead of being produced on one generatrix may also be exerted
on large surfaces.
The magnetic parts heretofore mentioned as being made of soft iron may be
made as well of any other magnetic substances or materials.
The important feature of the special adaptation of this electro-motor to the
regulation of arc lights is the maintenance of the constancy of the resistance of
the arc by the correction of the variations in the length of the said arc, variations
arising out of the waste of the carbon points.
This waste of carbon points being of permanent occurence, it is necessary, in
order to obtain a perfect regulation that the correction be also permanent that is
to say that the forward motion of the carbon pencils be continuous and proportionel
to their waste whatever may he the variations of resistance which for various
reasons the said carbons may offer to the emission of the arc.
This result has been arrived at in the following manner :
A and A' (Fig. 11) are two disks of soft iron mounted on a rotary axle O, O'
provided with two threads being cut one left and the other right hand. Two nicely
adjusted screws F F run smoothly and freely along the said threads, carrying with
them the two insulated arms or carbon nencil holders & G

page_text: b, b'; c, c', (Fig. I) are the armatures vibrating under the action of the electro-
motors B and C. One of the said electro-motors, B for example is wound with
thick wire and inserted in the lamp's circuit whereas the other, C, wound with fine
wire is inserted in a derived circuit or shunt from the arc, as shown in the diagrams
Fig. 1 & 2.
As already set forth, the system of the two disks A and A' is actuated by the
motive actions of the electro-magnets B and C which being in opposite directions
will cause the axle O to remain stationary or to rotate, and consequently the
distance between the carbon points to remain a fixed one or to vary, according to
these said opposing actions remaining equal or varying.
This condition is that of the normal regulation of the lamp and it is obtained by
constructing the electro-magnets in such a manner as to obtain the equilibrium
betwen two antagonistic motive systems for an arc of a given resistance.
But owing to the waste of the carbon points, the derived current from the arc
will have a constant tendency to increase since the resistance of the arc itself keeps
constantly increasing with the length of the said arc. The thin wire electro-
magnet, which is in the derived circuit of the arc will therefore have a constant
predominance over the thick wire one, placed in the main circuit. As the thin
wire electro-motor is adjusted so as to cause the two carbon pencils to travel
towards each other, the result is a permanent correction of the resistance and
consequently of the length of the arc to a pre-determined value, settled once for all
for a current of a given power.
The fixity or steadiness of the luminous focus naturally results from the equality
of the wearing of the carbon points with their feeding towards each other, provided
the current is alternating or uniformly reversed.
The kindling and rekindling of the lamp are effected as follows:
The diagram Fig. II illustrates an arrangement of safety switch V suitable both
as a short circuit and a relighter in case of a temporary extinction, accidental or
otherwise.
It is composed of a lever H I L oscillating round the point I and provided with
two magnetic armatures h and Z. The armature h is in the vicinity of the thin
wire electro-magnet C's pole. The armature is in the vicinity of the pole of an
electro-magnet V the resistance of which, when at work is slightly superior to that
of the normal arc.
The circuit feeding the electro-magnet V is constituted of a derivation taken at
the same points as the derived circuit of the electro-magnet C, since it is intended
to replace the arc. But it is interrupted between the spring m and the contact n.
Before the kindling, when the two carbon points are in contact, and after the
kindling, as long as the arc is maintained between the carbon points, the lever
HIL is maintained against the stop M by the pressure of the spring N. Should
the light go out, the whole of the current passes through the thin wire of C,
the magnetic power of which considerably increases. The resistance of N is over-
come, the armature h is attracted. The circuit of V is closed in mn and the coil V
is substituted for the arc in the derived circuit.
The combined actions of coils V and C contribute to keep closed the derived
circuit. The resistance of V being superior to that of the normal are, the electro-
motor Cacts with predominance and brings together the carbon points until contact
is effected. At this moment the circuit of the carbon pencils offering a minimum
of resistance, the electro-magnets C and V which are placed in derivation on the
carbon points abandon the lever HIL to the action of N. The circuit of coil V
is interrupted. The coil or electro-motor B becomes predominant and acts on the
disk A, separating the carbon points until the regulation is complete that is to say
until the arc has reached its normal resistance.
The safety shunt may be independent from the lamp and fixed in the circuit of
and at any distance from the latter (Fig. III).
When the lamp is alight the main current from P travels through the coil of a
solenoid A to the armature is attached a metallic fork f. The magnetic attraction

page_text: due to the action of the current keeps the said fork suspended its two prongs being
out of the mercury contained in the two cups m n.
From A the current goes through the lamp as already explained and returns
through T. S. R.
If the lamp is put out or goes out the fork ƒ falls into the mercury cups m. n,
establishing a short circuit between these two cups.
The current from P then find two paths: one going to the lamp as before and
the other going through coil B the resistance of which is nearly equal to that of
the arc; it will divide itself between these two paths the portion going to the lamp
causing the electro-magnet C to bring the carbon points nearer and nearer each
other whereas the other portion will go to feed the other lamps placed in the same
circuit and therefore preventing their extinction.
As soon as the carbon points are brought into contact the fork f will be lifted
out of the mercury cups and the lamp will be rekindled, everything being reinstated
in the same order as previously.
When the carbon pencils are entirely consumed, the carbon holder G' comes into
contact with a stop g' which is connected with the main circuit before the coil B.
The effect is to shunt the lamp out of circuit, as the totality of the current, at
that time, passes direct through the mains without passing through any part of
the lamp.
The electro-dynamic balanco may also have the following arrangement, (Fig. IV
& V):
If Fig. IV is an illustration of a regulator of our system, with a variable
luminous focus, and provided with a safety shunt, A and A¹ are the soft iron disks;
C is the coil inserted in the derived circuit of the carbon points, D is its magnetic
core; c and c' the motive magnetic armatures mounted on the elastic springs e;
FF' is a soft iron lever oscillating round the point f; one of its ends F' is in the
vicinity of the pole of the core D and the other F embraces the circumference of
the disk A with which its contact may be established on a portion of the said
circumference. A spring f' presses one arm of this lever upon the disk A, keeping
at the same time the other arin away from the core D; the pressure may be varied
or regulated at will by means of a regulating screw.
In this arrangement the lever F F takes the place of the thick wire electro-
motor in its function of antagonist to the thin wire electro-motor, and the latter
has a constant tendency to bring the carbon points nearer and nearer together.
If the said tendency was not checked, the carbon points would soon come into
contact but the spring f' is regulated in such a manner that its pressure counter-
balances the magnetic attraction of the core D when the are has its normal length.
The arm F therefore, acting as a mechanical and magnetic brake, presses upon the
circumference of the disk A, preventing any feeding motion when the arc has its
proper length, and releasing it, allows of the said feeding motion to take place
when the carbon points having consumed their distance grows greater and the
derived current becomes powerful enough to overcome the resistance of the
spring f'.
The result is a state of unstable equilibrium constituting a new kind of electro-
dynamic balance. Equilibrium is again, hero, a function of the resistance of the
are and, generally speaking, of any given electric resistance.
The succession of the actions of the motor and of the brake is of permanent
occurence owing to the waste of the carbon points, and the disks and the screw
upon which they are mounted, being operated upon by the said motor and brake
follow all the variations of the resistance of the arc and consequently of the waste
of the carbon points.
In this case the regulation is permanent also but with the advantage of the
economy of the portion of energy consumed by the thick wire in the case of the
electro-dynamic balance with two antagonistic electro-inotors.
A greater sensibility and power is obtained by making the lever F F' of a
magnetic material as advantage is thus taken of the effect of magnetic adhesion

page_text: when the lever is in contact with the disc, and of the favorable reaction which
take place between the lever and the disk at the moment of their contact or of
their separation.
As with this arrangement there is no provision for bringing away the carbon
points, the kindling of the lamp is effected in the following manner:
The lower carbon holder G is capable of an ascensional motion which can be
regulated at will; the said motion is produced at the time of sending the current
through the lamp and is due to the action of a solenoid S containing a fixed
magnetic core S' and another movable magnetic core 8. The latter is attached to
the base of the movable lower carbon holder G by means of the rod g' ending in a
spring through which the current is conveyed to the carbon point.
The carbon holder is lifted by the attraction exerted between S' and s when an
electric current circulates in the solenoid S.
The various functions which have been described and which are effected under
the influence of the electric current, in this type of regulator are secured by the
arrangements of circuits illustrated in the diagram Fig. V.
I and II are the terminals of the external circuit. On the current being sent
through, the carbon points not being in contact, the only path is through the
coil which receives the full force of the current; the lever H I L is attracted by D,
at H and the contact between m and n being established, the current is divided
between two paths: one the coil C, the other a circuit including the solenoid S, the
coil V, and the eventual additional resistance R; the core s is attracted by S' and
the lower carbon lifted in its waiting position.
As the two carbons are not yet in contact and the combined resistance of S, V and R
is calculated to be superior to that of the normal arc, the electro-motor C acts
energetically upon the disks A A' and the carbon points are brought in contact.
At that moment a third path is established through the carbon points; the
resistance of this new circuit being very small, the intensity of the current in the
circuit V diminishes and the armature L being released, a break occurs between
the contacts m and n. The solenoid S becomes inactive and the carbon holder G
falls. An arc is struck between the two points and the lamp is kindled.
From that time no waste of energy takes place outside the arc and the derivation
coil C.
When the carbon pencils are consumed and carbon holder G' has reached the end
of its fall a short circuit takes place owing to the contact of Y and Z as explained
previously in the case of the lamp with fixed focus, and the lamp is thrown out of
circuit.
Fig. IV illustrates the lamp such as it is constructed. The soft iron disks A A'
are mounted on the screw T to which they transmit the rotary motion which they
receive from the electro-motor regulator. A screw T, mounted on a pivot at the
top part of the carbon holder G', is kept in gear by means of a spring; it carries
the said carbon holder with it in its fall, and can be thrown out of gear in an
instant by means of the handle U and the cam t, for the purpose of lifting the
candle holder at candling or cleaning time. The carbons are held in split tubes
which receive a nut outside for the purpose of screwing the carbons firmly in
position.
The inside of these split tubes are in the shape of two inverted cones opposed by
their small bases; this arrangement allows of the carbon pencils to be nicely
adjusted in position as they can be slightly inclined one way or the other according
to requirements.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is
1° The system of permanent correction of the variations of the arc by means of
an electro-dymamic balance constituted of two electro-motors such as described,
and, in the case of a regulator, actuating in contrary directions the same movable

page_text: piece the rotation of which effects the feeding of the carbon points. The two
electro-motors are working differentially, one in the main circuit or in a derivation
of the same, the other in a derivation of the arc.
2° The arrangement of electro-dynamic balance essentially constituted by a
magnetic electro-motor and a magnetic brake and actuating in the same direction a
movable piece, also magnetic, and as heretofore described and illustrated.
3° The arrangement of electro-motor based on the utilization of the vibrations of
magnetic armatures or cores submitted to the action of electro-magnets or solenoids
the coils of which are traversed by alternating, ondulatory or intermittent currents;
the said vibrations being transformed into motive actions through the agency
of the magnetic adhesion existing between the movable picce and the said armatures
or cores, during certain periods of the vibratory motion, as described and illus-
trated.
4° The kindling arrangement which consists in bringing one carbon pencil
nearer the other, or the two carbon pencils towards each other but not in actual
contact and only in a waiting position for the contact to be afterwards effected. The
permanent electric work wasted in the ordinary coils used for kindling purposes
and through which the current passes during the whole period of lighting is thus
dispensed with, as described and illustrated.
5° The arrangement of shunt as described and illustrated in Figs. IV and 5, and
which also is possessed of the advantage of not requiring any electrical work
during the period of lighting.