LECT LIGHT APPARATUS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Charles Lever at the Office
of the Commissioners of Patents on the 3rd May 1882.
CHARLES LEVER of Bowden in the County of Cheshire
ELECTRIC LIGHT APPARATUS,"
"IMPROVEMENTS IN
The first part of this invention has for its object improvements in electric lamps
where the light results from the electric current passing between points or pencils
of carbon.
The way I accomplish this part of my invention is preferably by commencing in
an inverse manner to that usually employed in electric arc lamps, i.e. the carbon
electrodes in the lamp do not make contact with each other before the electric
current is sent through the lamp. The reason of this will be described hereinafter.
Instead of employing an electro-magnet or solenoid in the main circuit to
separate the carbon points for the production of the voltaic arc as is usually the
case, I employ an armature lever in combination with a spring, weight, gaseous or
fluid pressure to separate the carbon points to the required distance for the display
of the voltaic arc, this distance being regulated by means of a set screw acting on
the said armature lever and limiting its movement.
Acting on the opposite end of this armature lever, and in an opposite direction
to the spring weight, gaseous or fluid pressure is an electro-magnet in a shunt
circuit of a considerably greater resistance than that of the arc from which it is
shunted or derived. The armature lever is free to move on a pivot or fulcrum pin
fixed to the casting, preferably of brass or other diamagnetic metal-in which are
enclosed the shunt electro-magnet and clip or other device by which the said
armature lever can raise the upper carbon holder-which slides through the said
casting by means of the said spring, weight, gaseous or fluid pressure.
One method of carrying this invention into practice is as follows:-
At one end of the armature lever and resting loosely upon it is a clip, which is
simply a metal washer encircling the upper carbon holder, and which will allow

page_text: the upper carbon holder to fall by gravity when the clip is at right angles to the
said carbon holder. At the other end of the armature lever is attached the spring
or weight, the force of which can be regulated by any suitable means such as
adjusting the tension of the spring by a screw, or by moving the weight nearer to
or further from the fulcrum of the armature lever. The spring or weight must
however have sufficient force on the armature lever when no current is flowing
through the lamp, as will allow the spring or weight to raise the upper carbon
holder with its carbon pencil by means of the armature lever and clip to the
required distance for the display of the voltaic arc.
When the lamp is not in use, the carbon points are separated by means of the
said spring or weight acting on said armature lever, so that when the electric
current is sent through the lamp-the circuit of low resistance through the carbons
being broken by their not making contact with each other-all the current
momentarily goes through the shunt electro-magnet. But immediately this takes
place, the shunt electro-magnet will become so powerfully magnetised that it will
overcome the force of the weight or spring on the armature lever which raises the
upper carbon holder; and it will attract the armature lever, thus loosening the
clip and allowing the upper carbon holder to fall by gravity, until the upper carbon
pencil comes into contact with the lower carbon. As soon however as the carbons
come into contact, the shunt electro-magnet will lose nearly all its magnetism-the
main circuit having then been closed-and consequently the weight or spring will
raise the upper carbon holder and its carbon pencil to the regulated distance for
the display of the voltaic arc. This action will take place so quickly that there
will be no dangerous rise of temperature in the coils of wire on the shunt electro-
magnet.
But as the resistance of the arc increases as the carbons are consumed, more
current will flow through the shunt electro magnet, until a point is reached when
the force of the spring or weight which keeps the upper carbon raised, is over come
by the force of the shunt electro-magnet acting on the opposite end of the armature
lever, whereupon the clip will be loosened thus allowing the carbon to fall, until an
equilibrium is established between the shunt electro magnet and the force of the
weight or spring. This action will take place until the carbons are consumed.
Instead of employing a weight or spring to act on the armature lever and thus
raise the carbon pencil as already described, a piston and piston rod can be attached
to the said armature lever, and in this case a column of mercury, or gaseous or
other fluid pressure can be made to act on the piston and raise the carbon pencil
as before, the pressure being here adjusted by means of a stop cock on a tube.
A simpler modification of lamp is that where two springs fixed to the casting
through which the upper carbon holder slides alone are used, and which by their
elasticity impinge on the sides of the said carbon holder and raise the carbon point
to the required distance for the production of the arc, this distance being regulated
by two set screws acting on the said springs and limiting their upward movement.
The shunt electro-magnet attracts these two springs-which in this case are made
of steel as it would attract two armatures. The carbons in the lamp are separated
before the current passes as already described.
When the current passes through the lamp the main circuit being broken-all
the current momentarily goes through the coils on the shunt electro magnet and
magnetises it very powerfully, thus causing the said electro magnet to attract the
two steel springs-Immediately this takes place the upper carbon holder will slide.
by gravity through its bearings and consequently the carbons will come into
contact with each other. The main circuit is then closed, and the shunt electro-
magnet loses its power on the springs, and by the tension of the springs the upper
carbon bolder is again raised to the regulated distance thus forming the arc, which
will continue to be regulated as before. If desired solenoids could be substituted
for the electro-magnets.
It will be seen then, that any number of arc lamps constructed according to this
invention can be worked in series or single circuit as well as in multiple arc or

page_text: parallel circuit, because the regulation of the arc is effected solely in a shunt
circuit, and the lamps can be worked either by continuous or alternate currents
but the former are preferred as being more economical.
In order to prevent the arc forming between the carbon holder and the lower
carbon point, should by accident one of the carbons have fallen out of its carbon
holder, a simple cut out device is used which is constructed as follows.
On the top of the brass box which contains the shunt electro magnet and the
armature lever or the two steel springs which raise the upper carbon pencil, is
fixed a device similar to that used in sinall spring guns, i,e a small metal rod is
capable of rotating on its axis through a U piece of metal cast on the top of the
said brass box. A slot is cut into this U piece of metal, and the small metal rod
capable of rotating on its axis is bent at right angle outside one of the open ends
of this U piece. Between the two inside ends of the U piece of metal is a spiral
spring sliding on the said metal rod, and which can give the metal rod a longi-
tudinal motion when its bent arm comes over the slot on the U piece of metal.
At the end of the metal rod opposite to the bent arm and outside the U piece, is
attached a small flat piece of metal, and at a short distance from this flat piece of
metal is another smaller metallic piece insulated from the brass box, by connected by
means of a wire of low resistance with the negative binding screw of the lamp.
The bent arm of the motal rod is at the outer end of the U-piece nearest to the
upper carbon holder, and the said carbon holder has a brass flange or rim fixed at
its upper end, so that when the brass flange or rim comes into contact with the
bent arm of the metal rod, the weight of the carbon holder will cause the flange
or rim to give the bent arm of the metal rod a slight rotatory movement.
The
bent arm is however adjusted a little higher than the slot in the U piece, so that
when the flange or rin on the upper carbon holder noves the bent arm of the metal
rod downwards through the descent of the said carbon holder, the bent arm would
come opposite the said slot, and the spring would give the metal rod a longitudinal
movement as already described. But the depth of the slot is arranged so that
when the spiral spring gives the metal rod this longitudinal movement, the small
flat piece of metal attached to the end of the said metal rod opposite to the bent
arın, will come into contact with the metallic piece insulated from the brass box.
but connected with a wire of low resistance to the negative binding screw of the
lamp. It will be seen then that the arc will by this means be "cut out" and when
the weight, springs, fluid or gaseous pressure whichever are used, raise the upper
carbon holder, the arc cannot be formed between the said carbon holder and the
lower carbon pencil or vice versa, because the main current will then flow through
the new circuit which has been formed by the cut out device vis: from the +
binding screw of the lamp, through the brass casting and metal rod through the
contact of the two metallic pieces to the binding screw of the lamp by means
of the insulated wire of low resistance. Many other devices could be used for this
purpose.
-
I might thus have a small lever pivotted and provided with a detent or tooth
which can engage a spring, so that the weight of the upper carbon holder will
cause the flange or rim fixed thereto to press on the end of the small pivotted
lever opposite to the detent or tooth. This will lift the small lever up thus
allowing the detent or tooth to disengage the spring, and the spring being free
will make contact with the insulated metallic piece and cut out the lamp as before.
In a double carbon lamp when the first pair of carbons are consumed, the cut out
devices described can be used to switch the current from the first pair of carbons
to the second pair. This can be done by connecting the insulated wire of low
resistance from the metallic piece insulated from the casting, to the upper carbon
holder or lower carbon holder of the second pair of carbons.
One electro magnet can be made to work both pairs of carbons in a double
carbon lamp, by simply making T pole pieces from both limbs of the electro-
magnet in the case of the two steel springs or one T piece when the armature
lever and clip is used and a bar electro-magnet is employed.

page_text: The second part of this invention is intended to be used when continuous
currents are used with the form of lamps herein before described, and where it is
desirable that these currents should be generated by what is called a self exciting
dynamo machine.
If for example a number of these lamps are placed in series or single circuit,
the carbon points in the lamps being separated, the only path for the electric
current is through the shunt circuits on the electro-magnets in the lamps. But the
resistance of these shunt circuits would be so great that the dynamo machine could
not excite itself through this resistance. One method of obviating this difficulty
is as follows.
It is well known that when a dynamo electric machine is excited, the iron parts
of the machine become strongly magnetised and the magnetism of any of these
parts, whichever part is most convenient, is utilized to attract an armature fastened
to one end of a metal spring which spring is fixed at the opposite end to a suitable
piece of insulating material. A metal upright preferably of brass parallel with
the metal spring is also fixed in the same piece of insulating material, or where a
dynamo machine is expressly made for use with these lamps, a separate casting
could be made on the frame of the machine, and the brass upright and metal
spring could be attached thereto but insulated from each other. A metal screw
passes through the brass upright provided with a milled head, so that the said
metal screw can be moved nearer to or farther from the metal spring with the
armature fixed at its free end, the object of the screw being to establish electrical
connection with the said metal spring, and also to a adjust the armature on the
said metal spring nearer to or farther from the iron part of the dynamo which it
is intended to utilise for this purpose. This device is similar to that used in
"Ruhmkorff" coils to effect the make and break of the current in the primary
coil, and if desired the end of the metal screw and the part of the metal spring
with which it comes into contact can be platinised so as to establish good electrical
connection.
The shape of the insulated bed on which is fixed the device just described, will
of course be modified with different dynamo-machines, that is when a casting is
not made on the dynamo for this purpose. Suppose for example it is found
convenient to utilize the magnetism of the iron loop fixed on the top of most
dynamo machines or any other projecting piece of iron which becomes magnetised
when the machine is excited, then the insulating bed is fixed to the machine so
that the said iron loop or projection will come opposite to the armature on the free
end of the metal spring and at a small distance from the said armature, so that
when the said iron loop or projection becomes magnetised it will attract the said
armature on the free end of the spring, and thus cause the contact between the
metal screw and the metal spring to be broken. A wire of low resistance connects
the brass upright to one binding screw of the dynamo machine, and another similar
wire connects the metal spring with the other binding screw of the machine, so
that when the metal screw which passes through the brass upright makes contact
with the metal spring, and the main circuit and lamps are connected with the
binding screws of the dynamo, the contact of said metal screw with said metal
spring completes a shunt or derived circuit of low resistance
The action of this device is as follows:
When the armature of the dynamo electric machine commences to revolve the
dynamo will excite itself through the shunt circuit of low resistance which has
been formed by the contact of the metal screw with the metal spring the resistance
in the main circuit and lamps being too great to allow the dynamo to excite itself
through this resistance, until the electro-magnets in the dynamo become magnetised
to saturation, and likewise the iron loop or projection. But immediately this takes
place the iron loop or projection-whichever is used-will attract the armature on
the free end of the metal spring as herein before described and consequently the
said spring will cease to make contact with the metal screw passing through the
brass upright. The shunt circuit will by this means be broken and all the current

page_text: will then flow through the main circuit, whereupon the shunt electro magnets or
solenoids in the lamps will instantly form the arcs as described in the former part
of this specification But when the voltaic arcs are formed in the lamps, the
resistance in the main circuit will have been reduced very considerably to what it
was before the arcs were formed, so that the dynamo machine will continue to
excite itself through the resistance of the arcs thus formed.
It will be seen then that by meaus of the simple contrivance just described, a
dynamo electric machine can excite itself when used to supply the electric
light from electric lamps where the carbons are separated before the arc is formed.
But when the dynamo is exciting itself through the main circuit and the arcs
are burning it is obvious that if any break occured in the main circuit, that the
elasticity of the metal spring will cause the armature attached thereto to leave the
iron loop or projection, because the iron parts of the dynamo would then cease to
be magnetic so that the said metal spring would make contact with the metal
screw passing through the brass upright whereupon the shunt circuit of low
resistance will again be closed. The consequence of this would be, that the
armature and the spring to which it is attached would commence to vibrate, and
the dynamo machine would then be exciting itself through the shunt circuit of low
resistance and continue to do so until the armature of the dynamo might become so
heated as to destroy the insulation on the coils of wire, thus rendering the machine
useless. In order to prevent this, a small piece of insulating material shaped like
a wedge and fixed on a spiral or flat spring, is caused to press gently on the
underside of the part where the metal screw passing through the brass upright
comes into contact with the metal spring having the armature fixed at its
free end, care being taken that the said spiral or flat spring to which is
fixed the insulating wedge does not touch either the metal screw or the
said metal spring. When the dynamo is not excited and the metal screw
makes contact with the metal spring thus completing the shunt circuit as
already explained, the insulating wedge cannot be pressed upwards by its spring,
until the arinature fixed at the free end of the metal spring has been attracted by
the iron loop or projection, or in other words until the dynamo has excited itself
through the said shunt circuit. But immediately the dynamo has excited itself
and the armature fixed to the free end of the metal spring is attracted by the said
iron loop or projection the metal spring will leave the metal screw passing through
the brass upright and the insulating wedge will then be pressed upwards by its
spring between the said metal screw and metal spring so that the contact between
them can never be reestablished that is, the shunt circuit can never be completed
again until the insulating wedge has been moved back into its original position.
Instead of employing an insulated wedge, a detent could be used actuated by a
spring which would allow the said metal spring to which is attached the armature
to pass it when the said armature is attracted but which would catch or lock the
said metal spring and thus prevent its making contact with the metal screw when
the circuit is broken. Another method of preventing the armature of the dynamo
from heating when the main circuit is broken, is to make the exciting shunt
circuit of a resistance about equal to that of the main circuit when the arcs are
formed in the lamps.
When it is not desirable or convenient to utilise the magnetism of the iron loop
or other iron projection of the dynamo to allow the dynamo machine to excite
itself as already described, an electro magnet or solenoid of low resistance is
connected in the shunt circuit of low resistance and a spring of suitable tension
draws the iron core of the solenoid or the armature of the electro magnet whichever
is used, against a metal stud or metal screw passing through a brass upright as
before, and thus complete the shunt circuit when the dynamo is not excited as
before.
When however the dynamo has excited itself through the said shunt circuit, the
current generated in the said shunt circuit will cause the solenoid or electro magnet
to attract its iron core or armature, the tension of the spring attached thereto being

page_text: overcome by the attractive force of the solenoid or electro magnet, and it will
leave the metal stud or screw, whereupon the said shunt circuit will be broken the
current from the dynamo will flow through the main circuit thus forming the arcs
in the lamps; and the dynamo will then continue to excite itself through the
resistance of these arcs. It is desirable to have one of the locking devices
hereinbefore described when this apparatus is used in order to prevent the
armature of the dynamo becoming heated.
A modification of the electro magnetic apparatus just described, is where an
armature capable of moving on a pivot fixed at one end of the armature is used,
the said pivot or fulcrum pin being provided with a screw and screw head, so that
the armature can be made to move somewhat stiffly by screwing down the said
screw head. At the end of the armature opposite to the pivot, is a metal piece
sliding through the said armature, and a spring-spiral or flat-presses this metal
piece upon a metal stud. The electro-magnet in the shunt circuit-or if a solenoid
is used an iron core would have to be attached to the said armature-has the ends
of its coils, which are of coarse wire, connected one to the pivot of the armature
and the other to one of the binding screws of the dynamo-electric machine, the said
electro-magnet, armature and metal stud being fixed on a plate of insulating
material such as wood or vulcanite, the metal stud being made flush therewith.
When the metal piece sliding through the armature is resting on the metal stud,
and the said metal stud is connected by a wire of low resistance to the other
binding screw of the dynamo machine, the exciting shunt circuit is completed viz:
from the positive binding screw of the dynamo through the coils of the electro-
magnet, or solenoid, to the pivot of the armature, through the armature and metal
piece to the metal stud, and to the negative binding screw of the dynamo or vice
versu. When the shunt circuit is thus completed and the dynamo has excited
itself, the armature will be attracted by the said electro-magnet or solenoid-the
screw head having been so adjusted, that the armature will not be attracted until
the dynamo has sufficiently excited itself-and the metal piece sliding through the
said armature will leave its metal stud, thus breaking the shunt circuit and allow
the current generated by the dynamo to actuate the lamps as before.
It will be seen that in this modification, no locking device is necessary, because
when once the shunt circuit has been broken, it remains so until the armature has
been readjusted.
A. simple switch or key can also be used to form this exciting shunt circuit and
to break the said shunt circuit by hand when the dynamo has excited itself, but
this arrangement not being automatic would necessitate some skill on the part of
the operator in order to ascertain to a nicety, when the dynamo had sufficiently
excited itself for him to break the shunt circuit by releasing the key or moving the
switch.
The devices herein before described are however when once adjusted automatic.
The main objects then of this second part of my invention are as follows:-
1st To form a shunt circuit of low resistance to allow the dynamo to excite
itself by means of the devices herein before described when the resistance in the
main circuit is very great.
2nd To break this shunt circuit and allow the current thus generated by the
dynamo to actuate the shunt electro-magnets or solenoids in the lamps and thus
form the arcs as herein before described.
3rd When the shunt circuit has once been broken to prevent its being closed
again by means of the devices herein before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Lever in the Great Seal Patent Office on the 3rd November
1882.
CHARLES LEVER of Bowden in the County of Cheshire
ELECTRIC LIGHT APPARATUS
"
" IMPROVEMENTS IN
The first part of this Invention has for its object improvements in electric lamps
where the light results from the electric current passing between points or pencils
of carbon.
The way I accomplish this part of my Invention is by commencing in an inverse
manner to that usually employed in electric arc lamps 2,e, the carbon electrodes
in the lamp do not make contact with each other before the electric current is sent
through the lamp. The reason of this will be described hereinafter.
Instead of employing an electro magnet or solenoid in the main circuit to separate
the carbon points for the production of the voltaic arc as is usually the case I
employ an armature lever in combination with a spring, weight, gaseous or liquid
pressure to separate the carbon points to the required distance for the display of
the voltaic are this distance being regulated by means of a set screw acting on the
said armature lever and limiting its movement.
Acting on the opposite end of this armature lever, and in an opposite direction
to the spring, weight, gaseous or fluid pressure, is an electro-magnet in a shunt
circuit of a considerably greater resistance than that of the arc from which it is
shunted or derived. The armature lever is free to move on a pivot or fulcrum pin
fixed to the casting preferably of brass or other diamagnetic metal in which are
enclosed the shunt electro magnet and clip or other device by which the said
armature lever can raise the upper carbon holder which slides through the said
casting by means of the said spring, weight, gaseous or fluid pressure.
One method of carrying this Invention into practice is as follows as will be best
understood by reference to Figure 1 of the accompanying drawings which is a side
view showing the working part of a lamp.
At one end of the armature lever A and resting loosely upon it is a clip B which
is simply a metal washer encircling the upper carbon holder C and which will
allow the upper carbon holder to fall by gravity when the clip is at right angles to
the said carbon holder. At the other end of the armature lever A. is attached the
spring D (or weight) the force of which can be regulated by any suitable means
such as adjusting the tension of the spring by a screw E (or by moving the weight
nearer to or further from the fulcrum of the armature lever. The spring D (or
weight) must however have sufficient force on the armature lever A when no
current is flowing through the lamp, as will allow the spring D (or weight) to
raise the upper carbon holder C with its carbon pencil by means of the armature
lever A and clip B to the required distance for the display of the voltaic arc.
G is a set screw for adjusting the movement of the lever A and the length of
the arc.
When the lamp is not in use the carbon points are separated by means of the
said spring D (or weight) acting on said armature lever A so that when the electric
current is sent through the lamp the circuit of low resistance through the carbons
being broken by their not making contact with each other; all the current
momentarily goes through the shunt electro-magnet F. But immediately this
takes place the shunt electro magnet F will become so powerfully magnetised that
it will overcome the force of spring D on the armature lever A which raises the
upper carbon holder C and it will attract the armature lever A thus loosening the

page_text: clip B and allowing the upper carbon holder C to fall by gravity until the upper
carbon pencil comes into contact with the lower carbon. As soon however as the
carbons come into contact, the shunt electro magnet F will lose nearly all its
magnetism the main circuit having then been closed and consequently the spring D
will raise the upper carbon holder Č and its carbon pencil to the regulated distance
for the display of the voltaic arc. This action will take place so quickly that there
will be no dangerous rise of temperature in the coils of wire on the shunt electro-
magnet F.
But as the resistance of the arc increases as the carbons are consumed, more
current will flow through the shunt electro magnet F until a point is reached when
the force of the spring D (or weight) which keeps the upper carbon raised, is
overcome by the force of the shunt electro magnet F acting on the opposite end of
the armature lever A whereupon the clip B will be loosened thus allowing the
carbon to fall, until an equilibrium is established between the shunt electro magnet F
and the force of the spring D (or weight.) This action will take place until the
carbons are consumed.
Instead of employing a weight or spring to act on the armature lever and thus
raise the carbon pencil as already described a piston and piston rod can be attached
to the said armature lever A and in this case a column of mercury or gaseous or
other fluid pressure can be made to act on the piston and raise the carbon pencil as
before, the pressure being then adjusted by means of a stop cock on a tube.
The iron
Figure 1 shows an electric lamp complete constructed according to this part of
the Invention but where the armature lever A. Figure 1 is replaced by a lever L
preferably of diamagnetic material. The armature A is here fixed at the same end
of the lever L as the spring D; E is the nut for adjusting the tension of the spring D
and I is a projection attached to the lever L which cants or tilts the clip B by
means of spring D. G is the set screw for adjusting the length of arc.
screws J J with large heads passing through the armature A serve as adjustable
pole pieces and can be secured by means of lock nuts J¹ J. R is the dash pot and
SS are the binding screws from which the electro magnets F F is shunted or
derived. The current entering at the positive binding screw S passes through the
insulated flexible wire or cable S2 to the upper carbon holder C from thence
through the arc and lower carbon and through the frame of the lamp to negative
binding screw S¹. The side rods are insulated from each other; and the ends of
the coils of the electro magnets F F are connected to the binding screws S S¹ thus
placing the electro magnet F in derivation from the arc.
A simpler modification of lamp is that shown in Figure 2 where two springs B B
(fixed to two screws I which can be adjusted as required by their nuts in the
casting H through which the upper carbon holder C slides) alone are used, and
which by their elasticity impinge on the sides of the said carbon holder C and
raise the carbon point to the required distance for the production of the arc, this
distance being regulated by two set screws G G acting on the said springs B and
limiting their upward movement. The shunt electro magnets F F attracts these
two springs BB which in this case are made of steel and have soft iron pieces B₁ B₁
fixed thereon and which act as armatures. The carbons in the lamp are separated
before the current passes as already described.
When the current passes through the lamp the main circuit being broken all
the current momentarily goes through the coils on the shunt electro magnets FF
and magnetises it very powerfully thus causing the said electro magnets to attract
the two steel springs B B. Immediately this takes place the upper carbon holder C
will slide by gravity through its bearings and consequently the carbons will come into
contact with each other. The main circuit is then closed, and the shunt electro
magnet F loses its power on the springs B, and by the tension of the springs B the
upper carbon holder C is again raised to the regulated distance thus forming the
arc, which will continue to be regulated as before. If desired solenoids could be
substituted for the electro magnet F F.
Figure 3 is a side view and Figure 4 a plan showing one method of adapting

page_text: this principle of regulation in connection with a solenoid. F is such a solenoid
and Fits core which by means of a screw L is adjustably connected to a lever K
which has its fulcrum in the casting H as shown. B B are the springs adjustable
The two sides of the
in this case as before by nuts II fixed to the casting H.
lever K are shaped as shown in Figure 3 where they bear against the springs B.
The action is as follows. The carbous being separated as already described the
current will all pass through the coils of the shunt or derived solenoid F whereupon
its core F will be attracted thus causing the bearing points of the lever K to press
down the springs B B thus allowing carbonholder C to fall by gravity as before.
When however the carbons come into contact the shunt solenoid F losing its
power the elasticity of springs B B will raise the upper carbon holder C to the
regulated distance, thus forming the arc which will continue to be regulated as
hereinbefore described. Instead of the solenoid F. I may use an electro inagnet.
Figure 5 shows an arrangement in which the springs B B are coupled or
connected to an armature A common to both poles of the electro magnet F F for
example by means of uprights A' which have pins A2 which are free to slide in
slots in the brackets A³ fixed to the springs B so as to allow for the radial motion
of the springs B when the armature A is attracted.
I do not however limit myself to these particular methods of coupling the said
springs B B nor simply to their application in connection with a shunt magnet or
solenoid as they may also be applied with a magnet or solenoid in the main circuit
by reversing the action and causing the said magnet or solenoid to raise the carbon
holder C.
Figure 6 is a modification of Figure 1 where the spiral spring D and armature
lever A are replaced by a flat spring D and armature A the said spring being fixed
to the casting H and operating on the clip B as already described. This modifi-
cation I prefer to use in lamps having two or more sets of carbons although it can
be used in a single carbon lamp. Any of the lamps before described can also be
arranged as double carbon lamps. When however a clip is employed I have found
it desirable in practise to use a dash pot to check the sudden descent of the carbon
holder as shown at R, Figure 7, which I will presently describe
It will be seen then that any number of arc lamps constructed according to this
invention can be worked in series or single circuit as well as in multiple arc or
parallel circuit because the regulation of the arc is effected solely in a shunt circuit
and the lamps can be worked either by continuous or alternate currents but the
former are preferred as being more economical.
In order to prevent the arc formning between the carbon holder and the lower
carbon point, should by accident one of the carbons have fallen out of its carbon
holder or in order in a double carbon lamp to automatically switch out one set of
carbons and switch in another set a simple cut out device is used which is
constructed as follows:-I will now describe such a device as applied to a double
carbon lamp and with reference to Figure 7 of which Figure 6 also forms a
side view.
On the top of the brass box H which contains the shunt electro magnet F F and
the armature lever or the two steel springs D D which raise the upper carbon
holder C and pencil is fixed a device similar to that used in small spring guns i e a
small metal rod M is capable of rotating on its axis through a Ushaped piece of
metal N cast on the top of the said brass box H A slot n is cut into this U piece
of metal as shown in the detail view Figure 7* and the sinall metal rod M capable
of rotating on its axis is bent at right angles outside one of the open ends of this
U piece N. Between the two inside ends of the U piece of metal is a spiral
spring M sliding on the said metal rod M and which can give the metal rod a
longitudinal motion when its bent arm m comes over the slot n on the U piece of
metal N. At the end of the metal rod opposite to the bent arm m and outside
the U piece, is formed or attached a small conical or flat piece of metal M² and at
a short distance from this piece of metal is another corresponding metallic piece O
insulated from the brass box H but connected by means of a wire or slip Q of

page_text: low resistance with second carbon holder C¹ (or if applied to a single carbon
lamp with the negative binding screw of the lamp) The bent arm m of the metal
rod M is at the outer end of the U piece N nearest to the upper carbon holder C
and the said carbon holder C has a brass flange or rim P fixed at its upper end so
that when the brass flange or rim P comes into contact with the bent arm of the
metal rod M the weight of the carbon holder C will cause the flange or rim P to
give the bent arm of the metal rod a slight rotary movement. The bent arm m is
however adjusted a little higher than the slot n in the U piece so that when the
flange or rim P on the upper carbon holder C moves the bent arm m of the metal
rod downwards through the descent of the said carbon holder the bent arm m
would come opposite the said slot n and the spring M' would give the metal rod M
a longitudinal movement as already described. But the depth of the slot n is
arranged so that when the spiral spring M' gives the metal rod M this longitudinal
movement the small piece of metal M2 formed on or attached to the end of the said
metal rod M opposite to the bent arm m will come into contact with the metallic
piece O insulated from the brass box H but connected with the slip Q to the second
carbon rod C₁ which is insulated from the box H. It will be seen then that the arc
in the first pair of carbons C will by this means be "cut out" and when the
springs D D or weight fluid or gaseous pressure whichever are used raise the upper
carbon holder C the arc cannot be formed between the said carbon holder C and
the lower carbon pencil or vice versa because the main current will then flow
through the new circuit which has been formed by the cut out device viz:-from
the binding screw of the lamp through the brass casting and metal rod, through
the contact of the two metallic pieces M2 and O to the second carbon holder C¹
by means of the insulated slip Q of low resistance. Many other devices could be
used for this purpose.
In a double carbon lamp when the first pair of carbons are consumed the cut out
device described can thus be used to switch the current from the first pair of
carbons C to the second pair C³.
One electro magnet can as will be seen be made to work both pairs of carbons in
a double carbon lamp either by simply making T pole pieces from both limbs of
the electro magnet in the case of the two steel springs or one T piece when the
armature lever and clip is used and a bar electro magnet is employed; however
the method of connecting the two springs D D by means of one armature A is
preferred. This principal of regulation solely by ineans of a spring and a shunt
magnet or solenoid is applicable to the devices described in the specification of my
Patent No. 3599 Dated 18th August 1881.
The second part of this Invention is to be employed when continuous currents
are used with the form of lamps herein before described and where it is desirable
that these currents should be generated by what is called a self exciting dynamo
machine.
If for example a number of these lamps are placed in series or single circuit, the
carbon points in the lamps being separated, the only path for the electric current is
through the shunt circuits on the electro magnets or solenoids in the lamps but the
resistance of these shunt circuits would be so great that the dynamo machine could
not excite itself through this resistance. One method of obviating this difficulty is
as follows.
It is well known that when a dynamo-electric machine is excited the iron parts
of the machine become strongly magnetised, and the magnetism of any of these
parts, whichever part is most convenient is according to my Invention utilized to
attract an armature fastened to one end of a metal spring which spring is fixed at
the opposite end to a suitable piece of insulating material. A metal upright
preferably of brass, parallel with the metal spring is also fixed in the same piece of
insulating material, or where a dynamo-machine is expressly made for use with
these lamps a separate casting could be made on the frame of the machine, and the
brass upright and metal spring could be attached thereto but insulated from each
other. A metal screw passes through the brass upright provided with a milled

page_text: head so that the said metal screw can be moved nearer to or farther from the metal
spring with the armature fixed at its free end the object of the screw being to
establish electrical connection with the said metal spring and also to adjust the
armature on the said metal spring nearer to or farther from the iron part of the
dynamo which it is intended to utilize for this purpose. This device is similar to
that used in Ruhmkorff coils to effect the make and break of the current in the
primary coil and if desired the end of the metal screw and the part of the metal
spring with which it comes into contact can be platinised so as to establish good
electrical connection
The shape of the insulated bed on which is fixed the device just described will
of course be modified with different dynamo-machines, that is when a casting is
not made on the dynamo for this purpose. Suppose for example it is found
convenient to utilize the magnetism of the iron loop fixed on the top of most
dynamo machines or any other projecting piece of iron which becomes magnetised
when the machine is excited then the insulating bed is fixed to the inachine so that
the said iron loop or projection will come opposite to the armature on the free end
of the metal spring, and at a small distance from the said armature, so that when
the said iron loop or projection becomes magnetised it will attract the said armature
on the free end of the spring and thus cause the contact between the metal screw
and the metal spring to be broken A wire of low resistance connects the brass
upright to one binding screw of the dynamo machine and another similar wire
connects the metal spring with the other binding screw of the machine so that when
the metal screw which passes through the brass upright makes contact with the
metal spring and the main circuit and lamps are connected with the binding
screws of the dynamo the contact of said metal screw with said metal spring
completes a shunt or derived circuit of low resistance. The action of this device is
as follows
When the armature of the dynamo electric machine commences to revolve the
dynamo will excite itself through the shunt circuit of low resistance which has
been formed by the contact of the metal screw with the metal spring the resistance
in the main circuit and lamps being too great to allow the dynamo to excite itself
through this resistance until the electro magnets in the dynamo become magnetised
to saturation and likewise the iron loop or projection But immediately this takes
place the iron loop or projection whichever is used will attract the armature on the
free end of the metal spring as herein before described and consequently the said
spring will cease to make contact with the metal screw passing through the brass
upright.
The shunt circuit will by this means be broken and all the current will then flow
through the main circuit whereupon the shunt electromagnets or solenoids in the
lamps will instantly form the arcs as described in the former part of this
Specification with reference to Figures 1 to 7. But when the voltaic arcs are
formed in the lamps the resistance in the main circuit will have been reduced
very considerably to what it was before the arcs were formed, so that the dynamo
machine will continue to excite itself through the resistance of the arcs thus
formed.
It will be seen then that by means of the simple contrivance just described a
dynamo electric machine can excite itself when used to supply the electric current
to electric lamps where the carbons are separated before the arc is formed and
where the arc is regulated solely in a shunt circuit..
But when the dynamo is exciting itself through the main circuit and the arcs
are burning it is obvious that if any break occurs in the main circuit, that the
elasticity of the metal spring will cause the armature attached thereto to leave the
iron loop or projection because the iron parts of the dynamo will then cease to be
magnetic so that the said metal spring will make contact with the metal screw
passing through the brass upright whereupon the shunt circuit of low resistance
will again be closed. The consequence of this would be that the armature and the
spring to which it is attached would commence to vibrate and the dynamo machine

page_text: would then be exciting itself through the shunt circuit of low resistance and
continue to do so until the armature of the dynamo might become so heated as to
destroy the insulation on the coils of wire, thus rendering the machine useless. In
order to prevent this, a small piece of insulating material shaped like a wedge and
fixed on a spiral or flat spring, is caused to press gently on the under side of the
part where the metal screw passing through the brass upright comes into contact
with the metal spring having the armature fixed at its free end, care being taken
that the said spiral or flat spring to which is fixed the insulating wedge does not
touch either the metal screw or the said metal spring. When the dynamo is not
excited and the metal screw makes contact with the metal spring thus completing
the shunt circuit as already explained, the insulating wedge cannot be pressed
upwards by its spring, until the armature fixed at the free end of the metal spring
has been attracted by the iron loop or projection or in other words until the
dynamo has excited itself through the said shunt circuit. But immediately the
dynamo has excited itself and the armature fixed to the free end of the metal
spring is attracted by the said iron loop or projection, the metal spring will leave
the metal screw passing through the brass upright and the insulating wedge will
then be pressed upward by its spring between the said metal screw and metal
spring so that the contact between them can never be re-established, that is the
shunt circuit can never be completed again until the insulating wedge has been
moved back into its original position. Instead of employing an insulating wedge,
a detent could be used actuated by a spring which would allow the said metal
spring to which is attached the armature to pass it when the said armature is
attracted but which would catch or lock the said metal spring and thus prevent its
making contact with the metal screw when the circuit is broken. Another method
of preventing the armature of the dynamo from heating when the main circuit is
broken is to make the exciting shunt circuit of a resistance about equal to that of
the main circuit when the arcs are formed in the lamps. I have found in practise
that this method is preferable and perfectly reliable.
Figure 8 shows such an arrangement; D is a dynamo machine of which B B
are the terminals to which are connected four lamps L as shown. A is an armature
capable of moving on a pivot or fulcrum at A'. Z is the iron loop of the
dynamo D. The figure shows the lamps in action. A resistance R about equal
to the resistance of the four ares L is connected as follows viz: from + binding
scrow B to armature A. A short thick wire connects metal stud S with the
negative binding screw B¹. C is a spring contact shown in section at Figure 9
where A is the armature through which passes a large screw F having a hollow
part for the reception of the end of spiral spring J and forces the contact piece C
which has a stem guided through screw F, on to the metal stud S, (connected to the
negative terminal B. on the Dynamo D) The screw F serves to adjust the tension
of spring J. Before the lamps are lighted the arcs being broken the armature A is
moved by hand so that contact piece C makes connection with stud S thus com-
pleting the shunt circuit through resistance R. When however the armature of
the dynamo commences to revolve, the machine excites itself through shunt circuit
and resistance R until the iron loop Z becomes sufficiently magnetised to attract
armature A thus causing the said shunt circuit to be broken whereupon all the
current will flow through the main circuit and lamps L thus causing the shunt
electro-magnets, or solenoids in the lamps to instantly form the arcs as described
with reference to figures 1 to 7.
Any of the above devices may be placed at or in the electric lamp by arranging
an electro magnet or solenoid (in this case wound with a resistance preferably
equal to the arc) in derivation to the arc but such arrangements would not be so
practicable with a number of lamps on account of the difficulty of causing all the
devices to break the shunt circuits at the same time.
When it is not desirable or convenient to utilize the magnetism of the iron loop
or other iron projection of the dynamo, to allow the dynamo machine to excite
itself as already described an electro-magnet or solenoid of low resistance is

page_text: connected in the dynamo shunt circuit of low resistance and a spring of suitable
tension draws the iron core of the solenoid or the armature of the electro magnet
whichever is used against a metal stud or metal screw passing through a brass
upright as before which thus completes the shunt circuit when the dynamo is not
excited. When however the dynamo has excited itself through the said shunt
circuit, the current generated in the said shunt circuit will cause the solenoid or
electro magnet to attract its iron core or armature the tension of the spring
attached thereto being overcome by the attractive force of the solenoid or electro
magnet and it will leave the metal stud or screw whereupon the said shunt circuit
will be broken, the current from the dynamo will then flow through the main
circuit thus formning the arcs in the lamps and the dynamo will continue to excite
itself through the resistance of these arcs. It is desirable to have one of the
locking devices hereinbefore described when this apparatus is used in order to
prevent the armature of the dynamo becoming heated as already explained.
A modification of the electro magnetic apparatus just described, is shown in
Figures 10 and 11, where an armature A. capable of moving on a pivot A¹ fixed at
one end of the armature A is used. At the end of the armature A opposite to the
pivot A' is a metal piece C sliding through the said armature and a spring J
presses this metal piece C upon a metal stud S shown in Figures 9 and 11. The
electro magnet E in the shunt circuit (or if a solenoid is used an iron core would
have to be attached to the said armature A) has the ends of its coils which are
of coarse wire having a resistance about equal to that of the lamps L connected
one to the pivot A' of the armature A and the other to one of the binding screws
of the dynamo electric machine or to the binding screws B B¹ on the insulating
plate I and thence to the dynamo, the said electro magnet E, armature A, and
metal stud S being fixed on the plate I of insulating material such as wood or
vulcanite, the metal stud S being made flush therewith. When the metal piece C
sliding through screw F on the armature A is resting on the metal stud S and the
said metal stud is connected by a wire of low resistance as shown at Figure 10
to the other binding screw of the dynamo machine, the exciting shunt circuit is
completed viz from the positive binding screw of the dynamo through the coils
of the electro magnet E or solenoid to the pivot A¹ of the armature A through the
armature and metal piece C to the metal stud S and to the negative binding screw
of the dynamo or vice versa.
When the shunt circuit is thus completed and the dynamo has excited itself the
armature A will be attracted by the said electro magnet E or solenoid the screw F
having been so adjusted that the armature A will not be attracted until the dynamo
has sufficiently excited itself and the metal piece C, sliding through the said screw F
of the armature A will leave its metal stud S thus breaking the shunt circuit and
allowing the current generated by the dynamo to actuate the lamps L as before.
It will be seen that in this modification, no locking device is necessary because
when once the shunt circuit has been broken it remains so until the armature A
has been readjusted.
A simple switch or key can also be used to form this exciting shunt circuit and
to break the said shunt circuit by hand when the dynamo has excited itself but
this arrangement not being automatic would necessitate some skill on the part
of the operator in order to ascertain to a nicety when the dynamo had sufficiently
excited itself for him to break the shunt circuit by releasing the key or moving the
switch.
The devices hereinbefore described are however when once adjusted automatic.
The main objects then of this second part of my Invention are as follows.-
1. To form a shunt circuit of low resistance to allow the dynamo to excite itself
by means of the devices herein before described when the resistance in the main
circuit is very great.
2. To break this shunt circuit and allow the current thus generated by the
dynamio to actuate the shunt electro magnets or solenoids in the lamps and thus
form the arcs as hereinbefore described.

page_text: 3. When the shunt circuit has once been broken to prevent its being closed again
by means of the devices herein before described.
Having thus described the nature of this invention and the manner in which
it is or may be carried into effect. I declare I am aware that clips or clutches have
been used in combination with an electro magnet or solenoid inserted in the main
circuit and serving to separate the carbon points but I claim,-
First. In an electric are lamp the application of a clip or clutch which separates
the carbon pencils by means of a spring or equivalent mechanical means acting
directly on the said clip or clutch or by means of a lever, and an electro magnet
or solenoid inserted in a shunt circuit of considerably greater resistance than that
of the arc from which it is derived and serving to counteract the force of said
spring or equivalent mechanical means and to regulate the arc substantially as
described.
Second. In an electric arc lamp the combination of a clip or clutch with a shunt
electro-magnet or solenoid substantially as described with reference to Figures 6
and 7.
Third. In an electric arc lamp the application of the flexible armatures or
springs in combination with a main electro magnet or solenoid to separate the
carbons or in combination with a shunt electro magnet or solenoid to cause the
carbons to approach, or in combination with both substantially as described with
reference to Figures 2, 3, 4, and 5.
Fourth. In an electric arc lamp the combination of parts forming the device
to cut out the lamp or to automatically switch the current from one pair of carbons
to another pair of carbons as required substantially as described with reference to
Figures 7 and 8.
Fifth. In an electric arc light system having lamps constructed and regulated on
the shunt circuit principle and worked by a self exciting continuous current
Dynamo electric machine the application of a shunt circuit for enabling the
Dynamo machine to excite itself when the resistance in the main circuit is very
great and for breaking the shunt circuit automatically or by hand when the
dynamo has excited itself and thus allowing the current generated to actuate the
shunt electro-magnets or solenoids in the lamps and to form their arcs as set forth
whereby any number of such lamps may be worked in series from an ordinary self
exciting dynamo machine.
In witness whereof I the said Charles Lever have hereunto set my hand
and seal this Thirtieth day of October in the year of our Lord one thousand
eight hundred and eighty two.
CHARLES LEVER (LS)