IMPROVEMENTS IN ELECTRIC ARC LAMPS AND IN REGULATORS THEREFOR APPLICABLE ALSO TO REGULATING ELECTRIC CURRENTS FOR OTHER PURPOSES
Year: 1882

page_text: LETTERS PATENT to Sebastian Ziani de Ferranti of Richmond Gardens
Shepherds Bush Electrician and Alfred Thompson of Guildford Place Russel
Square Electrician both in. the County of Middlesex for an Invention
of "Tenn
PROVISIONAL SPECIFICATION left by the said Sebastian Ziani de Ferranti
and Alfred Thompson at the Office of the Commissioners of Patents on the
18th July 1882.
SEBASTIAN ZIANI DE FERRANTI of Richmond Gardens Shepherds Bush Electrician
and ALFRED THOMPSON of Guildford Place Russel Square Electrician both in
the County of Middlesex-" IMPROVEMENTS IN ELECTRIC ARC LAMPS AND IN
REGULATORS THEREFOR APPLICABLE ALSO TO REGULATING ELECTRIC CURRENTS
FOR OTHER PURPOSES
"
This invention has for its object improvements in electric arc lamps and in
regulators therefor applicable also to regulating electric currents for other purposes.
In our electric arc lamp we actuate the carbon holders by means of right and
left handed screws which we cause to rotate at the proper times to approach or to
separate the carbons by means of a pair of electric motors. Each of these electric
motors may consist of an electro magnet operating an armature connected with a
pawl which turns a ratchet wheel-So long as the motor is in action the armature
oscillates as in an electric bell and is caused to do so by like means
When an alternating current is used the armatures are caused to vibrate by the
alternation of the current and polarized inagnets may then be used.
The electro magnet of the motor which approaches the carbons has its coils
shunting the arc and the electro magnet of the motor which separates the carbons
has its coils shunting a portion of the main circuit or these coils may be in the
main circuit in which case the approach of the armature to the pole of the magnet
short circuits its coils.

page_text: The contacts for this pair of motors which bring one or other of them into
action are made by means of a rocking lever. The way in which this lever is
controlled will vary according to the sort of regulation which is desired-Thus a
single lamp may be regulated by selenoid in the main circuit operating upon an
iron core attached to one arın of the lever and resisted by a spring attached to the
other arm.
When the selenoid preponderates the contact is established for the
motor which separates the carbons and when the spring preponderates then the
contact is established for the motor which approaches the carbons.
Or the selenoid in place of being in the main circuit may shunt the arc and this
arrangement may be employed where there is more than one lamp in circuit. But
where there are several lamps in circuit a differential arrangement with two
selenoids is preferable; one selenoid in the main circuit and another shunting the
arc with cores on opposite sides of the fulcruin of the lever.
For a motor having its coils in the main circuit the regulating lever shunts the
motor until the time comes for the motor to operate and then the lever opens tho
shunt.
By like means we can maintain a constant electro motive force upon a circuit of
incandescent lamps-the influence of a selenoid in the circuit being in this case
balanced against a spring-The screws shift sliding contacts increasing or
diminishing the resistance in circuit-Other gear may be substituted for screws.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sebastian Ziani de Ferranti and Alfred Thompson in the Great
Seal Patent Office on the 18th January 1883.
SEBASTIAN ZIANI DE FERRANTI of Richmond Gardens Shepherds Bush Electrician
and ALFRED THOMPSON of Guildford Place Russell Square Electrician both in the
County of Middlesex "IMPROVEMENTS IN ELECTRIC ARC LAMPS AND IN
REGULATORS THEREFOR APPLICABLE ALSO TO REGULATING ELECTRIC CURRENTS
FOR OTHER PURPOSES"
This invention has for its object improvements in electric arc lamps and in
regulators therefor applicable also for regulating electric currents for other
purposes.
In our electric arc lamp we actuate the carbon holders by means of right and
left handed screws or equivalent mechanism such as a pinion acting on racks
which we cause to rotate at the proper times to approach or to separate the carbons
by means of a pair of electric motors. Each of these electric motors may consist of
an electro-magnet operating an armature connected with a pawl which turns a
ratchet wheel. So long as the motor is in action the armature oscillates as in an
electric bell and is caused to do so by like means.
Where an alternating current is used the armatures are caused to vibrate by the
alternation of the current and polarized magnets may then be used.
The electro inagnet of the motor which approaches the carbons has its coils
shunting the arc and the electro magnet of the motor which separates the carbons
has its coils shunting a portion of the main circuit, or these coils may be in the
main circuit in which case the approach of the armature to the pole of the magnet
short circuits its coils.
The contacts for this pair of motors which bring one or other of them into action
are made by means of a rocking lever. The way in which this lever is controlled
will vary according to the sort of regulation which is desired. Thus a single lamp
may be regulated by a solenoid in the main circuit operating upon an iron core
attached to one arm of the lever and resisted by a spring attached to the other
When the solenoid preponderates the contact is established for the motor
which separates the carbons and when the spring preponderates then the contact is
established for the motor which approaches the carbons.
arm.
Or the solenoid in place of being in the main circuit may shunt the arc and this
arrangement may be employed where there is more than one lamp in circuit. But
where there are several lamps in circuit a differential arrangement with two
solenoids is preferable, one solenoid in the main circuit and another shunting the
arc with cores on opposite sides of the fulcrum of the lever.
For a motor having its coils in the main circuit the regulating lever shunts
the motor until the time comes for the motor to operate and then the lever opens
he shunt.
By like means we can maintain a constant electro motive force upon a circuit of
ncandescent lamps; the influence of a solenoid in the circuit being in this case
balanced against a spring. The screws shift sliding contacts increasing or
liminishing the resistance in circuit. Other gear may be substituted for screws.
Figures 1 and 2 of the Drawings hereunto annexed shew two constructions of
lectric are lamps arranged as above described.
In Figure 1 A. B. are two electro magnets each operating an armature carrying by
ne arm of levers C the other arms of which carry pawls D. E shews one of two
atchet wheels which are side by side on an axis E-one pawl can be made to act
gainst the teeth of one wheel the other pawl to act against the teeth of the other

page_text: wheel. The pawls do not remain in contact with the ratchet wheels, springs F
press back the levers and keep the pawls clear of the wheels but when either one
or other of the magnet armatures is attracted by its magnet and so made to rock
the lever which carries it the pawl at the end of that lever acts against its ratchet
wheel and gives a partial turn to the axis E in one or other direction according to
which ratchet it is that comes into action. When the armatures are not attracted
by their magnets contact points on the ends of the levers which carry the armatures
rest against contact pieces one marked G the other H. The contact piece G is
connected to another contact piece G¹ and H to H'. The contact pieces G¹ H' are
in proximity to the ends of a rocking lever I. One end of the lever carries the
iron core of a solenoid K the other has a coiled spring J attached to it. The lever
is always in connection through the standard which carries it with one pole of the
battery a slight resistance L being interposed between this standard and the
terminal X. A shunt circuit from this terminal leads through the coil of the
magnet A and the contact G to G¹. When the spring preponderates over the
action of the solenoid K the lever is drawn by the spring against G-the shunt
circuit is then completed through the lever and the armature of the magnet A is
made to vibrate to and fro and the axis E is by this movement turned in a direction
to separate the carbons and continues to do so so long as the lever I remains in
contact with G¹. A shunt circuit is as shewn always passing through the coil of
the solenoid to the terminal Y. As the carbons are separated and the resistance of
the arc gets greater and greater more and more of the current traverses the shunt
circuit through the solenoid until the iron core is attracted sufficiently to overcome
the action of the spring J and lift the lever from the contact G'. A further increase
of resistance in the are will cause the iron core of the solenoid to bring the lever I
into contact with H. A shunt circuit will then as shewn be completed through H
and through the coil of the electro magnet B-the armature of this magnet will
therefore be vibrated to and fro and the axis E will be turned in a direction to
approach the carbon's.
In the Drawing the axis E is represented as having upon it two pinions gearing
on opposite sides with two racks one in connection with the holder of one
carbon the other with the holder of the other carbon-but other mechanism might
be used for conveying motion from the axis E to the carbon holders.
Figure 2 shews a diagram view of a regulator for an electric are lamp in which
In this
the regulation is effected by a differential arrangement with two solenoids.
figure the same letters indicate like parts to those shewn at Figure 1.
The main current passes from terminal X through the solenoid J to the standard
carrying the axis of rocking lever I and a shunt circuit of greater resistance
When the action of
through the coil of the solenoid K to the other terminal Y.
the solenoid K preponderates over the action of the solenoid J the lever is brought
against the contact piece H¹ and a shunt circuit is opened through the coils of the
electro magnet B as in arrangement shewn at Figure 1 and the axis E is conse-
quently turned in a direction to cause the carbons to approach one another. During
this time the current has passed to the lower carbon through a spring I' carried by
the lever I to the contact piece G³ and through G direct to the carbon holder as
shewn. When however the solenoid J preponderates over the solenoid K the
spring 1 is carried away from the contact piece G¹ and the current then passes
through the coils of the magnet A. The armature of this magnet being then
attracted draws a contact point on the lower end of the lever which carries it
against the contact G and so again opens a direct passage for the current to the
lower carbon and the magnet being no longer sufficiently excited to attract its
armature the armature is withdrawn from it and is so kept vibrating to and fro
and the axis E is revolved in a direction to separate the carbons.
A vibrating coil made to vibrate by a fixed coil or coils, or a rotating coil acted
upon by a stationary coil or other appliance for obtaining movement by electricity
might be employed, instead of using a fixed electro magnet and vibrating armature
for giving motion to the carbons as above described.

page_text: Other forms of solenoid than the one shewn might also be used for operating
contact apparatus for putting into action the electric motor apparatus used for
giving motion to the carbons.
The mechanism above described might also be used for controlling the strength
of electric currents the electric motor apparatus being for this purpose caused to
give a to and fro motion to a bar to shut out or bring in resistances or to a bar
caused to act upon the expansion gear or cut off valve apparatus of a steam
engine used for driving the dynamo machine employed for generating the electric
current.
Having thus described the nature of our said Invention and the manner of
performing the same we would have it understood that what we claim is :-
First. The construction of electric arc lamps substantially as herein before
described and illustrated in the Drawing annexed.
Second. The combination of a solenoid operated by a shunt circuit from the
main circuit acting against a spring for controlling contact apparatus for setting
into action either one or other of two electro-motors for moving the carbons of an
electric arc lamp either towards or away from one another or for regulating the
strength of an electric current substantially as herein before described
Third. The combination of two solenoids one operated by the main circuit the
other by a shunt circuit of greater resistance acting in opposition to one another
for controlling the action of contact apparatus for setting into action either one or
other of two electro motors for moving the carbons of an electric arc lamp either
towards or away from one another or for regulating the strength of an electric
current substantially as described.
In witness whereof I the said Alfred Thompson have hereunto set my hand
and seal this Seventeenth day of January in the year of our Lord One
thousand eight hundred and eighty three.
ALFRED THOMPSON (LS.)