An Electrical Regulator for Regulating Arc Lamps, and for other purposes.
Year: 1896

page_text: Date of Application, 6th Jan., 1896
Complete Specification Left, 5th Oct., 1895-Accepted, 6th Feb., 1897
PROVISIONAL SPECIFICATION.
An Electrical Regulator for Regulating Arc Lamps, and for
other purposes.
I, ALBERT LEWIS DAVIS, of No. 23 Alexandra Road, Gipsy Hill, in the County
of Surrey, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
According to my invention I employ an electromotor of any suitable known
kind, which is continuously supplied with current from any convenient source,
being preferably placed in the circuit of which the current or the pressure is to
he controlled, such motor being ordinarily prevented from turning by opposing a
resistance such as a friction brake or a spring or suspended weight.
As soon as, owing to an abnormal condition arising in the lamp or other object
to be controlled, the equilibrium is disturbed, the electromotor is rendered more or
less free to rotate under the action of its current, or by the action of the opposing
resistance, or spring, or suspended weight, and by such rotation re-establishes the
norinal condition of the lamp or other object.
The above described action can be carried out in a variety of ways, according to
the purpose to which the invention is to be applied. Thus for example in applying
the electromotor to the regulation of an are lamp, the motor may, according to one
arrangement, be so arranged as by its action to tend to bring together the carbons.
In this case a brake acted upon by an electromagnet included in the circuit to be
controlled is arranged to prevent the rotation of the motor by its current so long as
the carbons are at the normal distance apart, but when the resistance of the are
increases, the electromagnet causes the brake to more or less release the motor, which
then effects the approach of the carbons. The electromotor may also be arranged
to tend to separate the carbons in opposition to the action of a weight or spring
which tends to bring the carbons together.
In this case the motor would be included in the circuit to be regulated so that ou
the increase of the ares resistance the current acting on the motor would be
correspondingly weakened, and the constant action of the spring or weight in over-
coming the action of the motor, would bring the carbons nearer together until
equilibrium is re-established. With this arrangement the motor may or may not be
acted upon by a brake for controlling its motion. The reverse arrangement may also
be employed, that is to say, the motor being arranged to bring the carbons together
while the weight or spring tends to separate them.
It will be obvious that the invention can also be applied to other purposes, such
for instance as for regulating the supply of steam to an engine driving a dynamo.
In this case a current derived from the dynamo would be made to act upon the
electromotor so as to tend to cause this to close the steam supply, so that on the
dynamo current or pressure increasing beyond the normal, the motor would, in
overcoming a constant resistance, such as a spring, a weight, or other device, effect
the more or less closing of the steam supply while, if the dynamo current or pressure
were to sink below the normal, the constant resistance such as a weight or spring
would act upon the steam valve so as to open it against the action of the motor.
Or the motor may be made to tend to open the steam valve in opposition to a
resistance such as a spring, a weight, or other device. The electrical energy for

page_text: the motor may be taken from any suitable source when the engine to be controlled
is not itself driving a dynamo.
1000
ABEL & IMRAY,
Agents for the Applicant.
An Electrical Regulator for Regulating Arc Lamps, and for
other purposes.
I, ALBERT LEWIS DAVIS, of No. 23 Alexandra Road, Gipsy Hill, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of this invention and in
what manner the same is to be perforuied to be particularly described and ascertained
in and by the following statement :-
According to my invention I employ an electromotor of any suitable known kind,
which is continuously supplied with current from any convenient source, being
preferably placed in the circuit of which the current or the pressure is to be controlled.
such motor being ordinarily prevented from turning by opposing a resistance such as
a friction brake or a spring or suspended weight.
As soon as, owing to an abnormal condition arising in the lamp or other object to
he controlled, the equilibrium is disturbed, the electromotor is rendered more or less
free to rotate under the action of its current, or by the action of the opposing resistance,
or spring, or suspended weight, and by such rotation re-establishes the normal
condition of the lamp or other object.
The above described action can be carried out in a variety of ways, according
to the purpose to which the invention is to be applied. Thus for example in
applying the electromotor to the regulation of an are lamp, the motor may,
according to one arrangement, be so arranged as by its action to tend to bring
together the carbons. In this case a brake acted upon by an electromagnet
included in the circuit to be controlled, is arranged to prevent the rotation of the
motor by its current so long as the carbons are at the normal distance apart, but
when the resistance of the are increases, the electromagnet causes the brake to more
or less release the motor, which then effects the approach of the carbous. The
electromotor may also be arranged to tend to separate the carbons in opposition to
the action of the weight or spring which tends to bring the carbons together.
In this case the motor would be included in the circuit to be regulated so that on the
increase of the arcs resistance the circuit acting on the motor would be corre-
spondingly weakened, and the constant action of the spring or weight in overcoming
the action of the motor, would bring the carbons nearer together until equilibrium
is re-established. With this arrangement the motor may or may not he acted upon
by a brake for controlling its motion. The reverse arrangement may also be
employed, that is to say, the motor being arranged to bring the carbons together
while the weight or spring tends to separate them. It will be obvious that the
invention can also be applied to other purposes, such for instance as for regulating the
supply of steam to an engine driving a dynamo. In this case a current derived from
the dynamo would be made to act upon the electromotor so as to tend to cause this to
close the steam supply, so that on the dynamo current or pressure increasing beyond
the normal, the motor would, in overcoming a constant resistance, such as spring, a
weight, or other device, effect the more or less closing of the steam supply while, if
the dynamo current or pressure were to sink below the normal, the constant resistance
such as a weight or spring would act upon the steam valve so as to open it against the
action of the motor.

page_text: Or the motor may be made to tend to open the steam valve in opposition to a
resistance such as a spring, a weight, or other device.
On the accompanying drawings are shewn by way of example some of the
various arrangements by which my invention can be carried into effect.
Figures 1 to 5 shew the regulating device applied to the regulation of electric
lamps for search lights, stage lamps, photographic lamps, &c.
Figure 1 shews a back elevation, Figure 2 a side elevation, Figure 3 a plan,
Figure a back view with the gear and racks removed, and Figure 5 a front
view with the front plate removed.
It is necessary in lamps of the above mentioned kind that the regulation should
remain perfectly constant no matter in which position the lamp may be placed;
further, that lamps should he so con-tructed and the windings he such, that the
current supplied to the lamp may be varied at will, without interfering with the
regulation of the mechanism.
To meet these requirements I make use of two balanced racks or other suitable
device R to carry the carbons and carbon holders; these racks are placed on
opposite sides of and engage with a pinion E; fast with this pinion E and moving
with it, is a larger gear D which engages a small pinion fixed on to the driving
shaft of an electro motor A. F F¹.
This electro motor may be of any suitable type but for structural reasons I prefer
to use the type shewn in the drawings herewith.
The motor armaturu A and the pinion Care suitably mounted, together with a
friction wheel B, on one and the same shaft and move together.
At the correct centres from B and capable of engaging with it, is placed a brake
wheel H; this wheel has a flat or inoperative portion on its periphery as shewn at 0,
Figure 4, such that when the flat portion of the circumference is turned towards the
surface of the friction wheel B tun two wheels H and B are disengaged, and B is
thus free to turn.
Mounted on the same spindle as H, and turning with it, is a second armature
or pivoted yoke piece M; the motion of this movable magnet or yoke piece Mis
controlled and regulated by a spiral spring S, Figures 2, 4, 5, or other suitable
device.
The movable system comprising the pivoted magnet or yoke piece M and its
shaft, the spring S and the brake wheel H, serve the double purpose of controlling
the rotation of the motor armature A, and therefore the feed of the carbons, and
also serves to strike the arc when the lamp is switched into the circuit, in a
manner presently to be described.
The magnets FF serve as field magnets for the motor armature A, and also
supply the field for the movable yoke piece, armature, or magnet M.
Other suitable forms of gearing may be employed to replace the racks R R¹
and gears E, D, C, &c.; thus the motor armature shaft may serve to directly
control the movements of the carbons, without the addition of any intermediate
gears.
In like manner the combined magnetic brake mechanism and striking mechanism
H, M, S, may be replaced by an independent brake acting on the wheel B,
and independent striking mechanism acting on the carbons to strike or start the are.
But I prefer to make use of the special controlling mechanism herein described
and illustrated, which is the same as that described in the Specification to my
Patent No. 9966 of May 20th 1895.
In Figures 1, 2, 4, 5, portions of the bearing brackets are removed to render
the general view of the mechanism more clear.
Having thus described a convenient method of adapting my regulating device to
suit the above requirements, I will describe the working of the same.
On reference to Figure 6 which is a diagram of the lamp and the electrical
connections to the various parts, it will be seen that the main current to feed the
lamp enters by the terminal marked +; taking the paths marked by the arrow
heads, the current passes through the motor armature A to the terminal marked
-;

page_text: a second path for the current is by way of the exciting coils on the field magnet F,
through the coils of the movable yoke piece or magnet M, through the coils of
the field magnet F¹, and out by the terminal -.
A third path for the current when the lamp is burning is through the carbons,
and out by the terminal -..
The windings on A, F, F', and M are so proportioned as to allow but a small
fraction of the total current passing to the carbons to flow through these
windings A, F, F1, and M.
It will be seen that the windings here described are known as shunt windings
and although I do not bind myself to use this type of winding exclusively, yet for
the special purpose under consideration it is the most suitable.
When no current is passing through the lamp, the motor armature A and the
movable yoke piece or magnet M are inert; the spring S therefore exerts a pull upon
the break wheel H causing it to turn and engage with the friction wheel B causing
the latter to turn in a direction tending to separate the carbons; if now the current is
switched on, the motor armature A and fields F, F, and the movable magnet M will
be powerfully energised by the current.
The magnet M will overcome the opposing force of the spring S and will cause the
wheel H to turn in a direction such that the flat or inoperative portion of its
circumference O is turned towards and disengages the circumference of the friction
wheel B on the motor armature spindle; the motor being thus freed from restraint
and being already powerfully energised, will at once rotate in a direction such as to
cause the rapid approach of the carbons.
When however the carbons come into contact owing to the low resistance offered
by the carbons in contact compared to that offered by the exciting coils on A, F, F',
and M these latter will again be rendered inert the spring S will cause the
wheel H to turn and engage with B, turning the latter in a direction such that
the carbons become separated; thus striking the are and starting the lamp.
The carbons will now begin to consume away, and in proportion as the arc
lengthens so the motor armature A and fields F, F will be more strongly energised
and will endeavour to cause the approach of the carbons.
The magnet M will also gradually overcome the opposing force of the spring S
causing the flat portion on the brake wheel H to approach the circumference of the
friction wheel B until the surface friction between the two wheels H and B is
insufficient to completely check the tendency to rotate of the motor armature.
This latter will therefore slowly slip and rotate, causing the gradual feed of the
carbous until they are entirely consumed.
In the event however of the carbons being caused to approach each other too
rapidly or too near, the spring S will at once regain its force over M, turning the
motor armature in a reverse direction through B': thus causing the carbons to be
again separated to the normal extent, when the action described above will continue
until all the carbons are consumed.
Figures 7 to 10, show the regulating device adapted to regulate the carbons in an
ordinary hanging are lamp. Figure 7 shews a frout elevation, Figure 8 a side view,
Figure 9 an enlarged detail, and Figure 10 a diagram shewing the action.
Since this type of lamp is always used in a vertical position the special precautions
mentioned above are unnecessary.
In Figure 7 A is the motor arinature and F. F' are surrounding annular coils forming
the field magnet for the armature.
This motor may be of any suitable type: but I prefer to make use of the type set
forth in these drawings for the special purpose under consideration.
Fast to the motor armature and its shaft, is a small pinion or gear gearing
with the larger gear 1) which latter gives motion to the carbons through the
grooved pulley I and flexible suspension cord or chain J, the ends of which are
respectively fastened to the upper and lower carbon holders.
This system of gearing may, if required, be replaced by any other of suitable
design.

page_text: The upper carbon holder is weighted so that when no current is passing to the
lamp, the force of gravity acting on the weight W, causes the upper holder to
descend, turning the armature and gearing and raising the lower carbon holder until
the carbons are in contact.
If the lamp be now switched into circuit, the current enters the lamp by way of
the terminal marked + Figure 10, passes through the field coils F. F and from
thence through the carbons and out by the terminal marked. A second path is
from the terminal + through the armature A, through the carbons to terminal -
It will be seen therefore that the motor has a series field with the armature shunted
on the field terminals. I do not bind myself to this winding, but it is a simple and
suitable winding for the purpose under consideration. The passage of the current as
above described causes the inotor armature to rotate in a direction such, that the
carbons are separated, thus striking the arc. This separation continues until the are
assumes the normal length when the current is also norinal. At this point the
downward tendency of the weighted carbon holder W. is exactly equal to the lifting
tendency of the motor armature A, the latter therefore comes to rest and the motion
apart of the carbons censes, but owing to the gradual increase of the length of' are
and consequent lessening of the current flowing through the circuit and motor
fields F. and armature A. due to the consumption of carbon, the lifting ten lency
of the motor armature is thereby enfeebled and the opposing and downward force
of the holder and weight W overcomes the force of the motor, turning the latter
in a reverse direction to that which it receives from the energy of the current.
The carbons therefore approach each other at a rate exactly proportional to the
amount of carbon being consumed; and the arc remains therefore normal.
If however the weighted carbon holder descends too far and reduces the normal
distance apart of the carbons, the current in the circuit and through the motor
windings will be thereby increased.
The lifting tendency of the motor armature is consequently greater, the armature A
therefore is able to again separate the carbons until the normal distance is secured,
when further motion of the carbons is arrested by the balance existing between
the upward pull of the motor and the downward tendency of the weighted
holder W.
Figure is an enlarged view of the motor armature and commutator V showing
a simple and convenient method of maintaining equal pressure and contact on the
armature brusbes G. G; these latter being fixed into short levers pivoted and
electrically insulated at L and L', and having weights or springs K K tending to
constantly maintain an equal pressure between the brushes G and G and the surface
of the commutator V.
Suitable stops T. T may be provided to limit the motion of the brushes away
from the commutator in the event of the vertical position of the lamp being disturbed
from any cause, or during transport.
If it is required to place an additional check upon the motions of the motor
armature A, an independent hrake mechanism may be placed to act apon the wheel D
or to act upon a friction wheel placed upon the motor shaft or in any other suitable
position.
It will be evident that the motor might be arranged on a shunt of the lamp
circuit, instead of in series therewith, in this case the lower carbon holder would be
weighted instead of the upper one, so as to tend to separate the carbons, and
the motor would then be arranged so as to tend to bring the carbons together.
Figure 11 shows a simple adaptation of the regulating device for the automatic
control of steam engines, turbines, and other prime movers.
A is the armature and F the fields of any suitable form of motor coupled through
the gears and D or other suitable gearing, to the throttle or stop valve P, controlling
the supply of steam, gas water, &e., to the prime mover.
On the driving shaft of the motor is conveniently placed a drum 1 on which is
wound a chain carrying a weight W, or other suitable device, such that the weight or
other suitable device W acts in opposition to the motor armature A.

page_text: Thus assuming that the rotation of the motor armature A tends to close the
valve P, then the action of the weight W must constantly tend to open the
valve P.
The action of the regulating device will be as follows, assuming that P is the stop
valve on a steam engine, which engine is driving a dynamo electric generator, and
that it is required to control the speed of the engine so as to maintain either a
constant current or a constant pressure, in the electrical circuit, or to maintain
the speed of the engine constant; for this purpose the regulating motor A, F, may
he conveniently shunt wound and receive energy by being coupled directly across
the dynamo terminals.
It is assumed that the amount of weight at W has been so a ljusted as to exactly
balance the opposing action of the regulating motor A. F, and when the engine is
running at the correct speed, so that when this is the case there will be no motion or
action on the valve P.
If however the speed of the engine increases this will cause corresponding increase
of pressure at the dynamo terminals, resulting in an increase of energy being sent
through the regulating motor A F; this will upset the balance previously existing
between it and the weight W. The motor will therefore overcome the opposing
action of the weight W and turn the valve in a direction tending to cut off the
supply of steam to the engine thereby reducing the speed until the engine is running
at the normal again when the balance between the motor AF and weight W will
be re-established.
In a like manner should the engine speed fall below the normal then the regulating
motor will receive less energy from the dynamo and the action of the weight W
being able to overcome the opposing force of the motor A F; the weight will in
consequence descend and cause the valve P to open wider and allow a greater steam
supply to the engine, which will increase the speed until the normal is again reached,
and equilibrium is again established between the regulating motor A F and the
weight W.
It is obvious that the regulating device might be adapted to vary the amount of
resistance to be placed in or taken from a circuit to be controlled. Or it might be
made to vary the number of acenmulators to be put in or cut out of a circuit.
Or it might be made to operate the lover of an automatic switch and other
purposes.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. An electrical regulator consisting of an electromotor adapted to control the
apparatus to be regulated, which motor is continuously supplied with current, but
the rotation of whose armature is opposed by a resistance such as a friction brake or
spring or suspended weight in such manner that when the apparatus which the
regulator is to control works normally the electromotor is more or less held in
balance by the said resistance, while when the apparatus does not work normally,
the resistance is made to liberate or overcome the motor, or it is itself overcome by the
motor, so that this is set in motion and thereby effects the regulation of the apparatus
substantially as described.
2. An electrical regulator for regulating arc lamps consisting of the combination of
an electro motor which is continuously supplied with current and which is included
in a shunt of the lamp circuit and an automatically acting frictional resistance
which, when the lamp is working normally prevents the motor from working, but
which when the resistance of the are increases liberates the motor more or less so as
to cause it to move the carbons towards each other, substantially as described.
3. In an electrical regulator such as is referred to in the second claim constructing
the automatically acting frictional resistance as a break-disc controlled by an electro
magnet or armature influenced by the field magnets in such manner that when no
current is passing through the motor a spring or weight effects the turning of the

page_text: breik-lisc so as to move the motor shaft somewhat in the direction contrary to that in
which it is rotated by the current, while when a current is passed through the
motor, the said electro magnet and break dise are turned so as to free the motor,
substantially as and for the purposes set forth.
4. An electrical regulator for regulating arc lamps, consisting of the combination
of an electro motor which is continuously supplied with current and is in series with
the lanp circuit, and a pulley or equivalent device acting upon a weight or spring
tending to bring the carbon holders together, the spindle of such pulley being geared
to the motor shaft in such manner that when a normal current is passing through
the motor, its armature shaft will be held more or less in the balance by the weight
or spring, but when a stronger current is passing, the armature will be made to rotate
so as to separate the carbons substantially as described.
5. An electrical regulator for regulating arc lamps consisting of the combination
of an electro-motor which is continuously supplied with current and is in a shunt of
the lamp circuit, and a puliey or equivalent device acting upon a weight or spring
tending to separate the carbon holder, the spindle of such pulley being geared to
the motor shaft in such manner that when a normal current is passing through the
lamp, the armature shaft will be held more or less in balance by the weight or spring
but when a stronger current is passing through the motor owing to increased resistance
of the are, the armature will be made to rotate so as to bring the carbons together
in opposition to the weight or spring substantially as described.
6. An electrical regulator consisting of the combination of an electro motor which
is continuously supplied with current and whose armature shaft is directly or
indirectly connected with a regulating valve, electrical switch or contact, or other
power regulating device, and a weight or spring which is so connected or geared to
the armature shaft that when the power to be controlled is working normally, the
weight or spring holds the armature in balance, but when the power is not acting
normally either the weight or spring turns the armature or the armature is rotated
in raising or putting tension on the weight or spring, and thus actuates the valve or
other regulating device substantially as described.
Dated this 5th day of October 1896
ABEL & IMRAY,
Agents for the Applicant.