IMPROVEMENTS IN ELECTRIC LIGHT REGULATORS
Year: 1879

page_text: LETTERS PATENT to Sydney Pitt, of Sutton, in the County of Surrey, for
the Invention of "IMPROVEMENTS IN ELECTRIC LIGHT REGULATORS." A com-
munication from abroad by Charles Ezra Scribner, of Chicago, in the United
States of America.
Sealed the 14th May 1880, and dated the 16th December 1879.
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 16th December 1879.
SYDNEY PITT, of Sutton, in the County of Surrey.
" IMPROVEMENTS IN
ELECTRIC LIGHT REGULATORS." [A communication from abroad by Charles Ezra
Scribner, of Chicago, of the United States of America.]
This Invention has for its object improvements in electric light regulators. The
regulators to which the Invention applies are intended to be used in connection
with electric lamps in which the light results from the electric arc passing between
points or pencils of carbon. The regulators are intended to effect automatically the
following operations:-First, to separate the carbon points to the proper distance
for the display of the electric arc when the current is first established; second,
to feed forward one of the carbon pencils to compensate for the waste which takes
place so long as the current is passing; third, when the current is turned off, or
when from any cause the current ceases to flow, to instantaneously bring the carbon
points into contact.
For this purpose one of the carbon holders, say the upper, is attached to a rod or
metallic stem which is held loosely in a spring or friction clip, nevertheless the clip
embraces the rod sufficiently firmly to prevent its slipping through the clip from its
own weight and that of the parts which it carries.
This spring or friction clip is carried upon the armature of an electro magnet
which is capable of working up and down a distance about equal to that by which
the carbons are separated when the light is properly displayed. This electro
magnet is in the main circuit, and so as soon as a current passes the armature is
attracted and it raises with it the rod, the carbon holder, and carbon, for there is a
special device, hereinafter described, to insure that the armature shall in its
upward movement carry the rod with it, notwithstanding that the rod is but
lightly held in the spring clip before mentioned. On the other hand, immediately
that the electric are ceases the armature falls away from the magnet and the carbon
points are brought into contact, reestablishing the circuit.
The automatic feed to compensate for the consumption of the carbon while the lamp
is burning is effected by means of another electro-magnet and armature. The coils of
this magnet are in a short circuit or shunt by which the electric arc is shunted; hence,
as the resistance of the arc increases from the burning away of the carbons increasing

page_text: the distance between them, the amount of current passing in the shunt circuit becomes
gradually greater and the armature more strongly attracted. This armature is
suspended by springs, and its movement towards the poles of the magnot takes
place in a downward direction. During the movement the armature carries with it
by means of a clutching device, which is herein after described, the rod with the
carbon holder and upper carbon, the attraction of the magnet being sufficient to
cause the rod to slide through the spring clip in which as before mentioned it is
also held. In this manner, when the current passing through the shunt attains a
certain strength the distance between the carbons is automatically lessened.
During its return or upward movement the feeding armature releases the rod by
means hereinafter described, and whilst the rod is held stationary by the spring clip
it returns to position ready to again feed down the upper carbon when required.
The return motion of the fooding armature results from a separation which is made
in the shunt circuit in the following manner :-
There is a small slide mounted in the frame so as to be capable of moving in the
same direction as the feed armature, that is to say, vertically, and this slide when
in its highest position rests against a spring contact point and the shunt circuit is
completed through it. The slide also carries two adjustable screws which are so set
as to leave a space between their ends, and into this space a finger projecting from
the armature is received.
When the armature is in its uppermost position before the feeding motion has
commenced the finger is in contact with the upper screw, and the slide itself is
against the spring contact point and the shunt circuit is complete.
In the downward movement of the armature which causes the approximation of
the carbons the finger leaves the upper screw upon the slide and presently comes
against the lower screw, and then the slide partakes of the movement of the
armature, it leaves the spring contact point, and the shunt circuit is broken.
As the magnet now ceases to attract the armature the springs by which this is
suspended cause it to return to its highest position, the finger on the armature
again comes against the upper screw on the slido, and the slide itself is raised up to
the contact point completing the shunt circuit.
The clutching devices by which the two armatures are made to carry with them
the rod with the carbon holder attached at the time when they move towards the
poles of their magnets, whilst they release the said rod during the return movement
is the following:-The rod in each case passes through a hole in the armature which
it loosely fits, so that the armature is able to move independently of the rod so long
as the movement is parallel, i.e., when each end of the armature moves an equal
distance, but when the two ends of the armature move unequally and the armature
is thrown askew to the rod, the rod binds in the hole, and in any further movement
the armature carries the rod with it. Now at each end of the armature there is a
spring, and these springs which tend to draw the armature away from the magnet
are of unequal strength, and when the magnet attracts the arinature the weaker
spring yields first, and the armature assumes the skew position already referred to.
In this position the armature advances towards the magnet. But immediately the
attraction of the magnet ceases, the armature then being only acted on by the
springs ceases to bind upon the rod, to which consequently it does not impart
motion whilst it returns under the influence of the springs.
Other clutching devices may be resorted to, as for example, wedges may be
inserted into the hole between the rod and the armature, and by suitable incans
these wedges may be prevented from binding upon the rod during the return
movement of the armature, but the arrangement previously described is simpler and
is preferred.
These electric light regulators admit of a number of lights being exhibited in the
same circuit, as the regulation of each light depends on the resistance offered by its
own arc, and is practically independent of others included in the same circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sydney Pitt in the Great Seal Patent Office on the 15th June
1880.
SYDNEY PITT, of Sutton, in the County of Surrey "IMPROVEMENTS IN
ELECTRIC LIGHT REGULATORS." A communication from abroad by Charles Ezra
Scribner, of Chicago, in the United States of America.
This Invention has for its object improvements in electric light regulators. The
regulators to which the Invention applies are intended to be used in connection
with electric lamps in which the light results from the electric are passing between
points or pencils of carbon. The regulators are intended to affect automatically the
following operations:-First, to separate the carbon points to the proper distance
for the display of the electric arc when the current is first established; second, to
feed forward one of the carbon pencils to compensate for the waste which takes
place so long as the current is passing; third, when the current is turned off, or
when from any cause the current ceases to flow, to instantaneously bring the carbon
points into contact.
For this purpose one of the carbon holders, say, the upper, is attached to a rod
or metallic stem which is held loosely in a spring or friction clip, nevertheless the
clip embraces the rod sufficiently firmly to prevent it slipping through the clip
from its own weight and that of the parts which it carries.
This spring or friction clip is carried upon the amature of an electro magnet
which is capable of working up and down a distance about equal to that by which
the carbons are separated when the light is properly displayed. This electro magnet
is in the main circuit, and so as soon as a current passes the armature is attractod,
and it raises with it the rod, the carbon holder, and carbon, for there is a special
device, hereinafter described, to insure that the armature shall in its upward move-
ment carry the rod with it, notwithstanding that the rod is but lightly held in the
spring clip before mentioned. On the other hand immediately that the electric arc
ceases the armaturo falls away from the magnet and the carbon points are brought
into contact re establishing the circuit.
The automatic feed to compensate for the consumption of the carbon while the
lamp is burning is effected by means of another electro magnet and armature. The
coils of this magnet are in a short circuit or shunt by which the electric arc is
shunted, hence, as the resistance of the are increases from the burning away of the
carbons increasing the distance between them, the amount of current passing in the
shunt circuit becomes gradually greater and the armature more strongly attracted.
This armature is suspended by springs, and its movement towards the poles of the
magnet takes place in a downward direction. During the movement the armaturo
carries with it by means of a clutching device, which is hereinafter described, the
rod with the carbon holder and upper carbon, the attraction of the magnet being
sufficient to cause the rod to slide through the spring clip in which, as before
mentioned, it is also held. In this manner when the current passing through
the abunt attains a certain strength the distance between the carbons is auto-
matically lessened. During its return or upward movement the feeding armature
releases the rod by means hereinafter described, and whilst the rod is held
stationary by the spring clip it returns to position ready to again feed down
the upper carbon when required. The return motion of the feeding armature
results from a separation which is made in the shunt circuit in the following
Danner
Thero is a small slide mounted in the frame so as to be capable of moving in the
same direction as the feed armature, that is to say, vertically, and this slide when
in its highest position rests against a spring contact point and the shunt circuit is

page_text: completed through it. The slide also carries two adjustable screws which are so
set as to leave a space between their ends, and into this space a finger projecting
from the armature is received.
When the armature is in its uppermost position before the feeding motion has
commenced the finger is in contact with the upper screw, and the slide itself is
against the spring contact point, and the shunt circuit is complete. In the
downward movement of the armature which causes the approximation of the
carbons, the finger leaves the upper screw upon the slide and presently comes
against the lower screw, and then the slide partakes of the movement of the
armature, it leaves the spring contact point, and the shunt circuit is broken.
As the magnet now ceases to attract the armature the springs by which this
is suspended cause it to return to its highest position, the finger on the armature
again comes against the upper screw on the slide, and the slide itself is raised
up to the contact point completing the shunt circuit.
The clutching devices by which the two armatures are made to carry with them
the rod with the carbon holder attached at the time when they move towards the
poles of their magnets, whilst they release the said rod during the return movement,
is the following:-The rod in each case passes through a hole in the armaturo
which it loosely fits so that the armature is able to move independently of the rod
so long as the movement is parallel, ie., when each end of the armature moves an
equal distance, but when the two ends of the armature move unequally and the
armature is thrown askew to the rod, the rod binds in the hole, and in any further
movement the armature carries the rod with it. Now at each end of the armature
there is a spring, and these springs which tend to draw the armature away from
the magnet are of unequal strength, and when the magnet attracts the armature the
weaker spring yields first, and the armature assumes the skew position already
referred to. In this position the armature advances towards the magnet, but
immediately the attraction of the magnet ceases, the armature then being only
acted on by the springs ceases to bind upon the rod, to which consequently it does
not impart motion, whilst it returns under the influence of the springs.
Other clutching devices may be resorted to, as, for example, wedges may be
inserted into the hole between the rod and the armature, and by suitable means
these wedges may be prevented from binding upon the rod during the return
movement of the armature, but the arrangement previously described is simpler
and is preferred.
These electro light regulators admit of a number of lights being exhibited in the
same circuit, as the regulation of each light depends on the resistance offered
by its own arc, and is practically independent of others included in the same
circuit.
In order that the said Invention may be most fully understood and readily
carried into effect I will proceed to describe the Drawings hereunto annexed.
Figure 1 is a front view, and Figure 2 is a side view of this electric light
regulator; Figure 3 represents in side view a modification or alternative arrange-
ment of a part of the same.
C is an electro magnet of small resistance placed in the circuit of the carbon
points E, E', and of a suitable generator of electricity, connected with it by
appropriate wires.
The poles of the magnet C, C, are faced with copper or other non magnetic
metal, so that the iron armature N cannot come into contact with them; h, h, are
two brass screws fixed into the poles of the electro magnet, and passing through
holes in the armature. E, E¹, are the carbons; they are held in the metal supports
P, P', W, V, and T, are binding screws to receive the connecting wires.
There is a hole in the armature N, through which a rod F passes, and the hole
fits the rod so closely that when the armature is slightly inclined the rod becomes

page_text: nipped in the hole, but otherwise the hole is just large enough for the rod to move
freely through it.
To the armature N two springs M are attached, one on each side of the rod F.
These springs are sufficiently strong to sustain the rod F in the position it occupies
against the force of gravity acting on the rod, its carbon, and carbon carrier; K, L,
are two springs of unequal tension acting on the armature N. l, m, are regulating
screws screwed into the frame as shewn, and serving to regulate the tension of
the springs K, L.
D is an electro magnet of high resistance placed in a shunt circuit shunting the
voltaic arc; its poles are tipped with brass or other non metallic metal to prevent
the armature coming into actual contact with the poles of the magnet; g. 9.
(Figure 1) are two brass screws screwed into the poles of the electro inagnet D,
and passing freely through holes in the armature H. There is also another hole in
the armature H, through which the rod F passes.
The rod F fits the hole in the armature H so nearly that when the armature
assumes a slightly inclined position in relation to the rod; it locks itself fast upon
the rod, nevertheless the hole is sufficiently large to allow the armature to move
independently of the rod when it is at right angles to it; I, J, Figure 1, are two
springs of unequal tension acting on the armature H; f,f, are two regulating screws
screwed into the frame, and serving to regulate the tension of the springs 1, J; a is
a tongue projecting from the armature H; G is a metal support.
O is a piece of vulcanite or other nonconducting matter attached to the support G
by the screw o; P is a piece of metal mounted in a guide groove on G in such
manner that it can move vertically; i is a screw passing through the spring r, and
also through a slot in P, it is screwed into the support G. The spring r is held by
the head of the screw i so as to press against P with a force sufficient to maintain
it in place against the action of gravity; b, b', are screw stops tipped with vulcanite
or otherwise prevented from forming an electrical connection with the armature H.
They are screwed into the piece P; d is a flat spring, and c is a rigid stop for the
spring d; c is a platinum pointed screw screwed into a small boss upon the end of
the spring d. The electrical connections are as the Drawings indicate. The main
current may be traced from the generator of electricity by the binding screw W,
the voltaic arc, the rod F, and by a flexible wire to the binding screw V, from
thence by the coils of the electro magnet C, C, to the binding screw, and by &
return wire to the generator.
The current in the shunt circuit shunting the voltaic arc may be traced from
the binding screw W by the wire of the electro magnet D, the screw o, the fraine g,
the piece of metal P, the screw c, the spring d, and the wire connection to the
binding screw T.
When there is no current passing through the lamp or regulator the armature H,
sustained by the springs I, J, rests against the heads of the screws g, g, (Figure 1),
and the tongue a pressing on the point of the screw 6' (Figure 2) holds the piece P
in contact with the point of the screw c, and the shunt circuit is thus closed. The
armature N is also drawn away from the poles of the electro magnet C by the
springs K, L, until the points of the carbons E, E, come into contact.
As soon as the current from the generator passes through the regulator the
armature N is drawn towards the poles of the electro magnet C, C, and in conse-
quence of the unequal tension of the springs K, L, (Figure 2) the arinature N in
approaching the poles of the electro magnet assumes a position inclined to the rod F,
and nipping or locking fast with it, carries the rod up, and thus the carbon points
are separated and the voltaic are established.
When the armature N comes against the poles of the electro magnet it takes a
position square with the rod F, and ceases to nip or lock itself with the rod, which
is then maintained in position against the force of gravity acting upon it by the
friction holding of the springs M, M.
The electric current divides itself between the main circuit and the shunt circuit,

page_text: and the relative quantity of current in the two circuits is inversely proportional
to their resistance.
As the points of carbon burn away and become more distant the one from the
other the resistance of the voltaic are gradually increases, and consequently the
quantity of electricity passing in the coils of the electro magnet D also gradually
increases, and the attraction of the magnot upon the armature H becomes stronger.
When the attraction is sufficient to overcome the tension of the springs I, J, the
armature H approaches the poles of the electro-magnet D. In consequence of the
unequal tension of the springs I, J, the armature H when attracted towards the
poles of the electro magnet D takes a position inclined to the rod F, locks itself to
the rod, and as the armature itself descends carries it down in spite of the friction
holding of the springs M, and so the carbon points E, E¹, are brought nearer
together.
When the armature H is drawn down as described above the tongue a comes to
the point of the spring b, and pressing upon it causes the piece P to move, so as to
separate P from contact with the point of the screw c. By this means the shunt
circuit is broken and the electro magnet D loses its magnetism. The springs I, J,
immediately bring back the armature H to a position square with the rod F. The
armature then ceases to nip the rod, which remains in the position to which it was
brought during the descent of the armature, being supported in the frictional
holding of the springs M. The armature H is then brought back by the springs I, J,
to its first position against the heads of the screws 9.9 By the same movement
the tongue a is brought up to the screw b, and pressing on its point it raises the
piece P into contact with the point of the screw c, and the shunt circuit is again
complete.
The current passing in the shunt circuit has however been decreased by the
approximation of the carbons brought about during the descent of the armature H,
and so the armature will remain for a certain time against the heads of the
screws 9, 9, until by the further consumption of the carbons the resistance of the
main circuit again becomes sufficient to divert a sufficient proportion of the current
through the shunt circuit to enable the electro magnet D again to diawn down its
armature.
By the constant repetition of this action the carbon points are kept at a suitable
distance apart. The length of the voltaic are can be regulated by varying the
tension of the springs I, J. The length of movement of the armature H, and
consequently the distance the rod F is carried down at each movement of the
armature, can be regulated by adjusting the screws b, b¹,
In the modification indicated in Figure 3 the nipping of or locking with the
rod F is effected by means of wedges inserted between the armature and the rod.
v represents a spring attached to the frame and to a wedge W', this wedge is
inserted into the armature H; u is a stop for the wedge W. Now when the
current in the shunt circuit is sufficient to attract the armature H towards the poles
of the electro_magnet, the armature in descending presses against the wedge W¹,
and the rod F is locked or nipped and made to descend against the resistanco
offered by the frictional bolding of the springs M. When the shunt circuit is
broken and the armature H commences to rise towards the heads of the screws g, g,
the rod ceasing to be locked or nipped remains in the position to which it has been
brought during the descent of the armaturo, and is supported by the frictional
holding of the springs M. The spring V draws the wedge Wi back with the
armature, and the stop u coming into contact with the wedge W₁ prevents the
wedge locking the rod so long as the armature H rests against the heads of the
screws g. g.
The arrangement for locking the rod F by means of a wedge to ensure its being
ruised together with the armature N to produce the voltaic arc is substantially the
same as that above described. The letter W, Figure 3, represents the wedge; X, the
spring to which the wedge is attached; and Z, a screw screwed into the armature N;

page_text: lever pivotting at y`. in the lever y there is a slot through which the
screw passes.
When the current in the principle circuit is sufficient to draw the armature N to
the poles of the electro inagnet C, the armature N presses against the wedge, the
wedge is caused to nip and lock the rod, and the rod is raised. The lever y is also
carried up by the armature by means of the head of the screw z; this is adjusted in
such a way that just before the armature N comes against the poles of the
magnet C the end of the lever y touches the lower end of the w ge W, and when
the armature comes against the poles of the magnet the wedge is raised by the
end of the lever y, and the rod ceases to be locked or nipped; the rod is nevertheless
maintained by the frictional holding of the springs M against the force of gravity
acting upon it.
The means described above for locking the rod F and drawing it up to produce
the voltaic arc can be modified, and the points of the carbons may be separated by
placing the electro-magnets C, C, underneath the arc, attaching to the arinature the
lower carbon carrier P, in which is the carbon E. In this case the armature will
be above the electro-magnet, and when the current does not pass it will be
supported by springs at a distance from the poles of the magnet, springs similar
to M but carried by the frame will hold up the rod F against the force of gravity
acting upon it.
When the current comes from the generator the armature being attracted towards
the poles of the magnet will draw down the carbon E, and will thus produce the
voltaic arc, whilst the shunt circuit will continue to push down the rod F as the
carbon consumes in the manner described above.
By the arrangements described above the voltaic arc will be automatically
established and maintained as long as the current continues, and on the interruption
of the current the parts will be automatically placed, so that the action will be
repeated as soon as the current is again established.
It is well known that for the most part electric light regulators have been so
made that it is impossible to have more than one regulator at a time in the circuit
of a generator of electricity.
This is due to the fact that in the greater number of electric light regulators the
forward feed of the carbons is determined by the quantity of current which passes
coming from the generator, and this quantity of current is dependent on the quantity
of resistance in the que or the several voltaic arcs placed in the circuit. Conse-
quently, when several lamps are in the circuit, the one which is regulated to feed
with the smallest diminution of current feels first, and continues to feed until the
carbon points come into contact and the light is extinguished. Of the remaining
lamps, that which feeds with the smallest diminution of current is soon put out, and
so on until only one lamp remains, and in this the feed takes place only as the
carbons are consumed.
In the lamp herein described, the electro-magnet in the principle circuit simply
separates the carbons, whilst the points are adjusted and regulated in position
entirely by the force of the current in the shunt circuit which shunts the voltaic arc.
The strength of this current depends on the resistance of the are, and on nothing
else. The feed of each lamp is iegulated by its own voltaic arc, and it is possible
practically to employ a large number of these lamps in the same main circuit. In
some types of electric light regulators the current in the shunt circuit is employed
in connection with the current in the principle circuit to regulate the points so as
to maintain them at a suitable distance apart, but it is believed that the lamp
herein described is the only one in which, whilst the light is exhibited, the suitable
position of the carbons is maintained only by the current passing in the shunt
circuit shunting the voltaic arc. In consequence of this peculiarity this lamp is
believed to give better results than any other electric light regulator.
Having thus described the nature of the said Invention and the manner of

page_text: performing the same, I would have it understood that I claim as distinctive
characteristics of the Invention,-
First. In the regulator of an electric light the combination of an electro magnet
in the principle circuit to separate the carbons and cause the voltaic are to be
displayed, and another electro magnet in a shunt circuit shunting the voltaic arc,
and which latter alone regulates the distance of the carbon points so long as the
current passes, as herein described.
Second. The combination in the same principle circuit of two or more regulators
of electric light, each being furnished with an electro magnet in the principle
circuit to separate the carbons and cause the voltaic arc to be displayed, and each
being furnished also with an electro magnet in a shunt circuit shunting the arc, and
which latter alone regulates the distance of the carbon points so long as the current
passes, as herein described
Third. In an electric light regulator the combination of the following parts:
A rod carrying one of the carbons; an electro-magnet placed in the circuit of the
voltaic arc and of the generator of electricity; an armature to the electro magnet
provided with a friction holding appliance which sustains the rod against the
force of gravity acting upon it, but permits of its being moved forward by feed
mechanism as the carbon is consumed, as herein described.
Fourth. In an electric light regulator the combination of the following parts
A rod carrying one of the carbons, an electro magnet placed in the circuit of the
voltaic arc and of the generator of electricity; an armature to the electro magnet
provided with a friction holding appliance, which sustains the rod against the force
of gravity acting upon it, and also with a locking appliance which carries the rod
with it whilst the armature approaches the pole of the magnet, and leaves the rod
free when the armature comes against the poles of the magnet or against stops
suitably placed, as herein described.
Fifth. In an electric light regulator the combination of the following parts:-
A rod carrying one of the carbons; a friction holding appliance which sustains the
rod against the force of gravity acting upon it; an electro magnet placed in a shunt
circuit shunting the voltaic arc; an armature to this electro magnet with a locking
appliance which locks the rod and armature together when the armature approaches
the poles of the electro-magnet and leaves the rod free as the armature returns, as
herein described.
Sixth. In an electric light regulator the combination of the following parts :-
A rod carrying one of the carbons; a friction holding appliance which sustains the
rod against the force of gravity acting upon it; an electro magnet placed in a shunt
circuit shunting the voltaic arc; an armature to this electro magnet with a locking
appliance which locks the rod and armature together when the armature approaches
the poles of the electro magnet, and leaves the rod free as the armature returns, and
a circuit regulator which opens the shunt circuit when the armature has approached
the poles of the magnet and closes it when the armature has returned to its stops,
as herein described.
Seventh. In an electric light regulator the combination of the following parts:-
An electro-magnet placed in the circuit of the voltaic arc, and of the generator of
electricity; an armature to this electro magnet controlling one of the carbons and
causing the voltaic are to be displayed when the current passes from the generator
through the regulator; a rod carrying one of the carbons; a friction holding
appliance which sustains the rod against the force of gravity acting upon it; an
electro magnet placed in a shunt circuit shunting the voltaic arc; an armature to
this electro magnet with a locking appliance which locks the rod and armature
together when the armature approaches the poles of the electro-magnet and leaves
the rod free as the armature returns, as herein described.
Eighth. In an electric light regulator the combination of the following parts:-
An electro magnet placed in the circuit of the voltaic arc and of the generator of
electricity; an armature to the electio magnet which controls one of the carbons, and

page_text: causes the voltaic arc to be displayed when the current passes from the generator
through the regulator; a rod carrying one of the carbons; a friction holding
appliance which sustains the rod against the force of gravity acting upon it; an
electro-magnet placed in a shunt circuit shunting the voltaic arc; an armature to
this electro magnet with a locking appliance which locks the rod and armature
together when the armature approaches the poles of the electro-magnet, and leaves
the rod free as the armature returns, and a circuit regulator which opens the shunt
circuit when the armature has approached the poles of the magnet and closes it
when the armature has returned to its stops, as herein described.
In witness whereof, I, the said Sydney Pitt, have hereunto set my hand
and seal, this Fourth day of June, in the year of our Lord One thousand
eight hundred and eighty.
SYDNEY PITT. (L.S.)