IMPROVEMENTS IN ELECTRIC LIGHT REGULATORS
Year: 1881

page_text: LETTERS PATENT to Sydney Pitt, of Sutton, in the County of Surrey, for an
Invention of "IMPROVEMENTS IN ELECTRIC LIGHT REGULATORS." A com-
munication from abroad by Samuel Joseph Burrell, of Brooklyn, in the State
of New York, United States of America.
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 23rd August 1881.
- SYDNEY PITT, of Sutton, in the County of Surrey. "IMPROVEMENTS IN
ELECTRIC LIGHT REGULATORS." [A communication from abroad by Samuel
Joseph Burrell, of Brooklyn, in the State of New York, United States of
America.]
This Invention has for its object improvements in electric light regulators. The
particular class of regulators to which the Invention relates are those used in
connection with electric lamps which employ as a means of producing light the
electric-arc obtained by the combustion of carbon electrodes. The regulator is
intended to effect automatically the following operations :-First, to separate the
points of the carbon electrodes to a proper distance from each other for the
production of the electric-arc when the electric current is established; second, to
feed forward one of the carbon pencils at a rate sufficient to compensate the waste
or destruction of the same, which takes place so long as the current is passing;
and third, when the current from any cause is interrupted or ceases to traverse
the lamp to instantaneously bring the carbon electrodes into contact with each
other.
To this end one of the carbon electrodes or carbon holders (preferably the upper
one) is held in position by an electro magnetic clutch; this clutch consists in
general of a hollow helix or coil of wire within which is a hollow cylindrical soft
iron core divided longitudinally into two sections, one section being hinged or
pivoted to the other in such a manner that when magnetized by a current of
electricity traversing the coil or helix the two sections will tend to be repelled

page_text: from each other because they will be of like magnetic polarity. Through this
hollow core, which is preferably placed in a vertical position, extends either the
carbon electrode or a rod for holding the same. The diameter of the electrode with
reference to that of the opening through the hollow core is such that the former
may be grasped and held firmly by the clutch when the core becomes magnetized
by a peculiar nechanical device hereinafter referred to. The said hollow core is
also moveable freely within the coil in the direction of its axis, and is so con-
structed that it will be drawn axially into the coil by the influence of an electric
current traversing the helix. By this means two distinct but simultaneous move-
ments are produced by the influence of the electric currents, one of which movements
acts to grasp one electrode, and the other to separate it from the opposite electrode.
Another part of the Invention consists in an improved method or means of
suspending the movable electrode and establishing the electrical connection
between it and the generator.
In carrying out the Invention it is preferred to employ two hollow cylindrical
electro magnetic coils or helices which are placed vertically one above the other;
the upper one is formed of thin and the lower one of thick conducting wire. Each
coil encloses a cylindrical core of soft iron movable longitudinally within it, and
the two cores are mechanically united to each other by means of a tube or rod of
brass or other non magnetic substance to which they are screwed or fastened in
any convenient manner.
The core of the lower coil which acts as a clutch for the electrode is hollow, and
is constructed in two parts or sections, as herein before stated. One of these
sections is provided at its lower extremity with projections or ears, to which
projections the lower end of the other section is pivoted. The point at which the
sections are hinged together is preferably near the bottom of the lower coil.
When an electric current traverses the lower coil the free ends of the two sections
of the core instantly become magnetized of like polarity and repel each other.
This causes the opposite end of the section which extends below the hinge to bo
pressed inwardly against and to firmly grasp the moveable electrode, while at the
same time, by the force of the axial attraction, it is drawn away from the lower
electrode, and the arc is thus established.
The weight of the cores and the moveable electrode is counterbalanced by means
of a proper lever provided at its opposite extremity with a weight or spring.
For holding and guiding the movable electrode and establishing an electric
connection therewith, I make use of three friction rollers which bear against the
electrode at different points of its circumference, preferably at a distance of
120 degrees from each other. Two of these rollers have flat or slightly concave
peripheries, and bear against the outside of the electrode. The third roller is
provided with a sharp or wedge-like periphery which fits into a longitudinal
groove formed in and extending the whole length of the upper electrode. The
object of constructing the apparatus in this manner is to prevent the electrode from
turning or twisting as it moves, and at the same time to secure a more perfect
electrical contact. The last named roller may be mounted upon a stationary support
or upon a movable sliding support provided with a spring for pressing the roller
against the electrode.
The connections with the battery or generator are made in the usual manner,
that is to say, through the lower coil or helix, and thence through the rollers to the
upper or movable electrode, the opposite terminal of the generator being connected
with the stationary electrode. The upper coil is, as hereinbefore stated, composed
of thin wire, and it should offer a resistance nearly equal to that of the lamp
including that of the electric arc, hence it will act as a shunt circuit for maintaining
a constant resistance. The instrumentalities by which this is effected are con-
structed and applied in the usual and well known manner, and since they form no
part of the present Invention need not be specifically described.
The use of the magnetic clutch is not designed to be restricted to the particular

page_text: form of regulators herein described, as it may be applied to any regulator employing
electro magnetism to control the movement of either or both electrodes of an
electric lamp. It is preferred to use it in connection with lamps regulating the
upper electrode, but it may be easily applied to the lower electrode as well by
providing suitable mechanical means for exerting an upward pressure upon the
latter.
By means of this electric light regulator a number of lights may be exhibited in
series in the same electric circuit, as the regulation of each light depends upon the
resistance offered by its own arc, and is wholly independent of the action of other
lamps included in the same electric 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 22nd February
1882.
SYDNEY PITT, of Sutton, in the County of Surrey. "IMPROVEMENTS IN
ELECTRIC LIGHT REGULATORS." (A communication from abroad by Samuel
Joseph Burrell, of Brooklyn, in the State of New York, United States of
America.)
The Invention relates to that class of electric lamps which employs as a means
of producing light the voltaic are obtained by the combustion of carbon
electrodes. Its object is to secure a uniform and reliable balance movement of one
or both of the electrodes, and it further contemplates an improved method of
establishing an electrical connection with the electrode.
Various devices have been employed to govern the movement of the electrodes
in this class of electric lamps in order to secure a steady and unvarying light.
The principal difficulty lies in preventing frequent and sudden changes in the 1
distance of the electrodes from each other, which cause a flickering and unsteady
light.
The Invention is designed to overcome this difficulty by diminishing the
amount and extent of these variations through the agency of an improved
magnetic clutch which acts upon the movable electrode. This clutch consists in 2
general of a helix or coil of wire having a hollow cylindrical core constructed in
two sections, the one hinged or pivotted to the other in such a manner that when
magnetized by a current of electricity traversing the coil or helix they shall be
repelled from each other. Within this hollow core we extend the carbon electrode
or a rod for holding the same. The relative size of the electrode and the opening 2
through the core is such that the former shall be grasped and firmly held by the
clutch when the core is magnetized. The core is also movable within the coil in a
longitudinal direction and is so constructed that it shall be drawn into the coil
when magnetized by the current in the helix. Thus I secure two distinct
movements, one grasping the electrode, the other separating it from the opposite s
electrode.
The Invention further consists in an improved method of suspending the
electrode and establishing an electrical connection therewith.
Referring to the accompanying Drawings, Figure 1 represents a sectional front
elevation of the improved mechanism for regulating the movement of the upper
electrode of an electric lamp; Figure 2, a cross section of the magnetic clutch;
Figure 3, a cross-section of the friction or contact rollers for holding the electrode
or the rod to which it is attached.
In Figure 1 A and B represent two electro-magnetic coils or helices, A being
constructed of thick and B of thin wire; C, D, represent the hollow cylindrical
core of the coil A. and G of the coil B. The two coils are of soft iron united to
each other by means of a tube H of brass or other non-magnetic material, into
which they are screwed or fastened in any convenient manner. The whole
cylinder or hollow rod thus formed is fitted into and is movable longitudinally
within the hollow tube H¹, upon which the coils A and B are wound.
I is a lever for balancing the weight of the core and electrode. It is hung upon
the support I' and provided with a sliding connection with the core G through the
projection i.
To the opposite end of the lever is attached the coiled spring K, the tension of
which is regulated by an adjustable screw L and socket L¹.
The core C. D. of the coil A. which acts as a clutch for the electrode Fis AQ

page_text: before stated, hollow and is constructed in two parts or sections. To the lower end
of the main section C is secured a metallic disc E, which is provided with an
adjustable set-screw or stop e for limiting the upward motion of the entire movable
core. The core-section C is provided with two projections or ears c, c (see Figure 2),
to which the lower end of the other section D is pivotted by means of the
projections or pins d, d. The section D extends below the point where it is
pivoted a short distance for the purpose hereinafter shown. The point at which
the sections D and C should be hinged together is preferably near the lower end of
the coil A. The ends C³, D', of the two sections of the core being when magnetised
of like polarity will repel each other. This will cause the end D¹¹ of the section D
to be pressed against and grasp the electrode F. A sufficient space is left between
the interior of the coil A. and the exterior of the core-section D to allow of the
required motion.
It may be desirable in some cases to construct the portion of the section or
clamp D, which extends below the pivot d, of brass or other non-magnetic material.
In this manner the force with which the upper portion of the section D will be
repelled from the section C may be increased, since it will not be counterbalanced
by the repulsion of the opposite end from the lower end of the section C. The
diameter of the openings through the cores C and G is such as to allow free
movement of the electrode F when not detained by the clutch D. The upper end
of the core G is also provided with a disc or flange G₁ similar to that at the lower
end of the section C, which, like the disc E, is provided with a set-screw g for
limiting the movement of the entire movable core or tube.
M, M, M', are friction-rollers for holding or guiding the carbon electrode and
establishing an electrical connection therewith.
M, M, are simple flat or slightly-grooved rollers and bear against the side of the
electrode F.
The roller M is preferably constructed as shown in Figure 3, having a sharp
or wedge-like periphery m", which fits into a groove f along the length of the
upper electrode. The object in constructing it in this manner is to prevent the
electrode from turning or twisting, and at the same time to secure a more perfect
electrical contact. The roller M' may, like the rollers M, M, be hung upon a
stationary support m, or upon a movable sliding support m³, and provided with
a spring n for pressing the roller against the electrode.
The connections with the battery or generator are made in the usual manner, that
is to say, through the coil A, rollers M, M, M', to the electrode F, the opposite pole
of the generator being connected with the other electrode. The coil B is, as before
stated, of thin wire, and offers a resistance nearly equal to that of the lamp itself,
including the arc, and acts as a shunt-circuit for maintaining a constant resistance.
The arrangements by which this is effected are constructed and applied in the
usual and well-known manner, and since they form no part of the present Invention
need not be more particularly described. When no electric current is traversing
the coils, the upper carbon electrode F is dropped upon the lower electrode by
force of gravity. If however the connection is established with the battery or
generator, the current through the coil A magnetizes the core C, D. The upper
end of the section D is thereupon repelled from the section C, thus causing the
end D to grasp the electrode F, and at the same time the entire core C, D, is
drawn upward into the coil A as far as is allowed by the screw e, thus separating
the electrodes the required distance. This distance is regulated by means of the
adjustable screws c and As the current through the coil A. and electrode F
diminishes on account of the consumption of the ends of the electrodes and the
increased resistance thereby offerred by the arc, the magnetism of the entire
core C, D, diminishes proportionately. Thus the pressure of the end D¹¹ upon the
electrode F is diminished, allowing the electrode to descend, but arresting it as the
current becomes stronger.
The connection with the electrode F may be made in any of the usual methods,
instead of through the rollers M, M, M'. In some cases it may be preferable to

page_text: substitute a metallic or other suitable holding-rod for that portion of the electrode
which extends through the clutch and guiding-wheels. This may be readily done
without changing the form of the clutch.
I do not propose to limit myself to the method shown in the Drawings of
pivotting the section or clamp D. It may, for instance, be found desirable in certain 5
cases to extend the tube H to the lower end of the coil A, and pivot the core-
sections to the interior of this tube. The form of the sections of the core may also
be varied in any desired manner. It is not necessary to construct the core in two
sections merely, but it may be supplied with any desirable number of clamps so
'pivotted as to operate in a manner similar to that described with reference to the 1
clamp D. It is preferred however to construct it after the manner shown in the
Drawings, using the section C as the support for the movable portion D, and
pivotting the latter at a point located near or a little below the lower end of the
coil A. The use of this clutch is not confined to the particular form of regulators
herein described. It may be applied to various other regulators using an electro- 1
magnet to control the movement of either or both electrodes. It is preferred to use
it in connection with the lights regulating only the upper electrode, but it may be
easily applied to lower electrodes as well by providing a suitable means for exerting
an upward pressure upon this electrode.
Instead of having the clutch at the lower end of the core the upper end of the
section D may be provided with a ring-like extension or band to surround the
electrode or holding rod, and bind the same when the ends C₁ and D' are separated,
by pressing against it.
Having thus described the Invention, what I claim as new is,-
First. The combination, substantially as hereinbefore set forth, of a hollow helix 1
and a hollow core movable longitudinally within said helix, divided longitudinally
into sections, which sections are united by a hinge.
Second. The combination, substantially as hereinbefore set forth, of a hollow
helix, a hollow core divided longitudinally into sections which are united by a
hinge, and an electrode or rod for holding the same passing axially through the
hollow core, which is clamped between the sections thereof when the helix is
traversed by an electric current.
Third. The combination, substantially as hereinbefore set forth, of a cylindrical
carbon electrode or a rod for holding the same, a longitudinal groove formed in one
side of said electrode or rod, and a guiding wheel having a periphery of V shaped
section.
In witness whereof, I, the said Sydney Pitt, have hereunto set my hand and
seal, this Eighth day of February, in the year of our Lord One thousand