IMPROVEMENTS IN OBTAINING LIGHT BY ELECTRICITY AND REGULATING THE ELECTRIC CURRENT FOR THE SAME AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN
Year: 1882

page_text: LETTERS PATENT to William Phillips Thompson of the Agency for Foreign.
Patent Solicitors 6 Lord Street Liverpool in the County of Lancaster and
of 323 High Holborn in the County of Middlesex Civil Engineer for an
Invention of "IMPROVEMENTS IN OBTAINING LIGHT BY ELECTRICITY AND
REGULATING THE ELECTRIC CURRENT FOR THE SAME AND IN THE MEANS
OR APPARATUS EMPLOYED THEREIN "-A communication from abroad by the
Union Electric Manufacturing Company (Incorporated) of Numbers 7 and 9
Bond Street in the City of New York in the State of New York United
States of America
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 26th January 1882.
WILLIAM PHILLIPS THOMPSON of the Agency for Foreign Patent Solicitors
of 6 Lord Street Liverpool in the County of Lancaster and of 323 High Holborn
in the County of Middlesex Civil Engineer "IMPROVEMENTS IN OBTAINING
LIGHT BY ELECTRICITY, AND REGULATING THE ELECTRIC CURRENT FOR THE
SAME, AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN." (A communi-
cation from abroad by the "Union Electric Manufacturing Company (Incorporated)
of Numbers 7 and 9, Bond Street, in the City of New York, United States of
America.)
35°
This Invention relates to that class of electric lights in which the so-called
electric arc is maintained between two carbon electrodes. It relates especially to
the class of devices or appliances commonly denominated "regulators," the function
of which is to automatically maintain said electrodes in that relation to each
other which essential to the production of a uniform and maximum degree of
illumination.
To this end the Invention consists in a method of, and apparatus for maintaining
the proper relative position of said electrodes by means of the angular movements
of a pendulously suspended armature, which movements are controlled by magnetic

page_text: variations correlative with changes in the strength of the light-producing current.
Thus a movement of the armature toward its attracting magnet, and from that
point to its excursion which is its normal position during operation, causes the
seperation of the electrodes. A retrograde movement toward said normal position
permits the approach of said electrodes under the action of a constant force, and at
a velocity depending upon that at which the armature moves. And a retrograde
movement past said normal point liberates said electrodes to the action of said
constant force.
In the usual practice of this Invention the lower or negative carbon remains
stationary. Above it is suspended the positive carbon which, in moving, co-operates
through its support with a shaft; its descent under the action of gravity causing
said shaft to revolve in one direction, while by revolving the shaft in the opposite
direction it (the positive carbon) may be made to ascend.
The normal and constant tendency of the upper carbon to approach the lower is
counteracted and regulated by governing the revolutions of the said shaft, in the
following manner: The armature of an electro-magnet is carried by a system of
levers loosely pivoted upon the said shaft. When the electro-magnet is inactive
this armature is retained, by gravity or other constant force, at a distance from the
magnet, but when the latter is vitalized the armature advances toward the pole of
the magnet. Upon reaching a predetermined point it causes the levers to grasp or 5
clamp the shaft, so that further motion of the armature will compel the shaft to
revolve in the direction which separates the carbons. The armature in subsequently
receding towards said predetermined point, by reason of a decrease in the attractive
force will permit the upper carbon to approach the lower, at a speed depending
upon the rapidity with which the armaturo moves: and the armature, in receding
past the said predetermined point, will then cause the levers to release their grasp
of the shaft, leaving the upper carbon free to descend by gravity.
-
-The-electro-magnet-is-included in the circuit of the electrodes. Its attractive
force will therefore vary correlatively with the conductivity of that circuit, and
hence, as will readily be understood by those versed in the art, it will exert its 3
force in the manner and degree required to effect the necessary regulation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson. in the Great Seal Patent Office on the
11th July 1882.
WILLIAM PHILLIPS THOMPSON of the Agency for Foreign Patent Solicitors,
6 Lord St, Liverpool, in the County of Lancaster, and of 323 High Holborn, in
the County of Middlesex Civil Engineer "IMPROVEMENTS IN OBTAINING LIGHT
BY ELECTRICITY, AND REGULATING THE ELECTRIC CURRENT. FOR THE SAME,
AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN A communication
from abroad, by the Union Electric Manufacturing Company (Incorporated) of
7 and 9 Bond Street, in the City of New York in the State of New York United
States of America
"
This Invention relates to that class of electric lights in which the so-called
electric arc is maintained between two carbon electrodes. It relates especially to
the class of devices or appliances commonly denominated "Regulators," the function
of which is to automatically maintain said electrodes in that relation to each other
which is essential to the production of a uniform and maximum degree of
illumination.
To this end this Invention consists in a method of and apparatus for maintaining
the proper relative position of said electrodes; which method may be generally
described as follows:-
The lower or negative carbon remains stationary. Above it is suspended the
positive carbon, which, in moving, co-operates through its support with a shaft;
its descent under the action of gravity causing said shaft to revolve in one direction
while by revolving the shaft in the opposite direction it (the positive carbon) may
be made to ascend.
The normal and constant tendency of the upper carbon to approach the lower is
counteracted and regulated by governing the revolutions of the said shaft, in the
following manner:
The armature of an electro magnet is carried by a system of levers loosely
pivoted upon the said shaft. When the electro-magnet is in-active this armature
is retained, by gravity or other constant force, at a distance from the magnet, but
when the latter is vitalized the armature advances toward the pole of the magnet.
Upon reaching a predetermined point it causes the levers to grasp or clamp the
shaft, so that further motion of the armature will compel the shaft to revolve in
the direction which separates the carbons. The movements of the positive carbon.
will thus be brought under the complete control of the magnet, and the distance
between the carbons will be constantly governed by the variations. of the attractive
force of said magnet. Thus the armature in moving toward said magnet by reason
of an increase in the attractive force will cause the upper carbon to recede from the
lower carbon through a space, and at a speed depending upon the extent, and.
rapidity of the movements of the armature; and the armature in subsequently
receding toward said predetermined point by reason of a decrease in the attractive.
force, will permit the upper carbon to approach the lower, at a speed depending
upon the rapidity with which the armature moves; and the armature in receding,
past the said predetermined point will then cause the levers to release their grasp
of the shaft, leaving the upper carbon free to descend by gravity. By including
the electro magnet in the circuit of the electrodes, its attractive force will vary
correlatively with the conductivity of that circuit,, and hence, as will readily be
understood by those versed in the art, it will exert its force in the manner and
degree required to effect the necessary regulation.

page_text: This Invention further comprehends certain details of mechanism; the particular
matter claimed being hereinafter specifically designated.
In the accompanying Drawings, Figure 1 is a theoretical diagram, designed to
exhibit easily to the eye the principles of this Invention. Figure 2 is a vertical
projection of one of the forms of apparatus actually employed. It clearly sets forth
the details of construction. Corresponding parts appearing in both Figures are
similarly lettered.
Referring to Fig. 1,-The negative carbon cl is secured to the framework of the
lamp. The positive carbon c 2 is shown as suspended by the cord D passing round
the drum, D1 which is rigidly attached to the shaft X. A second drum D 2 shown
with its front face removed in order to exhibit the interior mechanism is secured
rigidly by its rear face to the same shaft.
The armature A of an electro-magnet M, is carried by the arm L' of the bent
lever L L L³, loosely fulcrumed upon the shaft X, at the point L. To the arm L'
of this bent lever is pivoted a clamping lever Ls, carrying a friction shoe S, the
sole of which is curved to fit the inner surface of the perimeter of the drum D³.
The electro-magnet M is wound differentially. The helix H' is of coarse wire
and is included in the main or light circuit. The helix H is of fine wire and
constitutes a shunt around the light. Its office will be hereinafter explained.
The Figure shows the position of the parts, when there is no current traversing
the light circuit. Under such condition the armature is retained, by the force of
gravity, at a considerable distance from the magnet, and the shoe S. is prevented
by the stop P. from binding, with the said perimeter as it would otherwise do under
the action of the spring G. The axis H is therefore free to revolve, allowing the
upper carbon to descend toward and meet the lower carbon.
If now a current of electricity be caused to traverse the light circuit the
magnet M will be vitalized, and the armature A under its attraction will describe
a pendulous motion. As the armature moves the shoe S. will also advance in the
Bame general direction, except that it will continually approach the perimeter of
the drum D' under the manifest operation of the several forces acting upon it.
When the armature has advanced to the position A¹, indicated by the dotted lines,
the shoe S. will have assumed the position S', at which point it will bind the
inner surface of the perimeter.
The armature becomes in this manner rigidly attached to the perimeter and
hence through the intermediate mechanism to the positive carbon. The subsequent
movements of the armature will therefore be transmitted to the positive carbon,
the armature being still free to move under the iufluence of magnetic variations.
The armature will come to rest at that point where the attraction of the magnet
for the armature is equal to the opposing force tending to return it to its original
position, when not in operation. Let this point of equilibrium, which will depend
upon the strength of current employed, be represented by A³. The shoe will
now be in the position S.. the upper end of the lever L³ having left the stop P.
and the full force of the now extending spring G will be exerted in pressing the
shoe against the perimeter of the drum D².
The gradual consumption of the points of the carbons which tends to increase
the length of the arc, tends also to increase the resistance of the light-circuit. This
will act to diminish the attractive force of the magnet, and the armature will
recede, lowering the upper carbon at a speed depending upon its own rate of
motion, and thus compensating for the material consumed.
The armature will continue to recede in this manner until the position A¹ and S'
(which are the normal positions during the operation of the lamp.) are regained.
Further consumption of the carbons will then cause the friction shoe to release
its hold of the drum, and permit a sinall fraction of the circumference of the
perimeter to slip past. This tends to diminish the length of the arc until the
magnetic force is sufficiently restored to cause the shoe to again bind with the
perimeter. In thus binding it not only stops the revolution of the perimeter, but
it again subjects both it and the carbons to the influence of the magnet. The shoe

page_text: does not therefore act as a brake for the purpose of bringing the movable carbon
to absolute rest. Its functions are first, to arrest the descent of the movable
carbon, and secondly to bring it again within the control of the variable magnetic
force. In this manner the desired relative positions of the carbon points are
automatically maintained.
As previously mentioned the electro-magnet M is wound with differential
helices, one of which H', is of low resistance and is included in the main or light
circuit, and the other H³ is of high resistance and forms a shunt circuit around
the light. By this device the process of demagnetization is quickly accomplished
when required, for, during the normal operation of the lamp the light-circuit is of
low resistance, and the current traversing the helix H will be feeble in proportion
to that which passes through the helix M', and the strength of the magnet will
not be materially weakened by its influence. If however an abnormal resistance
is created in the arc, (as by the breakage of one of the carbons or from other cause)
the proportion of current traversing the helix H will be correspondingly
increased, and the magnetizing effects of the currents will be more nearly equal,
and being opposite will tend to neutralize each other, thus freeing the armature,
causing the descent of the upper carbon, and re-establish the arc.
In Figure 2 is shown the details of construction of a practical working
apparatus.
For a given strength of current the distance between the carbons should remain
constant, but this distance should be varied when it is proposed to use a current
of different strength. As the length of the arc must depend upon the position of
the point S', and as the latter depends on the position of the stop P, the
distance between the electrodes may be varied by means of an adjustable stop.
The Figure shows a radial projection from the axle of the adjusting screw H. By
turning this screw the normal distance between the carbons may be suited to the
strength of any current employed.
In practice it is found advantageous to utilize both poles of the magnet M,
thereby increasing the sensitiveness of the apparatus. This is effected by giving
to the soft iron armature the peculiar shape shown in Fig. 2; the two ends being
simultaneously and respectively attracted by the polar extensions R' & R².
In place of the cord B it is evident that any equivalent inay be substituted. In
Fig. 2 is shown a rack and pinion operating upon the same principle as the device
shown in Fig. 1. It is also apparent that by an extended application of this
Invention both the electrodes may be made movable, and their relative positions
made the subject of regulation in the manner set forth.
Pendulous. clamping devices are known to have been used heretoforo, but all
such have been subject to the fatal objection that the pendulums have been
fulcrumed at a fixed point, and therefore a clamping shoe carried by such a
pendulum would operate as a brake, the only function of which would be to bring
the carbons to absolute rest, after which the normal length of arc, could only be
restored by the slow combustion of the carbons a process which occupies so long a
period as to destroy the efficiency of the lamp.
With a pendulous device so fulcrumed a dog has been used instead of a shoe,
and in place of the smooth perimeter a toothed wheel has been employed, the dog
co-operating with the said tooth. But at best the light furnished by such a device
would vary abruptly in brilliancy every time a tooth escaped, and at all other
times would be constantly varying as the carbons consumed away.
Having now described and particularly ascertained the nature of the said
Invention, as communicated to me, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the hereinbefore in part recited Letters Patent, is,-
1. The hereinbefore described method of maintaining the necessary relation of
the electrodes of an arc-light, by means of the angular movements of a pendulous
armature operating by pressure upon the inner surface of a controlling drum
whereby the armature while approaching the magnet from that point in its

page_text: excursion which is its normal position during operation, produces the separation of
the electrodes; and in receding toward said normal position permits the approach
of the said electrodes under the action of a constant force, and at a rate depending
upon that at which the armature moves; and when receding past said normal
point liberates said electrodes to the action of said constant force.
2. The combination, substantially as herein before set forth, of the movable
electrode of an arc lamp; an electro-magnet vitalized by the light-producing
current; and an intermediate regulating mechanism consisting of a drum,
mechanically connected with said electrodo, and an armature and a clamping lever
connected together and pendulously suspended from the axis of said drum,
said clamping lever being adapted to act against the inner periphery of said drum.
In witness whereof, I the said William Phillips Thompson have to this my
Specification set my hand and seal, this Third day of July in the year of
our Lord One thousand eight hundred and eighty two
W. P. THOMPSON. (L.S.)