IMPROVEMENTS IN ELECTRIC LAMPS AND CONDUCTORS THEREFOR
Year: 1882

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LETTERS PATENT to Francis Raymond Welles, of Antwerp, in the kingdom
of Belgium, for an invention of IMPROVEMENTS IN ELECTRIC LAMPS AND
CONDUCTORS THEREFOR."-A communication from Charles E. Scribner and
William R. Patterson, of Chicago, Illinois, United States of America.
COMPLETE SPECIFICATION filed by the said Francis Raymond Welles at
the Office of the Commissioners of Patents on the 15th August 1882.
FRANCIS RAYMOND WELLES of Antwerp in the Kingdom of Belgium "IMPROVE-
MENTS IN ELECTRIC LAMPS AND CONDUCTORS THEREFOR a communication from
Charles E. Scribner and William R. Patterson of Chicago Illinois United States of
America
"
This Invention has for its object, improvements in regulating the feed of the
carbons in electric are lamps and in the insulation and construction of the electric
conductors of the same.
For the purpose of controlling the distance between the carbons of an arc lamp
an electro magnet having its coils in the main circuit is employed; it operates
upon an armature wound with a coil by which the arc is shunted. The armature
by connection with a lever or otherwise carries a clutch or clutches in which the
upper carbon is held.
Sometimes two clutches are employed one in rising takes hold of the upper
carbon and lifts it away from the lower carbon; and the other as the armature
oscillates propels the upper carbon gradually downwards.
The conductors leading from the dynamo electric machine or other electric source
to the lamp or lamps may be contained in a cable. The cable has a central
conductor consisting of a cord of fine copper wire thus surrounded and insulated by
jute fibre. Copper wires laid over this form a second conductor on which again
there is an insulating layer of jute, and over the jute there is cotton. The whole
is contained in a double tube or casing of lead in which steel wires are embedded.
The objects of the several arrangements are hereinafter explained.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1, of the annexed drawings is a front elevation of an electric lamp
constructed in accordance with the invention. Figure 2 is a sectional elevation
thereof; the section is taken on the line x. x. of Figure 1. Figure 3 is a detail
view partly in section of the lifting and feeding clutches. Figure 4 is a detail
elevation of the friction pieces of the lifting clutch. Figure 5, Sheet 2, is a front
elevation of a modified form of the lamp. Figure 6 is a sectional elevation.
Figure 7 is a detail elevation of the lifting clutch. Figure 8 is a transverse
section of the cable containing two insulated conductors. Figure 9 is a side
elevation showing the different parts of the cable uncovered.
Referring to Sheet 1, the standards a and a¹ are insulated from the frame b, as
indicated by the bushing c and c¹. The carbon rod d, is shown carrying the upper
carbon e, and is electrically connected with the frame. The lower carbon e¹ is
supported in the usual manner as shown. The lever f, is pivotted at g to a lug
which forms a part of the frame. Upon this lever are carried the lifting clutch h,
the feeding clutch i, and the armature 7 of electro magnet m. The armature lis
the core of helix 'n. The circuit of the lamp may be traced in Figure 1 as follows:
From the hook o to the electro magnet m thence to frame b and the carbon rod d
as shown, thence in the usual manner through the carbon points e and e³ to the
carbon support and by standard a and wire p to hook q. A derived circuit
shunting the arc passes from 6 through helix n to wire p. When the lever fis
turned upon pivot g by attraction between magnet m and armature l, the feeding
clutch and lifting clutch h are raised. The lifting clutch consists of two friction
pieces h¹, h, see Figure 4 pivotted to the arms r, r. When the lifting clutch is
raised these arms are arrested by the springs, which normally rests against the
stop t.
The friction pieces h', are thus brought against the rod, clamping it
with sufficient force to sustain its weight. The carbon e is thus lifted and the arc
established. Until the arc is established there will be no effective current through
the helix n which is included in the shunt of the arc. An increase of resistance
in the arc increases the current in the shunt circuit. The current through helix n
charges to a north polarity that end of the armature which is adjacent to the
north pole of the magnet m and to a south polarity the end of the armature
which is adjacent to the south pole of the magnet m. Thus an increase of current
through helix n tends to cause repulsion between the armature and the poles of
the electro magnet m. As the carbon points are burned away the resistance of the
arc increases. Variations in the strength of the current also vary the resistance of
the arc.
That is, the stronger the current passing through an arc of any given
length the less will be the resistance of said arc.
When many lamps are in the same circuit there will be continual variations in
the strength of the circuit. Two independent causes will thus always be present
which unite in varying the resistance of the arc of any given lamp, that is to say ;
first the burning away of the carbons and second the variations in the strength of
the current passing through the arc. Continuous variations in the strength of tho
currents through the magnet m and helix n cause attraction and repulsion and the
rod d is thus kept in continuous movement up and down. If the carbon rod d
were carried by the clutch h alone it could not slip through said clutch until the
lever had descended to a point where spring s would rest upon the stop t thus
removing the friction of the pieces h¹, h", from the rod, This would occur were
the lamp to go out or the current to cease flowing.
When the resistance of the arc is so great as to shunt sufficient current through
the helix n, the armature lever f, will be moved down far enough to release the
rod. The lifting clutch thus alone is sufficient to feed the carbon point and a lamp
on this plan without the feeding clutch has worked successfully. It is found
however that the feeding clutch is a valuable adjunct and I will describe its
construction and operation more in detail. The feeding clutch i is attached to the

page_text: lever and pivotted as shown at screw u. The spring normally holds up the
clutch in the position shown so as to clamp the rod. The clamp being pivotted
may always move downward with the rod a little way until the rod is released.
The clutch therefore does not keep the rod from moving downward. The lever fis
pivotted at g. The greater the distance of any given point of the lever from this
pivot g, the greater distance will it move when the lever is turned upon the pivot.
It follows then that when the clutch is moved a given distance, the clutch i will
be moved in the same direction a greater distance, since the clutch i is carried by
point u, of the lever which is farther from pivot g than is the point which carries
the clutch h.
When the lever fis raised the lifting clutch and rod are respectively carried the
same distance, while the clutch i, which is free to slip upward upon the rod
is carried a greater distance. If now the lever f descend, the clutch i, clamps the
rod and moves it positively downward through the friction jaws of the clutch h.
Thus it will be seen that the rod is fed positively a short distance at each complete
vibration of the lever f, and as the lever fis in continuous vibration the carbon
may be feeding all the time. It is evident that if the feeding is more rapid than
the consumption of the carbon points they would eventually be fed together. To
prevent this the stop k is provided, it is so placed that when the lever f is lifted
beyond a certain distance the clutch will be arrested and its grip or hold upon the
rod loosened.
The armature lever fis in continuous vibration while the lamp is burning. Its
field of vibration however varies up and down as the resistance of the arc varies.
When the resistance of the arc is at its minimum the lever is at its maximum
height. The clutch i is then arrested by stop k and does not feed the rod.
Therefore the minimum length of the arc may be regulated by means of the
stop. It will be seen that the lever fat three different positions in its field of
vibration performs different functions. At its lowest position it releases the
clutch and allows the rod to fall; at its highest position it carries the rod simply
without feeding; while at its intermediate position or portion of its field the rod
is fed positively at each vibration.
In Figures 5, 6 and 7 the feeding clutch is omitted and the lifting clutch is so.
modified that as it descends to a certain point a portion of its friction is taken off
from the rod thus permitting the carbon to descend. The circuits are the same as
heretofore described.
The electro magnets are arranged somewhat differently. The armature a³
surrounds the carbon rod b² in the form of a sleeve and the lifting, clutch is carried
directly upon the armature. The poles c, d, of the electro magnet when charged
tend to repel the armature a² which is free to move within the helix e³. The
clutch consists of a collar or sleeve f2, the friction pieces g, h, the levers ³, k²,
toggle-joint and link m². The link m2 is connected directly to the armature a²
so as to be carried with the armature up and down.
2
The friction pieces g², 2, which clamp the rod are pivotted respectively to the
arms or levers 22, 2, which are pivotted at n² as shown.
When the link m² is drawn up by armature a³ the arms are brought
towards each other thus closing the friction pieces upon the rod.
The rod is thus clasped and raised sufficiently to separate the carbons and
establish the arc.
As the
When the current passing through the helix e' becomes sufficiently strong the
armature a² is repelled by the poles of the electro-magnet and descends.
collar fis arrested by the stop o' the friction of the pieces g², h², upon the rod is
lessened to such an extent as to allow the rod to slowly descend until the current
through the helix is weakened, when the armature again rises lifting the sleeve or.
collar from the stop.
It will thus be seen that the length of the arc is regulated automatically by the
varying resistance in said arc.
In Figures 8 and 9 is shown an electric or telegraph cable containing two

page_text: conductors, the central conductor a³ consisting of a rope of fine copper wires and
the outer conductor c³ consisting of larger copper wires of substantially the same
aggregate conductivity as the central conductor. The whole is contained in a pipe
of lead in which are embedded wires f³ preferably of steel so that the pipe may be
of great tensile strength and at the same time as flexible as may be necessary.
The conductors are insulated from each other by jute b³ wound about the central
conductor a³.
The conductor c³ is formed upon this jute covering by winding the copper wires
spirally thereon as shown.
It is found that the insulation of wires wound with cotton only is very easily
impaired by exposure to the air from the hygroscopic nature of the material.
Jute is much less hygroscopic and is therefore preferable as a covering for the
wires, but, in the process of manufacture the wires must be handled more or less
and necessarily are exposed to injury from drops of water perspiration, damp
hands and carelessness and ignorance of workmen.
A drop of water falling on a cotton covered wire is dissipated through a much
greater mass than if falling on a jute covered wire, thus lessening the escape of
current at that one point and the consequent electrolytic action. But if two
substances of different bygroscopic qualities are exposed together, moisture is
absorbed by the more hygroscopic substance until it reaches such a point of
saturation that the affinities of both substances for water are equalised. Therefore
in the manufacture of electric cables the several conductors are according to this
invention insulated from each other with one or more layers of jute yarn and
about the whole a covering of cotton yarn is wound or braided. The conductors
thus covered are then thoroughly dried before they are drawn into the pipe.
Moisture absorbed from the air or other wise brought into contact with the cable
of conductors is held by the outer cotton serving so as not to be distributed among
the conductors. It is found practically that two or three times higher insulation
can be obtained by using jute and cotton in combination as above described than
by using either substance separately.
The insulating material d³ is of jute and cotton, formed by first winding the
jute about the conductor c³ and then winding over the jute covering a serving of
cotton yarn not less than one twentieth of an inch in thickness. The core of
conductors thus formed is saturated with paraffin and drawn into the pipe after
which all interstices are filled with paraffin charged with gas in the usual manner.
The inner pipe e³ is covered with as many spirally wound steel wires ƒ³ as may be
necessary and the exterior covering of lead g³ is formed over the said wires f³ so
that the said wires f³ may be imbedded in the lead.
Having thus described the nature of the said invention and the manner of
performing the same I would have it understood that I claim
-
First. The use in an arc lamp as carbon regulator of an electro magnet in the
main circuit, and an armature with a helix in a shunt circuit whereby an increase
of current in the shunt circuit causes repulsion between the armature and the
electro magnet substantially as described.
Second. The combination in an arc lamp of the electro magnet and its armature
forming the core of the helix in the shunt circuit; with a lifting clutch controlled
by the said arinature and substantially as described.
Third. The combination in an arc lamp of a vibrating armature lever with a
lifting and a feeding clutch; the feeding clutch being adapted to move a greater
distance at each vibration of the lever than the lifting clutch whereby the carbon
is caused to be fed forward substantially as described.
Fourth. The feeding clutch i pivotted to the vibrating armature lever fat u
in combination with the spring vand stop k is substantially as described.
Fith. The combination of an electric conductor with jute wound directly
thereon and an exterior serving of cotton substantially as described.
Sixth. The combination in an electric cable of a core of conductors each insulated

page_text: separately with jute and an exterior serving of cotton wound about the core
substantially as described.
Seventh. The combination in an electric cable of the two conductors namely
the conducting core a of fine wires and the exterior conductor b of wires wound
spirally around and enclosing the conductor a substantially as described.
Eighth. The combination of the electrical conductors with the inner lead pipe,
the spirally wound strengthening wires and the exterior protection of lead applied
over the wires substantially as described.
In witness whereof I the said Francis Raymond Welles have hereunto set my
hand and seal this first day of August in the year of our Lord One thousand
eight hundred and eighty two.
F. R. WELLES (L.S.)