IMPROVEMENTS IN VOLTAIC ARC LAMPS
Year: 1883

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills of the firm of Harris and
Mills of 23 Southampton Buildings in the County of Middlesex, Patent Agent
for an Invention of IMPROVEMENTS IN VOLTAIC ARC LAMPS communicated
to him from abroad by Otto A. Moses of the City, County and State of New.
York in the United States of America, Chemist
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 31st March 1883.
BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent IMPROVE-"
MENTS IN VOLTAIC ARC LAMPS A communication to me from abroad by Otto A..
State of New York in the United States of
Moses of the City, County and
America, Chemist.
The invention relates to that class of electric lights known as voltaic arc lamps;
and its object is to furnish a lamp of exceedingly simple and economical
construction, with provision for automatically controlling the feed of the carbon,
by means of a solenoidal or magnetic governor of few parts, but efficient in
operation and especially adapted to be used in multiple arc systems, with other
lamps of the same type, or with incandescent lights, but also capable of being used
in series or multiple series.
In carrying the invention into practice a frame is used for supporting the various
parts which may consist of two metallic sides and a metallic bottom, for which
mere rods as offering the least obstruction to the light, will answer united at the
top or fourth side by an insulating material which forms the barrier in the lamp.
between its two electrical terminals or with a metallic top plate insulated from the
rods connected therewith.
Affixed to the top, is a hollow electro magnet or solenoid, to whose upper end
plate is attached, and projects upwardly a hollow tube, which may be called a
projecting tube.
Passing through the centre of the solenoid and fitting snugly therin, but
capable of easy movement therethrough, is a tube whose lower end is fitted with
a holder for the upper or positive carbon, which may be termed the carbon holding
*

page_text: tube. The carbon holder may be integral with this tube or a separate piece
attached to it. It consists of a screw threaded socket preferably slightly tapering
and having two or more longitudinal slots.
Upon it fits a tapering internally screw threaded thimble, which tends to cause
the lower edges of the slotted socket to press in toward each other, grasping and
holding, firmly the carbon.
When this carbon holding tube is well drawn up, its upper extremity passes into
and is protected by the protecting tube before referred to.
Within the carbon holding tube, is arranged the core or armature of the solenoid
affixed to a rod or tube supported by a spring, at its upper end from the projecting
tube, in such manner and so adjusted that the resistance of the spring tends
normally to cause the core or armature to project a little below and out of the base
of the solenoid or magnet.
This core or armature is of peculiar construction, consisting primarily of a rod or
bar of soft iron, of smaller diameter than the interior of the carbon holding tube
within which it is located. It is entirely covered by what may be called a
"brush" consisting of iron wires arranged longitudinally upon the entire exterior of
the core, and to which they are fastened at the top or middle the lower or both
ends being free and bent inwardly slightly toward the axis of the core.
The iron wire may be copper plated to reduce resistance, or a layer of copper
wire may be used in addition to the iron wires.
This
Below, or partly or wholly within the solenoid or magnet, and within its
magnetic field, is located external to the carbon holding tube, a piece of magnetic
material such as iron, steel or nickel which may be termed the "intensifier."
intensifier is preferably of annular shape, and surrounds the carbon holding tube
and is also preferably capable of motion to and from the solenoid or magnet and
fitted within a case or playing between stops or other devices for limiting the
extent of its motions although the "intensifier" may have other than an annular
shape, and whether annular or not may have a fixed position.
The solenoid is placed directly in the circuit, which is preferably a multiple arc
circuit, including one or more lamps. From the main circuit, one connection is
made to the free end of the solenoid or magnet coil, its other end being attached to
and forming electrical contact with the inner metallic shell of the solenoid, whence
the circuit continues to the carbon holding tube, passing principally through the.
brush which makes good electrical contact for the purpose thence to the carbon, to
the carbon, and the metallic frame of the lamp to the other connection from the
main circuit.
The operation of the lamp thus constructed and arranged in circuit is about as
follows.
Upon closure of circuit the solenoid or magnet renders both the core or armature
and the intensifier magnetic by induction attracting them, the ring or intensifier
toward its base and the core or armature within itself and against the stress of the
spring.
But the free ends of the wires of the brush referred to being all of one polarity,
are repelled each by the others, flying outwardly and impinging against the inner
side of the carbon-holding tube binding it between the intensifier and the brush, so
that it is lifted with them sufficiently to form the arc and then held in that
position.
As the arc increases of course the resistance in the lamp circuit increases,
diminishing the magnetic force of the solenoid or magnet.
The parts are so adjusted relatively to each other, that when the point of
greatest desired arc has been reached, the magnetic effect of the solenoid or magnet
is so weakened that the brush releases its hold upon the carbon holding tube to
some extent, which then drops by gravity and is forced downwardly by the move-
ment of the core or armature which is depressed by the spring until the magnetic
force of the solenoid is again restored.
Instead of having the core or armature divided into two or more repelling parts,

page_text: it may be of one single piece, having sufficient lateral movement to permit it to
strike the sides of the tube enclosing it and force the tube against its guides.
The brush form is preferred however since the movement is more uniform, and
better electrical contact is made to conduct the current to the carbon.
It will be seen from the foregoing that the distinctive feature of the regulating
mechanism is the location of a magnetic core or armature within the carbon holding
tube, such core or armature clamping the tube, and forcing it to move with the
core or armature, either by the clamping action alone, or assisted by the fluid in
the tube as bereinafter stated.
The carbon holding tube is preferably filled with some fluid, such as glycerine
which serves to lubricate its interior preventing excess of friction, regulating or
slowing down the movement of the contiguous surfaces and preventing a spark at
the points of contact of the tube and brush.
The fluid also forms a means of communicating motion from the brush to the
carbon holding tube in addition to that afforded by the contact of the brush with
the tube, the interstices between the brush and tube not being sufficiently large to
prevent the almost simultaneous movement of the brush and tube.
By another part of the invention a construction of regulating mechanism is
produced having a more uniform movement than that just described.
This is accomplished by the division of the "intensifier" into a number of inde-
pendently moveable parts, which press equally upon the carbon holding tube and
act evenly upon the magnetic brush or the divided core or armature of the
controlling solenoid or electro magnet making a uniform and steady light.
The improved intensifier is composed preferably of a number of balls or rollers of
magnetic material which balls or rollers are held together by a wire ring passing
loosely through them so that they have the desired extent of independent move-
ment. This ring of balls or rollers is limited in its vertical movement by stops or
by an enclosing cage, and the balls or rollers work freely by a rolling movement
upon the carbon holding tube as they are attracted by the solenoid or electro
magnet acting upon the magnetic brush to increase the repulsion between its parts.
This brush is of the construction before described with the exception that it is
always in contact with the interior of the carbon holding tube in order to complete
at all times the circuit to the carbon.
The action of the solenoid or magnet and the intensifier, serves to force the brush
with greater or less pressure into contact with the tube, for the purpose of controlling
its downward movement.
The brush or divided core or armature is supported by a spring at its upper end
as before described and rests in liquid within the carbon holding tube, the quick
and forcible vertical movements of the carbon holding tube being produced by the
vertical movements of the brush or divided core or armature through the medium
of the liquid with which the tube is filled.
A further object of this part of the invention is to produce a simple and efficient
device for holding the lower carbon electrode of the lamp for allowing it to be
readily centred or brought into line with the upper carbon and for permitting of an
upward adjustment by hand of such lower carbon.
This is accomplished by the employment of a tube in which the lower carbon is
placed the tube being split at its upper end and provided with a clamping ring for
bolding the carbon.
This tube has secured to it, or made in one piece therewith, a disk provided
with a concave lower face and resting upon the lower cross bar of the lamp
frame. The tube passes through an opening in the lamp frame, which opening is
large enough to permit a limited lateral adjustment of the tube in any direction.
A disc having a concave upper face is screwed upon the tube and is forced against
the lower side of the cross-piece of the lamp frame.
The proper position of the lower carbon in line with the upper carbon can be
first secured, and the parts then rigidly secured in position by turning up the
lower disc.

page_text: The lower carbon can be adjusted vertically at any time by loosening the
clamping ring at the upper split end of the tube.
By another part of the invention the core or armature has a sliding movement
to a limited extent upon its supporting rod, towards and away from a block
secured rigidly to such rod; which rigidly secured block may be of magnetic
or non-magnetic material, and if magnetic, will form a part of the core or
armature.
The core or armature is forced towards the block by an adjustable spring.
The space between the core or armature and the block is made wedge-shape
by the bevelling of the end surface of the block, and in this space are located balls
of magnetic or non-magnetic material which are jammed outwardly against. the
walls of the enclosing tube by the action of the core or armature.
The carbon carrying tube drops by gravity when the core or armature does not
exert much pressure upon the clamping balls but when the resistance, at the arc is
reduced below a certain point, the core or armature moves upwardly, forces the
balls outwardly clamping the carbon carrying tube and lifts such carbon carrying
tube.
In connection with this construction of internal clamping balls, an external
magnetic clamp may be used which may be a divided ring like the divided
"intensifier" before described.
This divided clamping ring is located upon the carbon carrying tube opposite or
below the lower end of the core or armature, or opposite the interior clamping balls
and is limited in its movement by stops or by an enclosing cage.
To produce a uniform movement of the core or armature, an additional dash-
pot is used, which may be connected with the upper end of the rod carrying
the core or armature, the stationary enclosing tube rising from the head of the
solenoid being extended upwardly to support the other part of the dash-pot.
'
By this part of the invention a simple device is also provided for holding and
centering the lower carbon. Two concave discs are used which are clamped to
the frame by a bolt and nut, the bolt passing through a hole somewhat larger
than itself and being allowed a lateral movement in any direction to center the
carbon.
The upper disc carries a split socket in which the carbon is held by a screw
ring.
The concave faces of the discs assure a firm holding of the carbon.
By another part of the invention the core or armature, or the principal part
thereof surrounds the carbon carrying tube and is connected by a tube and rod
with a plunger within the carbon-carrying tube. Said carbon carrying tube is
filled with glycerine or other suitable liquid.
The plunger may be of magnetic or non-magnetic material. It carries wires
which press constantly against the walls of the tube maintaining good electrical
contact therewith. The circuit connections are further maintained by wires or
springs pressing against the tube rising from the core or armature. The core or
armature has arms pivotted in slots in its sides and provided with clamping plates
which grasp the carbon carrying tube. These clamping arms carry armatures on
their lower ends which are attracted by adjustable pole pieces from extensions
of the main core or armature.
The main core or armature is supported by one or more adjustable springs at its
lower end or at the upper end of the tube rising therefrom. In the latter case an
outside enclosing tube rising from the head of the solenoid will be used, to which
the spring will be attached.
The movements of the carbon carrying tube will be produced and governed by
the action of the plunger within the same, the external magnetic clamp, and the
force of gravity.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Benjamin Joseph Barnard Mills in the Great Seal Patent Office
on the 29th September 1883.
"
'
BENJAMIN JOSEPH BARNARD MILLS of the Firm of Harris & Mills of
23 Southampton Buildings in the County of Middlesex Patent Agent "IMPROVE-
MENTS IN VOLTAIC ARC LAMPS A Communication to me from abroad by Otto
A. Moses of the City County and State of New York in the United States of
America Chemist,
The invention relates to that class of electric lights known as voltaic arc lamps
and its object is to furnish a lamp of exceedingly simple and economical construction
with provision for automatically controlling the feed of the carbon by means of a
solenoidal or magnetic governor of few parts but efficient in operation and especially
adapted to be used in multiple arc systems with other lamps of the same type
or with incandescent lights but also capable of being used in series or multiple
series.
In carrying the invention into practice a frame is used for supporting the various
parts which may consist of two metallic sides and a metallic bottom for which mere
rods as offering the least obstruction to the light will answer united at the top or
fourth side by an insulating material which forms the barrier in the lamp. between
its two electrical terminals or with a metallic top plate insulated from the rods
connected therewith.
Affixed to the top is a hollow electro magnet or solenoid to whose upper end-
plate is attached and projects upwardly, a hollow tube which may be called a
projecting tube.
J
Passing through the centre of the solenoid and fitting snugly therein but capable
of easy movement therethrough, is a tube whose lower end is fitted with a holder
for the upper or positive carbon, which may be termed the carbon holding tube.
The carbon holder may be integral with this tube or a separate piece. attached
to it. It consists of a screw threaded socket, preferably slightly tapering and
having two or inore longitudinal slots.
Upon it fits a tapering internally screw threaded thimble which tends to cause
the lower edges of the slotted socket to press in toward each other grasping and
holding firmly the carbon When this carbon holding tube is well drawn up its
upper extremity passes into and is protected by the protecting tube before
referred to.
Within the carbon holding tube is arranged the core or armature of the solenoid
affixed to a rod or tube supported by a spring at its upper end from the projecting
tube in such manner and so adjusted that the resilience of the spring tends normally
to cause the core or armature to project a little below and out of the base of the
solenoid or magnet.
This core or armature is of peculiar construction consisting primarily of a rod or
bar of soft iron of smaller diameter than the interior of the carbon holding tube
within which it is located. It is entirely covered by what may be called a "brush"
consisting of iron wires arranged longitudinally upon the entire exterior of the
core and to which they are fastened at the top or middle the lower or both ends
being free aud bent inwardly slightly toward the axis of the core.
The iron wire may be copper plated to reduce resistance or a layer of copper
wire may be used in addition to the iron wires
Below or partly or wholly within the solenoid or magnet and within its magnetio
1

page_text: field is located external to the carbon holding tube a piece of magnetic material
This
such as iron steel or nickel which may be termed the "intensifier."
"intensifier" is preferably of annular shape and surrounds the carbon holding tube
and is also preferably capable of motion to and from the solenoid or magnet and
fitted within a case or playing between stops or other devices for limiting the
extent of its motions although the "intensifier" may have other than an annular
shape and whether annular or not may have a fixed position.
The solenoid is placed directly in the circuit which is preferably a multiple are
circuit including one or more lamps. From the main circuit one connection is
made to the free end of the solenoid or magnet coil its other end being attached to
and forming electrical contact with the inner metallic shell of the solenoid whence
the circuit continues to the carbon holding tube passing principally through the
brush which makes good electrical contact for the purpose thence to the x carbon,
to the carbon, and the metallic frame of the lamp to the other connection from
the main circuit.
-
The operation of the lamp thus constructed and arranged in circuit is about as
follows-
Upon closure of circuit the solenoid or magnet renders both the core or armature
and the intensifier magnetic by induction, attracting them the ring or intensifier
towards its base and the core or armature within itself and against the stress of the
spring.
But the free ends of the wires of the brush referred to being all of one polarity
are repelled each by the others, flying outwardly and impinging against the inner
side of the carbon holding tube binding it between the intensifier and the brush
so that it is lifted with them sufficiently to form the arc and then held in that
position.
As the arc increases of course the resistance in the lamp circuit increases
diminishing the magnetic force of the solenoid or magnet. The parts are so adjusted
relatively to each other that when the point of greatest desired are has been
reached, the magnetic effect of the solenoid or magnet is so weakened that the
brush relaxes its hold upon the carbon-holding tube to some extent which then
drops by gravity and is forced downwardly by the movement of the core or
armature which is depressed by the spring until the magnetic force of the
solenoid is again restored
Instead of having the core or armature divided into two or more repelling
parts it may be of one single piece having sufficient lateral movement to permit
it to strike the sides of the tube enclosing it and force the tube against its
guides.
The brush form is preferred however since the movement is more uniform and
better electrical contact is made to conduct the current to the carbon.
It will be seen from the foregoing that the distinctive feature of the regulating
mechanism is the location of a magnetic core or armature within the carbon holding
tube such core or armature clamping the tube and forcing it to move with the core
or armature either by the clamping action alone or assisted by the fluid in the tube
as hereinafter stated.
The carbon holding tube is preferably filled with some fluid such as glycerine
which serves to lubricate its interior preventing excess of friction regulating or
slowing down the movement of the contiguous surfaces and preventing a spark at
the points of contact of the tube and brush.
1
The fluid also forms a means of communicating motion from the brush to the
carbon holding tube in addition to that afforded by the contact of the brush with
the tube, the interstices between the brush and tube not being sufficiently large
to prevent the almost simultaneous movement of the brush and tube.
By another part of the invention a construction of regulating mechanism is
produced having a more uniform movement than that just described.
This is accomplished by the division of the intensifier into a number of inde-
pendently moveable parts which press equally upon the carbon holding tube and

page_text: act evenly upon the magnetic brush, or the divided core or armature of the
controlling solenoid or electro magnet making a uniform and steady light."
The improved intensifier is composed preferably of a number of balls or rollers
of magnetic material which balls or rollers are held together by a wire ring passing
loosely through them so that they have the desired extent of independent move-
ment. This ring of balls or rollers is limited in its vertical movement by stops or
by an enclosing cage and the balls or rollers work freely by a rolling movement
upon the carbon holding tube as they are attracted by the solenoid or electro
magnet acting upon the magnetic brush to increase the repulsion between its parts.
This brush is of the construction before described with the exception that it is
always in contact with the interior of the carbon holding tube in order to complete
at all times the circuit to the carbon.
The action of the solenoid or magnet and the intensifier serves to force the brush
with greater or less pressure into contact with the tube for the purpose of controlling
its downward movement.
The brush or divided core or armature is supported by a spring at its upper end
as before described and rests in liquid within the carbon holding tube, the quick
and forcible vertical movements of the carbon holding tube being produced by the
vertical movements of the brush or divided core or armature through the medium
of the liquid with which the tube is filled.
A further object of this part of the invention is to produce a simple and efficient
device for holding the lower carbon electrode of the lamp for allowing it to be
readily centered or brought into line with the upper carbon and for permitting of
an upward adjustment by hand of such lower carbon
This is accomplished by the employment of a tube in. which the lower carbon is
placed the tube being split at its upper end and provided with a clamping ring for
holding the carbon
This tube has secured to it or made in one piece therewith a disk provided with
a concave lower face and resting upon the lower cross bar of the lamp frame.
The tube passes through an opening in the lamp frame which opening is large
enough to permit a limited lateral adjustment of the tube in any direction.
A disk having a concave upper face is screwed upon the tube and is forced
against the lower side of the cross piece of the lamp frame. The proper position
of the lower carbon in line with the upper carbon can be first secured and the
parts then rigidly secured in position by turning up the lower. disk. The lower
carbon can be adjusted vertically at any time by loosening the clamping ring at the .
upper split end of the tube.
By another part of the invention the core or armature has a sliding movement
to a limited extent upon its supporting rod towards and away from a block.
secured rigidly to such rod which rigidly secured block may be of magnetic or non-
magnetic material, and if magnetic will form a part of the core or armature.
The core or armature is forced towards the block by an adjustable spring.
The space between the core or armature and the block is made wedge shape by
the bevelling of the end surface of the block and in this space are located balls of
magnetic or non-magnetic material which are jammed outwardly against the walls
of the enclosing tube by the action of the core or armature.
The carbon carrying tube drops by gravity when the core or armature does not
exert much pressure upon the clamping balls, but when the resistance at the arc
is reduced below a certain point the core or armature moves upwardly forces
the balls outwardly clamping the carbon carrying tube and lifts such carbon
carrying tube.
In connection with this construction of internal clamping balls an external
magnetic clamp may be used which may be a divided ring like the divided
"intensifier" before described.
This divided clamping ring is located upon the carbon carrying tube opposite or
below the lower end of the core or armature or opposite the interior clamping
balls and is limited in its movement by stops or by an enclosing cage
To

page_text: produce a uniform movement of the core or armature, an additional dash pot is
used which may be connected with the upper end of the rod carrying the core or
armature the stationary enclosing tube rising from the head of the solenoid being
extended upwardly to support the other part of the dash pot.
By this part of the invention, a simple device is also provided for holding and
centering the lower carbon. Two concave disks are used which are clamped to the
frame by a bolt and nut the bolt passing through a hole somewhat larger than
itself and being allowed a lateral movement in any direction to center the carbon.
The upper disk carries a split socket in which the carbon is held by a screw ring
The concave faces of the disks assure a firm holding of the carbon.
By another part of the invention the core or armature or the principal part
thereof surrounds the carbon carrying tube and is connected by a tube and rod
with a plunger within the carbon carrying tube said carbon carrying tube is filled
with glycerine or other suitable liquid. The plunger may be of magnetic or non
magnetic material. It carries wires which press constantly against the walls of
the tube maintaining good electrical contact therewith. The circuit connections are
further maintained by wires or springs pressing against the tube rising from the
core or armature The core or armature has arms pivoted in slots in its sides and
provided with clamping plates which grasp the carbon carrying tube. These
clamping arms carry armatures on their lower ends which are attracted by adjustable
pole pieces from extensions of the main core or armature.
The main core or armature is supported by one or more adjustable springs at its
lower end or at the upper end of the tube rising therefrom. In the latter case an
outside inclosing tube, rising from the head of the solenoid will be used, to which
the spring will be attached."
The movements of the carbon carrying tube will be produced and governed by
the action of the plunger within the same, the external magnetic clamp, and the
force of gravity.
And in order that the said Invention may be more clearly understood and readily
carried into effect I will proceed aided by the accompanying drawings more fully

page_text: centre of E as clearly shown in Figures 2 and 3. As these wires are fastened
upon E in the similitude of a brush, the term "brush" has been applied herein to
this peculiar construction of a core or arinature.
Below the solenoid and surrounding the tube B, is an iron ring F, which,
becoming magnetic by induction from M, when M is charged, acts in turn by
induction upon E, aiding or intensifying the action of M thereon, to which
therefore the term "intensifier" is applied."
F is capable of sliding freely upon B and its motion is limited by either an open
case as shown, or by stops arranged in any suitable way.
In Figure 4 is seen more in detail the carbon clamp, R being a plug which is
screwed into the free end of B, slightly tapering, screw threaded and slotted as
at in several places, while T is a thimble tapering and screw-threaded, so that as
it is screwed upon R it forces together the lips or jaws formed by the slotting of R,
causing them to grasp the carbon.
It is found desirable to fill the tube B nearly to its top with some viscous liquid
like glycerine, for the reasons bereinbefore given.
As before stated, a particular feature of the regulator herein described is the
division of the armature or core into parts, adapted to be mutually repelled, and
located within the tube carrying the carbon, so as, when repelled, these parts shall
impinge on the inside of the tube and control its movement.
For this purpose,
the brush, core or armature shown is an excellent type, but only a type as its
mechanical construction, in order to avail of the principle of magnetic repulsion
existing between similar polarities, may be greatly varied, and in fact there are
many ways in which an armature or core acting in the same method may be made,
all of which, for the purpose of this case, are equivalents of the form shown.
The circuit connections in the lamp are as follows, 1, 2 being the connections
from the lamp to the main circuit.
As
Connection 1 leads directly to the coil of the solenoid, the other end of which
coil is electrically connected to the interior metal wall of the solenoid at 3.
the heads h h of the solenoid impinge on B, there is electrical connection between
them, and from B to the upper carbon; when the parts are in the position shown in
Figure 2, the current also passes through the brush and liquid to the tube B.
When however the parts are in the position shown in Figure 3 the principal
part of the current flows through the brush which makes good electrical contact
with the tube.
From B the circuit is through upper carbon O to lower carbon O¹ forming the
arc, thence by Q P¹ to 2 and main circuit.
When the lamp is not in operation, the parts are in the position relatively to
each other shown in Figure 2, the ring F resting at its lower limit of movement,
while E is protruded from the solenoid by action of S, the wires e e lying in their
normal position against the core E.
Circuit now being closed M renders E e e and F magnetic by induction, the
action of F in turn upon E e intensifying the action of M. thereon: e e immediately
repel each other, impinging firmly against the interior of B at the same time F is
drawn up toward M while E is attracted within it, seeking to place itself in a
neutral position the effect being that B is lifted with E, so that the carbons are
separated and an arc formed.
As M is directly in the circuit with the carbons, the magnetic effect of the
current therein is directly affected by the resistance at the arc, which of course
increases as the arc increases by consumption of the carbons. This finally reaches
such a point that M cannot hold E against force of S while e c loosen their hold
upon B. Thereupon B is forced downwardly by its own weight, and the action of
the spring through the core and fluid, until the magnetic effect of M is restored, by
the diminution of resistance effected by proper curtailment or relighting of the
arc, due to this dropping of B', thereupon e e again fly out and hold B firmly.
The relative movements of E and B are made regular and smooth by the liquid

page_text: within B, while the liquid prevents any sparks and oxidation due to sparks, at the
contacts between e and B, and also serves to communicate motion from E to B.
This construction forms a lamp exceedingly simple, involving very few parts,
regular and efficient in action, and especially adapted to be used in multiple are
circuits and in systems where incandescing lamps are used.
The second part of the Invention is illustrated in Figures 5 and 6 of the drawing
to which reference is now made.
Figure 5 is a vertical section of the principal operative parts of the lamp: and
Figure 6 a cross section of the carbon holding tube above the intensifier.
A is the solenoid or hollow electro-magnet, the coils of which are in series with
the carbon electrodes.
From the head of A, rises the supporting tube B, carrying a spring (not shown)
connected adjustably with the rod C as described in connection with Figures 1, 2,
3 and 4. D is the tube carrying the upper carbon electrode E.
This carbon holding tube which is filled with glycerine or other suitable liquid F,
passes through the solenoid or hollow magnet, being guided therein, and enters
the supporting tube B. The rod C extends down into tube D and carries on its
⚫ lower end the divided core or armature. This is composed preferably of a body G
of magnetic material, to which are attached wires H, also of magnetic material.
These wires forming what is termed the "brush," are secured at their upper
ends to the body G and extend downwardly and outwardly into contact with the
tube D.
I is the divided intensifier, limited in its vertical movement by arms a, or a
suitable cage.
It is composed of balls or rollers b of magnetic material, carried by a ring c and
surrounding the tube D.
The ring passes loosely through the rollers so that they may have an independent
movement thereon. This annular intensifier always retains a horizontal position
and acts uniformly upon the brush; it has a rolling movement upon the carbon
carrying tube, playing freely upon the same.
The upper carbon E is attached to the rod D, by means of a split socket and
clamping ring as described in connection with Figures 1, 2, 3 and 4.
The lower carbon K enters a tube L provided with a disc m, having a concave
lower side d as shown. The disc m, rests upon the lower cross piece N of the lamp
frame, through an opening e in which the tube L passes.
A. disc O having a concave upper side of screws upon the tube L and strikes the
lower side of the cross piece N.
The opening e is large enough to permit the tube L to be moved to a limited
extent in any horizontal direction in order that the lower carbon may be brought
into line with the upper carbon.
:
The concave faces of the disc assure a rigid holding of the parts. The carbon is
held in the tube L by a screw ring g turning upon the split upper end h of the
tube, and can be adjusted vertically by loosening such ring and held at any desired
point by again tightening the ring.
⋅
The third part of the invention is illustrated in Figures 7, 8, 9, 10 and 11 of the
Drawing, to which reference is now made. Figure 7 is a vertical section of the
principal operative parts of an arc lamp. Figure 8 a vertical section of a portion
of the carbon carrying tube and enclosed parts, showing a modified arrangement of
the parts Figure 9 a top view of the assisting magnetic intensifier and clamp.
Figure 10 a sectional view of the regulating dash-pot, and Figure 11 a vertical
section and partial elevation of the devices for holding and centreing the lower
carbon.
A is the solenoid or hollow electro magnet the coils of which are connected in
series with the carbon electrodes B. B¹. of the lamp and which alone operates the
regulating mechanism.
The tube C carrying the upper or positive carbon B passes through the solenoid
or electro magnet and is guided therein.

page_text: It is filled with glycerine or other suitable viscous liquid D and passes up within
the supporting tube E rising from the head of A
F is a rod supported by a spiral spring G, which is secured to the tube E and is
connected adjustably with the rod F by a block a, and set screw b. The rod F
carries the core or armature H of the solenoid or electro magnet, such core or
armature being sleeved or held loosely upon the rod.
Above H is secured rigidly to the rod F a block I of magnetic or non magnetic
material which block is bevelled on its lower side next to the core or armature
one or more balls K preferably of non-magnetic metal, being located in the
wedged shaped space between the flat upper end of the core and bevelled lower face
of the block.
The core or armature is held up in active position by a spring c and adjustable
nut d, on the lower end of rod F. The pressure of the spring c while holding
the balls K out against the tube C maintaining electrical contact constantly
therewith, is not sufficient to prevent such tube from dropping by gravity, its
movement being retarded by the friction of the balls, as well as by the liquid
within the tube, and the regulating dash-pot about to be described.
When the circuit to the lamp is completed the core H will be drawn up with a
quick forcible movement.
This will jam the balls K out against the tube C clamping the core to the
tube.
In this quick forcible movement the magnetic clamp formed by the balls might
not be certain in its action.
The viscous liquid D however, by reason of the atmospheric pressure thereon
and the limited passage way through which it can flow around the core, causes the
core and tube to move as one, and the tube is carried up with the core against the
resilience of the spring G separating the carbon electrodes and establishing the arc.
The lengthening of the arc causes the core to diminish the pressure on the balls
and to release the tube C and also permits the spring G to act downwardly and
between these two actions the upper carbon is given a regular downward
movement.
If the are however should be broken or be unduly lengthened by the sticking of
the tube in its guides, the spring G would act to give the rod and core a quick and
forcible downward movement and carbon carrying tube would be carried with the
core through the medium of the liquid.
To produce a more uniform movement of the core or armature the additional
dash-pot S shown in Figure 10 is employed.
For this purpose the supporting tube E is extended upwardly and provided
with a cap o, from the centre of which is suspended a hollow cylindrical dash
pot plunger ? open at its lower end, and closes at its upper end with the
exception of the sinall air holes q. This plunger works in the cylindrical vessel
partly filled with glycerine 8, or other suitable viscous liquid.
The vessel is attached to the upper end of the rod F, and the dash pot thus
nakes uniform the movement of said rod caused by the solenoid or electro-magnet
and the spring G.
The parts thus far described form a complete and efficiently operating regulating
mechanism. They may be assisted however by a magnetic intensifier, and
clamp L external to the. carbon holding tube, composed, of balls or rollers e,
held by a ring f, and having an independent movement thereon to a small
extent.
This magnetic clamping ring surrounds the tube C below A, and is limited in its
vertical movement by arms g or a suitable cage.
In the arrangement shown in Figure 7 the ring of balls located below the core
serves to lengthen such core and intensify the action of the solenoid, or throw the
magnetic centre of the core down to a lower point. The balls are all attracted
inwardly by the core, clamping evenly upon the carbon carrying tube and being
attracted upwardly by the solenoid, they serve to assist in raising the carbon

page_text: carrying tube forming an external magnetic clamp, acting in conjunction with the
internal magnetic clamp formed by the balls K.
This divided magnetic clamping ring may be used with the arrangement shown
in Figure 8 in which the balls K are brought down to a point opposite the ring,
the internal and external clamps acting upon the carbon holding tube opposite
each other.
To do this the block m, corresponding to I, is extended downwardly and is made
magnetic so as to form a part of the core or armature, the moveable part N of the
core or armature being made shorter than in Figure 7.
With this arrangement, it is desirable that the core should extend above the
solenoid the same distance that it extends below such solenoid.
To hold and centre the lower carbon B¹, a socket O is provided having a
clamp to hold the carbon which is preferably a ring h, turning upon the split end i,
of the socket.
This socket has a disc P provided with a concave lower side k, and a screw
shank, extending downwardly from the centre of this disc.
The shank 1, passes through an opening m in the lower cross piece Q of the
lamp frame, the opening m, being large enough to permit the shank to be moved
laterally a limited extent in any direction.
A disc R having a concave upper side n, screws on to the lower end of the
The concave
shank and impinges against the lower side of the cross piece Q.
faces of the discs assure the rigid holding of the parts, while the opening m, allows
the lower carbon to be brought into line with the upper carbon.
The fourth part of the invention is illustrated in Figures 12. 13 and 14 of the
Drawing to which reference is now made. Figure 12 is a vertical section of a
regulating mechanism embodying the invention. Figure 13 a cross section of the
carbon carrying tube shewing the top of the clamping arm; and Figure 14 a view
of a modified form of construction.
A represents the coils of a solenoid or hollow electro magnet, one end of which is
connected with circuit wire 1, while the other end is fastened to the shell a upon
which the coils A are wound such shell a, being connected with the supporting
and guiding heads b. c.
B is the core or armature of the solenoid.or magnet working within and
extending below the shell a.
This core or armature is also hollow and has passing through it the tube C
carrying the upper or moveable carbon D of the lamp such tube being guided by
suitable rings within the hollow core or armature and being filled with a liquid D¹
preferably a viscous liquid such as glycerine,
From the core or armature B rises the tube E passing through the head b and
extending above the same and enclosing the carbon carrying tube C.
A stationary protecting tube may rise from head b. and enclose the tube E if
desired.
Brushes or springs d. carried by head b, press constantly upon the tube E
maintaining good electrical contact with the same.
A rod F is secured to the upper end of tube E and extends centrally down
within the carbon carrying tube through the liquid D₁ of the same to near the
lower end of the tube when such carbon-carrying tube is at the highest point of its
movement within the hollow core or armature.
At its lower end the rod F carries a piston or plunger G which however does
not fill the tube completely, but permits a definite small flow of the liquid
around it.
This piston or plunger is provided with spring wires e. which are secured to
such plunger and spring outwardly so as to bear constantly against the inner side
of the tube C.
These spring wires within the carbon holding tube maintain uninterruptedly the
connection of the upper carbon with the circuit wire, and the liquid in which these
spring wires are submerged lubricates the surfaces so that the parts work smoothly

page_text: and prevents sparks at the points of contact. The wires e are preferably of copper,
although they may be made of a magnetic metal and be plated with copper or not
as found desirable The piston or plunger may also be either of magnetic or non-
'magnetic metal. In slots in opposite sides of the core or armature B are pivoted
3 vertical metallic arms H, having clamping plates f at their upper ends which
bear against the sides of the carbon carrying tube C,
These arms H extend below the core or armature B and have outwardly
projecting wings g, which carry on their ends armatures I of iron or other magnetic
metal. The core or armature B has wings h which attract the armatures I, when
the core is magnetized. The wings h, are preferably provided with adjustable
pole pieces which may be large screws i. turning through such wings. The wings h
are connected with the bead c. by means of spiral springs K, which are adjustably
held at one end by means of set screws k. These springs support the core or
armature and the parts connected there with and limit as well as cushion the
movement of said core or armature.
The operation of the regulator is as follows:-
:-
Before the circuit to the lamp is completed, the parts are in the position shown
in the Drawing. Upon completion of circuit, the core or armature B is magnetized
and drawn up into the coils A with a quick and powerful action against the stress.
of the spring K, The tube E rod F and plunger G are raised with the core or
armature, and so is the carbon carrying tube C, which in this quick movement is
practically connected positively with the plunger through the liquid D', This
lifting of the carbon D establishes the arc
The magnetism of the core or armature B attracts the armatures I at the
adjustable pole piece i, and forces the clamping plates f against the tube C³, but
these clamps would not alone be sufficient to hold the tube C, in the quick upward
movement of the core or armature.
As the carbons are consumed and the resistance of the arc increases the
magnetism of B is lessened to some extent and the clamping plates have their
pressure upon the tube C, diminished by the weight of the armatures I.
The tube C then drops, its movement being retarded by the resistance to the
flow of the liquid around the plunger, until the magnetism of B is increased and,
the carbon holding tube is again clamped.
In this way a continuous feed of the upper carbon is maintained.
If the arc is broken or increased to a definite extent beyond the normal resistance,
the core or armature will drop carrying the tube E and rod F and plunger G with
it. The tube C will also be forced down positively by this movement through the
liquid, the weight of the core or armature and attached parts and the force of the
spring K being added to the weight of the carbon carrying tube.
Instead of supporting the core and other parts by means of the springs K the
modified arrangement illustrated in Figure 14 may be employed. Here an outer
stationary tube M encloses the tube E.
Such tube M is supported on the top plate b, of the solenoid or magnet.
A spiral spring L attached to the top of tube M is also attached to tube E so
that the latter is supported by said spring.
This arrangement is equivalent to that before described. A suitable device m.
is employed to adjust the tension of the spring L.
Having thus described the nature of the said Invention and the mode in which
the same may be carried into effect I would have it understood that what I
claim is:-
First. The core or armature of the regulating electro-magnet, located within the
carbon carrying tube and clamping by magnetic action against the sides of the
same, substantially as herein described.
"
Second. The "intensifier located external to the carbon-carrying tube, in
combination with the core or armature within the tube, substantially as herein
described.

page_text: Third. The improved regulating mechanism herein described in connection with
Figures 2 and 3.
Fourth. The divided "intensifier" substantially as herein described.
Fifth. The clamp for the lower carbon permitting of its vertical adjustment the
parts being constructed and arranged as described in connection with Figure 5.
Sixth. The clamp acting upon the interior of the carbon carrying tube and
operated by the movement of the core or armature within such tube, substantially
as herein described.
Seventh. The combination with the carbon carrying tube and the clamp within
the same of the external magnetic clamp substantially as herein described.
Eighth. The clamp for the lower carbon having the concave discs and the
clamping socket for the carbon, independent of the means for securing said
discs the parts being constructed and arranged as described in connection with
Figure 11.
Ninth The improved regulating mechanism herein described in connection with
Figures 7. 8. 9 and 10.
Tenth. The carbon carrying tube containing liquid and working through a
hollow core or armature, in combination with a plunger connected with the core or
armature, and located within said tube, substantially as herein described.
Eleventh. The combination with a solenoid or electro magnet, and its moveable
core or armature of a carbon carrying tube connected with the core or armature
through a fluid column and having a retarded movement independent of such core
or armature and a magnetically operated clamp for regulating this retarded
independent movement, substantially as herein described.
Twelfth. The combination with a carbon carrying tube of an interior contact
piece or pieces for maintaining the circuit connection with the moveable carbon
uninterrupted substantially as herein described.
Thirteenth. The improved regulating mechanism herein described in connection
with Figures 12. 13 and 14
In witness whereof I the said Benjamin Joseph Barnard Mills have hereunto
set my hand and seal this nineteenth day of September in the year of our Lord
One thousand eight hundred and eighty three.
BJ. B. MILLS (L.S.)