Improvements in Arc Lamps.
Year: 1894

page_text: Date of Application, 23rd Jan., 1894
Complete Specification Left, 23rd Oct., 1894-Accepted, 23rd Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Arc Lamps.
1, JOHN BRUNSWICK BARTON, of 35 Seedley Road, Pendleton, Manchester, in
the County of Lancashire, Engineer, do hereby declare the nature of this invention
(as communicated to me from abroad by William Jandus, of Cleveland, in the State
of Ohio, United States of America, Engineer) to be as follows:→
This invention relates to improvements in are lamps by which certain advantages™
are obtained.
1
The annexed drawings and the following description set forth in detail, one
mechanical form embodying the invention; such detail construction being but one
of various mechanical forms in which the principle of the invention may be used.
In said annexed drawings:-
Figure I represents a vertical section of my improved electric are lamp,
Figure II an enlarged sectional detail view of the upper end of the tubes which
support the lamp ;
:
Figure III, a section of the auxiliary carbon holding tube; Figure III*, a cross
section of the same on the line A-B, Figure III;
Figure IV, a section of the magnets and the movable armature;
Figure IVA, a cross section on the line C-D, Figure IV;
Figure IVB, a cross section on the line E-F Figure IV;
Figure V, a vertical sectional detail view of the carbon feeding mechanism;
Figure VA, a cross section on the line I-J, Figure V ;
Figure VI, a vertical section of the carbon feeding mechanism, the surrounding
casing for the same, and the upper portion of the globe;
Figure VIA, a cross section on the line G-H, Figure VI;
Figure VII, a section of the support for the negative carbon ;
Figures VIII and XII, sectional detail views of the clutch mechanism,
respectively showing the positive carbon clutched and raised to form the arc, and
in its position of release;
Figures IX, X and XI, respectively a section, a top, and a bottom view of the
collar for the lower brushes,
Figures XIII and XIV sectional detail views of the negative carbon holder
and the lower end of the carbon supporting frame;
Figures XV and XVI sections of two other forms of magnets,
i
Figure XVII, a sectional detail view of another form of cut-off sleeve for the
shortcircuiting device, and
Figures XVIII and XIX, sectional detail views of the movable armature and
the clutch rings, the sections being made at right angles to each other.
The lamp illustrated in the drawings, is a hanging lamp or lamp destined to be
supported from above. An insulating plug, L', has a threaded socket, L³, secured
upon its upper end, by means of which socket the lamp may be secured pending
from the ceiling of a room or from other elevated support. A supporting tube L
is screwed with its upper end to the lower end of the insulating plug, and clamps
an insulating disc; L³, between its upper end and a shoulder upon the plug. The
ends of the conductors of a supply circuit are secured to a negative binding

page_text: screw,
L³, and a positive binding screw, L'; and the ends of the negative terminal
conductor, w', and positive terminal conductor, w, are secured in contact with said
line conductors by means of said binding screws. The lower end of the supporting
tube L is screwed upon the upper end of a carbon-containing tube, t, upon the
upper portion of which a disc, a, having a central aperture; a², is secured by said
central aperture. The disc a is of soft iron and forms a portion of the upper
magnet, having limbs, a', projecting downward. A similar disc, b, of the lower
magnet, is secured to the carbon-containing tube t, by means of a flange t¹, fitting
into a rabbet, 63, in the central opening 62, of the lower magnet dise; or said disc
may be brazed or otherwise secured to the tube. The lower magnet disc has
upwardly projecting limbs, ', and said limbs have axial bores; corresponding to
similar bores in the limbs of the upper magnet. The bores of the lower magnet
extend entirely through the limbs, while the bores in the limbs of the upper magnet
extend only partly through said limbs. Tubes, d, of brass are secured in the bores
of the magnet limbs and in airtight engagement therewith; their lower ends
resting upon shoulders formed in the lower ends of the lower bores, so as to make
continuous and smooth bores through the limbs. The ends of the limbs of the two
magnets are at a predetermined distance from each other, such distance being
determined by the length of the interior brass tubes, so as to produce a condensed
magnetic field between the ends of the magnet limbs; the said field being fixed and
adjusted according to the length of pull required or the length of travel of the
armature cores.
"
The series and shunt coils are wound in the usual manner, but in such directions
that all of the several poles of the magnets will be in magnetic series. Said
term, viz. magnetic series, is employed for the magnets as analogous to the term
" series
when employed to describe the arrangement of electrode generating or
translating devices, viz.-with their poles opposed to other poles of opposite
polarities or denominations; so that the north pole of one magnet is opposed to
the south pole of the other magnet and the south pole of said first-named magnet
is opposed to the north pole of the second maguet. The magnets are consequently
in magnetic series, and the magnetic circuit in the magnets will be completed when
the armature is so attracted that it closes the magnetic gaps between the poles of
the magnets.
I prefer to wind the series coil, M, upon the lower magnet, and the shunt
coil, M', upon the upper magnet, as illustrated in Figure 1, but may employ
compound winding, as illustrated at M³, in Figures V and VI, in which the
compound coil is shown as wound upon spools, M². In either case, the upper
magnet serves, so to speak, as a stationary armature to the lower magnet, and
vice versa; the magnetic circuit being completed through the gaps between the
poles, where the field is powerfully condensed. The same condensation of the field
may be obtained by simply forming the stationary armature in the shape of a bar
or disc supported at the desired distance from the ends of the magnet limbs by the
brass lining tubes, as illustrated in Figures XV and XVI. In the form illustrated
in Figure XV, the limbs of the movable armature are long, and extend through
the entire length of the limbs of the magnet; and in the form illustrated in
Figure XVI, the limbs of the movable armature are short and extend through the
stationary arinature into the ends of the magnet limbs. In either case the magnetic
circuit finds a path, from one pole to the other, through the stationary armature
and the field is condensed at the points between the poles of the magnet, and the
opposite poles of the stationary armature. This condensation of the field is of great
importance as it enables me to operate the movable armature and the carbon clutch
with a comparatively small number of ampère turns of wire in the coils, obviating
the use of levers and other power multiplying devices for producing a strong
differential effect.
The magnetic field is highly condensed within the gaps between the opposed
poles of opposite denominations of the two magnets, and the cores of the arinature
do not close the magnetic circuit until completely drawn up. into the gap so as to

page_text: be within the bores of the upper magnet. The strong pull caused by this
arrangement of magnets in magnetic series and with gaps between all of the
opposed poles of opposite denominations, is entirely dependent upon said gaps
within which the magnetic force is condensed. The gaps are absolutely essential
to the operation of this style of magnet, as it destroys or is detrimental to the
efficiency of the magnet to close the magnetic circuit before the armature arrives
at the end of its attracted position, when it simply acts as a keeper, uniting the
two magnets into one.
A circular armature disc, c, has two upwardly-projecting cores, c', and has a
central aperture for the carbon containing tube, from which aperture slots, c² and c³,
radiate; said slots having their outer ends bevelled to face upward; and the slots c³
having the bevels at a greater angle to the sides of the central aperture than the
slots Small metallic bodies, e, of spherical shape; such as shot, are placed
in the brass tubes, at the ends of the armature cores, so as to always insure
metallic contact.
The lower end of the positive terminal conductor w is secured, by means of a
nut y', to a screwthreaded binding post, y, which latter is secured in the upper
magnet disc a and insulated from the same by means of a non-conducting sleeve, w²;
and the current passes through said binding post to the terminal, m', of the series
coil, M, which terminal is secured to the binding post by a suitable nut. The series
coil is wound upon both magnet limbs, and its outer terminal, m³ is in contact with
the upper disc, a, conveying the current through said disc to the carbon-containing
tube t.
Said terminal m is held to the disc by a flange upon the lower end of an
insulating sleeve, wo, and by a suitable nut upon a screwthreaded rod, j, which
forms a part of the negative conductor within the lamp, the terminal being thus
insulated from said rod, which is also insulated from the disc by passing through
the insulating sleeve.
The negative terminal conductor w³, is attached to said negative conductor rod
by means of a binding nut w³.
The terminals, m³ and m², of the shunt coil, M', are clamped and connected to
the positive and negative terminals, across the arc.
A shortcircuiting device, a, is connected across the terminals of the series coil,
and is formed by a wire, ¹, doubled into the form of a loop having parallel limbs,
and wound in parallel strands around an insulating post, x², secured at its upper
end upon the lower end of the positive binding post y. The doubled, lower end of
the looped wire is secured to the post by means of a screw, a, screwed into a
countersink, x, in the post. The length of the shortcircuiting device and, conse-
quently, the degree of the resistance in the same may be varied by means of an
internally screwthreaded metallic sleeve, ³, having parallel threads cut in it to
engage the parallel limbs of the wire, so as to be moved up or down upon the coil
and thus shortcircuit it at any desired point. One terminal of the shortcircuiting
device is secured to the post by a screw, which is in contact with the positive
binding post y, or one terminal of the series coil,-and the other terminal of the
shortcircuiting device is secured against and in contact with the upper disc a,-or
the other terminal of the series coil,-by means of the lower binding screw upon
the positive binding post y, being insulated from the latter by the insulating
sleeve w².
Instead of employing the screwthreaded sleeve x³, a plain sleeve may be used, as
illustrated in Figure XVII, said sleeve having a set screw, 28, by means of which
the sleeve may be brought into metallic contact with different portions of the
wire, effecting a shortcircuit at any desired point.
The degree of the resistance of the shortcircuiting device may be thus adjusted
by sliding the sleeve, up or down, according to whether the resistance is to be
decreased or increased, and this adjustable shortcircuiting coil will be perfectly
certain in its operation and will occupy but a small space in the lamp.
The lower end of the negative conductor rod j is coupled, by means of a
coupling sleeve, k,—to a rod j¹, which passes through a metallic sleeve, l, inserted

page_text: through the lower magnet disc b, but insulated from the same by means of a
suitable insulating sleeve. The lower end of said rod is secured to a disc, o, which
forms a part of the negative conductor within the lamp. A nut, m, fits upon the
rod, and said nut and rod form one of the supports for the disc o. A corre-
sponding rod, j, has its lower end secured in the disc o, passes up through a metallic
sleeve, inserted through the lower magnet disc and insulated from the same,-
and enters the lower end of the insulating post for the shortcircuiting device.
A nut, m³, upon this rod, above the lower magnet disc, serves to support the disc o,
similarly to the nut m. The rod, and its sleeve l', form,-together with disc o
and the rod j¹, sleeve l, and rod j,-a part of the negative conductor within
the lamp.
The disc o has a downwardly projecting, screwthreaded neck, o², within which an
insulating sleeve or packing, o', is secured; said sleeve insulating the negative disc
from the positive carbon-containing tube t.
An oblong carbon-supporting frame, r, is secured with a screwthreaded opening r¹,
in its upper end to the screwthreaded neck o2, and said frame has a screwthreaded
opening, 2, in its lower end, formed with an upwardly contracted, smooth
portion, 3, which terminates in a smooth and straight opening, r, of a diameter
sufficient to admit a carbon pencil of the greatest diameter capable of use in the
lamp. A lower, negative carbon holder, s, has a screwthreaded sleeve, s², which
may fit into the lower screwthreaded opening of the carbon-supporting frame, and
has a tube, s¹, secured inside said sleeve; said tube having its upper end slightly
bevelled and having longitudinal slits in its upper portion, which admits of the tube
being contracted at its upper end to clamp the carbon, when the carbon holder is
screwed up into the lower opening of the carbon-supporting frame. An insulating
handle, 3, is secured in the lower end of the carbon-holder by means of a rivet or,
pin, s, inserted through the outer screwthreaded sleeve, the slitted tube, and the
end of the handle. A cup-shaped pan, st, is fitted around the handle, to slide upon
the same, beneath the lower ends of the tube and sleeve, and is insulated from said
tube and sleeve by an insulating washer, st. A spring, is coiled around the
handle, and bears against a shoulder upon the same with its lower end,
and said spring is inclosed by a sliding sleeve, s', having an inward flange, s³,
at its upper end, which rests upon the upper end of the spring, and bears against
the pan.
The carbon-containing tube, t, has longitudinal slots, to, and two rings, to and t2,
are suitably secured, one above the other, around the slotted portion of the tube.
Rings, having grooved peripheries to engage the carbon, and forming radial
clutches for the same, are hung upon supporting ring to, and have play in the upper
portions of the slots, and in the radial slots c2 and 3 of the armature. Similar
rings, t, forming the upper radial brushes, are bung,-to have play in the lower
portions of the slots,-upon the lower supporting ring t2.
The disc o has an up-turned edge or flange, o³, around its central opening, and the
upper radial brush rings t may have contact with said flange when the carbon is
removed.
A nut, u, is fitted upon the lower screwthreaded portion of the carbon-containing
tube t, and serves to rigidly clamp a casing, i, between the disc o and lower magnet
disc b, securely binding together the lamp structure on the central tube t.
A collar, v, is secured upon the lower end of the carbon-containing tube, and is
formed in its lower end with slots, 3, in which lower brush rings, ², have play, said
rings being supported by a ring, v', secured to the collar.
A casing, i, is clamped between the lower magnet disc b and the negative disc o,
said discs being drawn together by the nut u, asbestos rings or similar insulating
rings, p, are interposed between the under side of the lower magnet disc and the
upper edge of the said casing, and between the upper side of the negative terminal
disc o and the lower edge of the casing, so as to form an airtight, insulating and
non-combustible packing for the chamber formed by the parts and inclosing the
armature and clutch device.

page_text: Insulating sleeves, n, are secured upon the rods and j, serving as stops upony
which the armature may rest when lowered.
The edge of the upper opening in the globe, z, is clamped between the negative
disco and the carbon frame r; insulating asbestos washers, and p³, being interposed,
as well as a metallic washer, q, between the carbon frame and the lower washer p³,
which serves to stiffen and support said washer. The upper portion of the globe is
thus hermetically closed. The edge of the pan bears against the lower opening in
the globe.
A collar, , surrounds the lower end of the airtight chamber i, and rests upon,
the top of the globe.
A collar, 3, having openings formed in it, is secured upon the upper portion of,
the airtight casing i, and has a flange, g, into which the lower end of a cylindrical
casing,, fits. The upper portion of said cylindrical casing is formed with air
holes, The upper end of the cylindrical casing f is contracted, and the lower
end of a tube, f2, is secured to said contracted end. This tube f¹ surrounds the
tube L; and a canopy, L, is secured to the upper end of said outer tube f
surrounds the socket at the end of the inuer tube L and the binding screws.
and
A positive carbon-holding tube, N2, see Figure 3, may be used for the positive
carbon, and said tube has a slightly contracted, long socket portion, N³, at its
lower end into which the carbon may be inserted; said socket portion having.
longitudinal slits, N', which render the socket elastic. The upper end of the
elastic socket is formed with an inwardly projecting bead, N³, which serves as a
stop for the end of the carbon.
The positive carbon is lettered N, and the negative carbon is lettered N', in the
drawings.
If desired, the binding post connections at the upper end of the supporting
tube L and its surrounding tube, may be dispensed with, and the terminal conductors
may extend at the upper ends of the tubes L and f, through the insulating plug,
where they may be suitably connected to the circuit wires.
The carbons are inserted into the lamp by unscrewing the lower carbon-holder from
the threaded opening in the carbon supporting frame. The removal of the carbon
holder and pan admits of the inside of the globe, as well as the carbon-supporting
frame and other parts within the globe being cleaned; the lower opening of the
globe affording ample room for the insertion of the band and a cloth or other
cleaning means. The positive carbon may now be inserted through the opening in
the lower end of the carbon-supporting frame, the upper, contracted portion of the
said opening admitting a carbon of the greatest diameter capable of use in the
lamp, but preventing the insertion of a carbon of a greater diameter than what will
enter the radial brushes and clutches. The end of the carbon, as it passes up
through the lower brushes will push said brushes outward and will push them out
of contact with the up-turned rim of the negative terminal disc o, whereupon the
carbon pushes the clutch rings out, and is in position to be held by the same when
the current is turned on and the armature is drawn up. The negative carbon is
placed in the slitted tube of the carbon-holder, and will be clampe.l when the latter.
is screwed in place. As the negative carbon is pushed upward with the holder,
the positive carbon will be pushed up into its containing tube. The positive carbon
will have three supports,-the clutch rings, the upper brush rings, and the lower
brush rings, and will always be well centered, irrespective of any minor irregularities
in the shape of the carbon. The brushes and clutches will, on account of their
form, being shaped as rings, have a yielding contact with the carbon; such
contact being partly rolling and partly sliding. When the carbons are secured
and the current is turned on, the current will pass through the positive conductor
and the positive binding post, through the series coil, and to the upper magnet
plate a, from which it will pass into the carbon-containing tube to the positive
carbon, passing through the brushes and clutch. From the positive carbon it passes
through the negative carbon, through the carbon-holder and carbon-supporting

page_text: frame to the negative terminal disc o, through said disc to the negative terminal
rods and j, and to the negative conductor. The circuit being completed, the
series coil energises the magnets which attract the movable armature. The latter
draws the clutch rings upward, and forces them against the carbon, as the bevelled
ends of the slots in the armature strike upward, the arc is formed, and the lamp is
in operation. The clutch rings in the radial slots c² will first engage the carbon
with a slight clutch, when the armature is drawn upward, on account of the longer
.and less steep incline of the bevels of said slots and the clutch rings in the slots e³
will next engage the carbon with a stronger clutch, on account of the steeper
incline of the bevels of said slots so that the armature will gradually raise the
carbon and form the arc, even when it is suddenly drawn upward. When the
armature is lowered, a similar gradual release of the carbon, may take place,
corresponding to the gradual clutch of the carbon by the attracted armature; the
clutches which are engaged by the steep inclines releasing the carbon, where-
upon the clutches engaged by the less steep inclines will allow the carbon to drop,
exerting, however, a braking influence upon the carbon, as they revolve upon the
inclines. When the positive carbon has been consumed so that its upper end falls
below the clutches and cannot be held by the same, the current will first pass freely
through the carbons, energising the magnets so that they draw the movable
armature upward in contact with the cut-out sleeves 1; forming the circuit through
the armature, the cut-out sleeves and the negative terminal rods, and shortcircuiting
it from the electrodes. This cut-out will consequently be through the series coil and
by the series coil. In the event of the arc resistance becoming abnormally great,
the cut-out will be effected by the shunt coil and through the series coil; the shunt
coil overpowering or neutralizing the pull of the series coil and lifting the armature
into contact with the cut-out sleeves, 1, when the whole current will again pass
through the series coil and relieve the shunt coil in holding the armature in its
raised position. If the current should be turned on while no positive carbon is in
the lamp, the primary contact will be through the lower brushes, which hang
down in contact with the up-turned flange of the negative terminal disc 0,
and thus complete the circuit through the series coil; causing the latter to
raise the armature and establish the cut-out through the sleeves, such cut-out
being effected by the series coil and through the series coil. In case the shunt
should become opencircuited by some accident, the series coil will lift the armature
and form the cut-out through the sleeve l, the cut-out being established by and
through the series coil. In the event of considerable resistance offered the current
by the two electrodes when in cut-out,-the secondary cut-out having been effected
by the armature and sleeves 1,-the sliding cores might in some one particular
position fail to make good contact with the containing tubes. In such cases,―the
clutch rings having been lifted out of contact with the supporting ring, it would
leave the armature to effect the cut-out independent of any electrical contact,
except, such as it might have with the core containing tubes. An imperfect contact
then might possibly produce heating or sparking; but I prevent such sparks and
the damage which they might do, by establishing a permanent metallic contact
through the metallic pellets within the tubes.
The arc is enclosed in a globe which is hermetically tight at its top and provided
with a yielding closure at its bottom so that, as the carbons burn, they consume
the oxygen of the air without, however, readily allowing such oxygen to be renewed
from the surrounding atmosphere. The yielding pan at the bottom of the globe
will allow the expanding air and gases within the globe to escape, and little air,
only, will leak through the bottom opening, such as may be due to alternating
expansion and contraction of the globe contents due to a varying circuit and
consequent change of temperature. There can be no upward draft in the globe
on account of the hermetic closure of the upper end of the same, and on account
of the yielding fit of the cup against the lower opening of the globe. Therefore,
as the oxygen of the air contained in the globe is consumed, the globe will in its

page_text: place be filled with carbon-binoxide, CO₂, which in turn, will be reduced to CO,.
carbon-monoxide, which gas remains stable. In this manner the oxidation of the
carbon is greatly retarded; effecting a considerable saving in the use of the
carbons.
As the yielding closure, however, has no packed bearing against the lower edge
of the globe, but simply rests against said edge, atmospheric air may enter the
arc-inclosing chamber and equalize the internal and external pressure, if the internal.
pressure becomes less than the external atmospheric pressure. Bursting of the
globe by excessive rarefication within the same, and consequent excessive external
pressure, is thus avoided. The opening in the bottom of the arc-inclosing chainber
forms a hand-hole, through which the hand of the person trimming the lamp may
be inserted in the arc-inclosing chamber, for the purpose of cleaning said chamber
removing burnt out carbons, repairing the exposed parts in the chamber, or
inserting new carbons. Said bottom opening or hand-hole is, therefore, of sufficient
size to admit of the free and unobstructed outlet of gases formed within the
chamber, as said gases will bear against the large surface of the yielding pan, and
will escape sufficiently freely to prevent the possibility of explosion of the carbon-
monoxide mingled with air, by ignition of said mixture from the arc of the lamp.
Other modes of applying the principle of my invention may be employed for
the mode herein explained. Change may therefore be made as regards the
mechanism thus disclosed, provided the principles of construction set forth are:
employed.
A communication from abroad by WILLIAM JANDUS, of Cleveland, in the State
of Ohio, United States of America, Engineer.
I, JOHN BRUNSWICK BARTON, of 35 Seedley Road, Pendleton, Manchester,
in the County of Lancashire, Engineer, do hereby declare the nature of this
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention relates to improvements in arc lamps by which certain advantages
are obtained.
The drawings left with the Provisional Specification and the following description
set forth in detail, one mechanical form embodying the invention; such detail
construction being but one of various mechanical forms in which the principle of
the invention may be used.
In said drawings:-
Figure I represents a vertical section of my improved electric arc lamp, -
Figure II an enlarged sectional detail view of the upper end of the tubes which
support the lamp ;
Figure III, a section of the auxiliary carbon holding tube; Figure IIIA, a cross.
section of the same on the line A-B, Figure III;
Figure IV, a section of the magnets and the movable armature;
Figure IVA, a cross section on the line C-D, Figure IV;
Figure IVB, a cross section on the line E-F, Figure IV;
Figure V, a vertical sectional detail view of the carbon feeding mechanism;

page_text: Figure VA, a cross section on the line I-J, Figure V ;
Figure VI, a vertical section of the carbon feeding mechanism, the surrounding
casing for the same, and the upper portion of the globe;
Figure VIA, a cross section on the line G-H, Figure V1;
Figure VII, a section of the support for the negative carbon;
Figures VIII and XII, sectional detail views of the clutch mechanism,
respectively showing the positive carbon clutched and raised to form the arc, and
in its position of release;
Figures IX, X and XI, respectively a section, a top, and a bottom view of the
collar for the lower brushes ;
Figures XIII and XIV sectional detail views of the negative carbon holder
and the lower end of the carbon supporting frame;
Figures XV and XVI sections of two other forms of magnets and movable
armature, being modifications of the forms shown in Figure IV;
Figure XVII, a sectional detail view of another form of cut-off sleeve for the
shortcircuiting device being a modification of the form shown in Figures V
and VI, and
Figures XVIII and XIX, sectional detail views of the movable armature and
the clutch rings, the sections being made at right angles to each other.
The lamp illustrated in the drawings, is a hanging lamp or lamp destined to be
supported from above. An insulating plug, L', has a threaded socket, L³, secured
upon its upper end, by means of which socket the lamp may be secured pending
from the ceiling of a room or from other elevated support. A supporting tube L
is screwed with its upper end to the lower end of the insulating plug, and clamps
an insulating disc, L³, between its upper end and a shoulder upon the plug. The
ends of the conductors of a supply circuit are secured to a negative binding
screw, L³, and a positive binding screw, L'; and the ends of the negative terminal
conductor, w, and positive terminal conductor, w, are secured in contact with said
line conductors by means of said binding screws. The lower end of the supporting
tube L is screwed upon the upper end of a carbon-containing tube, t, upon the
upper portion of which a disc, a, having a central aperture, a², is secured by said
central aperture. The disc a is of soft iron and forms a portion of the upper
magnet, having limbs, a', projecting downward. A similar disc, b, of the lower
magnet, is secured to the carbon-containing tube t, by means of a flange t', fitting
into a rabbet, 3, in the central opening 2, of the lower magnet disc; or said disc
may be brazed or otherwise secured to the tube. The lower magnet disc has
upwardly projecting limbs, 61, and said limbs have axial bores, corresponding to
similar bores in the limbs of the upper magnet. The bores of the lower magnet
extend entirely through the limbs, while the bores in the limbs of the upper magnet
extend only partly through said limbs. Tubes, d, of brass are secured in the bores
of the magnet limbs and in airtight engagement therewith; their lower ends resting
upon shoulders formed in the lower ends of the lower bores, so as to make
continuous and smooth bores through the limbs. The ends of the limbs of the two
magnets are at a predetermined distance from each other, such distance being
determined by the length of the interior brass tubes, so as to produce a condensed
magnetic field between the ends of the magnet limbs; the said field being fixed and
adjusted according to the length of pull required or the length of travel of the
armature cores.
2
The series and shunt coils are wound in the usual manner, but in such directions
that all of the several poles of the magnets will be in magnetic series. Said term,
namely, magnetic series, is employed for the magnets as analogous to the terin
"series" when employed to describe the arrangement of electrode generating or
translating devices, namely, with their poles opposed to other poles of opposite
polarities or denominations; so that the north pole of one magnet is opposed to the
south pole of the other magnet and the south pole of said first-named magnet is
opposed to the north pole of the second magnet. The magnets are consequently in
magnetic series, and the magnetic circuit in the magnets will be completed when

page_text: the armature is so attracted that it closes the magnetic gaps between the pores or
the magnets.
I prefer to wind the series coil, M, upon the lower magnet, and the shunt
coil, M', upon the upper magnet, as illustrated in Figure I, but may employ
compound winding, as illustrated at M³, in Figures V and VI, in which the
compound coil is shown as wound upon spools, M. In either case, the upper
magnet serves, so to speak, as a stationary armature to the lower magnet, and
vice versa; the magnetic circuit being completed through the gaps between the
poles, where the field is powerfully condensed. The same condensation of the field
may be obtained by simply forming the stationary armature in the shape of a .bar
or disc supported at the desired distance from the ends of the magnet limbs by the
In the form illustrated
brass lining tubes, as illustrated in Figures XV and XVI.
in Figure XV, the limbs of the movable armature are long, and extend through
the entire length of the limbs of the magnet; and in the form illustrated in
Figure XVI, the limbs of the movable armature are short and extend through the
stationary armature into the ends of the magnet limbs. In either case the magnetic
circuit finds a path, from one pole to the other, through the stationary armature
and the field is condensed at the points between the poles of the magnet and the
opposite poles of the stationary armature. This condensation of the field is of
great importance as it enables me to operate the movable armature and the carbon
clutch with a comparatively small number of ampère turns of wire in the coils,
obviating the use of levers and other power multiplying devices for producing a
strong differential effect.
The magnetic field is highly condensed within the gaps between the opposed
poles of opposite denominations of the two magnets, and the cores of the armature
do not close the magnetic circuit until completely drawn up into the gap so as to
be within the bores of the upper magnet. The strong pull caused by this
arrangement of magnets in magnetic series and with gaps between all of the
opposed poles of opposite denominations, is entirely dependent upon said gaps
within which the magnetic force is condensed. The gaps are absolutely essential
to the operation of this style of magnet, as it destroys or is detrimental to the
efficiency of the magnet to close the magnetic circuit before the armature arrives at
the end of its attracted position, when it simply acts as a keeper, uniting the two
magnets into one.
a
A circular armature disc, c, has two upwardly-projecting cores, c¹, and has
central aperture for the carbon containing tube, from which aperture slots, c²,
and c, radiate; said slots having their outer ends bevelled to face upward, and the
slots having the bevels at a greater angle to the sides of the central aperture than
the slots c. Small metallic bodies, e, of spherical shape, such as shot, are placed in
the brass tubes, at the ends of the armature cores, so as to always insure metallic
contact.
The lower end of the positive terminal conductor w is secured, by means of a
nut y', to a screw threaded binding post, y, which latter is secured in the upper
magnet disc a and insulated from the same by means of a non-conducting sleeve, w²,
and the current passes through said binding post to the terminal, m', of the series
coil, M, which terminal is secured to the binding post by a suitable nut. The series
coil is wound upon both magnet limbs, and its outer terminal, m², is in contact with
the upper disc, a, conveying the current through said disc to the carbon-containing
tube t. Said terminal m² is held to the disc by a flange upon the lower end of an
insulating sleeve, w, and by a suitable nut upon a screwthreaded rod, j, which
forms a part of the negative conductor within the lamp, the terminal being thus
insulated from said red, which is also insulated from the disc by passing through
the insulating sleeve.
The negative terminal conductor w¹, is attached to said negative conductor rod
by means of a binding nut w³.
The terminals, m³ and mt, of the shunt coil, M', are clamped and connected to
the positive and negative terminals, across the arc.

page_text: A shortcircuiting device, x, is connected across the terminals of the series coil
and is formed by a wire, ¹, doubled into the form of a loop having parallel limbs
and wound in parallel strands around an insulating post, a², secured at its upper
end upon the lower end of the positive binding post y. The doubled, lower end of
the looped wire is secured to the post by means of a screw, a, screwed into a
countersink, a', in the post. The length of the shortcircuiting device and, con-
sequently, the degree of the resistance in the same may be varied by means of an
internally screwthreaded metallic sleeve, a³, having parallel threads cut in it to
engage the parallel limbs of the wire, so as to be moved up or down upon the coil
and thus shortcircuit it at any desired point. One terminal of the shortcircuiting
device is secured to the post by a screw a', which is in contact with the positive
binding post y, or one terminal of the series coil, and the other terminal of the
shortcircuiting device is secured against and in contact with the upper disc a,-
or the other terminal of the series coil,-by means of the lower binding screw
upon the positive binding post y, being insulated from the latter by the insulating
sleeve w².
Instead of employing the screwthreaded sleeve ³, a plain sleeve may be used, as
illustrated in Figure XVII, said sleeve having a set screw, 28, by means of which
the sleeve may be brought into metallic contact with different portions of the
wire c¹, effecting a short-cirenit at any desired point.
The degree of the resistance of the shortcircuiting device may be thus adjusted
by sliding the sleeve, up or down, according to whether the resistance is to be
decreased or increased, and this adjustable shortcircuiting coil will be perfectly
certain in its operation and will occupy but a small space in the lamp.
The lower end of the negative conductor rod is coupled,-by means of a
coupling sleeve, k,—to a rod j', which passes through a metallic sleeve, l, inserted
through the lower magnet disc b, but insulated from the same by means of a
suitable insulating sleeve. The lower end of said rod is secured in a disc, o, which
forms a part of the negative conductor within the lamp. A nut, m, fits upon the
rod, and said nut and rod form one of the supports for the disc o. A corre-
sponding rod, j, has its lower end secured in the disc o, passes up through a
metallic sleeve, l,-inserted through the lower magnet disc and insulated from the
same, and enters the lower end of the insulating post for the shortcircuiting
device. A nut, m³, upon this rod, above the lower magnet disc, serves to support
the disc o, similarly to the nut m. The rod 2, and its sleeve l, form,-together
with disc o and the rod j', sleeve 1, and rod j,-a part of the negative conductor
within the lamp.
The disc o has a downwardly projecting, screwthreaded neck, o², within which
an insulating sleeve or packing, o', is secured; said sleeve insulating the negative
disc from the positive carbon-containing tube t.
An oblong carbon supporting frame, r, is secured with a screwthreaded opening, r¹,
in its upper end to the screwthreaded neck o², and said frame has a screwthreaded
opening, 2, in its lower end, formed with an upwardly contracted, smooth portion, 7-³,
which terminates in a smooth and straight opening, r, of a diameter sufficient to
admit a carbon pencil of the greatest diameter capable of use in the lamp. A
lower, negative carbon holder, s, has a screwthreaded sleeve, s2, which may fit into
the lower screwthreaded opening of the carbon-supporting frame, and has a tube, s¹,
secured inside said sleeve; said tube having its upper end slightly bevelled and
having longitudinal slits in its upper portion, which admits of the tube being
contracted at its upper end to clamp the carbon, when the carbon holder is screwed
up into the lower opening of the carbon-supporting frame. An insulating handle, s,
is secured in the lower end of the carbon-holder by means of a rivet or pin, s,
inserted through the outer screwthreaded sleeve, the slit tube, and the end of the
handle. A cup-shaped pan, s, is fitted around the handle, to slide upon the same,
beneath the lower ends of the tube and sleeve, and is insulated from said tube and
sleeve by an insulating washer, s³. A spring, is coiled around the handle, and
bears against a shoulder upon the same with its lower end; and said spring is

page_text: enclosed by a sliding sleeve, 57, having an inward flange, s", at its upper end, which
rests upon the upper end of the spring, and bears against the pan.
The carbon-containing tube, t, has longitudinal slots, to, and two rings, to and t,
are suitably secured, one above the other, around the slotted portion of the tube.
Rings, having grooved peripheries to engage the carbon, and forming radial
clutches for the same, are hung upon supporting ring to, and have play in the
upper portions of the slots, and in the radial slots 2 and 3 of the armature.
Similar rings, t, forming the upper radial brushes, are hung,-to have play in the
lower portions of the slots,-upon the lower supporting ring t².
The disc o has an up-turned edge or flange, o³, around its central opening, and
the upper radial brush rings t' may have contact with said flange when the carbon
is removed.
A nut, u, is fitted upon the lower screwthreaded portion of the carbon-containing
tube t, and serves to rigidly clamp a casing, i, between the disc o and lower magnet
disc b, securely binding together the lamp structure on the central tube t.
A collar, v, is secured upon the lower end of the carbon-containing tube, and is
formed in its lower end with slots, v³, in which lower brush rings, v2, have play, said
rings being supported by a ring, vl, secured to the collar.
A casing, i, is clamped between the lower magnet disc b and the negative disc o,
said discs being drawn together by the nut, and asbestos rings or similar insulating
rings, p, are interposed between the under side of the lower magnet disc and the
upper edge of said casing, and between the upper side of the negative terminal
disc o and the lower edge of the casing, so as to form an airtight, insulating and
non-combustible packing for the chamber formed by the parts and inclosing the
armature and clutch device.
Insulating sleeves, n, are, secured upon the rods 1 and 2, serving as stops upon
which the armature may rest when lowered.
The edge of the upper opening in the globe, z, is clamped between the negative
disc o and the carbon frame r; insulating asbestos washers, p2 and p³, being inter-
posed, as well as a metallic washer, 7, between the carbon frame and the lower
washer p³, which serves to stiffen and support said washer. The upper portion of
the globe is thus hermetically closed. The edge of the pan bears against the lower
opening in the globe.
A collar, h, surrounds the lower end of the airtight chamber i, and rests upon the
top of the globe.
A collar, f, having openings formed in it, is secured upon the upper portion of
the airtight casing i, and has a flange, g, into which the lower end of a cylindrical
casing,, fits. The upper portion of said cylindrical casing is formed with air
holes, The upper end of the cylindrical casing fis contracted, and the lower
end of a tube, ƒ³, is secured to said contracted end. This tube 2 surrounds the
tube ; and a canopy, L, is secured to the upper end of said outer tube f2, and
surrounds the socket at the end of the inner tube L and the binding screws.
A positive carbon holding-tube, N2, see Figure 3, may be used for the positive
carbon, and said tube has a slightly contracted, long socket portion, N³, at its lower
end into which the carbon may be inserted; said socket portion having longitudinal
slits, N', which render the socket elastic. The upper end of the elastic socket is
formed with an inwardly projecting bead, N³, which serves as a stop for the end of
the carbon.
The positive carbon is lettered N, and the negative carbon is lettered N¹, in the
drawings.
If desired, the binding post connections at the upper end of the supporting tube L
and its surrounding tube, may be dispensed with, and the terminal conductors may
extend at the upper ends of the tubes L and 2, through the insulating plug, where
they may be suitably connected to the circuit wires.
The carbons are inserted into the lamp by unscrewing the lower carbon-holder
from the threaded opening in the carbon supporting frame. The removal of the
carbon holder and pan admits of the inside of the globe, as well as the carbon-

page_text: supporting frame and other parts within the globe being cleaned; the lower opening
of the globe affording ample room for the insertion of the hand and a cloth or other
cleaning means. The positive carbon may now be inserted through the opening in
the lower end of the carbon-supporting frame, the upper, contracted portion of the
said opening admitting a carbon of the greatest diameter capable of use in the lamp,
but preventing the insertion of a carbon of a greater diameter than what will enter
the radial brushes and clutches. The end of the carbon, as it passes up through
the lower brushes will push said brushes outward and will push them out of contact
with the up-turned rim of the negative terminal disc o, whereupon the carbon
pushes the clutch rings out, and is in position to be held by the same when the
current is turned on and the armature is drawn up. The negative carbon is placed
in the slit tube of the carbon-holder, and will be clamped when the latter is screwed
in place. As the negative carbon is pushed upward with the holder, the positive
carbon will be pushed up into its containing tube. The positive carbon will have
three supports, the clutch rings, the upper brush rings, and the lower brush
rings, and will always be well centred, irrespective of any minor irregularities in
the shape of the carbon. The brushes and clutches will, on account of their form,―
being shaped as rings, have a yielding contact with the carbon, such contact
being partly rolling and partly sliding. When the carbons are secured and the
current is turned on, the current will pass through the positive conductor and the
positive binding post, through the series coil, and to the upper magnet plate a,
from which it will pass into the carbon-containing tube to the positive carbon,
passing through the brushes, and clutch. From the positive carbon it passes
through the negative carbon, through the carbon-holder and carbon-supporting
frame to the negative terminal disc o, through said disc to the negative terminal
rods and, and to the negative conductor. The circuit being completed, the
series coil energises the magnets which attract the inovable armature. The latter
draws the clutch rings upward, and forces them against the carbon, as the bevelled
ends of the slots in the armature strike upward, the arc is formed, and the lamp is
in operation. The clutch rings in the radial slots c² will first engage the carbon
with a slight clutch, when the armature is drawn upward, on account of the longer
and less steep incline of the bevels of said slots and the clutch rings in the slots e³
will next engage the carbon with a stronger clutch, on account of the steeper
incline of the bevels of said slots so that the armature will gradually raise the
carbon and form the arc, even when it is suddenly drawn upward. When the
armature is lowered, a similar gradual release of the carbon, may take place, corre-
sponding to the gradual clutch of the carbon by the attracted arinature; the
clutches which are engaged by the steep inclines releasing the carbon, whereupon
the clutches engaged by the less steep inclines will allow the carbon to drop,
exerting, however, a braking influence upon the carbon, as they revolve upon the
inclines. When the positive carbon has been consumed so that its upper end falls
below the clutches and cannot be held by the same, the current will first pass freely
through the carbons, energising the magnets so that they draw the movable
armature upward in contact with the cut-out sleeves ; forming the circuit through
the armature, the cut-out sleeves and the negative terminal rods, and shortcircuiting
it from the electrodes. This cut-out will consequently be through the series coil
and by the series coil. In the event of the arc resistance becoming abnormally
great, the cut-out will be effected by the shunt coil and through the series coil;
the shunt coil overpowering or neutralizing the pull of the series coil and lifting the
armature into contact with the cut-out sleeves, l, when the whole current will again
pass through the series coil and relieve the shunt coil in holding the armature in
its raised position. If the current should be turned on while no positive carbon is
in the lamp, the primary contact will be through the lower brushes, which hang
down in contact with the upturned flange of the negative terminal disc o, and thus
complete the circuit through the series coil; causing the latter to raise the
armature and establish the cut-out through the sleeves 1, such cut-out being
effected by the series coil and through the series coil. In case the shunt should

page_text: become opencircuited by some accident, the series coil will lift the armature and
form the cut-out through the sleeve l, the cut-out being established by and through
the series coil. In the event of considerable resistance offered the current by the
two electrodes when in cut-out, the secondary cut-out having been effected by the
armature and sleeves 1,-the sliding cores might in some one particular position fail
to make good contact with the containing tubes. In such cases, the clutch rings
having been lifted out of contact with the supporting ring, it would leave the
armature to effect the cut-out independent of any electrical contact, except, such as
it might have with the core containing tubes. An imperfect contact then might
possibly produce heating or sparking; but I prevent such sparks and the damage.
which they might do, by establishing a permanent metallic contact through the
metallic pellets within the tubes.
The arc is, inclosed in a globe which is hermetically tight at its top and provideď
with a yielding closure at its bottom so that, as the carbons burn, they consume the
oxygen of the air, without, however, readily allowing such oxygen to be renewed
from the surrounding atmosphere. The yielding pan at the bottom of the globe
will allow the expanding air and gases within the globe to escape, and little air, only,.
will leak through the bottom opening,-such as may be due to alternating expansion
and contraction of the globe contents due to a varying circuit and consequent
change of temperature. There can be no upward draft in the globe on account of
the hermetic closure of the upper end of the same, and on account of the yielding
fit of the cup against the lower opening of the globe. Therefore, as the oxygen of
the air contained in the globe is consumed, the globe will in its place be filled with
carbon-binoxide CO₂, which in turn, will be reduced to CO, carbon-monoxide,
which gas remains stable. In this manner the oxidation of the carbon is greatly
retarded, effecting a considerable saving in the use of the carbons.
As the yielding closure, however, has no packed bearing against the lower edge
of the globe, but simply rests against said edge, atmospheric air may enter the arc-
enclosing chamber and equalize the internal and external pressure, if the internal
pressure becomes less than the external atmospheric pressure. Bursting of the
globe by excessive rarification within the same, and consequent excessive external
pressure, is thus avoided. The opening in the bottom of the arc-inclosing chamber
forms a hand-hole, through which the hand of the person trimming the lamp may
be inserted in the arc-inclosing chamber, for the purpose of cleaning said chamber
removing burnt out carbons, repairing the exposed parts in the chamber, or
inserting new carbons. Said bottom opening or hand-hole is, therefore, of sufficient
size to admit of the free and unobstructed outlet of gases formed within the
chamber, as said gases will bear against the large surface of the yielding pan, and
will escape sufficiently freely to prevent the possibility of explosion of the
carbon-monoxide mingled with air, by ignition of said mixture from the arc of
the lamp.
Other modes of applying the principle of my invention may be employed for
the mode herein explained. Change may therefore be made as regards the
mechanism thus disclosed, provided the principles of construction set forth are
employed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is.
1. The arrangement and combination of parts constituting my new or improved
arc lamp substantially as set forth.
2. In an electric arc lamp the means for securing limited inlet of air to and free
outlet of air from the arc chamber substantially as set forth.
3. The means for feeding the upper carbon and for striking the arc substantially
as set forth.
4. In an are lamp the means for securing the alignment of the carbons substan-
tially as set forth.

page_text: 5. The arrangement and combination of parts substantially as set forth with
reference to Figure 13.
6. In an arc lamp the form of magnet or magnets and armature substantially as
set forth.
7. The carbon holding tube substantially as set forth with reference to Figures
and 3ª.
8. In an arc lamp an arc inclosing chamber closed in an air-tight manner at
all parts save at the bottom and there provided with a device permitting of limited
inlet of air substantially as and for the purposes set forth.
...
1001