MENTS IN ELECTRIC ARC LAMPS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Francis Murray Newton at
the Office of the Commissioners of Patents on the 31st March 1883.
FRANCIS MURRAY NEWTON of Pakenham Place, Belfast, Ireland " IMPROVE-
MENTS IN ELECTRIC ARC LAMPS
""
My invention of improvements in electric arc lamps relates to means for
automatically feeding the carbons to maintain the electric arc.
For this purpose according to my invention the upper carbon or electrode is, or
both carbons or electrodes are fed forward by an arrangement as follows:-
An iron tube of a diameter considerably larger than the carbon or electrode is
surrounded with à coil of insulated wire in such a way as to form an electro
magnet. At one end of this tube there is situated a short piece of tube similar to
the first also of iron, and held at a short distance from the end of the first tube by
a spring.
The outer end of this tube is supported by a sheath or bracket of suitable
metal such as brass which by its contact with the first mentioned tube will complete
the circuit through the insulated wire coil which forms a shunt of high resistance
to the arc, or a shunt circuit which is only completed when the arc exceeds its
normal length. In either case the shunt current when the circuit is complete, is
made to flow as follows; starting from the positive terminal of the lamp it flows
round the insulated wire coil, thence through a spring to the short piece of tube,
aud from it through the sheath or bracket to the negative terminal.
flowing thus will evidently cause the short tube to oscillate rapidly up and down
between the first tube and the sheath or bracket, for every time it rises towards
the first tube under the magnetic attraction it will break contact with the sheath
and will be instantly forced down by the spring; the circuit being again completed
the vibrating action will continue as long as the current is strong enough to raise
the short tube out of contact with the sheath or bracket. In cases where the
[Prina 11
A current

page_text: insulated coil is a high resistance shunt to the arc this effect will take place when-
ever the arc becomes too long, and will continue till it is again shortened to its
normal length.
The two tubes are each provided with a number of metallic arms, fingers or
feelers converging towards the axial line, and inclined slightly in the direction in
which the carbon is to travel. For this purpose ordinary "card wire" such as is
used for file cleaning is suitable the length of the metallic arms, fingers or feelers
being so arranged that a carbon or electrode of the desired diameter will when
pushed down the tubes, be embraced, and its weight supported by their friction.
Now it is evident that if one of the tubes be fixed while the other moves up
and down alternately the carbon will be fed downwards by a step by step move-
ment dependent on the length and rapidity of the strokes,-for whereas the carbon
will slide freely in the direction of the inclination of the fibres, it cannot be
moved up against them, without using considerable force. When one tube riscs
its wires will slide over the carbon which will be prevented from rising by those
of the other tube. When the movable tube descends it will carry the carbon
with it, the wires of the stationary tube allowing it to slide through then freely.
Such an arrangement will work equally well in any position and the wires from
their number and even pressure will form an excellent contact between the carbon
and the working parts of the lamp. The arc is struck in the first instance either
by lowering the negative carbon by means of an electro magnet or solenoid, or
the whole of the previously described feed arrangement may be raised by
similar means.
It is evident that lamps according to this invention may be variously modified
without departure from the essential principles of the invention. For instance
the movable tube might be the core of a solenoid, and the fixed tube be replaced
by any appliance that would carry the fingers, arms or feelers, or the two sets of
fingers, arms or feelers might be moved by an electro-magnet and its armature
through the intermediary of levers or other suitable means.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis Murray Newton in the Great Seal Patent Office on the
28th September 1883.
FRANCIS MURRAY NEWTON of Pakenham Place, Belfast, Ireland IMPROVE-
MENTS IN ELECTRIC ARC LAMPS.
My invention of improvements in electric arc lamps relates to means for
automatically feeding the carbons to maintain the electric arc.
For this purpose according to my invention the upper carbon or electrode is or
both carbons or electrodes are fed forward by an arrangement as follows:-
An iron tube of a diameter considerably larger than the carbon or electrode is
surrounded with a coil of insulated wire in such a way as to form an electro-
magnet. At one end of this tube there is situated a short piece of tube similar to
the first also of iron and held at a short distance from the end of the first tube by
a spring.
The outer end of this tube is supported by a sheath or bracket of suitable metal
such as brass which by its contact with the first mentioned tube will complete the
circuit through the insulated wire coil which forms a shunt of high resistance to
the arc or a shunt circuit which is only completed when the arc exceeds its normal
length. In either case the shunt current when the circuit is complete is made to
flow as follows:-
:-
८
Starting from the positive terminal of the lamp it flows round the insulated wire
coil, thence through a spring to the short piece of tube and from it through the
sheath or bracket to the negative terminal.
A current flowing thus will evidently cause the short tube to oscillate rapidly up
and down between the first tube and the sheath or bracket, for every time it rises
towards the first tube under the magnetic attraction it will break contact with the
sheath and will be instantly forced down by the spring; the circuit being again
completed the vibrating action will continue as long as the current is strong enough
to raise the short tube out of contact with the sheath or bracket. In cases where
the insulated coil is a high resistance shunt to the arc this effect will take place
whenever the arc becomes too long, and will continue till it is again shortened to
its normal length.
The two tubes are each provided with a number of metallic arms, fingers or
feelers converging towards the axial line, and inclined slightly in the direction in
which the carbon is to travel. For this purpose ordinary "card wire" such as is
used for file cleaning is suitable, the length of the metallic arms, fingers or feelers
being so arranged that a carbon or electrode of the desired diameter will when
pushed down the tubes be embraced, and its weight supported by their friction.
Now it is evident that if one of the tubes be fixed while the other moves up and
down alternately the carbon will be fed downwards by a step by step movement
dependent on the length and rapidity of the strokes,-for whereas the carbon will
slide freely in the direction of the inclination of the fibres, it cannot be moved
up against them, without using considerable force. When one tube rises its wires
will slide over the carbon which will be prevented from rising by those of the
other tube. When the movable tube descends it will carry the carbon with it,
the wires of the stationary tube allowing it to slide through them freely. Such
an arrangement will work equally well in any position, and the wires from their
number and even pressure will form an excellent contact between the carbon and
the working parts of the lamp. The arc is struck in the first instance either by

page_text: lowering the negative carbon by means of an electro magnet or solenoid, or the whole
of the previously described feed arrangement may be raised by similar means.
It is evident that lamps according to this invention may be variously modified
without departure from the essential principles of the invention. For instance
the movable tube might be the core of a solenoid, and the fixed tube be replaced
by any appliance that would carry the fingers, arms or feelers, or the two sets of
fingers, arms, or feelers might be moved by an electro-magnet and its armature
through the intermediary of levers or other suitable means.
Fig 1 is an elevation, partly in section, of an electric arc lamp according to my
invention. A is an iron tube wound with a fine coil of insulated wire B, which is
When it is
so arranged as to form a shunt of high resistance around the arc.
traversed by a current the tube A. becomes an electromagnet. Below the tube A,
and in the same axial line is a second tube C acting as an armature to the first.
It is normally supported by the sheath or bracket E and is held away from the
tube or magnet A by a helical spring D. Within the tube C there is screwed or
otherwise fixed another tube C' of non magnetic material such as brass; it fits
loosely within the electromagnet A and serves as guide for the armature C.
Within the tube A and likewise within the tube C there are fixed a number of
elastic metallic fingers or feelers F converging towards the axial line of the tubes,
and inclined slightly in the direction in which the carbon is to travel. They are
fixed in backing which is bent into a cylindrical form, and secured from endwise
motion in the tubes by collars or abutments, the upper feelers being held between
the cap H and the internal collar G', and the lower feelers between the tube C¹ and
the collar or contraction G. The arc is struck by the electromagnet O which
draws down the negative carbon compressing a small spring within the body of
the electro magnet, which, when the lamp is extinguished by cutting off the
current by any means, serves to raise the lower carbon through a distance greater
than the length of the arc, and therefore into contact with the upper carbon, so
that the lamp can be relit by turning on the current without readjusting the
carbons. One end of the coil of this magnet is in connection with the framing,
and the other is connected by a wire to the right band standard P, which is
insulated at the bottom from the framing by the nonconducting washers R, R',
and at the top carries the negative terminal.
The current enters the lamp at the positive terminal I, and proceeds from thence
along a permanent conductor to the tube A. From that it is conveyed by the
feelers F, and also, when found necessary, as in lamps wherein large currents are
employed, by the contact springs K. K, to the carbon or electrode L down which
it flows through the arc M to the negative carbon N, and thence through the
electromagnet to the rod P and negative terminal Q. The shunt circuit
branches off from the main circuit through the lower feelers F in the small piece
of tube C, and thence through the sheath E to the shunt coil Band from this to
the negative terminal Q. T T is a piece of wood or insulating material to which
the various parts of the lamp are attached. It is provided with a recess T¹ T" to
hold a light cover of thin sheet metal or other suitable material.
When the current is first turned on the carbons are in contact and the arc is
instantly struck by the magnet O. The carbons then gradually consume until the
arc grows beyond the length for which the lamp is adjusted, a gradually increasing
amount of current passing through the shunt coil until the electro magnet A over-
powers the spring D and attracts the armature C, the feelers F sliding over the
carbon. Immediately C rises the shunt circuit is broken between C and E and the
magnet A loses its power. The armature C then falls back under the influence
of gravity and of the spring D, carrying with it the carbon or electrode L, as the
feelers F will not slide over it in this direction, but obtain a frictional hold upon it
after the manner of toggle levers. This alternate rising and falling action continues
until the arc is reduced to its normal resistance, the carbon being drawn at each
downward motion through the upper set of feelers F, which prevent its being
carried upwards by the friction of the lower set,

page_text: my invention, the cover being supposed to be removed.
Fig 3 is a plan of the same.
Fig 4 is a sectional view of the device A, and
Fig 5 a plan of the same.
A is a vibrating device hinged or pivotted by the arm B to the standard C and
surrounding the carbon or electrode. Its interior is provided with fingers, feelers
or cains here shewn as elastic wires A' fixed in a foundation A² of metal, leather,
or india-rubber after the manner of wire card filletting. The points of these wires
normally enclose a cylindrical space rather less in diameter than the carbon D (or
holder) they are intended to grasp and hence when the carbon D (or holder) is
passed through them from above they are deflected, and thus form a series of toggle
like arms which oppose but a very slight resistance to the motion of the device A
(relatively to the carbon D) in one direction, but take a firm grip on the carbon
when the device A is moved in the other direction. E is a stationary device,
similar in construction to the vibrating device A. It obtains sufficient frictional
hold of the carbon D to maintain it against motion in the direction of the arc in
opposition to the action of gravity, jarring and the like,-but cannot retain it
against the additional impulse of the forward stroke of the vibrating device A. In
the opposite direction the device E obtains a firm grasp, as already explained with
regard to A. The diameter of the space enclosed by the points of the elastic fingers
both in A and E can be varied by screws which draw the sides of the case more
tightly together. The vibration of the device A is effected by the electromagnet G
which is situated in a shunt circuit around the arc in a manner which is well under-
stood. This magnet attracts an armature F connected to the vibrating device A,
but so long as the arc does not exceed its normal length the attraction is not
sufficient to overcome the power of the spring H. When, however, the length of
the are increases beyond the determined amount the attraction of the magnet
overcomes the spring and the armature with the device A is drawn down.
Immediately it has moved, the shunt circuit is broken where it crosses the contact
points at I, the magnet loses its power and the armature rises carrying the
device A with it into position ready for the next stroke, which occurs immediately
the contact pieces touch, unless the previous stroke has reduced the arc to the
desired length. If the lamp be required to burn in parallel are with other lamps,
or to be actuated by a current of constant electro motive force as with a storage
battery, the spring H is replaced by an electro magnet whose coils are in the main
circuit acting upon an armature fixed to the arm B, in this case the attraction of
the electro magnet G remains constant, but that of H varies with the amount of
current passing, when this diminishes through lengthening of the arc to a certain
point G sets up the necessary vibration in the device A to feed the carbon forward.
The course of the current through the lamp is as follows.-it enters at the terminal
and passes by the wire L.to the casing M, thence through the contact springs N N
to the upper carbon across the arc to the negative carbon and from its holder to
the core of the electro magnet P. One end of the coil surrounding P is connected
to the core, and hence it receives the current which is conveyed from the other
end of the core by a wire to the rod Q and thence by a second wire to the
other terminal R. The shunt circuit passes up, through the positive carbon, from
the contact springs N N to the device A, thence to the pivotted arm B and
through the contact pieces I¹ to the column J, and through the electromagnet G
to the terminal R.
The arc is struck by the electro magnet P which attracts an armature T at the
bottom of the ball and socket jointed carbon holder U.
The motion of the armature which is guided by the non magnetic pin V is
opposed by the spring W which can be adjusted by the screwed plug X. Similarly
the resistance offered to the attraction of the magnet G can be varied by the
screw Y.
Z is a deflecting cup to shield the lamp from the rising gases, and M is a dust

page_text: cap or casing to protect the fixed device E. The springs N N which convey the
circuit to the upper carbon may in some cases be made to perform the office of the
fixed device E as well as their own.
Having thus explained the nature of the said invention and the manner in
which it is to be performed I would have it understood that what I consider to
be novel and original and therefore claim as the invention secured to me by the
Letters Patent herein before in part recited is :-
1. The use in an electric arc lamp of a vibrating device set in vibratory motion
by a make and break apparatus when the arc exceeds its normal length and which
'continues in vibratory motion until it has restored or reduced the arc again to its
normal length, such device grasping the carbon or its holder during one part of
its vibration feeding it forward, and sliding over it during the opposite part of its
vibration substantially as described.
2. The use in an electric are lamp of a vibrating device set in vibratory motion
by a make and break apparatus when the arc exceeds its normal length, and which
continues in vibratory motion until it has restored or reduced the arc again to its
normal length, said device being formed of clastic fingers or feelers, which grasp
the carbon or its holder during one part of the vibration or reciprocation, feeding
it forward, and slide over it during the opposite or reverse part of its vibration or
reciprocation substantially as described.
3. The use in an electric arc lamp of a vibrating device formed with elastic
wires fixed in a foundation of metal, leather, india rubber or other suitable material
after the manner of card filletting, which wires grasp the carbon or its holder when
moving in one direction, feeding it forward, and slide over it when moving in the
opposite direction, substantially as described.
4. In an electric arc lamp the use in combination of a vibrating device set in
vibratory motion by a make and break apparatus when the arc exceeds its normal
length and which continues in vibratory motion until it has restored or reduced
the arc again to its normal length, and which grasps the carbon or its holder
during one part of its vibration, feeding it forward, and slides over it during the
opposite part of its vibration, and a fixed device which opposes the backward
motion of the carbon but permits of its forward motion under the influence of the
vibrating device substantially as described.
5. An electric arc lamp constructed arranged and operating substantially as
described with reference to Fig 1 of the drawings.
6. An electric arc lamp constructed arranged and operating substantially as
described with reference to Figs 2 and 3 of the drawings."
In witness whereof I the said Francis Murray Newton have hereunto set my
hand and seal this twenty fifth day of September in the year of Our Lord one
thousand eight hundred and eighty three.
FM NEWTON (10)