IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1882

page_text: LETTERS PATENT to Francis Murray Newton of Barton Grange near
Taunton in the County of Somerset for an Invention of IMPROVEMENTS
IN ELECTRIC ARC LAMPS.
PROVISIONAL SPECIFICATION left by the said Francis Murray Newton at
the Office of the Commissioners of Patents on the 27th July 1882.
FRANCIS MURRAY NEWTON of Barton Grange near Taunton in the County of
Somerset "IMPROVEMENTS IN ELECTRIC ARC LAMPS
"
My invention has for object improvements in electric arc lamps and has
reference to means or apparatus for retarding, modifying, damping or regulating
the motions of the electrodes For this purpose I employ a hollow cylinder whose
interior is divided into a number of compartments by radial partitions, each
compartment communicating with those next to it by means of one or more small
holes or passages. The cylinder is partly filled with mercury or other suitable
fluid, and is mounted on a horizontal axis around which it can turn. When the
cylinder is at rest the mercury or other fluid accumulates in the lower part or
compartments, but if the cylinder be partly rotated the mercury or other fluid will
be carried into such a position that its centre of gravity is no longer in the vertical
plane through which the axis passes, and consequently its weight will oppose the
rotation. If the rotating force be now arrested the mercury or other fluid will
Bow back through the holes or passages and its centre of gravity will again be
situated under the centre of suspension of the cylinder so that the next motion,
after a sufficient interval, will take place under the same conditions as the first.
This apparatus may be substituted for the usual train of wheelwork ending in a
fly in most forms of electric lamp, to control the motion of the electrodes and
prevent them moving sufficiently rapidly to cause the extinction of the light by
the carbons coming in contact.
In such a lamp a small drum may be mounted upon the axis of the cylinder and
one or both carbon holders be connected to it by a cord or cords paid out or
wound up by the motion of the cylinder. When applied to a lamp where the

page_text: carbon is lifted and released by a clamp or locking device, as in the lamp described
in the specification of Letters Patent No 4559 dated 19 October 1881, granted to
me, or as in the well known Brush lamp the carbon holder is connected to the
cylinder in such way that when released from the clamp or locking device it must
rotate the cylinder in falling. The cylinder offers little or no resistance to the
motion in the first instance but as the centre of gravity of the mercury is moved
this resistance increases rapidly and checks the motion of the electrode, so that the
clamp or locking device may seize it before it has time to fall into contact with the
lower carbon.
According to another modification of my invention a rack attached to each
carbon holder gears into a pinion on the axis of the cylinder the two pinions being
so proportioned as to compensate for the unequal consumption of the carbons.
The positive carbon being raised by a clamp or locking device rotates the cylinder
and depresses the negative carbon the cylinder damping the motions of both
the carbons. In some cases the clamp or locking device is dispensed with,
and the carbons which are one or both connected to the cylinder by cords and
pulleys or racks and pinions, are separated by causing the cylinder to rotate by
means of a rack and pinion or equivalent device actuated by means of a solenoid
or electro magnet to whose core or armature the rack is attached.
The rack is moved in one direction by a spring and in the other by the power of
the magnet or solenoid, and is so constructed that when the spring overcomes the
magnet or solenoid it is no longer in gear with the pinion, consequently the
cylinder is free to rotate until the mercury or other fluid and the carbons and
holders balance one another, or until the solenoid or magnet again brings the rack
into gear with the pinion.
Various forms of electric arc lamps may be constructed to operate on the principle
of my invention as above set forth.

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
26th January 1883.
FRANCIS MURRAY NEWTON of Barton Grange, near Taunton in the County of
Somerset, "IMPROVEMENTS IN ELECTRIC ARC LAMPS"
My invention has for object improvements in electric are lamps and has reference
to means or apparatus for retarding, modifying, damping or regulating the motions
of the electrodes. For this purpose I employ a hollow cylinder whose interior is
divided into a number of compartments by radial partitions, each compartment
communicating with those next to it by means of one or more small holes or
passages.
The cylinder is partly filled with mercury or other suitable fluid and is mounted
on a horizontal axis which can turn freely with it.
When the cylinder is at rest the mercury or other fluid accumulates in the lower
part or compartments, but if the cylinder be partly rotated the mercury or other
fluid will be carried into such a position that its centre of gravity is no longer in
the vertical plane through with the axis passes and consequently its weight will
oppose the rotation.
If the rotating force be now arrested the mercury or other
fluid will flow back through the holes or passages and its centre of gravity will
again be situated under the centre of suspension of the cylinder so that the next
motion, after a sufficient interval will take place under the same conditions as the
first.
This apparatus may be substituted for the usual train of wheelwork ending in &
fly in most forms of electric lamps, to control the motion of the electrodes and
prevent them moving sufficiently rapidly to cause the extinction of the light by
the carbons coming in contact. In such a lamp a small drum may be mounted
upon the axis of the cylinder and one or both carbon holders be connected to it by
a cord or cords paid out or wound up by the motion of the cylinder.
When applied to a lamp where the carbon is lifted and released by a clamp or
locking device as in the lamp described in the specification of Letters Patent
No. 4559 dated 19 October 1881, granted to me, or as in the well known Brush
lamp the carbon holder is connected to the cylinder in such a way that when
released from the clamp or locking device it must rotate the cylinder in falling.
The cylinder offers little or no resistance to the motion in the first instance but
as the centre of gravity of the mercury is moved this resistance increases rapidley
and checks the motion of the electrode so that the clamp or locking device may
seize it before it has time to fall into contact with the lower carbon.
According to another modification of my invention a rack attached to each
carbon holder gears into a pinion on the axis of the cylinder and firmly attached
thereto, the two pinions being so proportioned as to compensate for the unequal
consumption of the carbons.
The positive carbon being raised by a clamp or locking device rotates the cylinder
and depresses the negative carbon the cylinder damping the motions of both the
carbons. In some cases the clamp or locking device is dispensed with, and the
carbons which are one or both connected to the cylinder by cords and pulleys or
racks and pinions, are separated by causing the cylinder to rotate by means of a
rack and pinion or equivalent device actuated by means of a solenoid or electro-
magnet to whose core or armature the rack is attached.
The rack is moved in one direction by a spring and in the other by an electro
magnet or solenoid, and is so constructed that when the spring overcomes the

page_text: electro maget or solenoid it is no longer in gear with the pinion, consequently the
cylinder is free to rotate until the carbons come in contact with one another, or
until the solenoid or magnet again brings the rack into gear with the pinion.
Various forms of electric arc lamps may be constructed to operate on the principle
of my invention as above set set forth.
Referring to the accompanying two sheets of drawings Fig. 1 is a vertical central
section of an apparatus according to my invention for retarding, modifying, damping
or regulating the motions of one or both of the electrodes of an electric arc lamp;
Fig. 2 is an elevation of the same with the cover removed and Fig. 3 is a section in
line a b Fig. 2.
The apparatus consists of a cylinder A whose interior is divided into a number
of compartments B B by radial partitions C C.
Each compartment communicates with those next to it by means of the small
passages a a. This cylinder is partly filled with mercury or other suitable fluid
and is mounted on a horizontal axis which can turn round freely. When the
cylinder is at rest the mercury or other fluid accumulates in the lower compartment
or compartments, but if the cylinder be partly rotated the 'mercury or other fluid
will be displaced into such a position that its centre of gravity is no longer in the
vertical plane through which the axis passes, and consequently its weight will
oppose the motion.
The greater the angular distance through which the cylinder is rotated the
greater will be the couple tending to bring the cylinder to rest. By suitably
proportioning the weight of the mercury and the radius through which it acts to
the couple tending to produce rotation of the cylinder the angular motion that will
take place before equilibrium is established if the rotating force be suddenly
applied, can be adjusted to any determined amount. As soon as the mercury or
other fluid is displaced by the partial rotation of the cylinder it begins to flow
through one or more of the passages a a in the direction opposite to that in which
the cylinder is rotated until it has reached its original position with respect to the
vertical line through the axis of the cylinder.
Fig. 4 is a vertical section and Fig. 5 a plan, partly in section of one form of
electric lamp, according to my invention in which the motion of one of the electrodes
is modified or regulated by an apparatus such as described with reference to Figs. 1,
2 and 3.
The upper carbon D is carried by a holder E which depends from a cord F which
is wound on a drum G fixed on a horizontal spindle H. Upon the same spindle is
keyed the controlling cylinder A, provided with compartments B B communicating
by passages a a as already explained. The lower carbon is fixed while the upper
one passes through the core of a coil or solenoid I and is held by a clipping device
consisting of a ball or roller and inclined plane as described in the specification
of former Letters Patent No. 4559 of A.D. 1881.
The bush G' is attached to the movable core 1¹ of the solenoid I in the lamp
circuit and follows its motions. It also carries the piston of a dash pot X by
which its motions are modified.
Within the guide G₁ is a roller or sphere O confined within a conical or angular
slot or gate, against which it presses at one side, whilst its other side is in contact
with the upper carbon.
The weight of the roller or sphere O tends to force it down the slot or gate and
to jamb it against the electrode. It is advantageous that the sphere or roller
should be of non-conducting material.
H¹ is an arm or finger fixed to the frame of the lamp, and so situated that its
end enters the slot or gate immediately below the sphere or roller to such an extent,
that when the core of the solenoid descends below the point at which it stands
under the influence of a normal current the roller or sphere rests upon the point of
the finger and is forced up the slot or gate and out of frictional contact with the
electrode.
The current enters at the terminal P circulates through the coil I, passes down

page_text: the upper carbon, across the arc, through the lower carbon, and up the rod D¹ to
the terminal P¹. As soon as the circuit is completed the core of the solenoid is
raised and as soon as it has moved sufficiently far to carry the ball or roller away
from the finger H₁ the carbon or electrode is gripped and is carried upwards
establishing the arc.
As the carbons consume, the core I' descends until the ball or roller O is forced by
the finger up the incline, and the carbon depends from the cord. The weight of
the carbon and its holder immediately rotates the drum G and with it the con-
trolling apparatus and thus the carbon descends a certain amount, which will
depend upon the adjustment of the apparatus. If the descent be sufficient to
reduce the arc to its normal length the locking device will again hold it, but if
it be not the carbon will continue to descend slowly at a velocity corresponding to
the speed at which the mercury or other fluid flows through the passages a until
the locking device comes into action.
Fig. 6 is a vertical section and Fig. 7 a plan, partly in section, of another form
of lamp according to my invention in which the motions of both carbons are
modified or regulated by an apparatus such as described with reference to Figs. 1,
2 and 3. Upon each carbon holder K and K' there are cut rack teeth which gear
each into a pinion upon the horizontal shaft. One of these pinions L is about
double the diameter of the other to compensate for the unequal consumption of the
carbons, and is insulated from the shaft H.
Upon the same shaft is fixed the controlling apparatus A whose action is similar
to that of the apparatus described with reference to the preceding Figures 4 and 5
except that it operates upon both electrodes instead of one only and also controls
or modifies the action of the solenoid in separating the carbons.
The locking device is also similar to that shewn in Fig. 4 except that no dash
pot is shewn to retard its upward motion, this being done by the controlling
wheel A. The lamp case M has a hinged door the whole length of one side for
access to the interior for cleaning etc.
In
Figa 8 and 9 are two sections at right angles to each other of another form of
lamp according to my invention and Fig. 10 is a sectional plan of the same.
this lamp the motions of both carbons are modified or controlled by an apparatus
similar to that described with reference to Figs. 1, 2 and 3. The two carbon
holders have racks attached to or formed upon them gearing into opposite sides of
two unequal sized pinions B and C upon the shaft H. The pinion B is insulated
from the shaft, and the shaft is insulated from the lamp case by being carried on
'ebonite female centres or other suitable device.
Upon the same shaft, and firmly fixed thereto are controlling apparatus A and
the friction or brake wheel G. Against this latter there bears a shoe or brake
block, shewn in the drawings as a tube of india rubber I surrounding an iron rod
or core H¹ whose upper and lower ends are more or less inserted respectively into
the two solenoids K and J.
The weight of this core is supported by a spring L which is sufficiently powerful
to keep it, when no other influence is in operation, in such a position that the
friction of the shoe or block I upon the periphery of the friction wheel is not
sufficient to prevent the latter from rotating under the action of the positive carbon
holder and rack.
The two solenoids are wound differentially and their actions upon their common
core are antagonistic as is well understood, the lower one J being of small resistance
and placed in the lamp circuit, while the upper one K is of large resistance and
situated in a shunt circuit around the arc. When the lamp is started the current
entering at + passes mainly round the solenoid J and thence through the rollers
PP to the upper carbon holder D. From this it flows across the arc and returns
by the negative carbon holder E and the rollers N to the negative terminal at
The effect of this is that the solenoid J draws down the core H¹, bringing the india
rubber tube I into firmer contact with the periphery of the brake wheel G, so that
the two form a kind of frictional rack and pinion.

page_text: The motion of the tube I causes the wheel to rotate in the direction of the arrow
and at the same time turns the pinions B and C raising the upper carbon holder D
and lowering the lower one E, thus establishing the arc, the rapidity of the action
being modified or regulated by the action of the controlling apparatus as already
explained with reference to Figures 1, 2, and 3.
As the carbon consumes the power of the upper solenoid increases and that of
the lower diminshes as is well understood, the result being that the core H³ rises
until the friction wheel is released from the brake I and the carbons approach
each other under the action of gravity a certain distance regulated by the
controlling apparatus.
In some cases where extreme steadiness of action is essential the motions of the
core Hare also controlled by causing it to rotate a controlling apparatus similar to
A by means of the friction of the tube I against it or against a friction wheel
attached to its axis this wheel being placed on the side of I most distant from the
brake wheel G or in other convenient position.
It is evident that this arrangement of the lamp can be altered without departing
from the principle of my invention, as for instance a rack with its lower portion cut
away to clear the wheel G may be substituted for the tube I, G in this case being
a pinion as shewn in Fig. 11.
Also in place of the carbon holders D and E the carbons may either be raised
and lowered by cords and pulleys or the upper carbon or its holder may be geared
to the axis of the controlling apparatus A by grooved friction rollers; the lower
carbon being fixed or drawn up through a suitable guide by means of a cord or two
cords wound round the pinion axis and passing through hollow rods to the lower
carbon holder.
Having thus described 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 therefor claim as the invention secured to me by the Letters
Patent herein before first in part recited is:-
In an electric lamp the use for retarding, modifying, damping or regulating the
motion of one or more of the electrodes of apparatus containing fluid such as
mercury and caused to rotate when change occurs in the distance apart of the
electrodes, the arrangement being such that when the apparatus is so rotated the
said fluid opposes to the motion an increasing resistance, but when the apparatus is
at rest the said fluid tends to take up a position of equilibrium substantially as
described.
In Witness whereof I the said Francis Murray Newton have hereunto set my
hand and seal this twenty third day of January in the year of our Lord,
one thousand eight hundred and eighty three.
FRANCIS MURRAY NEWTON (L.S.)