IMPROVEMENTS IN ELECTRIC LIGHTING APPARATUS
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN ELECTRIC LIGHTING APPARATUS." A communication
from abroad by Alfred G. Holcombe, of Danielsonville, Connecticut, United
States of America Electrician
PROVISIONAL SPECIFICATION left by the said William. Robert Lake at
the Office of the Commissioners of Patents on the 29th March 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent.
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC LIGHTING
APPARATUS." [A communication from abroad by Alfred G. Holcombe, of
Danielsonville, Connecticut, United States of America, Electrician.]
This Invention has for its chief object to provide means for regulating and'
maintaining the proper arc-distance between the points of carbon rods or other
electrodes of electric lighting-apparatus, when an alternating or to and fro current
is employed to produce the electric arc. The said Invention comprises the
application of the reciprocal action produced between two plain solenoids, one
placed within the other, when an electric current is caused to pass through them,
said solenoids being free of any iron or other magnetic material, so that the sudden
changes of direction of the to and fro current which occur simultaneously in the
two solenoids, and in like manner as they are connected together, cause the
solenoids to mutually act on one as would a continuous current, said action being
opposed by a retractile force.
The coils may be connected so that the current passes through their adjacent
ends either in the same or opposite direction, thus utilizing the attractive or
repulsive force of them as may be desired to regulate and maintain the proper arc
distance between the ends of the carbon rods.
In carrying this Invention into practice I use a friction-brake operated by the
moving coil or solenoid for arresting the downward movement of the
carbon;
upper

page_text: and it also acts to draw the carbons apart and maintain the proper arc distance
between them. I also use an automatic switch so arranged and constructed as to
cause the current always to pass through the coils or solenoids, and an extra
resistance about equal to the resistance of the are when either or both of the carbons
are entirely consumed; also an improved form of platinum fingers, against which
the burning ends of the carbon are caused to press by means of a weight or spring,
or other suitable device, whereby the sudden movements of the carbons caused by
the sudden breaking away of the parts immediately under the fingers are prevented,
These fingers, as heretofore made, bear only at the commencement of the taper ends
of the carbons, allowing them to burn away beyond these parts.
This Invention also embraces an improvement in electric lighting apparatus, in
which the electric current is divided into two circuits, in each of which is an
electric regulating device. The one is for operating the feed mechanism to allow
the upper carbon to feed down on to the lower carbon. This circuit is always in
the main line whatever number of lamps are in single circuit, so that when any one
of the lamps is inoperative the continuity of the main line is unbroken. The
second circuit of the lamp comprises the carbons, and an electric regulating
arrangement adapted to depress the lower carbon to form the arc between the ends
of the carbons. The proportional resistances of the two circuits are such, that
when the arc adapted to the current is formed, the current that passes through the
feed regulating device is insufficient to release the upper carbon; but the slightest
increase in the length of the arc, which means an increase in the resistance of the
circuit through which it is supplied, changes the ratio of the conductivity of the
two circuits by raising that of the feed circuit; consequently a greater proportion
of the current passes through it, and actuates the electric device, to allow the upper
carbon to gradually fall until the arc is again of normal length and resistance.
In place of one or both of the solenoid regulating devices, a device consisting of
two flat coils of insulated wire or copper ribbon may be used, arranged parallel to
one another in close proximity, the one coil being held stationary, and the other
being free to move to govern the feed or arc producing mechanisms; said flat coils
mutually attract each other when the electric current is caused to pass through
them in the same direction, and mutually repel when the current flows in opposite
directions.
When it is desired to use a continuous current with the divided circuit lamp,
then ordinary axial magnets or electro-magnets with fixed iron cores and movable
armatures may be used if desired to regulate the downward movement of the
upper carbon and the formation of the are by depressing the lower carbon.
This Invention further embraces a means for indicating when the carbons are
consumed and require renewal, which consists in incorporating with the carbon of
the rods at their ends by which they are held in the sockets suitable metals or
chemical compositions, or in encasing their said ends with the same, so that as soon
as the electric arc reaches these parts of the carbon rods so prepared, a coloured
light is produced, which if desired may be of one color for the upper carbon, and of
another color for the lower carbon. I also propose to fit the cores of axial magnets
to act as loosely fitted pistons in cylinders, in which is confined air or any suitable
fluid, so that when the cores are acted upon by the electric current flowing through
the surrounding coils, their movement is impeded by the air or other fluid
gradually flowing up between the core and the cylinder; or the cylinder provided
with a loosely fitted piston may be placed immediately under the magnet, and the
piston connected directly to the moving core.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the
16th September 1881.
.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC-LIGHTING
APPARATUS." A communication from abroad by Alfred G. Holcombe, of
Danielsonville, Connecticut, United States of America, Electrician..
This Invention relates to improvements in electric lighting apparatus as herein-
after described and illustrated in the accompanying Drawing, in which
Figure 1 is a side elevation partly in section of an electric lighting apparatus,
in which the current is divided to actuate independent feeding and arc-forming
devices.
Figure 2 is a vertical section of the same through the line y, y.
Figure 3 is a transverse section through the line x, x.
Figure 4 is a transverse section through the line <, z.
Figure 5 is a side elevation of a single circuit lamp with solenoid regulator
shewing the upper part in section, and
Figure 6 is a plan or top view of the regulating device of the same.
In Figure 1 the two carbon rods a and a¹ are held in the sockets 6 and b¹.
These sockets have taper holes, thereby forming guides and bearings for the ends
of carbons of different sizes, and they are provided each with three set screws b³, b³,
radially arranged, so that the carbons are firmly gripped by them, and by their
adjustment the free ends of the carbon rods may be set directly opposite each
other. The socket 6 of the upper carbon is secured to the lower end of the
vertically sliding rod c, provided with the rack c¹, into which meshes the pinion c²
fixed on the shaft of the gear wheel d; and into the gear wheel d meshes the
pinion d¹ fixed on the shaft of the brake wheel e. The periphery of this brake
wheel is smooth, and on it bears the shoe e¹ carried by the lever f pivoted at f¹ to
the bottom-plate g..
The outer end of the lever fis formed into a ring in which is placed a coil of copper
ribbon f, with a ribbon of paper or other suitable insulating material wound between
its successive turns and on the outside of the coiled copper ribbon. A similar
coil of insulated copper is secured to the plate g immediately below the coil f².
The outer end of the fixed flat coil f³ is connected to the binding post j by which
the current enters the lamp, and its inner end is connected to the outer end of the
coil f carried by the lever f; the inner end of this coil f2 is connected to the
binding post, which is secured to the plate g of the frame, and by which
the current leaves the lamp. The connecting wires pass along the lever f, as
shewn.
The spring h, fastened to the lever f near its outer end, and provided with the
adjusting nut h¹, causes the shoe e¹ to bear on the wheel e with sufficient pressure
to prevent the falling downward of the rod c'and carbon a.
The electric current passing through the flat coils f and f³ being parallel and
moving in the same direction, the upper coil f² is attracted towards the lower
one f³, and takes off the pressure of the shoe e' from the brake wheel e, and so
allows the rod c to move downward. In this class of feeding device to ensure a
steady and uniform movement of the carbon rod I have found it essential that the
bearing surface of the shoe on the periphery of the brake-wheel should be limited
in extent, a dull knife edge being all that is required; and it is also essential that.
the movement of the brake lever should be limited to what is necessary to just
free the brake wheel of the shoe, so that the electrical actuating device may

page_text: instantaneously actuate the brake in response to the smallest variations of the
current passing through it; whereas if the shoe be allowed to move away from the
wheel any great distance the carbon rod will fall farther than is necessary to bring
the arc to its normal resistance before the shoe can be brought to bear on the wheel
to overcome the momentum of the carbon. To limit this movement of the shoe e',
I provide the adjustable stop or set screw e³ against the end of which the bottom
of the lever f comes in contact when the shoe e¹ is just clear of the brake-
wheel e.
The binding post j¹ and plate g are on the non conducting plate k; at the ends
of the latter are secured the tubes and P, which are joined at their lower ends by
the bar 12, in the centre of which is secured the arc producing device consisting of
the outside solenoid m placed in a case, and the inside solenoid m¹ on the upper
end of which is secured the lower carbon bolding socket 6¹. The inside solenoid m³,
socket b¹, and carbon a¹ are upheld by the spring n, which forms the connections
between the two solenoids m, m³, being connected to one end of each of them;
the other end of the inside solenoid is attached to the socket b¹. The binding
post is connected to the other end of the solenoid m by the insulated conductor o
which passes down the inside of the tube and under the bar . The arrows
marked 1 indicate the direction of the arc producing current, and the arrows
marked 2 indicate the direction of the current in the upper carbon feeding circuit,
and both circuits leave the lamp by the binding post ².
The spring g of the upper plate of the frame bears against the rod
a perfect electrical connection between the frame and the rod c.
C, and insures
From the foregoing description it will be seen that the electric current from the
generator are secured to the binding post j, and jis divided and passes through
two independent circuits 1 and 2. The circuit 2 includes the two parallel flat
coils and f³, and is always closed; and the other circuit 1 includes the
solenoids m, m¹, and the carbons a, a¹, and is closed only when the carbons are
in contact, or when the arc is produced between their ends. The whole of the
current first passes through the two flat coils f2 and f³, thus instantly releasing
the brake wheel e, and allowing the rod c and carbon a to fall until arrested by
the carbon a'; the circuit, including the solenoids m, m³, and the carbons a, a²,
is thereby closed, and the greater part of the current passes through it, as its
resistance is much less than that of the circuit 2. The solenoid m' is now attracted
within the solenoid m against the action of the spring n drawing the carbon a¹
with it from the carbon a, and forms the electric arc between the ends of the
carbons. The upper carbon a is now held up by the brake devices e, e', as the
spring his adjusted to oppose the mutual attraction of the flat coils f² and ƒ³, due
to the amount of the current now passing through them.
Any number of lamps may be worked in a single circuit, and the extinction of
any one of any number of such lamps in the circuit in nowise affects the proper
working of the others, as the brake-operating circuit virtually forms a part of the
main line for the current.
A simple resistance device to prevent the too sudden movement of the lower
carbon a¹ is provided by inserting the small cylinder o¹ in the solenoid m; and
attaching the piston o³ to the end of the solenoid m¹; the said piston fits loosely
in the cylinder o¹, so that the air or other fluid placed in the cylinder is free to
pass between the piston and the cylinder as the solenoid m¹ moves.
It is obvious that as there is no iron to be magnetised in the carbon-feeding or
arc-producing devices, the lamp as above described is adapted to be used with a
to-and-fro or alternating current, and it is also obvious that the parallel coils f?
and f³, and the solenoids m and m' may be substituted the one for the other. If
it is desired to use a continuous current, then axial or electro-magnets may be
substituted for the coils and solenoids, although the said coils and solenoids will
operate perfectly with both kinds of currents.
Figures 5 and 6 shew the application of solenoids to a single circuit lamp.
The lower carbon a' of this lamp is held up against the fixed platinum fingers p

page_text: by means of the weight p¹. These fingers are so shaped as to bear on the carbon
rod for some distance down the sides of it, and on the commencement of its taper
end, so that the heat of the arc is conducted away by the said fingers at a part of
the carbon below which the heat is sufficient to cause it to burn, thus preventing
sudden feeding of the carbon by the sudden breaking away thereof below the
fingers, as occurs when the fingers bear only on the commencement of the taper
end.
The outside solenoid q is secured in a vertical position on the plate r; the
solenoid q is placed in the solenoid q and rests on the spring q², which is adapted
to just counteract the weight of the solenoid q'. To the upper end of the solenoid q¹
is attached the brake band 1 of thin metal or other suitable material. This band
passes over the upper surface of the pulley r², and to its end is secured the upper
end of the spiral spring which is provided with a stem passing through the
plate r,
and on which is a thumb screw to regulate the tension of the spring. The
shaft on which the pulley is secured has bearings in standards projecting up
from the plate r. On one side of the pulley is fixed the drum 8, around which is
wound a cord or chain, whose free end passes over the guide-pulley s², and is attached
to the holder & of the upper carbon a. This holder s2 slides between the guide-
bars 3, s. The holder 84 is pivoted to the plate r, and is pressed towards the
other one by means of an adjustable spring so as to clamp the carbon a between
the platinum blocks & secured to the lower ends of the bars 83, 84. t is a block of
metal secured to the bar t¹ of the frame, but insulated therefrom; it is connected
to the resistance coil 2 by the conductor t³. The other end of the resistance
coil 2 is connected to the plate r. Two other insulated blocks u and u¹ are secured,
one to each of the guide bars 83, 84, in such position that they are electrically
connected by the bar u² secured to the sliding carbon-holder 82 (but insulated
therefrom) when the carbon-holder falls into its lowest position. The insulated
block u is connected to one of the side rods of the frame, and the block u¹ to the
resistance coil 2 by means respectively of the conductors u³, u*.
The current enters the solenoid q, and after passing through the entire length of
its wire passes through the inside solenoid q', and from it to the plate r, and down
the guide-bars 83, 84, to the carbon a, and down the carbon a' to the fingers p, and
down the rods p² to the bar t, and from the side bars of the frame which are
insulated from the plater back to the electric generator.
When the upper carbon is consumed so that the arc is broken, the insulated
bar u falls on the blocks u and u¹, and so allows the current to pass through the
resistance coil 2 after passing through the solenoids q and q¹; and when the lower
carbon is consumed the counterweight p¹ falls on the insulated block t and on a
projection on the bar t¹, which also allows the current to pass through the resistance
coil t, so that under all circumstances there is a closed circuit through the lamp of
uniform resistance; therefore other lamps that may be in single circuit with it will
not be effected when the arc breaks.
The arc is formed between the ends of the carbon rods by the solenoid q¹ being
drawn down within the solenoid q when the electric current passes through the
lamp, the brake band r¹ being thereby carried down so that it turns the pulley r³
and raises the upper carbon a by winding its suspension cord on the drum 8..
To indicate when the carbons are nearly consumed I coat the ends marked a² of
the carbons with a metal or suitable chemical composition which will produce a
colored light when the arc reaches these parts; or this metal or composition may
be incorporated in the body of the carbons, and if desired a different colored light
may be produced by each of the carbons by using different metals or chemical
compositions.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
hat I claim,
'
First. In an electric are producing apparatus an electrical device adapted to
celease the feeding mechanism of the upper carbon rod, and included in the main

page_text: circuit from the generator in combination with an electrical device for forming the
arc between the ends of the two carbon rods by depressing the lower carbon, and
included in a branch circuit, substantially as and for the purpose hereinbefore set
forth.
Second. In a to-and-fro current regulator the combination of two solenoids,
substantially as and for purpose herein before set forth.
Third. In a feeding device for electric lighting apparatus the combination of
parts compressing the brake-wheel actuated by the gravity of the carbon a and its
holding rod c by suitable gearing, the lever f provided with the narrow contact
shoe, the spring h, and the adjustable stop-screw e³, substantially as and for the
purpose herein before set forth.
Fourth. The combination of parts comprising the fixed flat coil fs, the lever f,
and brake shoe, the brake wheel, the rod c and gearing, the two carbons, the inside
solenoid m³, the outside solenoid m, and the spring n, substantially as and for the
purpose set forth.
Fifth. In an electric lighting apparatus the combination of a resistance coil in a
shunt circuit with the connecting bars carried by the carbon holders and insulated
blocks, whereby the current is caused to pass through the resistance coil when the
carbons are consumed, substantially as set forth.
Sixth. In electric lighting appparatus the combination of a metal or chemical
composition with the holding ends of the carbon rods for the production of colored
lights before the carbons are entirely consumed, substantially as and for the purpose
set forth.
Seventh. The combination of the cylinder o' placed in the end of the coil of an
electric regulator with the moving core or solenoid provided with the piston o²,
substantially as and for the purpose set forth.
Eighth. In an electric lighting apparatus the carbon retention-fingers constructed
and arranged to bear on the commencement of the taper point and down the sides
of the carbon rod a³, substantially as and for the purpose hereinbefore set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Thirteenth day of September, in the year of our Lord
One thousand eight hundred and eighty one.
WM RORT LAKE (LS)