IMPROVED MEANS AND APPARATUS FOR PRODUCING LIGHT AND HEAT BY ELECTRICITY
Year: 1879

page_text: LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gate,
Westminster, in the County of Middlesex, for the Invention of "IMPROVED
MEANS AND APPARATUS FOR PRODUCING LIGHT AND HEAT BY ELECTRICITY."
PROVISIONAL SPECIFICATION left by the said Charles William Siemens at
the Office of the Commissioners of Patents on the 27th May 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVED MEANS AND APPARATUS FOR PRODUCING LIGHT
AND HEAT BY ELECTRICITY."
In the Specification to Letters Patent granted to me on the 22nd October 1878,
No. 4208, I described the cooling of the terminal of an electric lamp by means of a
stream of water passed through a cavity formed in the terminal. My present
Invention relates to arrangements in which, by the use of such water cooled
terminals, I am enabled conveniently to apply the electric current to the production
of light as in electric lamps, or of intense heat within a crucible, for the purpose of
fusing refractory materials. My arrangement of electric lamp is as follows:-The
negative terminal consists of a vertical wire, preferably of iron, enclosed within a
thin copper tube which is surrounded by an outer tube or casing of larger diameter,
so that between the two tubes there is an annular space through which water is
made to flow. By connecting the upper and lower ends of the casing by flexible
tubes with the upper and lower parts of a water cistern the heating of the water at
the terminal causes a circulation which is sufficient for keeping the terminal cool.
The wire forming the core of the terminal is pressed upwards by a weight, float, or
spring against a sinall shoulder or burr at the mouth of the inner tube, and as the
wire wastes at its upper end it is continually fed upwards by the weight, float, or
spring. The positive terminal consists of a carbon rod which is free to slide down-
wards within a water cased tube, the lower end of the carbon resting against the
end of a pin of platinum or other refractory metal screwed obliquely through an eye
at the lower end of the casing. As the carbon wastes at its lower end it slides
downwards, still bearing against the pin. I prefer to fix on the lower end of the
casing a convex facing of porcelain or other refractory material, which acts as a
reflector and diminishes the heat communicated to the casing. Although I have
described the negative terminal as consisting of a wire of iron, which is of advantage

page_text: in respect of the colour which it gives to the arc, it may be of carbon arranged as in
the positive terminal. For automatically adjusting the distance between the
terminals I adopt the following arrangement :-I fix the negative terminal above
described at the end of a lever, which may be tubular, so as to constitute one of the
circulating tubes. This lever works on a fulcrum on the fixed framing of the lamp,
and near its fulcrum it is attached to and suspended by a long thin metal strip,
which forms part of the lamp circuit. According to the electricity passing through
this circuit varies, so the metal strip varies in length, and by these variations
the lever is caused to oscillate more or less, bringing the lower terminal nearer to
the upper terminal, or lowering it farther from it, so adjusting the length of the
voltaic arc.
The metal strip hangs in the middle of a tube which has a water
casing, constituting the cistern that communicates with the casings of the terminals
for circulation. The water heated at the terminals may be used for domestic or
warming purposes, and when this is required on a considerable scale the arc may be
Instead of
more or less surrounded by or enclosed in a heating vessel or boiler.
applying the expansion and contraction of a metal strip for adjustment a solenoid
may be employed, its coil being in the circuit of the lamp, and its sliding core being
attached to the lever of the lower terminal, so as to depress the terminal when the
coil is too powerfully excited, and to raise it when the exciting current becomes too
weak. In applying the electric current to the production of intense heat for the
fusion of refractory substances I employ two carbon rods, fitted to slide towards
each other horizontally, within water cased tubes, which are attached to the opposite
sides of a crucible made of highly refractory material, such as lime or alumina, also
water eased if necessary. The substance to be fused is introduced into the crucible,
and the carbon rods are advanced sufficiently near to each other to form the voltaic
are within the crucible. They are thereafter made to advance by clockwork, each
at a speed proportioned to its rate of consumption, so as to maintain the arc always
within the crucible. The clock-work which advances them has a flyer which can
be retarded or arrested by a brake or stop connected to a thin metal strip which
forms part of the electric circuit, or to the armature of an electro-magnet, the coil
of which forms part of the circuit. As the heat in the crucible increases, the resist-
ance to the voltaic arc within it diminishes, and consequently the arc can be clongated,
an effect which results from the automatic retardation or stoppage of the feeding
clockwork. The crucible may be closed by a cover having apertures through which
air or other gases may be blown or drawn to act on the substance under treatment.
In some cases, instead of employing carbon for the terminals, they may be made of
the material that is to be fused, when it has sufficient conductivity.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the
26th November 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVED MEANS AND APPARATUS FOR PRODUCING LIGHT
AND HEAT BY ELECTRICITY."
In the Specification to | Letters Patent granted to me on the 22nd October 1878,
No. 4208, I described the cooling of the terminal of an electric lamp by means of a
stream of water passed through a cavity formed in the terminal. My present
Invention relates to arrangements in which by the use of such water-cooled termi-
nals I am enabled conveniently to apply the electric current to the production of
light as in electric lamps or of intense heat within a crucible, for the purpose of
fusing refractory materials. My arrangement of electric lamp is as follows:-The
negative terminal consists of a vertical wire, preferably of iron, enclosed within a
thin copper tube, which is surrounded by an outer tube or casing of larger diameter,
so that between the two tubes there is an annular space through which water is
made to flow. By connecting the upper and lower ends of the casing by tubes with
the upper and lower parts of a water cistern, the heating of the water at the terminal
causes a circulation which is sufficient for keeping the terminal cool. The wire
forming the core of the terminal is pressed upwards by a weight, float, or spring
against a small shoulder or burr at the mouth of the inner tube, and as the wire
wastes at its upper end, it is continually fed upwards by the weight, float, or spring,
The positive terininal consists of a carbon rod which is free to slide downwards, the
lower end of the carbon resting against the end of a pin of platinum or other
refractory material screwed obliquely through an eye at the lower end of the casing.
As the carbon wastes at its lower end it slides downwards, still bearing against the
pin. I prefer to fix on the lower end of the casing a convex facing of porcelain or
other refractory material, which acts as a reflector and diminishes the heat commu-
nicated to the casing. Although I have described the negative terminal as consisting
of a wire of iron, it may be of carbon, arranged as in the positive terminal. For
automatically adjusting the distance between the terminals I adopt the following
arrangement-I fix the terminal at the end of a lever, which may be tubular, so
as to constitute one of the circulating tubes. This lever works on a fulcrum on the
fixed framing of the lamp, and is suspended by a long thin metal strip or wire,
which forms part of the lamp circuit. According as the electricity passing through
this circuit varies, so the metal strip varies in length, and by these variations the
lever is caused to oscillate more or less, bringing the terminals nearer to or farther
from one another, so adjusting the length of the voltaic arc. The metal strip or
wire may hang in the middle of a tube, which has a water casing constituting the
cistern that communicates with the casings of the terminals for circulation. Instead
of applying the expansion and contraction of a metal strip for adjustment a solenoid
may be employed, its sliding core being attached to the lever of the terminal. In
applying the electric current to the production of intense heat for the fusion of
refractory substances I employ two carbon rods fitted to slide towards each other
horizontally through holes in the opposite sides of a crucible made of highly refrac-
tory material, such as lime or alumina, which may be water-cased if necessary. The
substance to be fused is introduced into the crucible, and the carbon rods are
advanced sufficiently near to each other to form the voltaic are within the crucible.
They are therefore made to advance by clockwork or other suitable motor each at a
speed proportioned to its rate of consumption, so as to maintain the are always
within the crucible. The clock work which advances then may be retarded, arrested,
or reversed by the action of a thin metal strip or solenoid as in the electric lamps
above described. As the heat in the crucible increases the resistance to the voltaic

page_text: are within it diminishes, and consequently the arc can be elongated, an effect which
results from the automatic retardation, stoppage, or reversal of the feeding clock-
work. The crucible may be closed by a cover having apertures through which air
or other gases may be blown or drawn to act on the substance under treatment.
In some cases, instead of employing carbon for the terminals, they may be made of
the material that is to be fused when it has sufficient conductivity.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a vertical section of one form of electric lamp according to my Inven-
tion. The lower terminal A is an iron or steel wire loosely fitting a water-cased
tube, and pressed upwards by a volute spring a, for which might be substituted a
weight and pulley. The mouth of the water-cased tube has a bush a closely fitting
the wire A, or having a burr at its mouth, so as to prevent the wire from being
pushed through it, except when its point becomes softened, fused, and dissipated by
the heat of the voltaic arc. The water circulating through the casing of the terminal
may flow to and from an open cistern, or it may, as shewn in Fig. 1, circulate
The
through a closed coil of tube a² presenting a considerable cooling surface.
upper terminal B is a carbon rod free to slide in a tube b, having two internal ribs
b, as shewn in Fig. 1, which is a sectional plan at X, X. At the lower end of the
tube bis provided an oblique adjusting screw C, the point of which c bears against
the carbon and presses it against the ribs b¹ on the opposite side of the tube, so
that being in a manner clamped between these ribs and the screw C it cannot slide
down. Moreover from this pressure of the carbon against the ribs b' close
contact results, so that the electricity or the principal part thereof enters the
carbon at its point of contact with the ribs, and consequently the heating
of the carbon is confined mostly to the portion of it which projects below
the tube. As the lower end of the carbon gradually wastes away from the
point c, the carbon gradually slides down the tube. The screw C may be
of copper, as a good conducting material, or its point c may be of refractory
metal, such as platinum, or it may be a refractory gem, such as diamond, let into
the point of the screw C, which is guarded from the heat of the arc by a
shield c¹ of porcelain or refractory metal. The screw C works in a shield c² of
convex or inverted conical form enainelled or faced with porcelain on its lower
surface, so as to reflect the light as well as to protect the tube b from the heat of
the arc. Fig 1b is a section, and Fig. 1c a plan, shewing a modified arrangement,
which may be employed instead of the screw C and its shield. In this arrangement
a bar c of copper faced on its underside with platinum terminates in a chisel edge,
which bears against the carbon B. It is adjusted by a screw gearing with rack
teeth on the upper side of c³. As the carbon B becomes consumed and descends
down the tube ba fresh carbon B₁ can be added to it; for this purpose the upper
end of the one carbon is hollowed out a little, and the lower end of the fresh carbon
is served with a little moistened sugar, or with tar, which, as the junction approaches
the lower end of the tube, becomes carbonised by the heat cementing the two carbons
together. It is of advantage to provide in each carbon a short piece of wire b² to
act as a dowel, centering the carbons to one another; or the one carbon might be
made with a point projecting as a tenon to enter a hole in the end of the other
carbon. The automatic adjustment of the distance of the terminals is effected in
the following manner :-The tube b has on it a cylindrical casing D of soft iron; or
instead of a complete cylindrical casing the iron may be put on the tube as a
number of strips arranged round its circumference. Around the tube b is the coil
of a solenoid E consisting of a great number of convolutions of insulated wire, so as
to present very considerable electrical resistance. This solenoid coil forms part of
a circuit connecting the one terminal with the other, as will be understood by
tracing the course of the clectrical current from the one line wire L to the other
line wire L'. The one wire L is attached to an insulated connecting piece l, from
which a flexible metallic strip l' connects to the tube b, holding the upper carbon,

page_text: and a wire 1 connects to the solenoid coil E. The other wire L' is connected
directly to the frame of the lamp which is all in metallic connection with the lower
terminals, and also by a wire with the solenoid coil E. The tube b and its carbon
being a little more than counterbalanced by an adjustable weight F on a lever
connected to the tube by a non-conducting link f, the regulation of the distance of
the terminals depends upon the relative quantities of electricity passing through the
voltaic arc between them and through the solenoid E. When the terminals are too
near each other, very little of the electricity passes through the solenoid, and the
counterweight F then draws the terminals apart; when they are too far apart a
larger portion of the electricity passes through the solenoid E, the iron D is thereby
attracted down into the solenoid, and the terininals are thus brought nearer toge-
ther. Should the lamp be extinguished so that there is no passage of electricity
from the one terminal to the other, then the whole of the current passes through
the solenoid, and the terminals being thus brought close together the arc is re-
established. In order to damp the oscillations that might result from the action of
the solenoid, the tube b is attached to a flexible non-conducting diaphragmn G,
which forms the cover of an air vessel g having a small air hole g'. This acts
as a dash-pot, a ring 92 laid on the diaphragm G preventing it from bulging out-
wards.
A modified form of electric lamp according to my Invention is shewn at Fig. 2 in
elevation, partly in section. In this case both terminals are carbons, the lower
one A is pressed upwards in a slotted tube a by a hook a¹ acted on by a weight a².
The upper end of the carbon is pressed by two oblique screws C, C, against a couple
of chisel edges c, c, at a lower level on the opposite side. Fig. 2 is a plan taken on
the line Y, Y, shewing the arrangement of these screws and edges. As the carbon
wastes from under the points of the screws C it is raised by the action of the
weight a²; when it is nearly consumed the hook a¹ can be drawn down to the end
of a fresh carbon served at its coned point with moistened sugar or tar to cement it
to the hollowed end of the old carbon. The upper carbon B, a sectional plan of
which on the line Z, Z, is shewn at Fig. 2b, is fed in the following manner:- In a
groove on one side of it there is let in a small strip b of zinc or other metal that
will fuse or consume under a moderate heat. Two loaded levers b' press against the
carbon, making the electrical contact with it, and pushing the strip b against the
edge of the hole in the reflecting shield c². As the heat of the lower part of the
carbon softens or fuses the end of the strip b which supports the carbon, by resting
on the edge of c² the carbon gradually descends. The automatic regulation of the
distance between the carbons A and B is effected as follows:-Both carbon tubes
are attached to arms of bell crank levers H and I, the other arms of which
are connected by a non-conducting liuk J. The lever H carries an adjustable
weight h, and its extended end rests in the loop of a thin wire or strip of platinum
or iron K, which, as shewn in cross section at Fig. 2c, is carried over several non-
conducting pulleys k, and can be adjusted on its tension by a barrel worked by a
worm. The line wire L is, through the metallic framing of the lamp, in electrical
connection with the lever H and the upper carbon B, and also with one end of the
wire or strip K. The other line wire L' is attached to an insulated piece l', which
is connected by a flexible metallic strip 12 to the lever I, and through it to the
lower carbon A, the fulcrum of the lever I being insulated from the framing. From
the piece there is also connection by a wire to the strip or wire K which offers
considerable electrical resistance. When the carbons A and B are too far apart, so
that little or none of the electrical current can pass from the one to the other, a
large portion of it passes through the strip or wire K, and heats it so that it expands
in length, whereupon the lever H descends and I rises, bringing the carbons nearer
together. When they are too near a small portion of the electricity passes through
the strip or wire K, and this contracting as it cools raises the lever H and depresses
I, thus farther separating the carbons.
Fig. 3 is a section of a lamp in which the carbons A and B are placed horizontally.
They are pressed forward by volute springs a and b, but their front ends are

page_text: clamped by chisel edges c bearing them against the contact ribs c¹, as shewn in
Fig. 3, which is a section on V, V. As the ends of the carbons waste where the
chisel edges c bear upon them, the carbons are advanced. The pressure of the chise!
edges c is adjusted by screws c². Over the arc is fixed a porcelain reflecting guard
R. The automatic regulation of the distance between the carbons is effected as
follows: The line wires L, L³, are connected by flexible metal strips 1, l', to the
carbon guides respectively, and these guides are linked to the vertical arms of
counterweighted bell crank levers H and I, in which arms are mounted the spring
barrels a and b. On the horizontal arms of the levers H and I bears a disc M of
nonconducting material attached to an iron core D, which is free to move up or
down within a highly resisting solenoid coil E, the two ends of which are connected
by the wires 12, 13, to the line wires L, L¹. To the core D is attached a piston P
working in an air cylinder with a small air hole, and the piston rod is made to
terminate in a cup Q for the reception of shot or other small weights for adjust-
ment. When the carbons are too far apart, so that little or none of the electricity
can pass from the one to the other, there will be a considerable current through the
solenoid E, and its core D being thus attracted upwards, relieving the levers H aud
I of part of the load pressing them down, these levers moving in obedience to their
When on the other
counterweights, will cause the carbons to approach each other.
hand, the carbons are so near, that little of the electricity passes through the
solenoid E, the core D and its load will cause the carbons to separate. The piston
P working in its cylinder acts as a dash pot to damp oscillations.
Fig. 4 shews apparatus according to my Invention for applying the heat of the
voltaic are within a crucible. Fig. 4ª is a section on the line W, W. I have shewn
in the Figure one of the terminals A to be a carbon, and the other B as a metal
pole cooled by circulation of water as described in the Specification above referred
to. Both terminals might however be carbons, and both or either might be tubular,
as shewn with respect to A, so that currents of air or other gas might be sent
The
through them into the crucible for effecting chemical re-actions therein.
terminals rest on grooved rollers R, R, being pressed down thereon by heavy upper
rollers r, r.
The rollers R have on their axes worm wheels 71 gearing with worms
on a spindle S, which is made in two parts coupled between the terminals by insu-
lating material at 8. The spindle S is the axis of a bladed wheel T, which is
mounted within a casing. Above the casing is a receptacle t for holding sand or
other heavy powder (or it might be liquid), and below it is another receptacle t¹ for
receiving the same after it has worked the wheel. Under the mouth of the upper
receptacle t is a funnel tube U, mounted on a pivot u, so that it can oscillate. A
lever arm u carrying an adjustable weight projects from the funnel, and is linked
to the iron core D which works freely within a solenoid E, having a coil of high
resistance which is in a circuit connecting the line wires that supply the terminals
A and B. The funnel U has on its upper face a curved guard plate, having through
When the funnel U stands
it two ports v1, v2, with a closed portion between them.
in its middle position as shewn, no sand can pass from the receptacle t to the wheel
T which remains at rest, keeping the terminals A and B stationary. When the
terminals A and B are so far apart that little or none of the electricity can pass
from the one to the other, a considerable portion will pass through the solenoid E,
and the core D being thereupon attracted upwards, will cant the funnel U, causing
it to present its port v¹ to the mouth of t, and to direct its own mouth U₁ towards
the right of the crown of the wheel T. The sand or heavy powder will thereupon
run down the funnel, and acting on the blades on the right of the wheel T, will
cause it to revolve in such a direction, as to cause the terminals A and B to move
towards each other. When they are so near that little of the electricity passes
through the solenoid E, the core D descends, canting the funnel U towards the
other side, so as to direct the sand or powder on to the left hand blades of tbe
wheel T, thus reversing its direction of rotation, and thereby causing the with-
drawal of the terminals from one another. It is obvious that a similar arrangement
might be applied to the adjustment of terminals used for illumination.

page_text: When the material treated in the crucible is a conductor, the arrangement shewn
in Fig. 5 may be adopted. In this case, the material A, such as fused metal
forming the one terminal, lies in the bottom of the crucible in contact with a screw
or pin a faced with the platinum or other metal that will not be acted on by the
material A. The other terminal B which is cooled by the passage of water through
it, as described in the Specification above referred to, is suspended through a hole
in the crucible cover, and it can be made to ascend or descend as required for regu-
lating the distance between the terminals, by the action of a solenoid or expanding
inetal wire or strip as described above with reference to the carbons of the electric
lamps.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,-
First. Effecting the feed of the terminal of an electric lamp, by causing it to bear
against a point or edge near its heated extremity, so that it can advance as it
wastes, substantially as herein described.
Second. The use for the lower terminal of an electric lamp, of a wire passed
through a casing cooled by circulation of water through it, substantially as herein
described.
Third. The use for applying the hent of the voltaic arc, of a crucible having
introduced into it terminals, such as are employed in electric lamps, adjusted so
that the arc is produced and maintained within the crucible, substantially as herein
described.
Fourth. The use for applying the heat of the voltaic arc to substances, having
conductivity, of a crucible having introduced into it a terminal, such as is employed
in electric lamps, adjusted so that the arc is produced and maintained in the
crucible between the said terminal and the substance acted on, which is in contact
with one of the conductors of the cricuit, substantially as herein described.
Fifth. Effecting the automatic regulation of the distance between terminals pro-
ducing a voltaic are for illumination or heating, by the expansion or contraction
of a metallic strip or wire of high resistance, forming part of a circuit connecting
the conductors of the terminals, the said wire or strip being mechanically connected
to either or both of the terminals, so as to cause their approach when it expands,
and their separation when it contracts, substantially as herein described.
Sixth. Effecting the automatic regulation of the distance between terminals
producing a voltaic are for illumination or heating by the movement of the core of
a solenoid, having a coil of high resistance, forming part of a circuit connecting the
conductors of the terminals, the said core being mechanically connected to either or
both of the terminals, so as to cause their approach when it is attracted by the
solenoid, and their separation when it is not so attracted, substantially as herein
described.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Twenty fourth day of November, in the year of
C. WILLIAM SIEMENS. (L.S.)