IMPROVE- MENTS IN ELECTRIC LAMPS
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 "IMPROVE-
MENTS IN ELECTRIC LAMPS." A communication from abroad by Friedrich
von Hefner Alteneck, of Berlin, in the German Empire.
SANA
LONA
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents on the 1st July 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS." [A communication
from abroad by Friedrich von Hefner Alteneck, of Berlin, in the German Empire.]
'
In the Specification to Lettera Patent No. 4949 of 1878, was described a method
of regulating electric lamps by the counteracting forces of two coils of different
resistance, through one or other of which the lamp was current was shunted. The
present Invention relates to improvements in the construction of electric lamps
regulated in this manner. For this purpose the electric conductor in some part of
its course to or from or in the lamp divides into two branches, the one leading
through the coil of a solenoid or electro-magnet of high resistance directly back to
the external circuit, and the other through a coil of low resistance indirectly tack
to the external circuit through the carbons and are of the lamp. The cores of the
two solenoids or the armatures of the two electro magnets are connected to either
or both of the carbon holders in such a manner that when the one solenoid or
electro-magnet, namely, that having the coil of high resistance is excited, the
movement of its core or armature causes the carbons to approach towards each
other, and when the other solenoid or electro-magnet, namely, that having the coil
of low resistance is excited, the carbons are caused to recede from one another, and
thus when both are excited the carbons are caused to take a position dependant
on the relation of the two counteracting forces operating upon them, which position
by suitable adjustments can be determined so as to produce the desired illuminating
voltaic arc. In the working of the lamp, should the carbons approach too nearly
to each other, then the resistance of the arc between them being diminished less of
the electricity passes through the coil of high resistance, and more passes through

page_text: the coil of low resistance, exciting more vigorously the solenoid or electro-magnet
that causes the separation of the carbons. If, on the other hand, the carbons should
be too far apart the resistance of the carbon are being greater, less olectricity passos
through the coil of low resistance and more passes through the coil of high
resistance, exciting more vigorously the solenoid or electro-magnet that causes the
approach of the carbons. As, notwithstanding considerable variations in the
quantity of electricity supplied to the circuit or drawn from it, the relation between
the forces developed by the two coils remains practically constant; this method of
regulation secures great uniformity in the illuminating power of each lamp, and
allows of the introduction of a variable number of lamps into one circuit without
rendering each of these lamps subject to the fluctuations of others of the set.
Moreover, the lamps thus introduced into the circuit may be made of varied illu-
minating power by connecting them to the circuit either directly in series or in
parallel branches. In lamps regulated as above described the feed of the carbons
as they are consumed may be effected in the manner set forth in the Specification
above referred to or in any other known manner. The two coils may be wound on
separate bobbins, each when wound as a solenoid having its own moveable core,
or when wound on a stationary core forming an electro-magnet having its own
armature; or they may be arranged to act in opposite directions on one core or
armature. Or again both coils may bo wound on one bobbin and connected to the
circuit so as to have their currents in opposite directions, a single polarised core or
armature being acted on by both. The whole current may be passed through
the coil of low resistance, the conductor therefrom dividing into two branches,
the one through the carbons and arc, and the other through the highly resisting
coil.

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
20th October 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS." A communication
from abroad by Friedrich von Hefner Alteneck, of Berlin, in the German Empire.
In the Specifications to Letters Patent No. 2006 of 1873 and No. 4949 of 1878,
was described a method of regulating electric lamps by the counteracting forces of
two coils of different resistance, through one or other of which the lamp current
was shunted. The present Invention relates to improvements in the construction
of electric lamps regulated in this manner. "For this purpose the electric conductor
in some part of its course to or from or in the lamp divides into two branches, the
one leading through the coil of a solenoid or electro-magnet of high resistance
directly back to the external circuit, and the other leading through the coil of a
Bolenoid or electro-magnet of lower resistance indirectly back to the external circuit
through the carbons and are of the lamp. The cores of the two solenoids or the
armatures of the two electro-magnets are connected by a lever. to one of the carbon
holders in such a manner that when the one solenoid or electro-magnet, namely,
that having the coil of high resistance is excited, the movement of its core or
armature causes the carbons to approach towards each other, and when the other
solenoid or electro-magnet, namely, that having the coil of low resistance is excited,
the carbons are caused to recede from one another, and thus when both are excited
the carbons are caused to take a position dependant on the relation of the two
counteracting forces operating upon them, which position by suitable adjustments
can be determined so as to produce the desired illuminating voltaic arc. In the
working of the lamp, should the carbons approach too nearly to each other, then
the resistance of the are between them being diminished less of the electricity passes
through the coil of high resistance and more passes through the coil of low resistance,
exciting more vigorously the solenoid or electro-magnet that causes the separation
of the carbons. If, on the other hand, the carbons should be too far apart, the
resistance of the voltaic are being greater, less electricity passes through the coil of
low resistance, and more passes through the coil of high resistance, exciting more
vigorously the solenoid or electro-magnet that causes the approach of the carbons.
As, notwithstanding considerable variations in the quantity of electricity supplied
to the circuit or drawn from it, the relation between the forces developed by the
two coils remains practically constant; this method of regulation secures great
uniformity in the illuminating power of each lamp, and allows of the introduction
of a variable number of lamps into one circuit without rendering each of these
lamps subject to the fluctuations of others of the set. Moreover, the lamps thus
introduced into the circuit may be made of varied illuminating power by connecting
them to the circuit either directly in series or in parallel branches. In lamps regu-
lated as above described the feed of the carbons as they are consumed may be
effected in the manner set forth in the Specifications above referred to or in any
other known manner. The two coils may be wound on separate bobbins, each
when wound as a solenoid having its own moveable core, or when wound on a
stationary core forming an electro-magnet having its own armature; or they may
be arranged to act in opposite directions on one core or armature. Or, again, both
coils may be wound on one bobbin and connected to the circuit so as to have their
currents in opposite directions, a single polarised core or armature being acted on
by both. The whole current may be passed through the coil of low resistance, the
conductor therefrom dividing into two branches, the one through the carbons and
are and the other through the highly resisting coil.

page_text: Fig. 1 shows diagrammatically one arrangement of electric lamp with regulating
apparatus according to this Invention; 9 and h indicate the carbons held
respectively in the sockets a and b, and provided with any known means
of feeding as they are consumed. The one socket a is attached to one arm c
of a lever pivotted at d, and having its opposite arm c connected to a piece
of non magnetic material uniting a pair of iron cores 8, 8¹. The core & is
free to play up and down within a solenoid R, the coil of which is of large wire
offering small resistance, and forms part of the lamp circuit.
The core s¹
is free to play up and down within a solenoid T having a coil of smaller wire
offering greater resistance than the coil of R. The coil of T is in a circuit external
to the lamp, that is to say, joining the conductors L, L, excluding the carbons.
When the solenoid R being excited draws in its core s the points of the carbons
are separated; when on the other hand the solenoid T draws in its core & the
carbons are caused to approach each other. As the relative force of the two
solenoids depends upon the quantity of electricity passing respectively through
their coils, and as this depends upon the relative resistance of their respective
circuits, the one circuit consisting of the coil T and its connections to tho main
circuit of L, L', and the other consisting of the coil R, the two carbons, and the are
between them, that portion of the latter which consists of the arc being dependent
on the distance of the carbons apart, this distance will become adjusted automatically
by the action of the two solenoids, so as practically to maintain constant action of
the lamp. If, for example, the carbons should be too near together a larger pro-
portion of the electric current passing through the coil R than through the coil T
will cause superior attraction of the core 8, separating the carbons, and thereby
increasing the resistance of the are between them, and so lessening the quantity of
electric current that passes through them. If, on the other hand the carbons should
be too far apart, then the coil R being less excited than the coil T will exert less
attractive force on its core 8, permitting the other core 8' to be drawn into its coil,
and thus causing an approach of the carbons which will lessen the resistance of the
are between them, and so permit the passage of a larger proportion of the current
through them; thus the regulation of the lamp being dependent only on the
resistance of its voltaic arc, and independent of the strength of current, the action
of any one lamp in a circuit will not affect that of other lamps in the same circuit,
and consequently a number of such lamps can by means of this Invention be
effectually worked in one and the same circuit. In like manner as above described
instead of employing two solenoid coils with cores attracted into them in opposite
directions two electro-magnets acting in opposite directions on an armature may be
arranged as shewn diagrammatically in Fig. 2; R and T are two electro-magnets,
the coil of R of small resistance is in the lamp circuit, the coil of T of greater
resistance is in a circuit external to the lamp, both electro-magnets act on
an armature c at one end of a lever, the other end of which carries one of the
carbon holders. The distance of the carbon points will obviously be automatically
adjusted as above described with reference to the arrangement indicated in Fig. 1.
The arrangement of the two solenoids or electro-magnets, and of their mechanical
connections to the carbons, may be varied in many ways, as for example, in the
manner shewn diagrammatically in Fig. 3, in which the two solenoids R and T are
arranged side by side with their cores acting at opposite ends of a lever. Another
arrangement is to combine the two coils into a compound solenoid exerting opposite
actions on one polarised core as indicated in Fig. 4. In this case the polarised
core N, S, which is connected to the lever c, c', carrying one of the carbons, works
within two coils, the one a coil of low resistance forming part of the lamp circuit,
the other a coil of greater resistance in a circuit external to the lamp; theso coils

page_text: being connected for passage of current in such directions that the one of low
resistance shall when excited tend to attract, the core inwards; and thereby separate
the carbons, and the other shall tend to repel the core outwards, and thereby cause
approach of the carbons. In like manner a compound or double coiled electro-
magnet may be employed, as indicated in Fig. 5, so as to attract or repel a polarised
armature on the carbon lever cc. Instead of dividing the conductor into two
branches before reaching the two coils it may be branched after passing the coil of
low resistance, as indicated in Fig. 6. Here the arrangement of the two solenoids R
and T with their cores connected to the carbon lever is similar to that described
with reference to Fig. 1, but the whole current passes through the low resistance
coil R, and then a portion passes through the carbons and arc, and a portion
branches through the coil T of the higher resistance. When lamps are arranged
as above described with two solenoids or electro-magnets having coils of different
resistance operating in opposite directions on cores or armatures connected to the
carbons, so as to effect their automatic adjustment, a number of such lamps can be
placed in one circuit, and can be worked with various degrees of power, according
to the manner in which they are connected thereto, whether in-series or in parallel
branches as illustrated diagrammatically at Fig. 7. In this diagram the lamps a,
b, c, would receive the full power of the current, the lamps 1 and 2 would receive
each about one half, and the lamps 3, 4, and 5 would receive each about one third
of the full power; Fig. 8 is a vertical section of a lamp with a pair of regulating
solenoids operating as described with reference to Fig. 1 in combination with one
of the arrangements for feeding the upper carbon described in the later Specification
above referred to. In this construction R is the one solenoid having its coil of low
resistance in the lamp circuit surrounding the core 8, which is connected to the
lever arm c. The other solenoid T having its coil of higher resistance in a circuit
external to the lamp surrounds the core s', which is connected by a piece of non-
magnetic material to the core a. The lever c is pivotted at d on the fixed framing
of the lamp, and carries on its arm c' the slide and rack for the upper carbon, and
the disengaging gear described in the Specification above referred to, which permits
the carbon slide to descend a little to allow for waste when the automatic adjust-
ment effected by the action of the solenoids brings the disengaging gear down to a
fixed stop. To provide for continuation of the circuit in cases where a considerable
separation of the carbons g, h, occurs, as when a piece of the carbon breaks off, the
following arrangement is adopted :-To the frame A (which is moved up and down
by the action of the solenoids R and T) is attached an insulated bracket a, of which
a front view is shown at Fig. 8. On this bracket is pivotted a lever b immediately
over two spring contacts 1, 1, connected respectively to the conductors of the
external circuit. When the frame A descends to its full extent the lever b resting
on the contacts l, l', completes the external circuit, so that other lamps in that
circuit may continue in action, even if the one lamp becomes extinguished. When
by the approach of the carbons this lamp again comes into action the lever b is
raised off the contacts 1, 1, by the ascent of the frame A. Fig. 9 shews a mode of
applying to a known construction of lamp the arrangement of two solenoids R
and T, having their coress and s¹ connected to opposite arms of a lever as illustrated
in Fig. 3, the lever o worked by these cores being in the lamp shown in Fig. 9 made
to operate on the gearing connected to the carbon slides.
Having thus described the nature of this Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent I
claim,―
First. Dividing the conductors to and from an electric lamp into two branches,
the one including with the lamp circuit a solenoid or electro-magnet coil of low
resistance actuating a core or armature connected by a lever to one of the carbon
alides so as to separate the carbons, and the other including in a circuit connecting
the conductors externally to the lamp a solenoid or electro-magnet coil of higher
resistance actuating a core or armature connected by the said lever to the carbon
slide, so as to bring the carbons nearer together; the regulation of the lamp being

page_text: thus effected by the differential action of the two coils independently of fluctuations
in the electrical circuit with which the lamp is connected, substantially as herein
described.
Second. Combining into one compound solenoid or electro-magnet two coils, such
as are referred to in the preceding claim, so that they act in opposite directions on
one polarised core or armature connected by a lever to either of the lamp carbons,
substantially as herein described.
In witness whereof, I, the said Charles William Siemens, have hereunto set my
hand and seal, this Ninth day of October, in the year of our Lord One
thousand eight hundred and seventy nine.
C. WILLIAM SIEMENS. (L.S.)