IMPROVE- MENTS IN ELECTRIC LAMPS, AND IN SOLENOIDS APPLICABLE FOR THEIR REGULATION
Year: 1880

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN ELECTRIC LAMPS, AND IN SOLENOIDS APPLICABLE FOR THEIR
REGULATION." A communication from abroad by Franz Krizik and Ludwig
Piette, both of Pilsen, in tho Austrian Empire.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 6th April 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS, AND IN SOLENOIDS
APPLICABLE FOR THEIR REGULATION." [A communication from abroad by Franz
Krizik and Ludwig Pietto, both of Pilsen, in the Austrian Empire.]
This Invention relates to a method of effecting automatically the regulation of
the distance of the carbons in an electric lamp, without the aid of clockwork or
other like mechanism, by the use of solenoids having special cores, such solenoids
and cores being applicable whore, as in electric lamps, uniformity of attractive force
has to be maintained throughout a considerable length of stroke. In an electric
lamp, according to this Invention, there are two solenoid coils placed end to end,
with their axes in the same straight line, and with one iron core free to slide
lengthwise within both, this core carrying at its end one of the carbons of the lamp,
and being balanced when it is vertical or running on rollers when it is horizontal.
The one solenoid coil of low resistance is in the lamp circuit; the other of high
resistance is in a branch circuit connecting the conductors to and from the lamp.
The core is so shaped, that so long as the two solenoids exert equal attractive forces,
it remains stationary, notwithstanding that it may have been previously moved
lengthwise, so as to extend further into or through the one coil than the other, and
in order that it may have this property, it is made with the mass of its metal reduced
towards the ends. This may be done either by tapering it from the middle of its
length to a less diameter at each end, or by boring it from each end with a
tapering bore; or instead of giving the metal a regular taper externally or internally,
its diameter or thickness may be reduced by steps from the middle each way. Or
it may be made of a number of pieces of iron rod or tube united end to end with
pieces of non-magnetic material of different lengths intervening between the

page_text: lengths of iron. The core so constructed carrying one of the carbons will then
adjust itself, moving the one carbon to or from the other, until the attractive forces
exerted on the core by the two solenoids in opposite directions become balanced.
When the carbons are too near, the resistance of the arc is so far lessened, that the
solenoid in the circuit of the carbons becomes the more powerful of the two, and the
core thereupon moves so as to separate the carbons. When on the other hand the
carbons are too far apart, the resistance of the arc is so much augmented, that the
solenoid in the circuit of the carbons becomes the weaker, and the core thereupon
moves so as to bring the carbons nearer together.
According to a modified arrangement, when it is desired to retain the voltaic arc
in one position, each of the carbon holders has attached to it a half taper or stepped
-core, such as has been described above, cach half core being free to move longitudi-
nally within one of the solenoids; and the carbon holders are connected together in
the usual way by gearing, so as to move in opposite directions through spaces
proportioned to the relative rates of consumption of the two carbons. It is of 1
advantage to combine with the lamp an automatic shunt of any known construction,
so that when the lamp is extinguished, the current is shunted into the general
circuit.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Soal Patent Office on the 2nd
October 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS, AND IN SOLENOIDS
APPLICABLE FOR THEIR REGULATION." A communication from abroad by Franz
Krizik and Ludwig Piette, both of Pilsen, in the Austrian Empire.
L
This Invention relates to a method of effecting automatically the regulation of
the distance of the carbons in an electric lamp, without the aid of clockwork or
other like mechanism, by the use of solenoids having special cores, such solenoids
and cores being applicable whero, as in electric lamps, uniformity of attractive force
has to be maintained throughout a considerable length of stroke. In an electric
lamp, according to this Invention, there are two solenoid coils placed end to end,
with their axes in the same straight line, and with one iron core free to slide
lengthwise within both, this core carrying at its end one of the carbons of the lamp,
and being balanced when it is vertical, or running on rollers when it is horizontal.
The one solenoid coil of low resistance is in the lamp circuit; the other of high
resistance is in a branch circuit connecting the conductors to and from the lamp.
The core is so shaped, that so long as the two solenoids exert equal attractive forces
it remains stationary, notwithstanding that it may have been previously moved
lengthwise, so as to extend farther into or through the one coil than the other;
and in order that it may have this property, it is made with the mass of its metal

page_text: reduced towards the ends. This may be done either by tapering it from the middle
of its length to a less diameter at each end, or by boring it from each end with a
tapering bore; or instead of giving the metal a regular taper externally or internally,
its diameter or thickness may be reduced by steps from the middle each way. Or
5 it may be made of a number of pieces of iron rod or tube united end to end with
pieces of non-magnetic material of different lengths intervening between the lengths
of iron. The core so constructed carrying one of the carbons will then adjust
itself, moving the one carbon to or from the other, until the attractive forces exerted
on the core by the two solenoids in opposite directions become balanced. When
the carbons are too near, the resistance of the arc is so far lessened, that the solenoid
in the circuit of the carbons becomes the more powerful of the two, and the coro
thereupon moves so as to separate the carbons. When on the other hand the
carbons are too far apart, the resistance of the arc is so much augmented, that the
solenoid in the circuit of the carbons becoines the weaker, and the core thereupon
moves so as to bring the carbons nearer together. According to a modified
arrangement, when it is desired to retain the voltaic arc in one position, each of the
carbon holders has attached to it a half taper or stopped core, such as has been
described above, each half core being free to move longitudinally within one of the
solenoids; and the carbon holders are connected together in the usual way by
gearing, so as to move in opposite directions through spaces proportioned to the
relative rates of consumption of the two carbons. It is of advantage to combine
with the lamp an automatic shunt of any known construction, so that when the
lamp is extinguished, the current is shunted into the general circuit.
DESCRIPTION OF THE DRAWINGS.
Figs. 1., II, III, and IV., are diagrams illustrating the principles on which this
Invention is founded. If an iron core of uniform section, as shewn in Fig. I., be
placed within two solenoid coils S and S¹ of equal magnetic force, the attraction on
the core will depend on its position relatively to the coils; it is strongest when one
end of the coro is in the middle of the coil, and weakest when the middle of the
core is in the middle of the coil. Hence, when the core is in the position shewn in
Fig. L it will be more strongly attracted by S¹ than by S. When however the
mass of the core at different parts of its length varies, the attraction of the two
coils upon it may be equalised. Thus by making the core in the form of a double
cone, as shewn in Figs. II., III., and IV., notwithstanding the different positions
occupied by the core, it remains equally attracted by the two coils S, S¹, Figs. II.,
and IV., shewing its extreme positions each way, and Fig. 3 its middle position.
The core instead of being truly tapered towards each end, may be reduced by steps,
as indicated in Fig. V; or it may be hollowed out by tapering holes, as in
Fig. VI. Or it may be made up of a number of separate lengths of iron connected
together by non-magnetic material, as indicated in Fig. VII.; and these lengths
may be bored through with holes of different diameter, as indicated in Fig. VIII.
By thus constructing the cores, they may be made to move over considerable
distances without undergoing change of attraction, and they are therefore suitable
for regulating the distance of the carbons in electric lamps. Figs. IX., X., and XI.,
shew various constructions of lamps in which they are so applied. In Fig. IX.
the double coned core F is attached to the socket of the upper carbon, the whole
being balanced by a weight q attached to a cord passing over a pulley R, and
free to move within the two solenoid coils S and S¹. The coil S of large wire
presenting small resistance is in the circuit of the carbons, and S¹ in a shunt circuit
consists of fine wire in many convolutions, so as to get with a weak current mag-
netic force equivalent to that of S with a strong current, and to present considerable
resistance. When the carbons are too near, the attractive power of S being increased
while that of S¹ is diminished, the core F is attracted upwards, separating the carbons.
When on the other hand the carbons are too far apart, S loses force and S' gains
force, so that the core F is attracted downwards, causing the carbons to approach.

page_text: In Fig. X., shewing a pendant lamp partly in elevation and partly in section, the
core F and upper carbon E with its socket are balanced by the lower carbon E¹
and the rods B, B', which carry it, the pullios R, R¹, over which the balancing cords
pass, serving as guides to the socket tube of the upper carbon. In this lamp the
connections and action of the two solenoid coils S, S₁, are as described with referenco
to Fig. IX. A standard lamp arranged to maintain a constant focal position of the
arc produced by a continuous current is arranged, as shewn at Fig. XI., the racks
2, 2, of two carbon sockets being connected by insulated gear G, D, proportioning
their movements to their respective rates of consumption. The shunt coil S¹ may
consist of two or more layers of thick insulated copper wire, furnishing the con-
volutions required with several layers of thin copper and German silver wire to
provide the required resistance. An electro-magnet M acting on an armaturo.
contact lever H serves to short circuit the coil Si in case of interruption of the
lamp circuit.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondents,
I claim, in respect of electric lamps and solenoids applicable for their regulation,-
First. The use of solenoid cores having the mass of the metal of which they
consist lessened towards each end, substantially as and for the purposes herein set
forth.
Second. The combination of cores, such as are referred to in the preceding
claim, with two solenoid coils, arranged and operating for the regulation of an
electric lamp, substantially as herein described with reference to the accompanying
Drawings.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this First day of October, in the year of our Lord One
thousand eight hundred and eighty.