Improvements in Electric Arc-lamps.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Arc-lamps.
I, KARL SCHLEYDER, Engineer, Royal and Imperial State Railways, Tabor,
Bohemia, Austro-Hungary, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
In proportion as the use of the electric light becomes more general, so does the
necessity become manifest of cheapening the construction of individual parts, so
as to promote its extension.
An essential element of an electric-lighting installation consists of a good,
faultless, regulating arc-lamp, the simpler it is in construction the more accurate it
is in point of regulation, by that alone being rendered both cheaper and more
economical.
In developing this idea I have succeeded in devising an arc-lamp of very simple
construction, which is illustrated in the accompanying drawings.
Figure 1 is a front view.
Figure 2 a side view and section on the line - of Figure 1.
Figure 3 is a complete side view of the arc-lamp which is composed of the
following principal parts:
-
1. A short metal tube R provided with two slits i
2. An iron core E adapted to move up and down in the said tube its vertical
oscillations being communicated by the cross-piece k to the rollers o and levers C ;
3. Bent levers C arranged to pivot or rotate easily on the fulcra a₁ a, and
carrying at one end the rollers o and at the other end the insulated carbon-
holders H, H, as well as the arms ei e, carrying the movable weights q which serve
to counterbalance the entire mechanism;
4. A brake-apparatus for the iron core E devised to prevent any backward (or
downward) movement of the core whereby the carbon points would be separated;
5. A solenoid S of inconsiderable resistance.
Two modifications of the brake-arrangement adopted by me, are shown in the
drawings Figures 4, 5, 6 and 7.
Figure 4 shows one modification in section on the line - of the following
Figure 5; while,
-
Figure 5 is a section thereof on the line y-y of Figure 4;
Figure 6 shows a second modification in vertical section, and,
2
Figure 7 gives a view of that part of the tube R which carries the brake device.
The first modification consists of the Saladin brake already known. Inside the
tube R (Figure 4) there is a short fixed tuber within which, by means of a pin u
is hung a ring R₁ provided with a central aperture and also with a annex or pro-
longation which projects through slots t in R₁ and in which it is free to move
up and down. It is clear that the rod or spindle b, which passes through the hole
in the centre of the ring R₁, can move freely therein in the upward direction, the
ring offering no hindrance; but, when it moves downwards, the ring R₁ assumes a
slanting position (shown in continuous lines in Figure 4) with the periphery of the
central opening in contact with the rod on one side, exerting thereon a brake-
action.
The second modification (shown in Figure 6) consists of a block q, fixed within
the tube R by means of a screw y and having a central opening through which the
is held in a slot
rod 6 passes. A flanged ring 7, fitted to the top of the block 91
in the tube R by means of a pin qs (after the manner of a bayonet lock joint)
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Figure 7 and the said ring 9, is connected by a screw 9, with an inner ring %
provided with a large central aperture 9. (Figures 6 and 7).
Between the flange 9, at the bottom of the ring 92 and the inmost ring 9, an
annular rubber washer q, rests on the top of the block 9 whereof the central
aperture almost exactly fits the diameter of the rod or spindle b. It is clear that
the latter can move upwards freely, inasmuch as the rubber washer 1, (raised at
the same time by friction against the periphery of b) is free to expand in the
hollow space 98,
above it; whereas, when the rod 6 descends, the rubber washer
is held fast, and prevented from flexure by the block 7, and the inmost ring-9, the
consequent friction acting as a brake upon b.
The working of the arc-lamp is as follows:-'
-When no electric current is flowing,
the action of gravity on the levers C maintains close contact between the carbon-
points K, K, carried by the carbon-holders H, H,. The lamp is put in the electric-
circuit by switching the current on the terminal k₁ whence it passes through the
solenoid S, and by the contact-piece p₁ and the holder H₁ to the carbon-point K₁:
thence, passing over to the carbon-point K,, it traverses the holder H, and contact-
piece p to the other terminal ks, by which it passes away. In the meantime, the
electromotive force of the solenoid S depresses the core E and causes the separation.
of the carbon-points, whereby the voltaic arc is established.
Hereafter the following forces operate in the lamp-On the one hand the
constant and invariable intensity of the electric current, and the variable resistance
of the voltaic arc which gradually increases in proportion as the carbons are con-
sumed; and, on the other hand, the constant force of gravity, and the varying
friction of the brake-device.
Inasmuch as, in the entire electric system, there is only one variable force
present viz. the arc-resistance, in opposition to which the constant force of gravity
tends to bring the carbon-points together, I thus attain the accurate regulation and
automatic adjustment of a constant electric arc-light.
Should the separation of the carbons tend to increase at any given moment, by
their gradual burning away, the arc-resistance increases simultaneously, whereby
the current is weakened and ceases to have sufficient power to maintain the normal
depression of the core in the solenoid; gravity-gaining the ascendency causes the
carbon-points to approach each other, raises the iron core, and thus maintains the
constancy of the arc-light.
By this extremely simple and easy construction and arrangement, the desired
result is obtained, without the usual complications of sets of geared wheels, chains,
etc., or the differential working of a combination of solenoids, magnets, etc., whereby
the carbon-points are brought near each other.
At first sight it would seem as though, by this construction a principal or
inducing current lamp were established which might be very well adapted for
single are lights, but not at all suited for a series of arc-lights in circuit. But, as
numerous trials have demonstrated, this lamp is admirably adapted for combined
lighting as well in series as in parallel, without the supplementary aid of a second
solenoid with great resistance. If, however, it be desired to construct the lamp
as a differential lamp, all that is needed is to add a second solenoid.
For the very reason that this lamp is constructed as a principal or inducing
current lamp, and is at the same time applicable for combined lighting, it can also
be employed with currents of the most widely different intensities, which is also,
indeed, attained in the most suitable and efficient way, because the balancing
devices can be adjusted, according to requirement, by altering the position of the
adjustable weights y, which, for instance, if fixed at the extreme end of the
arms ei es that carry them, render a greater power necessary to separate the carbons
and establish the voltaic arc.
The essential advantages of the arc-lamp are as follows:-
1. Inasmuch as the lamp, without the supplementary aid of a second solenoid
of high resistance, regulates with perfect precision the illuminating voltaic are,
because, the whole of the regulating mechanism being balanced, the frictional

page_text: resistance is reduced to a minimum, a considerably smaller expenditure of force is
required for the establishment of the voltaic arc; as the loss of force by the
second solenoid of high resistance is entirely avoided, and owing to the simple
construction the frictional resistance (as above stated) is reduced to a minimum.
2. The lamp is equally well adapted to be used in single circuit or with a divided
current in series or parallel circuit.
3. The lamp, owing to the balancing of the mechanism being adjustable can be
used for electric currents of the most widely different intensities (which is not the
case with differential lamps).
4. The lamp is extremely light (weight without armature 4 kilogs.) and casts no
downward shadow, wherefore it is admirably adapted for lighting enclosed spaces.
5. The lamp is extremely inexpensive, both in first cost as compared with
other well-regulated arc-lamps, and in point of maintenance which, owing to
simplicity and facility of construction, is completely minimised.
6. The lamp can be used for a 16-hours lighting-period, for which the total
displacement of the iron core within the solenoid will not exceed about
30 millimetres, whereby the perfect working and accurate regulation of the lamp.
is materially promoted.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An electric are lamp wherein the triple combined action of counterpoise-
weights solenoid S and brake device on the core of the solenoid E effects the
regulation of the lamp while owing to the adjustable arrangement of the weights
a variable differential working between the said weights and the solenoid-core E is
obtained thus enabling the lamp to be used with currents differing widely in
intensity, substantially as described and illustrated in the accompanying drawings.
2. In an electric arc lamp such as described the combination with the solenoid-
core E of a brake-device comprising a ring R₁ through the central aperture of
which the rod or spindle of the solenoid core E passes the slantwise or angular
displacement of the ring R₁ pivoting on the pin u by its own weight exerting
brake-action upon the said rod substantially as described and illustrated in the
accompanying drawings.
Yo.
3. In an electric arc lamp a brake device comprising a rubber disc or washer
which is laid between a ring 7, and block qi and is free to bend or expand upwards
into the hollow space thereby allowing the stem or spindle b when pushed
upwards to pass freely whereas on the fall of the said stem any such bending
downwards of the said disc is prevented by the block q₁ whereby the stem b is
hindered or obstructed in its descent by the consequent friction substantially as
described and illustrated in the accompanying drawings.
Dated this 26th day of February 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.