Improved Arc Lamp having Two Arcs in Series.
Year: 1899

page_text: Date of Application, 26th July, 1899-Accepted, 7th Oct., 1899
Improved Arc Lamp having Two Arcs in Series.
I, WILHELM MATHIESEN, of Leutsch, near Leipsic, in the German Empire,
Electrician, 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:-
1
The present invention relates to an arc lamp with two arcs inserted one behind
the other in series which is preferably constructed as an enclosed lamp substantially
as shewn in Figure 1.
Arc lamps with two arcs are already known, but such lamps have been hitherto
constructed with two pairs of carbons side by side, and these moreover usually
arranged in the same plane as the rods of the lamp.
In
In lamps with open burning are this arrangement is permissible, but in
lamps with enclosed arc it has the serious disadvantage that two globes side by
side and enclosing the mechanism render a very large space necessary, conse-
quently the surrounding outer globe must have very considerable diameter.
order to overcome this drawback in the present invention the carbons are not
placed side by side, but one above another, whereby it becomes possible to enclose
both ares in one and the same air-tight small globe, and also in spite of the
presence of two ares to retain the normal dimensions of the mechanism and of the
outer globe.
In this construction, the carbon constitutes an electrode common to both arcs
in such a manner that it forms at the one end the negative, and at the other end
the positive, electrode. This carbon is supported by the holder b which in the case
of lamps with enclosed arc is connected with the cover d of the globe e by means
of the Hat bars c. In lamps of open are as shewn in Figure 2, the said holder b is
attached to the rods of the lamp. Whilst the middle combined carbon is fixed,
The motion of these
the upper and the lower carbon move with relation to it.
two carbons is controlled by two separate apparatuses. Both carbons remain
under the influence of their own weight or of the difference of their own weight
including that of the carbon holder, and that of a counterweight f, taking into
consideration the two friction couplings g and h, which are here shewn as ball
couplings.
It is desirable that the controlling devices should be suitably selected for
working in series, but as it is also possible to give one thereof a main current
magnet, if the other is provided with a shunt or differential magnet, this has been
taken into consideration, and the magnet i of the upper carbon is shewn as being
inserted in the main circuit, whilst the controlling device of the lower are contains
two differential coils k kl.
The small globe e is rendered airtight at its upper end in the wellknown
manner by means of a metal cover, through the central aperture whereof the
carbon m can pass, whilst the lower carbon a moves freely through the support or
holder o, in which the access of air is prevented also by exact workmanship, or
by air tight packing rings p.
Although it is preferable to construct the globe of one piece, it is also possible

page_text: to form it in two parts, which parts either come directly into contact at the point
where the carbon holder 6 is placed, or are held by special metal sockets. In this
case also it is desirable that both globes should be one above the other.
It is also possible to utilize the arrangement of the carbons placed one above
another for lamps with open arcs as shewn in Figure 2. It is, however, necessary
in this case to have a negative and a positive carbon of the usual dimensions
held by a common holder in place of the united central carbon first described.
In both cases it is assumed that the globe e is fixed and that only the upper and
the lower carbons move against the middle one. It would, however, easily be
practicable to make the globe movable in unison with the carbon holder by
suspending the upper carbon by means of a chain passing over a roller to the other
end of which chain the globe is attached. This would cause the lower carbon to
double its motion. In the first place, it would be obliged to follow the central
carbon when it moved upwards, and secondly, it would have to advance corre-
spondingly in accordance with the combustion of the lower arc.
Or the globe
might equally well possess a common motion with the lower carbon, whilst the
motion would be reproduced in a double degree by the upper carbon.
The lamp is capable of being actuated either by uniform or by alternating
current.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. The improved age lamp having two arcs arranged in series one above the
other, possessing a common electrode, and in which the two other electrodes are
movable by means of separate mechanisms and independently from one another
with regard to the common electrode.
2. A modification of the arc lamp set forth in Claim 1 in which two fixed
electrodes connected together take the place of the common electrode.
3. An arc lamp such as set forth in Claims 1 and 2, in which for the one arc a
regulating mechanism is used having a main current magnet, and for the other
are a regulating mechanism is used having a differential or shunt magnet, sub-
stantially as described.
י
T 1
1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.