Improvements in Arc Lamps.
Year: 1898

page_text: Date of Application, 22nd Dec., 1898--Accepted, 28th Jan., 1899
COMPLETE SPECIFICATION.
Improvements in Arc Lamps.
I, HANS REALF OTTESEN, of 24, Schlägerstrasse, Hanover, in the Empire of
Germany, Engineer, 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 :-
My invention relates to an are lamp, in which the carbons owing to the way in
which they are suspended form a Voltaic arc which remains of constant length and
always occupies the same position, quite independently of the combustion of the
carbons. In the invention an insulating plate is introduced between the ends of
the carbons giving an intense illuminating effect when raised to white heat.
The invention is illustrated in the accompanying drawings, in which:
Figure 1 shows the mathematical principle, on which the invention is based.
Figure 2 represents the improved are lamp in front elevation, and
Figure 3 represents the same in side elevation and,
Figure 4 represents a part in detail.
With points A, B, and C (Figure 1) as centres three segments of circles whose
radii are respectively r, and ¹, are drawn intersecting each other at the point F,
so that from every straight line drawn from the point F, equal lengths p are cut off
between the two circles whose centres are A and B on one side and whose centres
are A and C on the other. Thus for instance, D¹ Et D2 E2
== D3 E3 and
so on.
=
If now the radii 7 and represent rods pivoted at A, B and C and connected by
pivots at their outer extremities to a third rod as will be hereinafter more fully
described equal to p in length, then, whatever may be the position occupied by
and 7, p will always occupy such a position, that its elongation passes through F.
This fact has been utilized by me in my improved arc lamp.
The two carbons at a (Figure 2) are not arranged vertically one over the other,
but are both slightly inclined relatively to the horizon, so as to form an obtuse
angle with one another. They are secured in the carbon holders cc (shown in detail
in Figure 4) by means of screws bb.
Rods and g are pivoted respectively to the carbon holders by the pins d and e
and are adapted to turn on the pivots h and i, suitably fixed in the face plates k, k.
The distance between the centres of the joints & and e corresponds with the constant
length pin Figure 1. The rods g are provided with lateral arms l, on which
weights n can be placed.
The arms and y are of insulating material or are insulated by insulating pieces
from the holders.
Between the two carbon rods, which are pressed towards each other by the
weights m and which always meet in the focus n, passes the separating piece q
fixed to the rod o. This piece consists of an incombustible non-conducting
substance such as kaolin, porcelain, or the like. The voltaic are now passes in a
curve around the bottom of the plate q, and since this plate is of a constant
thickness, the arc is likewise always of the same length. The thickness of the

page_text: plate is chosen in accordance with the tension employed and thus ares varying in
length may be obtained.
The current may pass through the magnets and the carbons in series.
The rod o is connected to the armature t of the magnets u. Weights w capable
of adjustment upon the arms » connected with the armature t tend to lift the
armature and consequently also the plate q. When the current through the
magnets is switched off, the plate is drawn away from between the two carbons, and
the latter coine into contact; when the current is switched on again, the armnature t
is pulled downwards, the carbons are forced apart by the plate q and the arc is
struck.
The whole lamp is suspended from the bolt s which passes through the face
plates k, k.
If the lamp is not to be used as a suspended lamp, but in any other position, for
instance in connection with a reflector, springs must be substituted for the
weights m and w.
My improved lamp may be equally well employed for continuous or for alternating
currents.
My improved lamp presents certain advantages in as much as by my method of
suspending the carbons, the regulating mechanism is dispensed with, while never-
theless the length of the arc remains practically constant and is not subject to
displacement in space. Moreover a very favourable illuminating effect is obtained
seeing that the insulating plate is raised to a white heat and emits an intense light
similar to lime light.
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 :-
M
1. The method of suspending the carbons so as to cause them to meet at a given
point substantially as set forth.
2. The means of supporting the carbons substantially as set forth.
3. The means for separating the carbons and enabling the are to be maintained of
uniform length substantially as set forth.
4. The arrangement and combination of parts substantially as set forth with
reference to Figures 2 and 3.
Dated this 2nd day of Doeumban 1000