Year: 1898

page_text: I, ALEXANDER STUTTMANN, of Rüsselsheim-on-the-Main, Germany, Engineer,
do hereby declare the nature of this invention to be as follows:-
Attempts to fix the luminous point in an arc lamp by feeding two carbons at
an angle towards the same constant point of intersection have been unsuccessful
for many reasons. First, in using the ordinary carbons and particularly cored
carbons a good light cannot be obtained for the reason that two craters are
formed in the upper carbon which also accounts for the fact that the proper
softening and incandescing of the mass does not take place at the point of con-
tact with the two carbons towards which point they are pressed by spring power
or other means, so that the feed takes place only by fits and starts as soon as the
edge of the crater is broken away. But it has further been found that carbons
cannot be produced with such uniformity or so homogeneous as to ensure the
uniform burning away necessary for a uniform feed and consequently one carbon
soon moves past the other. The present invention has for object to completely
obviate these drawbacks.
The formation of a central crater, the deepest point of which extends close up
to the meeting point of the two carbons, may be ensured by employing cored
carbons whereof the core is exposed at the side, which is situated within the
angle which the two carbons form with each other. Such carbons are prefer-
ably made of semi-circular form in cross section and placed with the flat sides
together. The manufacture of such carbons is more simple than that of the
ordinary cored carbons. The fact that the luminous arc is kept in the centre
nd that the heat is concentrated close to the point of contact of the carbons
ensures that the carbon becomes burnt at that place and becomes soft so that
the carbons can be fed on towards this point. For the purpose of preventing,
with complete certainty, all movement of the carbons past each other both
carbons may be transversely fluted or serrated on their adjacent sides so that
if at any time the circumstances at the point where the carbons bear against
each other should be such that one carbon tends to slip past the other, then
this carbon would at once catch by the point of its next tooth or serration
against the point of the corresponding tooth or serration of the other carbon.
Further the uniform forward feed of the carbons may be effected, in case the
carbons are formed perfectly homogeneous, by connecting the feeding mechanism
positively in such a manner that the corresponding carbons shall advance
through equal distances in equal times. Finally it may be stated that with
this arrangement of the carbons the use of a closed globe is considerably facili-
tated because it is possible to place the whole mechanism in the interior of a
hermetically closed casing.
In the accompanying drawings Figure 1 shews two carbons with their flutings

page_text: and with the crater formed by them. Figure 2 is a section through the two
carbons where they bear against each other. A and A are the carbons, d indi-
cates the serrations, and C is the core.
Figure 3 shews the general arrangement in a closed casing. The carbons A A
are guided in the slotted tubes a a in which followers B B are drawn towards
their point of intersection by means of the cords b b passing over the pulleys c c
and a spring barrel D. The same applies to the lower carbons A, A, tubes a¹, a¹,
small blocks B1, B1, cords 61, 61, pulleys c¹, c¹, and D¹. The tubes a a are
stationary with relation to the globe N. The tubes a¹, a¹, and the spring
barrel Di, are fixed to an arm E of the rod F which itself is connected to the
soft iron core M of a solenoid coil P. The core M is suspended from a lever R
by means of a spring Q and to its lower end is connected by a link f a lever g
which by meeting a set screw h limits the ascending movement of the core M.
The solenoid coil P acts in the well known manner to produce the upward and
downward movement of the core M and serves in a considerable degree to raise
the core M and with it the carbons A¹, A', sufficiently to strike the arc and to
allow them to descend again to the proper distance after the luminous arc has
been formed.
Dated this 1st day of Novemba 1000
provements in Electric Arc Lamps.
I, ALEXANDER STUTTMANN, of Rüsselsheim-on-the-Main, 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:―
Attempts to fix the luminous point in an arc lamp by feeding two carbons at
an angle towards the same constant point of intersection have been unsuccessful
for many reasons. In using ordinary carbons, and particularly cored carbons, a
good light cannot be obtained for the reason that two craters are formed which
also accounts for the fact that the proper softening and incandescing of the mass
does not take place at the point of contact, so that the feed takes place only
by fits and starts at the times at which the edge of the crater is breaking away.
It has further been found that carbons cannot be easily produced with such
uniformity or so homogeneous as to ensure the uniform burning away necessary
for a uniform feed and consequently one carbon soon moves past the other.
The present invention has for object to completely obviate the above men-
tioned drawbacks and to ensure the formation of a central crater, the deepest
point of which extends close up to the meeting point of the two carbons by the
employment of cored carbons whereof the core is exposed at one side, namely
that side which is situated within the angle which the two carbons make with
each other. Such carbons are preferably made of semi-circular form in cross
section (their manufacture therefore being more simple than that of the ordi-
nary cored carbons) and they are placed with the flat sides towards each other.
The core of the carbons is composed of the material usually employed viz.,
charcoal with or without an admixture of salts.
The fact that the luminous arc is kept central and that the heat is concen-

page_text: trated close to the point of contact of the carbons ensures that the carbon shall
be burnt at that place and shall become soft so that the carbons can be fed on
towards this point. For the purpose of preventing, with complete certainty, all
movement of the carbons past each other both carbons may be transversely
fluted or serrated on their adjacent sides so that if at any time the circum-
stances at the point where the carbons bear against each other should be such
that one carbon tends to slip past the other, then this carbon would at once
catch by the point of its next tooth or serration against the point of the corre-
sponding tooth or serration of the other carbon.
The lamp which is thus produced contains two meeting carbons at its upper
side which are both connected with the same end of the electric circuit and two
meeting carbons at its lower side connected with the other end of the circuit
in which the lamp burns and having the opposite polarity to the upper carbons
as usual in all arc lamps. The electric wires may be connected in any suitable
well known way with the tubes guiding the carbons.
In the drawings accompanying my Provisional Specification Figure 1 shews
two carbons with their flutings and with the crater formed in them. Figure 2
is a section through the two carbons where they bear against each other.
A and A are the carbons, d indicates the serrations, and C is the core.
Figure 3 shews the general arrangement in a closed casing. The carbons A A
are guided in the slotted tubes a a and are fed towards their point of inter-
section by followers B B drawn forwards by means of the cords bb passing over
the pulleys c c and both wound on the same spring barrel D. The same descrip-
tion applies to the lower carbons A¹ A¹ tubes a¹ a¹ followers B¹ B₁ cords 61 1
pulleys and spring barrel D¹. The tubes a a are stationary with relation
to the globe N whilst the tubes a¹ a¹ and the spring barrel D¹ are mounted on
an arm E of the rod F which is connected to the soft iron core M of a solenoid
coil P. The core M is suspended from a lever R by means of a spring Q and
to its lower end is connected, by a link f, a lever g which by meeting a set
screw limits the ascending movement of the core M. The spring and the
solenoid coil P act in the well known manner to produce the upward and down-
ward movement of the core M and with the carbons A' A¹ necessary to strike
the are and to allow them to descend again to the proper distance after the
luminous arc has been formed.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
:
1. In an electric arc lamp, the combination of a set of converging carbons
meeting at a point each of which carbons has inlaid therein a continuous body
of material along its side which is included within the angle of convergence,
the said carbons being of the same polarity, with another set of converging
carbons meeting at a point each of which carbons has inlaid therein a con-
tinuous body of material along its side which is included within the angle of
convergence, the said converging carbons being of a polarity opposite to that
of the first mentioned carbons whereby an arc may be maintained between the
meeting points of the two sets of carbons.
2. In an electric arc lamp, the combination of an electrode constituted by a
set of converging carbons meeting at a point, each carbon having a continuous
body of inlaid material along its side lying within the angle of convergence and
a second electrode co-operating with the set of carbons to form the arc.
3. In an electric arc lamp, employing carbons meeting at an angle each carbon
having a continuous inlaid portion within the angle of convergence, means for
preventing the carbons from becoming displaced comprising teeth or serrations
located upon the sides of the carbons which lie within the angle of convergence,
the said teeth or serrations of the one carbon being adapted to engage with
those of the other to prevent the carbons from slipping past each other.

page_text: 4. As a new and useful article of manufacture a carbon substantially semi-
circular or half round in cross section with a continuous body inlaid in the
side of the carbon corresponding to the diameter of the circle, substantially as
described.
Battl
this on day or
uly low.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.