Appliances for the Carbons of Electric Arc Lamps for Increasing the Duration thereof.
Year: 1894

page_text: Date of Application, 26th Feb., 1894-Accepted, 28th Apr., 1894
COMPLETE
SPECIFICATION.
Appliances for the Carbons of Electric Arc Lamps for Increasing the
Duration thereof.
We, FRANCIS JEHL XVIII Wienerstrasse No. 32, Vienna, Engineer, and
MORIZ VON HARDTMUTH, of XVIII Shegargasse Vienna, Austria, Manufacturer
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 :-
This invention has for its object to increase the duration of the carbons of electric
arc lamps when in action by preventing the lateral burning and detaching of the
carbon particles which occur when the current is passing.
In certain cases the devices employed for this purpose can also be made to
maintain the arc in one and the same position. Hitherto it was attempted to attain
this end by coating or plating the carbons with different kinds of metals or alloys
which melted in the burning, or by enclosing the lamp or the carbons in an
exhausted casing, or by treating the carbons with various chemicals or solutions
which were volatilised in the burning. All these means have however proved to
be more or less ineffective for the purpose in view, and at the present time the
carbons are used without any such preparations being applied thereto.
The appliances which form the subject of the present invention, and which
effectually fulfil the object of increasing the duration of the burning of the carbons
without requiring these to be prepared in any way before hand, consist essentially
of a protecting socket or sleeve surrounding the upper carbon, and formed of a
refractory material, and of a protective guide or support placed free upon the point
of the lower carbon and in some cases suitably connected to the socket or sleeve of
the upper carbon.
The said guide either sinks with the burning away of the lower carbon, and is
thereby made to carry the protective sleeve of the upper carbon with it, or it is
stationary and the lower carbon is raised up against it as it burns away, in which
case the arc is always maintained in one and the same position.
The protective sleeve or socket of the upper carbon can also be used
independently of the guide and be actuatel by the regulator that feeds the carbon
forward.
The accompanying drawing shews diagrammatically several modes of carrying
out the said invention.
Fig. 1 shews the arrangement of an arc lamp in which the protective sleeve is
actuated by the burning away of the lower carbon.
Fig. 2 shews an arc lamp in which the sleeve and guide are stationary, and the
lower carbon is raised up to the guide as it burns away.
Fig. 3 shews an arrangement in which the sleeve is moved by the upper
carbon;
Figs. 4 to 6 shew several forms of protective sleeves.
Figs. 7 to 12 shew several kinds of guides or supports.
As shewn, the upper carbon k is surrounded near its end by a tubular socket or
sleeve s, which is either cylindrical as at Fig. 1, or conical as at Fig. 4 and can be
formed with a flange, as at Fig. 5 or with an external thread or grooves as at Fig. 6
tor the attachment of the wires or arms a a¹.
This protective sleeve, through which the carbon k can slide freely but without
allowing currents of air to pass upward between the carbon and the sleeve, is made of
a material which offers sufficient resistance to the heat to which it is subjected by the
electric arc, such for instance as steatite, asbestos, fire clay, porcelain, or metals such

page_text: as platinum, nickle or brass, or metallic oxides, or other suitable metallic compounds.
This protective sleeve is either cast or pressed, according to the nature of the
material, or it is formed by lining or coating one material with another. The
sleeves can be maintained in position by means of wires a a', bb, c c as at Fig. 1,
which wires are connected by articulated joints d d', so that they can be brought
into any desired position; the wires bb' are advantageously made of two separate
parts and adjusted in length by junction pieces e el with setting screws.
The wires c c are fixed to a guide which has the form of a ring f surrounding the
lower carbon, to which are attached wires g carrying a ring the diameter of
which is somewhat smaller than that of the carbon ¹.
As the lower carbon, in burning forms an approximately conical point, the ring
placed upon the same, and consequently the entire device will be held in a reliable
manner.
On the burning away of the lower carbon the device will consequently sink to a
corresponding extent and thus maintains the same relative position to the upper
carbon fed forward by the regulator. The latter will thus be always protected
by the sleeves, which will prevent any useless burning away or detaching of
particles of carbon, and will thus enable the carbons to last much longer in
action.
.
In place of the ring may also be employed a smooth or grooved conical
cap Figs. 7 and 8, or a plate with a hole in it such as Figs. 9 and 10 or the
wires g can be bent into hook shape at their free ends as at Fig. 11 so as to rest
upon the carbon.
The several parts of the guide are made of a sufficiently refractory material,
preferably metals, such as platinum, nickel, brass or other alloys.
In order also to increase the duration of the lower carbou there may be
combined with the above described guide or support a tubular protective sleeve s¹
as shewn at Fig. 12, similar to the sleeve s, and made of the same refractory
materials; this sleeve can be held on the carbon point, for example by means of
claws h³.
If with such an arrangement the luminous are is to be maintained stationary, the
sleeves of the upper carbon k is secured to the lamp framing by means of arnis a a¹
and the lower guide by means of arms c c' as shewn at Fig. 2, so that the entire
device remains stationary while the upper carbon is fed forward by the regulator,
and the lower carbon is kept up to the guide by means of a suitable arrangement.
This arrangement may advantageously consist of a clamping ring or cup i bearing
against the lower end of the carbon k', which cup is suspended from wires or cords
that pass over rollers carried by the lamp frame and have counterweights attached
to their other ends, which weights consequently tend to press the carbon continually
upwards against the ring h, or other holding or clamping device, in proportion as the
carbon burns away.
Instead of effecting such upward pressure by weights, the raising of the carbon k¹
may of course also be effected by springs or other mechanical device, or by means of
an electrical device such as an electro magnet or solenoid.
The upper protective sleeves can also be suspended from cords or wires ; as shewn
at Fig. 3 and which carry counterweights and pass over suitably arranged rollers,
in which case the sleeves have hooks or claws at their lower ends, against which
the end of the carbon k bears, so that in this case the protective sleeve moves
together with the carbon.
Also in this case the weights can be replaced by the before mentioned mechanical
or electrical devices which are also fixed to the lamp framing.
If the protective sleeve s is made of a metal or alloy it must of course be
suitably insulated from the lower guide in order to prevent the short circuiting of
the currents.
A reflector or shade of enamelled metal or other refractory material may be
attached to the sleeves, and he so arranged as to its shape and position as to throw
the light to any desired point.

page_text: Also, radiators of any known kind may be combined with the device for rapidly
carrying off and distributing the heat produced.
Having now particularly described and ascertained the nature of this inven-.
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In electric arc lamps the employment of a device for increasing the duration
of the burning of the upper carbon, consisting of a protective sleeve or socket
such as s of refractory material surrounding the end of the carbon, which sleeve
permits of the forward feed of the carbon by the regulator or is carried forward
with the carbon, substantially as described.
2. In combination with the protective sleeve or socket referred to in the
first claim, a device for the protection of the lower carbon consisting of a
supporting or clamping device h h h or h³ applied thereto in such manner that.
it is supported by the conical point formed by the burning of the carbon, and
sinks with the same, whereby the protective sleeves of the upper carbon is carried
along therewith in the case where the two parts are connected together, substantially
as described.
་
3. In the devices referred to in the first and second claims, for producing a.
stationary luminous arc, the arrangement of the lower carbon in such manner that
it is continually pressed upward against the fixed holding device h, h³, h², or h³, as
the carbon burns away, such action being effected either by a mechanical or electrical
appliance, the protective sleeve 8 of the upper carbon k being either fixed or made
moveable with the carbon by means of a mechanical or electrical device, substantially
as described.
Dated this 26th day of February 1894
ABEL & IMRAY,
Agents for the Applicants.