Improvements connected with Electric Arc Lamps.
Year: 1895

page_text: Date of Application, 9th July, 1895-Accepted, 10th Aug., 1895
COMPLETE SPECIFICATION.
Improvements connected with Electric Arc Lamps.
We, ALBERT COOPER SEIBOLD, of No. 36, 15th Avenue in the City of
Mount Vernon, in the County of Westchester and State of New York, United
States of America, Electrician, EDGAR OLCOTT CLARK, of No. 537 West
152nd Street, in the City, County and State of New York, United States of
America, Manufacturer, and WILLIAM SOWDON, of No. 65 West 131st Street, in
the City, County and State of New York, United States of America, 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 relates to electric arc lamps and its object is to prolong the
duration of the life of the carbons or electrodes of such lamps, that is to say, to
increase the number of hours during which the carbons or electrodes will burn,
thereby reducing the frequency with which the lamp must be supplied with new
carbons and reducing the consequent cost of operation of arc lighting systems.
The invention consists in part in means for retarding the consumption of the
carbons by excluding oxygen from the arc, and in part in means for preventing the
obstruction of the light by the particles of carbon which are thrown off in burning
and usually settle upon the inner wall of the surrounding or enclosing shell or
globe. The means last referred to are supplemental to the first mentioned means
and are particularly advantageous when low grade carbons are used which throw
off much dust and quickly cloud the enclosing shell or globe, but such means may
be dispensed with altogether, if desired, as when high grade, expensive carbons are
employed which are cleaner in consumption and do not as quickly smut the interior
of the surrounding shell or globe.
The present improvements may be embodied in various forms, but the form
shown in the accompanying drawing is well adapted to attain the objects stated.
In said drawing,-
Figure 1 is a view in sectional elevation representing the application of the
improvements hereinafter described to the two carbons or electrodes of an arc
lamp.
Figure 2 is a partial section on the plane indicated by the line 2-2 of
Figure 1.
Figure 3 is a side elevation of the cap which closes the lower end of the
globe.
The globes of electric arc lamps are usually of considerable size and are open at
the top and bottom, thereby permitting free access of air to the arc. It has been
discovered that by excluding the air and the oxygen which is a constituent thereof
from the are, the consumption of the carbons is retarded and the time during
which the carbons will burn without requiring to be replaced by others will be
correspondingly prolonged. Accordingly the arc is enclosed within a translucent
globe or shell A, which is relatively of small size as compared with the globes
commonly used, and is closed at both ends, and at the same time it is adapted to
receive the two carbons and to permit movement of one carbon as it is fed forward
to compensate for the consumption of the carbons. It is obvious that the globe
Day fit tightly around the fixed carbon and that while having a snug fit around the
other or movable carbon, it should permit free movement thereof.
In the drawing
the globe A is represented as closed at its upper end by a metallic screw cap a
having a central orifice for the upper carbon or electrode. If it is deemed

page_text: necessary to provide for any eccentricity of the upper carbon with respect to the
lower the orifice through the cap a may be of somewhat greater diameter than
the carbon itself while a loose washer (not shown) having an orifice which fits the
carbon, covers the space between the carbon and the walls of the orifice in the cap.
The bottom of the globe is also represented as closed by a metallic screw cap B
having a conical portion for the collection of the carbon dust and a tubular
portion or sleeve d through which the lower carbon or electrode is passed and in
which it fits tightly. The sleeve d, if desired, may be secured in the frame which
supports the usual large globe. It will be apparent that the globe A is not
absolutely air tight, but it is nevertheless sufficiently tight, to prevent the free
access of air to its interior and consequently there will not be a sufficient amount
of oxygen within the globe at any time to promote, rapid consumption of the
length
carbons. As represented, the globe is preferably cylindrical, and is of a
corresponding to the feed movement of the upper carbon. It is not absolutely
essential that the usual large globe should be employed in addition to the closed
globe A, but nevertheless it may be employed as a protection for the smaller
globe.
If high grade, expensive carbons are employed in a lamp equipped with the
closed globe A the accumulation of carbon dust upon the interior of the globe will
be very slow and it will be a correspondingly' long time before the light is obscured.
Consequently, if such carbons are used, it may not be considered necessary to
provide means for preventing the accumulation of the dust upon the globe. On
the other hand, if the ordinary low grade and inexpensive carbons are employed,
the accumulation of dust upon the interior of the globe will be rapid and the light
will soon, be ‘obscured to such a degree as to obviate in part the advantages secured
by the use of the closed globe. Accordingly, by this invention -means, are also
provided for preventing the accumulation of the carbon dust -upon- the interior of
the closed globe A Such means comprise a foraminous guard C which is disposed
within the globe or shell A in such position as to surround the are at all times.
In the example shown in the drawing the guard is represented as cylindrical in
shape and as made of such material as wire gauze; it extends from end to end of
the globe and is supported in position by the upper end thereof and by the cap B.
In use, the guard intercepts the particles of carbon that are thrown off from the
proximate ends of the electrodes and acts to direct them downwardly into the
collecting chamber c of the cap B and prevents the same from settling upon
the sides of the globe.
.
It is not essential that the wire gauze or other foraminous material sheuld have
very small openings, although the carbon dust is itself in the form of very minute
particles, and in fact it has been found that a wire gauze having twelve wires to
the inch answers all purposes. It will be obvious that if the particles of carbon
were thrown at right angles against the foraminous material, they might pass
through the perforations, but under the usual conditions the particles fly from the
ends of the electrodes in directions more or less oblique to the guard. It may be
assumed, therefore, that for this reason the particles do not pass through the
perforations of the guard but strike the intermediate portions and are thereby
deflected and caused to fall downwardly within the guard. It may also be assumed
that the interposition of the foraminous guard induces or causes currents of gases
to flow parallel with the inner surface of the guard, which currents may act to
some extent to arrest the motion of the particles. Whatever theory may be
adopted as to the action of the foraminous guard it is certain, as shown by practical
tests, that the result of its interposition is to prevent the gathering of the particles
of carbon upon the interior of the surrounding globe and to cause them to fall
within the guard and to collect in the cap B, from which the dust may be removed
readily when the carbons are replaced. The guard itself, especially when made of
wire gauze, offers no apparent obstruction to the passage of light and in addition to
its chief function it reduces the danger of breakage of the surrounding globe by
absorbing and evenly distributing the heat from the arc.

page_text: It is to be understood that the invention, so far as it relates to the provision of
a closed globe, is not to be restricted to any particular size or shape nor to the use
therewith of the inner guard; and it is also to be understood that so far as the
invention relates to the provision of a foraminous guard it is not restricted to any
particular form nor to any particular material of which the guard may be made.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is,-
-
1. A device for retarding the consumption of electric arc lamp carbons, which
consists of a translucent globe or shell of relatively small size and closed at both
ends but adapted to receive carbons with a snug fit and to permit one of the
carbons to be fed forward as the carbons are consumed, substantially as shown and
described.
2. A device for prolonging the duration of the life of electrodes for arc lamps
or for retarding the consumption of such electrodes, which consists of a globe or
chamber enclosing the proximate ends of said electrodes, said globe or chamber
being closed at both ends around said electrodes so as to substantially exclude the
air from its interior, substantially as shown and described.
3. The combination with the enclosing globe of an arc lamp, of a foraminous
guard located within said enclosing globe and surrounding the proximate ends of
the carbon electrodes so as to intercept the particles of carbon that are thrown off
while the electrodes are burning, substantially as and for the purpose set forth.
4. A device for prolonging the duration of the life of electrodes for arc lamps
or for retarding the consumption of such electrodes which comprises a globe or
chamber enclosing the proximate ends of said electrodes, said globe or chamber
being closed at both ends so as to substantially exclude the air from its interior and
a foraminous guard located within said globe or chamber and surrounding the
proximate ends of the carbon electrodes so as to intercept the particles of carbon
that are thrown off while the electrodes are burning, substantially as and for the
purpose set forth.
5. The combination with the globe of an arc lamp of an internal, cylindrical
guard of foraminous material surrounding the arc and extending throughout the
length of the globe, substantially as shown and described.
6. The combination with the globe of an arc lamp, of an internal foraminous
guard surrounding the arc and extending throughout the length of the globe, a cap
attached to the bottom of said globe and having an opening to receive the lower
electrode and a cap closing the top of the globe and provided with an opening for
the passage of the upper electrode, substantially as shown and described.
Dated the 0th dox of Tule 1005
PHILIP M. JUSTICE,
Chartered Patent Agent, London,
For the Applicants.