Year: 1893

page_text: Date of Application, 19th Sept., 1893-Accepted, 18th Aug., 1894
COMPLETE SPECIFICATION.
Arc Lamp.
I, ARTHUR STANLEY ATWATER, of 240 Beach Street, in the City of Cleveland,
State of Ohio, United States of America, 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:-
My invention relates to improvements in are lamps, and the objects are to
provide a type of lamp which will be self-sustaining, and will require adjustment
only at very long intervals. To accomplish these results, I employ the distinctive
mechanism and combination, and arrangement of the various parts, hereinafter
described, shown in the accompanying drawings, and more specifically pointed out in
the claims.
In the drawings,
Fig. 1 is a side elevation of my improved lamp; Fig. 2 is a plan view of the
same; Fig. 3 is an end view;
Fig. 4 is a vertical section of the dash pot, and
Fig. 5 is a view of operating magnet.
In the drawings, A is a horizontal metallic bar, mounted as a wall bracket by
support a; B is a bar similar in length to the bar A, and oscillating thereon upon
the fulcrum point b, which is placed considerably below the center line between the
bars A and B, the effect of this position being to insure a tendency of the carbon
end of the bar B to fall toward the bar A, when the center of gravity has been
displaced toward that end of the bars, the lower the point of fulcrum, the greater
the displacement caused thereby.
C, Care narrow flat carbon plates clamped to the outer extremities of the
bars A and B, by thiu plates C2, in such a manner as to touch throughout their
adjacent edges when the outer ends of the bars are brought together. Between
these carbon edges is formed the arc.
In order to regulate the distance between the carbons and secure an unvarying
are, the magnet D is secured to the inner end of the bar A with corresponding
armatures d, on the bar B, the effect of this magnet being to pull down the
armatures and separate the carbon edges whenever the edges of the carbon
approach too near, so that the arc becomes too short and the current too strong.
The electrical connections are shown in the dotted lines in Fig. 1, the currents
being alternating. E and E' are the binding posts.
The current runs from the binding post E to the magnet D, thence along bar A,
to lower carbon C; thence forms the arc to upper carbon; thence runs upon the
upper arm to fulcrum 6, which rests upon the insulated plate ', and thence out at
post E. Both posts are insulated as shown.
G is a dash pot placed upon the lower bar A, and H is a plunger upon the upper
bar working therein; the valve h in the plunger will be seen to be so placed that
the bars will separate freely and bring the carbons together, but the carbons will
be separated with much more difficulty since the liquid will be more slowly
displaced in the downward movement of the piston plunger.
and are weather guards to preserve the fulcrum point
under the cover & omitted in Fig. 2.
from rain driving
It will be seen that the action of the lamp is automatic since any too great
separation of the carbons weakens the current and the hold of the magnet, so that
the carbons again approach until the requisite are is formed between them. Again,
the arc once formed will travel from end to end of the plates of carbon, as it cats
D

page_text: its way slowly, so that a long time will elapse before another adjustment will be
necessary.
An additional shunt winding of fine wire X may be utilized to limit the power
of the magnet and prevent excessive magnetism when the current is strongest.
This is wound the reverse of the coarse wire Y, and so tends to neutralize its effect.
when the current is in excess of the usual capacity of the coarse wire. In Fig. 1,
P and O represent the main and shunt circuits.
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 :-
1. In an arc lamp, the combination of flat carbon candle plates, having linear
edges presented to each other for the formation of the arc, a stationary holder for
the lower carbons, and an oscillating upper holder, whose fulcrum point is located
upon the lower holder at a point below the horizontal center liue between said
holders, substantially as described.
2. In an arc lamp, the combination of flat carbon candles having linear edges
presented to one another for the formation of the arc between them, a rigid lower
carbon holder, an oscillating upper carbon holder and means for adjusting the
relative positions of the upper and lower carbon plates, consisting in the electro-
magnet D, upon the lower holder, and armatures upon the upper holder, substantially
as described.
3. In an arc lamp, provided with flat carbon plate candles, the combination of a
lower fixed carbon holder, upper oscillating holder, and means for regulating the
length of the arc between the plates, consisting in the magnet D on the lamp
circuit, located upon one of the holders, and armatures upon the other holder, with
a modifying shunt coil upon the magnet reversely wound to the main circuit,
substantially as described.
4. In an arc lamp, provided with plate carbon candles having linear edges
presented to one another for the formation of an arc, a fixed lower bolder, an
oscillating upper holder with means for controlling the movement of the upper
holder and length of the are, consisting in the electro-maguet D, upon the lamp
circuit placed on the lower holder, one or more armatures upon the upper holder,
and a dash pot between said holders whereby an easy movement is given the
oscillating arm in bringing the carbons together, but a different movement in
separating them.
Dated this 27th day of July 1893.