Year: 1892

page_text: COMPLETE SPECIFICATION
Electric Arc Lamp.
1, WILLIAM EDWIN IRISH, of 48 Long Street County of Cuyahoga City of
Cleveland and State of Ohio, United States of America, Electrician, do hereby
leclare 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 consists of the combination of a thermo expansive electric conductor,
a clutch, an operating lever and spring or similar devices for communicating the
motions of the said conductor to the said clutch, and carbon electrodes engaged
with said clutch.
Reference being had to the accompanying drawings
Figure 1 is an elevation of the complete lamp ;
Figure 1 a diagram of circuits in a shunt lamp;
Figure 2 an enlarged elevation of the clutch;
Figure 2 a detail modification ;
Figure 3 a view of a portion of that shewn in Figure 2 in a different phase;
Figure 4 a view similar to that in Figure 3 except that a modification is
involved.
The device for operating the clutch consists of the combination of the rod a,
forming part of the frame of the lamp; a top plate b, of the lamp; a lever e
engaged with the clutch d, and fulcrumed at e to the rod a; and a therino expansive
electric conductor and actuating spring fastened respectively to the said top
plate to the adjustable screws h, and pivoted to the lever respectively at the.
joints i i
The clutch consists of tubes j, j³, located, the one above the other, and surrounding.
the carbon, or carbon holder k, loosely, when their axes coincide with that of the
carbon holder, but with a drag or grip when tipped to the least extent. The tubej.
has a flange m, on its lower edge, and the tube has a flange m' on its upper end.
When the axes of the tubes jj and holder & coincide, the flanges m, m' are parallel.
n, n', are stationary rods, parallel to each other and to the carbon holder and pass
loosely through holes in the flanges m, m'. They are threaded and provided with
nuts o so that the tension of the helical springs surrounding the same may be varied.
At or near their centres are shoulders p. The several helical springs 'q" qu
abut against the respective shoulders p and nuts o, or the frame cross piece of the
lamp.
11
In Figs. 2 and 3
The rods n, n' are suspended rigidly from the cross piece r.
one of the springs, 7, is omitted, and the corresponding rod a terminates between
the flanges m, m³. The springs 9, 7", q, are normally under compression,
tending to lengthen. In Fig. 2, the lower tubular clutch j is tipped, in Fig. 3, the
upper one is tipped, and in Fig. 4 neither is tipped. The supports of the clutches
are such that they are capable of independent motions, and each may be tipped as
if about a flexible and elastic hinge. In Fig. 3, the position of the upper tube is
shown as tipped. Any adjustments may be made, as desired, by means of the nuts o
and rods n, n¹. For example, the compression or tension of the spring may
be made greater than that of spring by adjusting the lower nut on the rod n¹.
In Figs. 2 and 3, the lever has a fork of two tines, the upper ones being
In Fig. 4, the
between the flanges in, m', and the lower one s' below the flange m
lower one is omitted i.e. there is no fork, and the lever c simply terminates
between the clutches.
In general, the clutch is controlled by the arc, so that any tendency to variation
immediately affects the clutch, so that, to the eye, the arc is without fluctuation.
:

page_text: The carbons t, t¹, normally touch, and the current passes through them and the
thermo expansive electric conductor which expands, and the spring g, which is
first placed under the proper tension by the screw lifts the forked end of the
lever, as shown in Fig. 3, and the upper carbon & is raised forming the arc.
the same time, the tubular clutch is placed in a vertical position as shown in
Fig. 3.
At
As the arc grows longer, the current becomes less and the conductor contracts,
and. in joint action with the spring y, and lever c, releases the grip of the tubular
clutch and simultaneously tightens that of the clutch whereby the carbon t is
lowered. These operations are continually repeated. The clutch is delicately
responsive to the least movement of the lever, as it should be, because the expansions
and contractions of the conductor are very small to permit of current. The least
expansion, elevates the carbon t; the least contraction, lowers it. The upper tube
clutches and raises the carbon, while the grip of the lower one is lessened and the
lower tube, clutches and lowers the carbon, while the grip of the upper one is
lessened.
In the shunt lamp, the conductor is in circuit with the resistance or rheostat u
in shunt around the carbons t, t'. The operation of the clutch after starting, is
substantially the same as already described. The carbons are normally out of
contact. When the current is turned on, the conductor f expands, and being
connected in this case to a point between the fulcrum and the clutch, allows the
spring to cause the clutch to lower the carbon whereby the circuit is closed
through the carbons and the current through the conductor weakened, whereby
the conductor and spring y cause the carbon to be raised in the manner similar to
that described with reference to former figures.
It should be noticed that the tubes not only tip; but also. move bodily: the
springs, being properly compressed. In this manner, the carbon is raised or
lowered through as long a range as necessary for great fluctuations of current which
sometimes occur even with the best. dynamos.
As soon as the upper carbon is too short for further operation, the spring v falls
into the notch and holds the carbon t. This spring continually presses upon the
carbon or carbon holder through the guiding tube and may form one of the paths.
of the current if desirable.
In Fig. 24, the carbon is without a carbon holder. I have used carbons thus
24 inches in length successfully. By the use of the spring e, the carbon ends are
prevented from falling to the ground or against the glass globe and breaking it.
In Fig. 1 the fork having the tines s, s¹, is separated electrically from the
lever e by the insulator w.
A, is a disc of mica located in the globe holding ring B, to collect particles of
hot carbon and at the same time to allow light to be transmitted, thereby obtaining
as little shadow as possible beneath the lamp.
When the electrode is held with or without the holder k, the current can get to
the arc by going through the carbon only to that distance between the clutch and
the carbons located below said clutch.
The nuts serve as stops to limit the downward motion of the upper clutch and
the upward motion of the lower clutch.
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. An arc lamp in which the principle of expansion and contraction of electric
conductors by heat is applied by a construction substantially as herein before set
forth.
2. In an arc lamp, a single expansible conductor capable of expansion under the
passage of the current and acting with a spring to control two independent clutches,
one of which tends to raise and support the carbon and the other to lower the
carbon while partially supporting it against falling by gravity.

page_text: 3. In an arc lamp, the combination of a thermo-expansive electric conductor, a
longitudinally extensible and compressible spring, a rod a forming a part of the
frame of the lamp, a lever fulcrumed thereon and pivoted at different points to
said conductor and spring, adjusting screws fastened to said rod and to said
conductor and spring, a movable carbon or carbon holder, and a clutch for said
carbon or carbon holder engaged with said lever.
4. In combination with the globe retaining ring, of a disc of mica or similar
translucent material held in said ring.
Dated this 19th day of July 1892.
F. W. Golby,
WILLIAM E. IKISH.
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.