Improvements in Arc Electric Lamps.
Year: 1892

page_text: Date of Application, 5th Oct., 1892-Accepted, 5th Nov., 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by LOUIS BARDON, of 61, Boulevard National,
Clichy (Seine), France, Engineer.]
Improvements in Arc Electric Lamps.
I, ERNEST DE PASS, of 78 Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, reference being had
to the accompanying drawings and to the letters and figures marked thereon, that
is to say:
This invention relates to improvements in arc electric lamps whereby simplicity
is combined with strength, and a durable working obtained without requiring any
attention. For this purpose the regulating means are simplified to the fullest
extent, so that they may be readily, but rigidly, connected together.
In order that the invention may be more fully understood, I have shown, by way
of example, in the accompanying drawings some arrangements whereby the invention
may be carried into effect.
In these drawings,
Figs. 1, 2, and 3 are diagrammatic views showing these different arrangements.
Fig. 4 is an elevation of the regulating mechanism, with constant potential, such
as diagrammatically shown in Fig. 3.
In the arrangement shown in Fig. 1, the principal part is a solenoid B upon
which are wound: 1, for lamps in derivation, one single circuit of coarse wire
through which the whole of the current passes; 2, for lamps in series, two circuits,
one of coarse wire, like the preceding, and the other of fine wire in shunt with the
arc terminals and acting in a contrary direction to that of the coarse wire circuit.
In the axis of the solenoid are two soft iron cores, a fixed core N and a movable
core N', to the latter of which the current imparts, in its passage, a rising movement,
thus causing the brake lever A to turn about the point o, and hence the lever C,
here termed lighting or striking lever, to be actuated. The lever A wedges the
fly-wheel V which is arranged at the upper part of the lamp and carries, at its
centre, a grooved boss p. A silk cord, attached to the upper carbon holder, passes.
first around the grooved boss p, then under the pulley p', the frame of which forms
a part of the framing carrying the lower carbon, and is finally connected to the
end of the lighting or striking lever C.
All connections are made by means of flexible wires arranged in such a manner
that the two carbon holders may be free to move; and furthermore, the lamp
contains no frictional device which is generally the chief cause of derangement.
When the lamp is out of action, the spiral spring R keeps the brake lever down,
and the weight of the upper carbon holder brings the two carbons together and
maintains them in contact.
When the circuit is closed in the lamp, and a heavy current flows through the
solenoid B, the movable core N¹ is forcibly attracted towards the fixed core, and
the lever A bears upon and wedges the fly-wheel V. This movement of the
lever A allows the lighting or striking lever to turn about the point o', its
extremity C to be lowered, and the pulley p¹ to descend, as well as the frame
supporting the lower carbon, so that the two carbons are separated and the arc is
struck. The lamp being alight, the carbons are consumed, resistance increases,
and the intensity of the current diminishes. The movable core then becomes less
attracted, the brake lever allows the fly wheel to turn or slip and to bring the
carbons back to their normal distance apart. This regulation is effected in a
ΓΑ
019

page_text: manner so perfectly continuous that it is impossible, in a lamp thus regulated. 1
perceive the turning of the flywheel, so slight are its movements. The upper
carbon moves forward twice as fast as the lower one, and is twice the length of
the latter, and as its consumption in the arc is double, the luminous point remains
fixed.
The long traverse of the carbons (o.m. 55) allows of carbons having relatively
small diameters being used for long periods, thus effecting an economy and an
advantage, as regards the yield in lighting power, which is accordingly greatly
increased.
The arrangement shown in Fig. 2 enables the lighting or striking lever and the
spiral spring to be dispensed with, and thus avoids any possible inconvenience
which may arise from a physical change in the spring due to time and wear. This
modification has reference to the form of the brake lever which is also made to
serve as the lighting or striking lever.
The solenoid is placed in the centre of the lamp, the soft iron cores are arranged
in a similar manner to that already described, but the rising movement of the
movable core causes a lever m, n, pivotted at o and articulated at o', to rock and to
act as a brake for the purpose of wedging the fly wheel V. A silk cord,
attached to the extremity m of the lever, passes over a pulley p, the frame of
which carries the upper carbon holder, is led up to and over three grooved
pulleys, the smallest of which is fixed to the centre of the fly wheel V, is then led
down and passed around a pulley p', similar to the pulley p, which supports the
lower carbon holder, and is finally attached to the other end n of the lever.
When no current is passing, the weight of the upper carbon holder is such as to
cause the carbons to approach each other, until they come into contact, but when
the current is passing, the core N is forcibly attracted against the core N¹ and the
brake lever locks the fly wheel V by slightly rising. This rising of the lever has
the effect of elevating the upper carbon, and lowering the lower one, that is to
say, to produce the lighting or striking in such a manner that the lamp immediately
assumes its normal brilliancy. The theory of the regulation is identical with that
previously set forth, the carbons in the last case being moved towards one another
at the same rate, it is necessary, in order to maintain the luminous point fixed, that
the upper carbon should have a sectional area double that of the lower one. The
mechanism is practically continuously regulated, the motion being perfectly uniform
and imperceptible to the eye.
An important advantage of the apparatus is that the action of the solenoid upon
the movable core does not vary, whatever may be the position of the carbon holders
upon their rods, a decrease in the intensity of the current causing a similar decrease
in the attraction of the movable core, whether the carbons be at the commencement
or at the end of their travel and without the use of any expedient such as exists
in lamps of the same type as heretofore constructed, wherein a physical change
in the cords causes the lamp to be completely thrown out of order.
The lamp is regulated by virtue of its construction, and this is an important
feature, as, when it is once regulated, it can be stopped and tested, and henceforth
cannot undergo any accidental or wilful alteration.
Figs. 3 and 4 show an arc lamp constructed in a similar manner, but with a
constant potential, and with a recoil or receding action. This apparatus may be
worked either in derivation only, or a number of them may be worked in series.
Its characteristic feature is the recoil or receding action which may be used at any
time. This recoil, or receding action, serves to produce the striking or lighting.
There is no need of any special coarse wire bobbin, and consequently winding in
series is dispensed with and the lamp is able to work whatever may be the intensity
of the electric current; it is sufficient in order to produce an alteration in the
working to alter the resistance interposed in the circuit. The number of amperes
is only limited by the excessive heating to which certain metallic pieces adjacent to
the arc may be subjected.

page_text: In this apparatus, the two carbon holders are movable and connected together by
means of a silk cord, the two extremities of which are fixed to the points m and n
of the lever m, n, turning about a point o, this cord passing successively over the
pulleys, secured to the ends of the carbon-holders, and through the fly wheel box,
over the guiding rollers, and around the groove of the boss of the fly wheel V. A
fixed brake F is arranged upon the bobbin, and the fly wheel box, which is articu-
lated at o, bears against the brake by the aid of the fly wheel. The bobbin
remains always in the same condition, but is wound exclusively with fine wire.
The movable core, having a tendency to ascend towards the fixed core, actuates the
lever m n by means of levers pivotted upon the upper end of the bobbin. The fly
wheel box carries fixed pins at
and g¹.
When the lamp is not working, the fly wheel box is acted upon by its own
weight, and by that of the lower carbon holder suspended at the end n of the lever,
which latter bears upon said fly wheel box through the intervention of the pin g'.
The fly wheel rests upon the fixed brake, and the carbons being unable to move,
remain separated. When a current is sent through the lamp the movable core
tends to rise, and raises the end n of the lever m, n, which withdraws the lower
carbon holder and quickly reaches the pin g, at the same time raising the whole
mechanism. The fly wheel being now released, the carbons are free to move and
come into contact. At this moment the difference of potential at the terminals has
fallen very low, the bobbin ceases to act, and the whole mechanism re-descends.
The fly wheel is first wedged by the brake and prevents the movement of the
carbons, then the lever m, n, continues its descent, while producing the lighting or
striking as it separates the carbons, owing to the end m of the lever being raised
and the end n lowered. The lighting or striking being effected, the carbons.
commence to burn, and the difference of potential increases at the terminals; the
movable core rises slowly, while imperceptibly bringing the carbons together, until
the lever has again reached the pin 9; the fly wheel box is shifted and the
movement of the carbon takes place by the perfectly continuous sliding of the fly
wheel upon the brake. The lever m, n, may, however, when its end n is depressed,
produce at any time a recoil or receding action which is limited by the pin g.
striking or lighting by the recoil is perfect, the normal brilliancy is immediately
attained, while the certainty of its working avoids the possibility of any impediment
which may arise, during the working, by reason of accidents, bad carbons, or any
other extraneous cause.
The
One of the important features of this invention consists in making the cheek a,
on the upper face of the bobbin, of iron, and in affixing to the sides thereof two
soft iron bars b, b, tending to close the magnetic circuit at the bottom. The
immediate advantage derived therefrom is, that for a like regulation of the movable
core, the lamp is regulated at a lower intensity, whence less heating in the windings
and decrease in the ampere-turns in the coarse wire are obtained, that is to say, the
lamp becomes more differential.
There is also provided, for sake of convenience, an arrangement of slides (Fig. 4)
whereby the globe can be lowered for the purpose of changing the carbons without
it being necessary to put it onto the ground. For this purpose the two tie-rods,
generally used to hold the guiding hoop which is arranged below the lamp, are
replaced by two tubes c, through which pass two rods d, fixed to the globe frame
and entering the casing of the lamp mechanism when the globe is hooked in its
service position.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim, as communicated
to me by my foreign correspondent :
1. The construction of differential regulators for arc lamps substantially as herein
described.
2. In regulators for arc lamps, the construction of the cheek of the upper face of

page_text: the bobbin of iron, and the combination therewith of two lateral bars of soft iron,
for the purpose set forth.
3. The arrangement of slides above described, for permitting the carbons to be
changed without the necessity of detaching the globe, substantially as herein
described.
ERNEST DE PASS.