IMPROVEMENTS IN ELECTRIC ARC-LAMPS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Ernest de Pass at the Office of the
Commissioners of Patents on the 7th June 1882. Communicated to me from
abroad by Joseph Gloker, of 17 Boulevard Saint-Martin, Paris, France,
ERNEST DE PASS, of the Office for British and Foreign Patents, 68 Fleet Street,
in the City of London, Patent Agent, IMPROVEMENTS IN ELECTRIC ARC-LAMPS,
Communicated to me from abroad by Joseph Gloker, of 17 Boulevard Saint-
Martin, Paris, France,
This Invention has for its objeet a new arrangement of electric lamp, in which-
the luminous arc is automatically regulated by the current passing in a single.
circuit.
For this purpose I employ two solenoids whose casings are of suitable form, and.
bear great resemblance to the frame carrying the wire of a multiplying
galvanometer. The outside of the casing is covered with several coils of wire.
In this casing moves an iron bar or plate, mounted on an arbor which carries a
piece of soft iron, and which serves as an armature for the upper-carbon-holder
passing into the casings of two resistance coils, and said armature is magnetized-
when the current passes in the single circuit; the carbon holder is moveable in a
vertical direction.
When a current is caused to pass through such an arrangement of solenoids, the
iron bar or plate moving in the casing tends always to occupy a position perpendicular
to the direction of the parallel coils of the solenoids, so that, in the case under
consideration, the armature which is fixed on the same arbor as the iron bar or
plate, and almost normally to the same, approaches the stem of the carbon holder.
and being in the magnetic field of this stem all the oscillatory movements of the.
armature will be. transmitted to the stem which will receive corresponding
rectilineal movements, and will thus cause approach or separation of the upper,
carbon from the lower carbon, which latter is a fixture.
I proceed to describe two arrangements of lamps constructed according to this
system.
In the first arrangement, the lamp is actuated by a current from a magneto-
electric machine, the currents of which may be.strong or weak.
A lamp constructed according to the second arrangement is actuated by a battery
or by weak currents only.
:

page_text: According to the first arrangement, the lamp consists of two solenoids arranged
in the manner hereinbefore stated.
Inside the casings is an iron bar or plate mounted on an arbor held by two
supports, on which the upper part of the lamp rests. On this arbor and fixed
almost normally to the bar or plate, is a piece of soft iron or armature, to one end
of which is attached a spring, while the other end is fixed to the end of a pivotted
lever, whose other end abuts against a screw for regulating the tension of the
spring. This spring may, if preferred, be dispensed with, as the iron bar or plate
and the armature may be so arranged that the equilibrium of the two pieces
maintains the armature in its proper position.
The inner end of the armature is fitted in a frame, the greater part of which is
so covered at top and at bottom by coils of wire as to form two other solenoids, or
resistance coils, which constitute, with the solenoids first mentioned, the only
circuit, and the wires are connected in such way as to have the same pole at a
suitable point.
•
Within the frame, and therefore within the second pair of solenoids or resistance
coils, the stem of the upper carbon holder passes, a spring presses against it to
retard its descent by gravity and at the same time to ensure contact.
If a current be passed into the circuit through the positive terminal, the negative
terminal being in connection with the lower carbon holder, the bar or plate would
immediately tend to assume a position perpendicular to the coils of the first
mentioned solenoid, and the armature would describe an arc of a circle until
entering the magnetic field of the stem of the upper carbon holder magnetized by
the current, the armature would adhere as it were to the stem, and if the current
be stronger than the resistance of the arc, the armature continues its movement,
thereby causing the stem to rise, and to separate the upper from the lower carbon,
the arc increasing, its intensity diminishes, and as by the consumption of the
carbons, this intensity diminishes more and more until the equilbrium between the
resistance of the arc and the current in the solenoids is disturbed, the bar or plate
tends to return to its first position, and the stem will descend to re-establish the
arc under the required conditions of intensity, and so on.
By this arrangement the delicate mechanical arrangements heretofore employed
for the same purpose are dispensed with, and I obtain cheapness and great
simplicity of construction, while ensuring a stable light, and one not subject to
fluctuations of intensity of the current.
Although I have stated that the upper carbon-holder is moveable, yet, by
suitable gearing the lower carbon-holder can be made moveable (whilst the upper
is fixed) and be affected by the equilibrium between the resistance of the arc and
the current.
According to the second arrangement of lamp which, as before stated, is worked
by a battery or by weak currents, is also based on the application and employment
of the solenoids with the iron bar or plate, but the arbor instead of being provided
with a piece of soft iron serving as an armature, has mounted directly thereon two
coils which, when a current passes, serve as electro-magnets for a disc-shaped
armature. A support for the coils or electro-magnets is furnished with a bar or
arm which, when it describes its oscillatory movement abuts against a regulating,
screw which determines the extent of its motion and of that of the armature;
this piece is also provided with a hook to which is attached one end of a spring,
the other end of which is attached to a rod or spindle.
On the armature is fixed a socket, through the interior of which passes an arbor,
and this socket carries a roller in contact with the upper carbon holder, against
which bears another roller situated in the same plane and at the same level, as the
first one.
This second roller, by means of a spring bearing on its axis also presses
against the upper carbon-holder.
The upper carbon-holder is guided in its vertical movement by a hollow rod in
which is a spring, acting as a break, to prevent the too rapid descent of such holder

page_text: on the lower carbon which, in this arrangement, is fixed on the upper plate of the
lamp This carbon-holder may also be worked by a rack and pinion.
When the current passes in the single circuit of the lamp, it tends to cause the
iron plate or bar to assume a position which is perpendicular to the direction of
the wire coils of the solenoids, the electro-magnet attracts the armature, and as it
is mounted on the same axis as the plate or bar, it will perform the same oscillatory
movement as the former and force the armature to move which will cause the
rollers to raise the upper carbon-holder. When the intensity of the arc diminishes,
the plate or bar returns to its first position and causes a movement opposite to
that above set forth, which will cause the upper carbon-holder to redescend and
re-establish the arc.
Thus it will be seen that whatever may be the intensity of the current, the
luminous are can always be regulated by the current, and without the aid of
complicated mechanism as now employed.
A lamp embodying this invention can easily be modified so as to serve as a
differential lamp.