Improvements in Electric Arc Lamps.
Year: 1890

page_text: Date of Application, 15th May, 1890
Complete Specification Left, 7th Feb., 1891-Accepted, 7th Mar., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by PHILIP LANGE, of Pittsburgh, Pennsylvania, in
the United States of America, Electrician.]
Improvements in Electric Arc Lamps.
I, REGINALD BELFIELD, of No. 4, Victoria Mansions, Westminster, in the
County of London, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the construction of an electric arc lamp, more especially
adapted for alternating electric currents producing an are between the edges of
two carbon slabs and travelling along those edges; the construction, however, is
such that carbon rods or pencils might be used, and that the electric current might
be continuous. The lower carbon is stationary, but the upper carbon is attached
to a rod having a rack gearing with a pinion on the axis of an escapement wheel.
When the brake
which is engaged by an anchor on the axis of a brake wheel.
wheel is free, the weight of the carbon and its holder causes it to descend slowly
When the brake
turning the escapement wheel and causing the anchor to vibrate.
wheel is stopped by the pressure of a brake on its periphery, the anchor is
prevented from vibrating and the carbon cannot descend. The escapement anchor
and brake wheel are mounted in bearings in a frame suspended from one arm of a
nearly balanced lever nears its fulcrum, and the opposite arms of this lever have
suspended from them iron cores, preferably made of wires or lamina, which are
free to move within two solenoids. The coil of the one solenoid is of fine wire in
a shunt to the lamp circuit; the coil of the other solenoid is of large wire in the
lamp circuit. When the carbons are in contact, most of the current passing
through the second solenoid coil causes it to attract its core downwards thereby
raising the frame that carries the gearing and along with it the upper carbon,
striking the arc and pressing the brake wheel against a brake. When, owing to
consumption of the carbons, the distance between them becomes too great, less of
the current passes through the second solenoid coil and more passes through the first
solenoid coil; thus the first solenoid is made to attract its core downwards, lowering
the frame that carries the gearing and releasing the brake wheel, thus permitting
the upper carbon to descend a little and to reduce the distance between it and the
other carbon. When, owing to the absence of carbon, or other cause of excessive
resistance to the arc, the core of the first solenoid descends beyond a certain
distance, a spring arm on the lever from which it is suspended makes a contact by
which the coil of large wire of a third solenoid, is brought into circuit with the
terminals of the lamp, thus forming a by-pass for the current to other lamps when
this lamp is extinguished. This third solenoid is situated immediately above the
second, the core of which is common to both, so that, when the third solenoid is
brought into circuit by the extinction of the lamp, this core is attracted upwards
maintaining the contact for the by-pass.
1 1
1000
ABEL & IMRAY,
Agents for the Applicant.

page_text: +
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
1, REGINALD BELFIELD, of No. 4, Victoria Mansions, Westminster, in the
County of London, Electrical Engineer, 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:-
This invention relates to the construction of an electric arc lamp, more especially
adapted for alternating currents, producing an are between the edges of two
carbon slabs which are travels to and fro along those edges. The construction
however is such that carbon rods or pencils may be used, and that the electric
current may be continuous.
Figs. 1 and 2 of the accompanying drawings are elevations of the opposite sides
of the regulating mechanism of a lamp according to this invention.
Fig. 3 is a diagram shewing the circuits.
The regulating mechanism is carried from an upper frame A and below this
mechanism are the carbons the upper A' held in a clamp 131 at the end of a rod C',
and the lower A2 also held in a clamp in a lower frame of any suitable kind
suspended from the plate a which is attached to but insulated from the main
framing A. The rod C¹ which has rack teeth, is kept by a roller 2 in gear with
a pinion which can revolve on an arbor e and is connected by ratchet and
pawl oo to an escapement wheel fon the arbor e so that whenever the rod C¹
descends it must turn the wheelf but C can be raised by hand without turning f.
An anchor on an arbor f engages with the teeth off so that fis caused to
oscillate when f revolves.
On the arbor is fixed a wheel f2 or it might be only a segment of a wheel the
edge of which is presented towards a brake f³ resting on a stop m. The arbors of
the escapement wheel fand of the brake wheel 2 are mounted in a frame H which
hangs from a pin at h of a lever K pivotted at k, which lever carries at its one end
a solenoid core n and at the other end a solenoid core n'. In order that the lamp
may work with alternating currents both the cores n n¹ should be made up of iron
wire or laminæ insulated from one another.
The lever K may be loaded with a weight the position of which can be
delicately adjusted by a screw k². As shewn in Fig. 3 the coil of the solenoid M
which is of fine wire is in a shunt or by-pass to the lamp circuit, the terminals of
which are indicated at X and Y. The coil of the solenoid M' is in the lamp
circuit, and the coil of M² is so arranged as to be brought into the main circuit
when a spring J is pressed against a contact j.
In Fig. 3 I have shewn the carbons A¹ A2 as being in the form of slabs
presenting towards each other edges along which the arc travels to and fro.
I am
thus enabled to obtain considerable duration with moderately.long carbon slabs, but
obviously rods or pencils might be employed instead of slabs. The operation of
the lamp is as follows.
Assuming the carbons to be in contact, when the lamp is put in circuit, almost
the whole current passes through the coil M' drawing down the core n' and thus
raising the frame H, and with it the escapement wheel fand pinion e and the
anchor and brake wheel 2 and as by this movement the periphery of f² is
pressed against the lower face of the brake f³ and so prevented from turning,
the rod is lifted raising the upper carbon A' and so striking the arc. When,
owing to consumption of the carbons, the resistance of the arc increases then
less of the current passes through the solenoid M' and more of it through M,
and thus the core n is attracted down lowering the frame H releasing the
brake wheel f² from the brake f³, and thus allowing the escapement anchor fl to
oscillate and the escapement wheel and the pinion e to revolve, so that C¹
descends at a moderate rate, determined by the escapement, advancing the upper
carbon A towards the lower carbon A².

page_text: When the carbons are quite consumed or when excessive resistance results from
the extinction of the lamp or from any other cause, the solenoid M¹ becomes
inert while the solenoid M becomes more excited.
The core is then drawn down so far that the spring J is brought to press
against the contact ; and now the current can pass from X through the coil M³,j, J,
and the support of the lever K to Y thus closing the external circuit.
The core n' is now drawn upwards by the solenoid M², so that the contact of J
with is maintained and the external circuit is kept closed.
In cases where lamps of the kind described are connected parallel in circuit,
so that the extinction of one of them does not open the circuits of the others, the
solenoids M and M may be dispensed with, a suitable counterweight being
substituted for the core n, preferably with a dish pot to deaden excess of
oscillation.
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In an arc electric lamp, in combination with a rack rod carrying the upper
carbon, a pinion and escapement wheel and an anchor and brake wheel or segment
all suspended from a lever carrying a core acted on by a solenoid so that when the
resistance of the arc increases, the brake wheel descends from a brake thus
liberating the escapement and allowing the upper carbon to descend slowly
towards the lower, substantially as described.
2. In combination with the lever above referred to, having two cores acted on
differentially by two solenoids the one in the lamp circuit and the other in a shunt,
a third solenoid which in case of excessive resistance in the lamp circuit is brought
into and closes the external circuit and maintains it closed, substantially as
described.
Dated this 5th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.