Improvement in Electric Arc Lamps.
Year: 1899

page_text: Date of Application, 24th July, 1899-Accepted, z0th Nov,
Improvement in Electric Arc Lamps.
I, FRÉDÉRIC GEORGES CHAGNAUD, of 21, Rue de Belfort, Paris, France, Con-
ructor, do hereby declare the nature of this invention and in what manner the
me is to be performed, to be particularly described and ascertained in and by
e following statement:-
This invention relates to an improvement in electric arc lamps, which is illus-
rated by way of example in the accompanying drawing,
Fig. 1 being an elevation, partly in section,
Fig. 2 a modified form of the solenoid core, and
Fig. 3 a diagram of the lamp illustrated in Fig. 1 in which the same parts
are represented by the same letters.
The lamp. is composed of two parts; (1) the upper part or body, in which the
regulating arrangement for adjusting the carbons is placed, and (2) the lower
part which comprises the carbon-carriers and the means for guiding them.
The upper part or body of the lamp is placed in the space comprised between
two circular plates z and z¹, connected together by four screw bolts 22 and 23, and
is closed by a casing d, which protects the parts of the regulator from dust.
The upper plate z which has a rim, into which the casing d is fitted, serves to
support the whole moveable portion of the lamp. Two brackets b fixed to
this plate are placed sufficiently apart for receiving the two shafts O and O¹
which form the fulcrums of the levers J and I, N, pivoted in these brackets. Two
other small brackets e support the shaft c of the lever G. In the top of the plate
is the suspension ring, and the two terminals, which are insulated therefrom.
The lever J is composed of two arms joined together on the fulcrum O. In
these arms the shaft o of the pulley P is pivoted. The lever J supports the
"brake" E moveably jointed at u, and the piece Q which holds the disengaging
roller M.
This piece Q, which is screwed to the lever J is easily displaceable for enabling
the lamp to be adjusted. The lever I N, likewise formed of two flat pieces joined
together by two abutments and two screws v serves as support for the shaft o
of the fly wheel D. Two small extensions s
0 of the pulley P' and to the shaft
turned inwards prevent the cord from slipping off the grooved pulley K.
The lever I N supports the moveable roller a through the medium of a bearing
screw.
One part of the connecting rod H is joined to the core C by means of the
35 adjusting screw T and the rod F, and the other part to the lever G by mean
The highe
of the articulated joint f. The lever G which is pivoted in c is furnished at it
extremity with a fork pq, which forms an incline on the roller a.
the lever G is raised, the more the strain of p is reduced on the roller a, th
object of this being to regulate the motion of the core C which is more strongl
40 attracted in approaching the upper extremity of the solenoid A B.
The solenoid is composed of a tube, to which three plates are brazed or soldere

page_text: one in the middle and the others at the ends. The upper part or space A is
wound with thick wire and the lower part or space B with thin wire. The sole-
noid is fixed to the lower plate ¹ by screws. The same lower plate ¹ through
which the two bolt supports 22 run is perforated with two holes for the free
passage of the rods g and h of the carbon carriers R and S and has a tube 24
screwed into it, which tube is joined at its lower end to a metal ring to which the
two rods or bolt supports 2 are secured and by which they are kept apart.
The guiding of the upper carbon-carriers is effected by means of the piece i
and the block R, joined together by the rod g and furnished with insulating
rings and sliding on the rods 22. The lower carbon-carrier is guided by the
piece furnished with insulating rings 6 sliding on the rods and, by the rod h
sliding in the ring m fixed in the tube by the perforated plug n which is
screwed to its extremity.
The carbon-holders X and Y are formed by a tube with a number of longi-
tudinal slots in it, the ends and a¹ of these slots being cone-shaped and screw
threaded, and furnished with tightening screws h¹ and 2 likewise cone-threaded,
the object being to press the carbons concentrically.
66
3
The upper holder X is screwed into the block R and the lower Y furnished
with a socket Z held by the nut r, in order to centre the carbons that might
not be entirely straight. This socket Z, joined to a rod y¹ is firmly connected
with the block S by means of the nut t.
The casing d is supported by two screws fixed beneath the lower plate z¹, on
which the edges rest.
Two supple constructing cables connect the carbon-carriers with the terminal,
on the one hand, and with the thick wire running from the part A of the sole-
noid, on the other, as shown on the drawing..
i
:
In this lamp the regulator, the principal part of which is a solenoid A, B,
with two windings, is composed of a brake E and a fly wheel D. Under the action
of the current, the solenoid holds the wheel tightly against the brake in order
to render it motionless and to prevent the upper carbon-carrier R from descending.
The solenoid (Fig. 1) is formed of thick wire in the upper part A mounted in
series with the carbons, and of thin wire B in the lower part connected in shunt
with the lamp terminals. The moveable soft iron core C, can ascend or descend
according as it is more or less attracted by the one or by the other winding. It
will be easily understood that an equilibrium of motion is produced in the
solenoid.
The core may be cylindrical or made of two conical bodies joined by their
broader bases to a cylindrical piece as shown in Fig. 2. This latter arrangement
allows of an equal attraction, whatever the position of the core in the solenoid.
The carbon carriers are connected with one another by means of a cord run-
ning from the upper carbon carrier R, over the pulley P, which is mounted on
the lever J, thence under the pulley K attached to the fly wheel 1) up again over
the pulley P' mounted on the lever I N, being finally attached to the guide piece j
of the lower carbon carrier S.
In a state of rest the weight of the upper carbon carrier R and its connections,
being heavier than the lower carbon carrier S releases the fly wheel D from its
brake E through the medium of the roller M mounted on the lever J, which
produces a strain on the lever NI on which the axis of the fly wheel D is mounted
and the core C is then in the lower part of the solenoid and the carbons are in
contact.
When the circuit is completed in the lamp, the current, passing into the car-
bons runs through the thick wire A of the solenoid, and raises the core C which
causes the lever G to oscillate through the medium of the connecting rod H.
The "incline" of the lever G producing a strain on the roller a causes the
lever I N, which supports the fly wheel D, to oscillate, and the last mentioned
comes into contact with the brake E and is thereby rendered motionless. The
motion being continued, the fly wheel raises the lever J, by means of the brake E

page_text: ich is attached to it, and the upper carbon carrier R is thus raised
wer carbon is lowered. Thus the arc is formed.
As the carbons wear away the arc becomes larger, its resistance greater, the
fference of potential at the terminals increases, a part of the current passes
rough the fine wire and attracts the core downwards whilst the latter is less
ttracted by the thick wire in which the intensity has diminished.
The carbons approach one another until the moment when the roller M, coming
nto contact with the part N of the lever N I which supports the fly wheel D,
arrests the lever J and releases the fly wheel D from its brake E.
The upper carbon carrier R descends until the arc is normal, at this moment
the solenoid core C produces renewed contact between the brake and the fly wheel
and arrests the latter; these successive releasings and arrests are effected con-
tinuously and insensibly.
If in consequence of an accident the carbons should touch one another, that
The arc
is to say, if the resistance of the are should diminish, the intensity becoming
greater should raise the core, which would render the fly wheel motionless and
raise the upper carbon carrier whilst the lower one would descend.
would resume its normal dimensions.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is: -
1. An arc lamp in which the solenoid is composed of two parts A B the one A
wound with thick wire in series, the other B wound with thin wire in shunt
substantially as described with reference to the accompanying drawings.
2. An arc lamp in which the cylindrical or cylindro-conical core is common to
the two parts of the solenoid substantially as described.
3. An arc lamp in which the motion of the solenoid core C and the weight of
the upper carbon carrier R cause a brake E to act on a fly wheel D and render it
motionless at the moment of the passing of the current, substantially as and for
0 the purpose herein described with reference to the accompanying drawings.
4. An arc lamp in which the movement of the core causes a lever to oscillate
by means of an inclined plane and a roller substantially as described, and for the
purpose stated.
5. An arc lamp in which the supports of the fly wheel and the brake are move
35 able substantially as described.
40
6. An arc lamp in which the fly wheel is released by the weight of the uppe
carbon carrier through the medium of a roller acting on the support of the f
wheel and assisting on the other hand in raising the lower carbon carrier substan
tially as described.
7. An are lamp in which the carbon holders are so arranged as to hold th
carbons concentrically.
4th day of July 1899.
GOT DV
S
CO
ated this 24th day of July 1899.
F. W. GOLDY
Patent Agent, 36, Chancery Lane, London, W.C.,
Agent for the Applicant.