NEW ELECTRIC ARC-LAMP
Year: 1885

page_text: I, HENRI PIEPER fils, at Liege, kingdom of Belgium, Electrician, do hereby
declare the nature of my invention for a "NEW ELECTRIC ARC-LAMP," and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—
My invention relates to electric arc lamps, and it consists in a carbon-feeding
device substantially comprising two resilient frictional palls actuated through the
agency of the electric current, one of the said palls operating to feed the movable
carbon, in the measure required, towards the stationary one, the other pall serving
to check and retain the movable carbon during the retrograde motion of the feeding-
pall, the carbon being thus continuously kept under control by the palls and
prevented, in case it is arranged vertically, from being acted upon by gravity
independently of the palls.
On the annexed sheet of drawings Fig. 1 is a sectional elevation of the top part
of an electric lamp to which my improved feed-motion is applied. Fig. 2 shows the
whole lamp in a section taken at a right angle to Fig. 1, a portion of the same being
broken away. Fig. 3 is a sectional plan on line 1, 2, Fig. 1. Figs. 4 and 5 show
two different nodes of connecting the feeding-device with the electric circuit.
Fig. 6 represents in principle the mechanical part of the device in different
positions, for the purpose of illustrating its operation.
c is
I shall first proceed to describe the nature of the invention with reference to
Fig. 6. In this figure a represents the upper carbon of an electric lanp of vertical
arrangement, the said carbon being suitably guided and movable lengthwise.
a lever pivoted at g. f and f¹ are resilient arms fixed to the lever c, and which
press with their ends, provided respectively with the friction-blocks d and e,
against the carbon. The parts c, f, fi, d and e are shown by full lines in their
normal position. The said arms are attached to the lever c in such a manner that,
when the lever is turned on its centre in the direction of the arrow y, the arm f
will push the block d downward, while the arm f' relieves the block e of pressure,
and may eventually lift it off the carbon, without materially moving it up or down.
These effects may be attained by fixing the arm f to the lever at a point y' being
at a certain distance from the centre g, and by making the arm fl radial to the
said centre, as shown in the figure. The strength of the arms has to be suitably
regulated, and for lamps with vertical carbons it must be so determined that the
friction between the said blocks, or either of them, and the carbon, is sufficient to
prevent the latter from descending by gravity.

page_text: When, under these conditions, the lever c is depressed into the position shown by
dotted lines, the pressure of the arm f¹ and the block e on the carbon is reduced
or taken off the same, whereas the arm f, in bending slightly, increases the pressure
of the block d against the carbon, and simultaneously moves downward together
with the block d, so that on account of the friction between d and a, it will push
downward the carbon, which is at the time unimpeded by the block e. The lever c
being then returned to its normal position, the arm fi presses the block e with
increasing force against the carbon, while the arm f, in receding, draws the block d
with it in upward direction. During this part of its motion, the block d, however,
slides along the carbon without moving it, because the carbon is kept stationary by
the block e.
The arm thus constitutes a frictional feed-pall, and the arm fl
a frictional retaining-pall.
The described device will operate in like manner in whichsoever position the
carbons may be placed, whether horizontally, inclined, or even inverted.
For the purpose of actuating the mechanism it is combined with an electro-
magnet connected with the circuit of the lamp. The coil of the said electro-magnet
may either be placed in a shunt-circuit branching off from the main circuit, as
shown by Fig. 4, or in the main circuit itself, as represented by Fig. 5. Thus in
Fig. 4, in which t is the end of the main conductor connected the upper carbon,
and u the end connected, to the lower one, the shunt-current passes from a point of
the conductor t to the tongue k, attached to, but isolated from the lever c, thence
(provided the lever c be in raised or normal position) to the coutact-knob l, and
from there through the windings of the coil to the conductor u. The lever c
either forms or carries at its end the armature of the core of the electro-magnet.
The lever c is maintained in its normal position by the arms f and f¹; but a spring p
provided with means for adjusting its tension may be employed to draw down the
lever against the force of the arm f, and another spring, acting in upward direction
on the lever, may be added thereto, if considered advantageous. The parts being
thus arranged, and the carbons at the proper distance from each other for the
generation of the luminous arc, the current through the shunt-circuit will be too
feeble as to cause the feed-apparatus to act; but, when the distance between the
carbons becomes too great, the increase of resistance in the main circuit will cause
the shunt-current to become stronger; so that the electro-magnet will then attract
the lever c. The contact between and being, however, broken by this motion of
the lever, a series of vibrations of the latter will result, in like manner as in electric
alarms, the said vibrations being transmitted to the arms f and f¹ and the blocks d
and e, as described with reference to Fig. 6. After the upper carbon has been
advanced sufficiently, the resistance in the arc thereby diminished, and consequently
the strength of the shunt-current reduced, the feeding device will stop again.
In the arrangement Fig. 5, it is the main current which passes through the coil i,
a shunt-conduit being however branched off from the wire connecting the carbon b
with the coil i and leading along the tongue k and through the contact-piece 7 back
to the main circuit. In this case the lever c will permanently be held down by the
magnetized core h so long as the portion of the main current, passing through the
coil i, is strong enough; but when the main current becomes weaker on account of
the increase of resistance in the arc, the lever c will be detached from the core / by
the force of the arm f, together with that of any spring introduced for the purpose.
The contact between and being thereby broken, the portion of the current which
had so long passed through the shunt-connection, will then be united with the
portion continuously circulating in the coil i, so as to increase the power of the
electro-magnet h, which will thereupon again attract the lever. In this manner
also, vibrations of the lever and its attachments are produced, which advance the
carbon.
In Figs. 1, 2 and 3 the described feed apparatus is shown in combination with a
lamp; an electro-magnet with two coils i placed in a shunt-circuit, being in this
case employed. The parts already described are indicated in these figures by the
same letters as in Fig. 4, 5 and 6. The upper.carbon a is inserted into a holder a',

page_text: sliding in a sleeve a², o is a spring attached to, but insulated from the sleeve a²,
and having a knob which presses through a hole in the sleeve a³ against the
holder a¹, so as to be in perimanent contact therewith. The blocks d and e also
press against the holder a¹, and not against the carbon itself as in Figs. 4 and 5.
The lower carbon is placed in a holder b¹ fixed to the movable core q of a solenoïd »,
and having a screw-threaded part 6 working in the boss 68 of the frame of the
lamp. The core is carried by and free to turn on a centre q¹, arranged at the end
of the movable pin s, which is supported by a spring acting against a collar thereof.
By means of this arrangement the lower carbon being in contact with the upper
one, is drawn down and slightly rotated when a current is sent through the lamp
to light the same, the rotation of the carbon being of advantage in developing
the luminous are. This portion of the lamp, however, does not form a part of my
present patent-application.
The electric main current passes from the wire t and the binding screw m
through plate v, sleeve a³, and holder a¹ to the upper carbon a, thence through the
lower carbon b, holder b¹, core q, pin 8, sleeve 8', connecting wire s³, coil 1, wire r¹
and binding-screw n to the wire. The shunt-current, which is branched off from
the main current by means of the contact spring o, passes from there through
wire o¹, the coils i, wire i¹, tongue %, adjustable screw 7, wire and binding-screw n
back to the main circuit. The action of these currents on the feed-mechanism is
precisely the same as that set forth with reference to Fig. 4.
By means of the described feed-apparatus a very steady light is obtained even
with lamps of small power.
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, In an electric arc-lamp, the combination, with the movable carbon, of two
resilient frictional-palls to which an alternating motion is imparted by the inter-
mittent action of an electro-magnet connected with the circuit of the lamp; one of
the said palls operating by longitudinal motion to feed the movable carbon forward,
the other one acting by transverse oscillations to alternately release and hold the
same, substantially as hereinbefore described.
2, In an electric arc-lamp, the combination, with the movable carbon-holder a¹
and an electro-magnet connected with the circuit of the lamp, of a lever c arranged
to be vibrated by the electro-magnet and carrying two resilient frictional palis
bearing against the said holder, the palls being so attached to the lever c that,
when this lever is vibrated, the pall f will advance the carbon, while the pawl fl
will alternately release and hold the same, substantially as and for the purpose
specified.
3, In an electric arc-lamp, the combination, with the movable carbon-holder a¹
and an electro-magnet connected with the circuit of the lamp, of a lever c, arranged
to be vibrated by the electro-magnet and carrying two resilient frictional palls f
and f1, bearing against the said holder; the pall branching off from the lever at
a certain distance from its fulcrum, the pall f¹ radiating from the fulcrum,
substantially as and for the purpose herein-before set forth.