Improvements in Electric Arc Lamps.
Year: 1892

page_text: Date of Application, 16th Mar., 1892
Complete Specification Left, 16th Jan., 1893-Accepted, 18th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
I, LADISLAS LENCZEWSKI of No. 3 Rue Clotaire, Paris, France, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an electric arc lamp with differential movement, having
the advantage over similar apparatus as usually constructed of ensuring in a perfect
manner the moving apart of the carbons and the lighting of the lamp when from
accident or other cause the carbons come in contact.
The invention consists in the adaptation to an arc lamp, for the lighting and for
the first regulation of the same, of a differential solenoid composed of two superposed
bobbins wound respectively with thick and with fine wire, (or of a single bobbin
with a double winding of thick and fine wire). The bobbin of thick wire is
placed in the main circuit of the lamp, whilst the bobbin of fine wire is placed in
a shunt to said circuit. The two bobbins act in opposite senses upon the same
soft iron core.
The bobbin of thick wire has for object to effect the moving apart of the carbons
when lighting, or when by reason of any accident the carbons should happen to
have come in contact. It thus acts to move the carbons apart and its action on
the soft iron core diminishes in proportion as the resistance of the voltaic arc
increases.
The bobbin of fine wire acts to move the carbons nearer together; its resistance
is much greater than that of the thick wire bobbin, and is such that it will come
into operation only when the resistance of the voltaic are increases in consequence
of the carbons being too far apart; the resistance of the internal or main circuit of
the lamp in which the bobbin of thick wire is included becoming in such case
greater than the resistance of the bobbin of fine wire, the shunt solenoid
overcomes the action of the series solenoid and moves the carbons together in
order to effect the first regulation of the lamp and bring the voltaic arc to its
normal length.
The movable core of the differential solenoid may conveniently be connected by
an endless screw and gearing with a toothed wheel over which passes the chain or
cord to the two ends of which the carbon holders are attached. This toothed
wheel is furthermore operated, when the lamp is working, and only after the first
regulation of the latter, by a known ordinary regulating device. This combination
of devices by effecting the lighting and regulation of the lamp in a gradual manner,
and without jerks or disagreeable fluctuations, ensures a perfect steadiness of the
light produced.
Dated this 16th day of March 1892.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I LADISLAS LENCZEWSKI, of No. 3 Rue Clotaire, Paris, France, Electrical
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement :-
The invention relates to an electric arc lamp with differential movement, having
the advantage over similar apparatus as usually constructed, of ensuring in a

page_text: perfect manner the moving apart of the carbons and the lighting of the lamp, when
from accident or other cause, the carbons come in contact.
The invention consists in the adaptation, to an arc lamp, for the lighting thereof
and for the first regulation of the arc of the same, of a differential coil composed
of two superposed solenoids wound respectively with thick and with fine wire, (or
of a single coil with a double winding of thick and fine wire). The solenoid of
thick wire is placed in the main circuit of the lamp, whilst the solenoid of fine
wire is placed in a shunt to said circuit. The two solenoids act in opposite
directions upon the same soft iron core.
The solenoid of thick wire has for object to effect the moving apart of the
carbons when lighting, or when, by reason of any accident, the carbons should
happen to have come in contact. It thus acts to move the carbons apart, and its
action on the soft-iron core diminishes in proportion as the resistance of the voltaic
arc increases.
The solenoid of fine wire acts to move the carbons nearer together; its resistance
is much greater than that of the thick wire solenoid, and is such that it will come
into operation only when the resistance of the voltaic are increases in consequence
of the carbons being too far apart; the resistance of the internal or main circuit of
the lamp in which the solenoid of thick wire is included becoming in such case
greater than the resistance of the solenoid of fine wire, the shunt solenoid
overcomes the action of the series solenoid and moves the carbons together in order
to effect the first regulation of the arc and bring the voltaic arc to its normal
length.
o
The movable core of the differential coil may conveniently be connected by an
endless screw and gearing with a smooth drum over which is wound the cord to
the two ends of which the carbon holders are attached. This drum is furthermore
operated, when the lamp is working, and only after the first regulation of the latter,
by a known ordinary regulating device. This combination of devices for effecting
the lighting of the lamp and regulation of the arc in a gradual manner, and.
without jerks or disagreeable fluctuations, ensures a perfect steadiness of the light
produced.
The annexed drawing shows a lamp constructed in accordance with the herein-
before mentioned principles.
Fig. 1 is an elevation, partly in section, of my improved lamp;
Fig. 2 is a partial side elevation, viewing Fig. 1 from the left or right;
Fig. 3 is a plan in section on the line 3, 3, of Fig. 1, taken at right angles thereto
and corresponding to Figure 2.
The lamp is mainly composed of two disks 1, 2 connected by columns 3, 4 & 5,
the upper disk 1 having fixed to it two binding posts 6, 7. The post 6 for the inlet
of the current is suitably insulated from the so called "mass," whilst the post 7 for
the outlet of the current is electrically connected with the said mass. On the lower
disc 2 is fitted a double coil composed of two solenoids 8, 9, the one 8 of which
is formed of thick wire and the other 9 is formed of fine wire. One terminal
of the solenoid 8 is connected to the binding post 6 by a conductor 10 and its
other terminal is connected by a wire 11 (Fig. 1) to a flange 12 formed on the
tubular guide. 13 for the lower carbon-holder 14. The flange 12 and guide 13 are
suitably insulated from the mass by an insulating washer 15 and the same is
connected by a wire 16 to the lower carbou-holder 14. The upper carbon-holder 17
is connected by a wire 18 to the mass of the lamp. From the foregoing, it will
be readily understood that the thick wire solenoid 8 is placed in the circuit of the
lamp. The fine wire solenoid 9 is on a shunt from the main circuit of the lamp,
one of its terminals being connected by a wire 19 to the conductor 10 and its other
terminal being connected by a wire 20 to the upper disk 21 of the differential
coil 8, 9 and electrically connected to the mass.
The carbon-holders 14 & 17 are suspended from the two ends of a cord 22 which
is wound once around a drum 23 keyed on an axis 24 pivotted in a suitable
support 25 secured to the upper disk 1. It will be readily understood that according

page_text: to whether the drum 23 turns in one or the other direction, the carbons will
separate from or approach each other. Such rotation of the drum 23 is obtained
by means of a mechanism which, as will be seen hereinafter, is acted upon either
by the differential coil 8, 9, for the lighting and first regulation of the arc, or by
an electro-magnet 26 (shunted from the main circuit as hereinafter described) and
acting to cause the carbons to approach each other in proportion to the consumption
thereof. Upon the axis 24 of the drum 23 is fastened a pinion 27 meshing into
another pinion 28 secured on an axis 29 which is suitably pivotted in the support 25
and carries a worm wheel 30. The worm wheel 30 is in gear with a worm 31
pivotted vertically in two brackets 32, 33 fastened to a vertical rod 34 guided
at the top in a socket 35 fixed to the disk 1, and having a groove 36 in which
slides a pin 37 borne by the rod 34.
At the lower part of the rod 34 is secured a piece of soft iron 38 acting as a core
which is common to both solenoids 8 & 9. The core 38 and the rod 34 are normally
sollicited upwardly by a spring 39 bearing in a socket 40 which is screwed into
an extension 41 of the lower portion of the coil 8, 9 and held therein by a lock-
nut 42. By this arrangement, the tensile strength of the spring 39 can be regulated
in accordance with the amperage of the current. Upon the vertical rod 34 is also
fastened an adjustable stop 43 by which the downward stroke of the rod itself can
be regulated, as will be explained hereinafter.
The carbons are caused to move towards each other, in proportion to their con-
sumption, when once the lighting operation and the regulating operation of the arc
have been accomplished, through the action of the electro-magnet 26, the oscillating
armature of which operates the worm 31, so as to transmit by the said worm and
hereinbefore described mechanism, viz.: worm-wheel 30, axis 29, pinions 28, 27 and
axis 24, a rotary movement to the drum 23.
In order to accomplish this result, the electro-magnet 26 is on a shunt from the
main circuit, as follows: One of its terminals is connected by a wire 44 to the
conductor 10, whilst its other terminal is connected by a wire 45 to a contact-
piece 46 secured to the oscillating armature 47 of the electro-magnet 26, but
properly insulated from the said armature.
The core 48 of the electro-magnet extends into two pole-pieces 49, 50, the
one 50 of which serves for securing the magnet to the disk 1, whilst the other
one 49 constitutes a support for a bearing 51 in which is pivotted, at 52, the
oscillating armature 47. This armature, is normally attracted out of contact with the
pole-pieces 49, 50 by a spring 53, one end of which is secured to an eye 54 on the
lower face of the armature 47 and the other is connected to an adjusting pin 55,
fitted in a clamp 56 fixed to the column 3. The action of the spring 53 upon the
armature 47 is limited by an adjustable stop 57 carried by the bearing 51. The
free end of the armature 47 carries a pawl 58 acting upon a ratchet-wheel 59 keyed
on the axis 60 of the worm.31, the pawl being held in engagement with the wheel
by a spring 61. A counter click or retaining pawl 62, fitted with its spring 63 so
as to pivot at 64 in a part 65 fastened upon the rod 34, co-operates with the active
pawl 58 and prevents any backward movement of the ratchet wheel 59 and
worm 31. An arm 66, Fig. 3 pivotted at 67 in the armature 47 is normally held
in contact with the insulated contact-piece 46 by a spring. 68. But when the
armature 47 is attracted by the pole-pieces 49, 50, as hereinafter explained, the free
end of the arm 66 meets an adjustable abutment screw 69 which is carried by the
pole-piece 50 and passes through the armature 47, a suitable opening 70 being made
in the same, see dotted lines in Fig. 3. It will be readily understood that the
arm 66 fitted in the armature 47 is electrically connected with the mass and that
at the insulated contact piece 46, it normally closes the circuit which controls the
electro-magnet 26, but that when the latter is energized and attracts its armature,
the arm 66 of the latter, in coming in contact with the abutment 69, moves the
arm 66 away from the contact-piece 46 in opposition to the.action of the spring 68
and thus breaks the circuit of the electro-magnet 26.
Assuming the lamp to be ready for being lighted, the points of the carbons

page_text: touching each other and all the parts then occupying the position shown in the
drawing, the operation is as follows:-
As the current enters the lamp through the insulated binding post 6, it finds a
minimum resistance at the carbons, since the latter are in contact, and passes
through the conductor 10, the thick wire solenoid 8 situated in the main circuit, the
wire 11, the flange 12, the wire 16, the lower carbon-holder 14 and then through
the carbons to the upper carbon holder 17, after which it passes through the
wire 18 to the mass and leaves the lamp through the binding-post 7.
This passage of the current energizes the thick wire solenoid 8, whereby the
core 38 is attracted and the rod 34 receives a downward movement, which is
limited by the stop 43; by means of the worm 31 which is moved downwardly
together with the rod 34, the wheel 30 receives a rotary movement in the
direction of the arrow a, Fig. 1. This rotary movement is conveyed by the
axis 29 and pinions 28, 27 to the axis 24 of the drum 23, whereby the latter
is rotated in the direction of the arrow b, Fig. 1 so as to cause the upper carbon-
holder 17 to be moved upwardly by the cord 22, whilst at the same time the lower
carbon-holder 14 is moved downwardly so as to separate the points of the carbons
and cause the lighting of the lamp to take place.
יוי
The separation of the carbons having been accomplished, the voltaic are is
established between the points thereof and the resistance of the main circuit of
the lamp will be increased by the amount of resistance of the arc. If such
resistance is above the normal resistance, in consequence of a too great separation
of the carbons or in other words, if the arc produced by this first separation due
to the action of the solenoid 8 is too great, the current will find at such arc a
resistance which will be greater than the normal resistance of the lamp in operation,
and consequently greater than that of the solenoid 9, and will then be shunted
into the latter solenoid and energize the same, whilst at the same time, the
energizing action of the solenoid 8 will decrease in consequence of the increase
of resistance presented by the arc. The solenoid 9 being energized will cause
the core 38 to be moved upwardly and thus act in a reverse direction to that
previously described with reference to the solenoid 8 and the carbons will be
moved towards each other until the arc has reached its normal length, that is
to say until equilibrium is established between the resistance of the complete
circuit of the lamp, including the arc, and the resistance of the solenoid 9.
At such moment, the lighting operation of the lamp and the first regulation of
the arc are accomplished.
As the carbons burn down, they will likewise be caused to approach each other
during the first moments of the operation of the lamp, by the solenoid 9 which, as
the carbons are burning down, that is to say, as the action of the solenoid 8 is
decreased by the increase of resistance at the arc, will gradually raise the core 38°
and the rod 34, whereby the carbons will move towards each other, as already
stated, this action taking place until the upper end of the rod 34 strikes the bottom
of its guiding socket 35. From this moment, the differential coil no longer acts to
cause the carbons to move towards each other and the said carbons are caused to
be fed one towards the other by means of the electro-magnet 26 the resistance of
which is at least equal to, if not slightly less than, that of the solenoid 9, the said
magnet causing the armature 47 to vibrate so as to transmit rotary movement to
the ratchet wheel 59 and worm 31 by the pawl 58; such movement is transferred
to the carbon-holders, as previous described.
When the differential coil ceases to act for causing the carbons to approach each
other, the main current of the lamp is shunted into the electro-magnet 24 and takes
the following course: from the conductor 10 through the wire 44 to the electro-
magnet 26, wire 45, insulated contact-piece 46, arm 66, armature 47 and the mass.
This passage of the current has for its effect to energize the solenoid 26 and
attract its armature, and the latter in oscillating meets the abutment screw 69,
Fig. 3 which breaks the circuit at the contact-piece 46, as hereinbefore explained.
The circuit being broken, the armature is drawn back by its spring 53 and a rotary

page_text: movement is imparted by the pawl 58, to the ratchet-wheel 59, so as to cause the
carbons to approach each other.
The withdrawal of the armature again re-establishes the circuit at the contact
piece 46 and again energizes the electro-magnet 26; the same action is repeated
until the armature shall have been attracted such a number of times as to impart to
the pawl 58 and worm 31 a sufficient amount of rotary movement to cause the
carbons to approach to the required extent.
If during the operation of the lamp, it should happen that for any reason, the
carbons were to touch each other or to approach each other too closely, the
resistance will decrease at the arc in an abnormal manner and the current will act
upon the solenoid 8, whereby the carbons will be separated, as has been explained
for the lighting operation, after which the solenoid 9 will again, as before,
accomplish the regulating operation for the arc
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. The application, in an electric arc lamp, of a differential coil composed of a
solenoid 8 formed of thick wire, situated in the main circuit of the lamp, and of a
solenoid 9 formed of fine wire on a shunt from the said circuit, both solenoids acting
in contrary directions upon one soft-iron core 38, for the purpose of effecting the
lighting operation of the lamp and the initial regulation of the arc, substantially as
hereinbefore described and shown in the annexed drawing.
2. In an electric arc-lamp, the combination, with a differential coil formed of two
solenoids 8, 9, of two carbon-holders 14, 17 suspended from both ends of a cord 22
wound once around a drum 23, the said drum being acted upon through any suitable
gearing, by the movement imparted to the core-carrying rod 34 having the worm 31,
substantially as herein before described and shown, and for the purpose set forth.
3. In an electric arc-lamp, the mechanism for causing the carbons to move
towards each other as they are burning down, the said mechanism acting to impart
rotary movement to the worm 31 and being constituted by an electro-magnet 26,
pole-pieces 49, 50, an armature 47, a pawl 58, a spring 61, a lever 66, a spring 68,.
an insulated contact-piece 46, a spring 53, a stop 57, and an abutment screw 69,.
substantially as hereinbefore described and shown in the annexed drawing.
Dated this 16th day of January 1893.