IMPROVEMENTS IN ELECTRIC ARC-LAMPS
Year: 1881

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, in the County of
Middlesex, for an Invention of 'IMPROVEMENTS IN ELECTRIC ARC-LAMPS."
<<
A communication from abroad by Alexis Jean-Baptiste Cance, of Paris,
France.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office
of the Commissioners of Patents on the 14th September 1881.
PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVE-
MENTS IN ELECTRIC ARC-LAMPS." (A communication from abroad by Alexis Jean-
Baptiste Cance, of Paris, France.)
These improvements refer to an electric arc lamp having the light always kept in
the same position, and with automatic regulation possessing important advantages,
all as herein after described.
The carbons are fixed in carbon holders formed each of two vertical rods united
by cross bars at bottom. The holder for the lower carbon has at the top of each
vertical rod a pulley, round which passes a suspension cord, one end of which is
fastened to the base plate of lamp situated at the top, and having a hook or loop
for suspending the lamp, while the other end is passed round a pulley (fixed to the
said base plate at top), and is fixed to an upper cross bar uniting the side rods of
the holder for the upper carbon.
"
This latter cross bar forms a movable weight having a receptacle for shot; it is
guided vertically by vertical columns fixed to the upper base plate, and is formed
as a nut which fits on a steep threaded vertical screw working at top in a centre
in the upper base plate of lamp, and below in a "centre" in a cross head or lower
base plate of the lamp, so that the screw, which is immovable in the vertical direction,
is made to turn when the nutformed weighted cross bar descends; the weighted
cross bar has a constant tendency to descend, and thus cause the screw to turn, and
by this descent of the weighted nut the lower carbon by its cords pulled upwards
at a speed depending upon the diameter of the lower guide pulley, while the upper
carbon by the turning of the screw is made to descend by wheel gearing, as will
ለ

page_text: be presently described. There is thus a constant tendency to keep the two carbons
close together.
The upper base plate and the lower base plate are united by the four columns,
forming thus the frame work of the lamp; the columns also serve as guides, as
already stated.
The lower base plate carries two supports for an electro magnetic bobbin, in the
interior of which there is a tubular solenoid core capable of moving freely therein,
and having an upper brass prolongation of a length in proportion to the desired
magnetic intensity. The lower or step prolongation of the screw passes through
the core, and is made of brass to avoid all magnetic effect. The weight of the core
may be more or less balanced by helical springs.
The bobbin is inserted in the lamp current circuit and serves as a regulator. For
this purpose the core has at top and at bottom a cross piece which are guided on
the frame columns of the lamp. A set screw through the upper cross piece against
the top of the bobbin serves to regulate the depths of entry of the core into the
bobbin, and also the position of an escapement wheel which arrests the movement
of the carbons, as will be presently described. Another set screw on the opposite
side limits the distance between the carbons or the length of the arc.
The mode of operation of the lamp is as follows:-Before lighting the carbons
are in contact. The current passing along by the wire to a terminal on the upper
base plate distributes itself into the mass, and passes to the lower carbon holder
and to the upper carbon holder, ascends by the two corresponding vertical rods of
same, insulated from the mass and communicating with each other by the lower
cross bar. The rods of the lower holder slide easily through brass bushes in the
lower base plate, which bushes are connected by a conducting wire, which is also
connected to one end of the coil of the bobbin; the other end of the coil is
connected to the other terminal on the upper base plate. As the bottom becomes
thus magnetized the core is drawn up quickly and regulates the arc distance as
follows: The lower cross bar of the core carries an arm to which is connected a
rod of adjustable length, which is connected also to one arm of a bell crank lever
mounted on the bobbin support, and the other arm of which is bent and engages
with a tappet on a swinging frame or bar mounted loosely on the lower or step
prolongation of the screw. In the middle of this bar there is a tooth wheel having
a bush entering the bar loosely and fitting on a key or keyway on the screw
prolongation. This wheel gears with a pinion mounted-in-centres-on-the-bar.-The-
spindle of the pinion carries the escapement wheel, which advances against a stop
spring or recedes therefrom according as the carbons approach to or recede from
each other. This wheel has by preference such a form, as shown, as to act as a
brake as well as a stop. Two consecutive escapement wheel notches are separated
by a stop appliance on which the stop spring rests, and which suffices to arrest the
wheel when the magnetic variation due to the approach is not large enough to bring
the notch in front of the spring, and thus facilitates a subsequent approach.
In the moment of lighting the core is drawn up smartly, bringing up with it the
connecting rod, and actuating the bell crank lever, the curved arm of which pushes
back the swinging bar, so that the escapement wheel engages with the stop spring,
which enters one of the wheel notches, stopping the wheel and the tooth pinion in
one therewith from turning. This pinion, which always gears with its tooth wheel,
causes the swinging bar to turn a little in the opposite to its normal direction of
movement; being fast with the vertical screw this latter is turned, whereby its nut
is caused to rise a little, raising thereby the upper carbon, while the lower carbon
descends correspondingly.
The arc being thus established, the intensity of the magnetism in the bobbin will
diminish as the carbons are consumed, and the core will descend; the escapement
wheel goes away from the stop spring and finally escapes from it; the carbons will
thus approach or recede according as they are consumed.
The solenoid may be replaced by an ordinary electro magnet; the screw pro-
longation will then pass freely through its interior, and the armature placed below

page_text: will act in the same manner as described in connection with the connecting rod and
escapement.
The advantage of this arrangement is that very fine wire may be used, and the
regulator will thus be very sensible.
The lamp works alone in a circuit, or two or more may without inconvenience be
placed in the same circuit, but in the latter case it is preferred to replace the
magnetic apparatus described by one of derivation, so as to better ensure the action
of the lamps.
The lamp is used with continuous currents, in which case the point of the positive
carbon consumes twice as fast as that of the negative; it thus descends half as fast.
In order easily to employ alternate currents, in which case the consumption of both
carbons is equal, it is only necessary to make the lower cord guide pulleys equal in
size to the upper ones.
The carbons may be fixed in their holders by making the latter with a hole
through large enough for the largest diameter carbon to be used, and by placing a
clamp round the carbon, which clamp is pressed by a pinching screw passing through
one side of holder.
:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Jensen in the Great Seal Patent Office on the 14th March
1882.
PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex.
MENTS IN ELECTRIC ARC LAMPS."
Jean-Baptiste Cance, of Paris, France.
"IMPROVE-
A communication from abroad by Alexis
These improvements refer to an electric arc lamp having the light always kept
in the same position and with automatic regulation, possessing important advantages,
all as hereinafter described.
Figure 1 of the accompanying Drawings is a longitudinal section of a lamp con-
structed according to my Invention.
Figure 2 is a view in section of that part showing the escapement.
Figure 3 is a view in plan of the escapement.
As will be seen by the Drawings, the carbons a, b, are fixed in carbon holders
c, d, formed each of two rods united by cross bars at bottom. The holder c for the
lower carbon has at the top of each vertical rod a pulley e, round which passes a
suspension cord f, one end of which is fastened to the base plate g of lamp situated
at the top, and having a hook or loop for suspending the lamp, while the other end
is passed round a pulley h (fixed to the said base plate at top) and is fixed to an
upper cross bar d, uniting the side rods of the holder for the upper carbon.
This latter cross bar & forms a moveable weight having a receptacle / for shot;
it is guided vertically by vertical columns i fixed to the upper base plate g, and
is formed as a nut which fits on a steep threaded vertical screw j working at top
in a "centre" in the upper base plate of lamp, and below in a "centre" in a cross
head or lower base plate of the lamp, so that the screw, which is immovable in the
vertical direction, is made to turn when the nut formed weighted cross bar d
descends; the weighted cross bar has a constant tendency to descend, and thus
cause the screw j to turn, and by this descent of the weighted nut the lower carbon
-is-by-its-cords-f-pulled-upwards-at-a-speed-depending-upon-the-diameter-of-the-
lower guide pulleys e, while the upper carbon by the turning of the screw j is
made to descend by wheel gearing as will be presently described. There is thus
a constant tendency to keep the two carbons close together.
The upper base plate g and the lower base plate k are united by the four columns i,
forming thus the framework of the lamp; the columns also serve as guides as
already stated.
The lower base plate carries two supports 7 for an electro magnetic bobbin m,
in the interior of which there is a tubular solenoid core n capable of moving
freely therein, and having an upper brass prolongation o of a length in proportion
to the desired magnetic intensity. The lower or step prolongation p of the screw j
passes through the core, and is made of brass to avoid all magnetic effect.
The weight of the core may be more or less balanced by helical springs.
The bobbin is inserted in the lamp current circuit and serves as a regulator
for this purpose, the core has at top and at bottom a cross piece q and respectively,
which are guided on the frame columns of the lamp, a set screws through the
upper cross piece q against the top of the bobbin serves to regulate the depth of
entry of the core n into the bobbin, and also the position of an escapement. wheel
which arrests the movement of the carbons, as will be presently described.
Another set screw t on the opposite side limits the distance between the carbons
or the length of the arc.
The mode of operation of the lamp is as follows:-Before lighting the carbons
are in contact; the current passing along by the wire to a terminal u on the upper

page_text: base plate g distributes itself into the mass and passes to the lower carbon holder
and to the upper carbon holder, ascends by the two corresponding vertical rods of
same, insulated from the mass and communicating with each other by the lower
cross bar; the rods of the lower holder slide easily through brass bushes v in the
lower base plate k, which bushes are connected by a conducting wire w, which is
also connected to one end of the coil of the bobbin; the other end of the coil is
connected to the other terminal x on the upper base plate g.
As the bobbin becomes thus magnetised the core is drawn up quickly, and
regulates the arc distance as follows:-The lower cross bar r of the core carries
an arm y, to which is connected a rod z of adjustable length, which is connected.
also to one arm a¹ of a bell crank lever mounted on the bobbin support l, and
the other arm b of which is bent, and engages with a tappet c on a swinging
frame or bar d' mounted loosely on the lower or step prolongation p of the screw j.
In the middle of this bar there is a tooth wheel e¹ having a bush entering the bar
loosely and fitting on a key or keyway on the screw prolongation. This wheel,
gears with a pinion f mounted in centres on the bar.
The spindle g of the pinion carries the escapement wheel which advances against
a stop spring or recedes therefrom according as the carbons approach to or recede
from each other. This wheel has by preference such a form as shown, as to act as
a brake as well as a stop; two consecutive escapement wheel notches are separated
by a stop appliance on which the stop spring rests and which suffices to arrest the
wheel when the magnetic variation due to the approach is not large enough to
bring the notch in front of the spring, and thus facilitates a subsequent approach.
In the moment of lighting, the core is drawn up smartly, bringing up with it the
connecting rod z, and actuating the bell crank lever a', b', the curved arm b' of
which pushes back the swinging bar d' so that the escapement wheel engages with
the stop spring h¹, which enters one of the wheel notches, stopping the wheel and
the tooth pinion in one therewith from turning; this pinion, which always gears
with its tooth wheel e', causes the swinging bar d to turn a little in the opposite
to its normal direction of movement; being fast with the vertical screw j, this latter
is turned, whereby its nut d, h, is caused to rise a little, raising thereby the upper
carbon while the lower carbon descends correspondingly.
The are being thus established the intensity of the magnetism in the bobbin will
diminish as the carbons are consumed, and the core will descend; the escapement
wheel goes away from the stop spring and finally escapes from it; the carbons will
thus approach or recede according as they are consumed.
The same effects are constantly reproduced, the regular movement of the
apparatus is ensured until the carbons are completely consumed or the current is
purposely cut off.
The solenoid may be replaced by an ordinary electro magnet, the screw
prolongation p will then pass freely through its interior, and the armature placed
below will act in the same manner as described in connection with the connecting
rod z and escapement.
The advantage of this arrangement is that very fine wire may be used, and the
regulator will thus be very sensible.
The lamp here shown works alone in a circuit, or two or more may without
inconvenience be placed in the same circuit; but in the latter case it is preferred to
replace the magnetic apparatus described by one of derivation so as to better
ensure the action of the lamps.
The lamp is used with continuous currents, in which case the point of the
positive carbon consumes twice as fast as that of the negative, it thus descends half
as fast. In order easily to employ alternate currents, in which case the con-
sumption of both carbons is equal, it is only necessary to make the lower cord
guide pulleys equal in size to the upper ones.
The carbons may be fixed in their holders by making the latter with a hole
through large enough for the largest diameter carbon to be used, and by placing a
clamp round the carbon, which clamp is pressed by a pinching screw passing

page_text: through one side of holder, and thereby an opening is formed equal to the large
diameter by an angular prolongation, as seen at Figures 4 and 5; the carbon is
passed to the three openings, those of the clamp and that of the cross bar and
screw traversing the head of the clamp allows the latter to be shifted relatively to
the cross piece; by thus tightening the carbon is exactly centred, and will be held
without danger of breaking whatever its diameter may be.
Having now described and ascertained the nature of the said Invention, and in
what manner the same is to be performed, I declare that I claim,―
First. The combined arrangements forming the electric lamp, substantially as set
forth.
Second. The employment of a screw to automatically produce the regulating
movement under the action of a motor weight which regulates the approach of the
carbons, substantially as herein before set forth.
Third. The arrangements together and in detail of the escapement mechanism,
and particularly the kind of escapement wheel hereinbefore described and repre-
sented in the accompanying Drawings.
Fourth. The combination of the escapement mechanism with the screw, in the
manner and for the purpose herein before set forth.
Fifth. The special means employed for the instantaneous distancing of the
electrodes at the moment of lighting, substantially as herein before described.
Sixth. Arranging the carbon holders, as above described, thus allowing of the
centreing of the carbons whatever the diameter of the clamp rings may be.
Seventh. The mode of suspension of the carbon from the bottom, thereby enabling
its advance to be regulated at will according to the nature of the currents employed,
as before set forth.
Eighth. The above mentioned arrangement of the hollow bobbin, or of the
electro magnet intended to automatically regulate the movement of the carbons.
In witness whereof, I, the said Peter Jensen, have hereunto set my hand and
seal, this Fourteenth day of March, in the year of our Lord One thousand
. eight hundred and eighty two.