Year: 1888

page_text: Date of Application, 26th May, 1888
Complete Specification Left, 2nd Feb., 1889
Complete Specification Accepted, 23rd Mar., 1839
I JULIEN DULAIT of Charleroi Belgium, Engineer, do hereby declare the nature
of this invention to be as follows:-
This invention relates to an improved construction of electric arc lamps in which
the light from the fixed luminous point is thrown upward against a reflecting surface
and in which the positive carbon for this purpose placed at the bottom, the negative
carbon being directed upward, the two carbons being made to move at speeds pro-
portional to their rate of consumption, so as to maintain the luminous point always
at the same distance from the reflector and thus giving a constant angle of projection
and a uniformly reflected light.
This result is obtained by the following construction of regulator.
The regulator consists mainly of a frame composed of two circular horizontal discs
connected by vertical columns, carrying the principal parts of the mechanism so that
at the lower part of the lamp, i.e. that below the lower disc there are only the positive
and negative carbon holders, of which the former receives an upward motion and the
latter a downward motion in the proportions before mentioned.
These motions are imparted by means of mechanism with an upper and a lower
scrow spindle rotated by the weight or pressure exerted on the thread of the lower
screw spindle by a screw nut from which is suspended the descending negative carbon
holder, the rotation of whose screw spindle transmits the necessary motion at the
required relative speed to the upper spindle of the ascending lower carbon."
For this purpose the negative carbon holder is made proportionately very heavy
and it made of cylindrical external form in order that it may be guided in its descent
in a corresponding cylindrical guide in which it passes through the lower disc of the
framing. On the upper end of the negative carbon holder is fixed a laterally projecting
screw nut fitting on the lower screw spindle.
This screw spindle turns on pivots on its upper and lower ends carried in bearings
on the upper and lower cross pieces of a frame the object of which will be presently
described. On the upper end of this screw spindle is arranged a horizontal toothed

page_text: wheel, which is held on the spindle between two insulating washers by a screw nut,
this wheel being in gear with a pinion fixed on the positive upper screw spindle, so
that this is rotated at a proportionately slower speed by the lower spindle.
The upper spindle also runs in bearings at its two ends, the lower one of which is
carried on a cross bar of the frame while the upper one is carried by the top disc
thereof. The positive carbon holder consists of a thin rod sliding in a guide on the
lower disc of the frame, being necessarily made as light as possible as it receives an
upward motion.
It has at its upper end two projecting thin arms forming together a screw nut
fitting the upper screw spindle.
The two screw spindles have each several screw threads of the same quick pitch.
The weight of the positive carbon holder may be partly counterbalanced by a weight
connected thereto by a cord passing over a pulley at the upper part of the frame.
The two carbon holders have suitable clamping devices for holding the carbons so
arranged that these are accurately in line with each other and in the axial line of the
lamp, in which is also situated the upper screw spindle.
If the consumption of the carbons is maintained in the proportion of two to one, the
positive carbon will be twice as long as the negative one, and the before mentioned
toothed wheel and pinion are correspondingly proportioned.
If the proportions of the carbons are altered, the gearing is altered in a correspond-
ing manner.
From the above it will be seen that the downward pressure of the upper negative
carbon rotates the lower screw spindle which in rotating the upper spindle at a pro-
portionately quicker speed, causes the lower positive carbon to be raised. These motions
are regulated by a clockwork mechanism consisting of a barrel mounted on the upper
end of the upper screw spindle to which it is connected by a ratchet and pawl in such
a manner that the rotation of the screw spindle in one-direction carries the barrel with
it, but it can turn independently thereof in the contrary direction. The barrel carries
a toothed ring gearing with a pinion on an axis carrying a star wheel and a flyer,
the axis being mounted on a slide vertically adjustable on one of the pillars of the
frame.
The barrel being rotated by the screw spindle as this revolves in raising the positive
carbon holder, it imparts a corresponding motion to the star wheel and flyer, so that
if the star wheel's motion is stopped, the motion of the screw spindles is also
stopped.
Bolow the star wheel is a horizontal lever having on its one end a knife edge which
when that end of the lever is raised, enters between the teeth of the star wheel and
stops its motion.
When the carbons are at the normal distance, an adjustable spring acts on the other
end of the lever drawing it down so as to raise the knife edge and thus stop the feed
mechanism.
When the distance of the carbons increases so as to increase the resistance of the
lamp, an increased current passes through the coils of an electromagnet on a shunt
circuit, and causes this to attract an armature carried by the said lever whereby the
knife edge end of this is drawn down in opposition to the spring thus freeing the
star wheel and allowing the foed mechanism to act.
The upper end of the before mentioned frame carrying the lower screw spindle
constitutes the armature of an electro magnet, the coils of which are of thick wire and
are included in the lamp circuit.
The said frame is suspended by springs from a transverse bar that carries the last
named electro-magnet; when the current passing through the lamp is sufficiently
powerful, the said frame is held in a raised position by the electro magnet attracting
its armature; when the electro magnet is not sufficiently powerful the frame drops
away gently by virtue of its spring suspension.
When the lamp is first put in action, the screw nut of the positive carbon holder is
at the bottom of its screw spindle, and that of the negative carbon holder is at the top
of its screw spindle, the ends of the carbons being in contact.

page_text: As soon as the current passes through the lamp the electromagnet in the main
circuit attracts the armature of the frame carrying the lower screw spindle, which,
being raised, causes the carbons to be moved in the contrary direction to the feed
motion, so as to separate them sufficiently to produce the are, and the parts then continue
in this position until the resistance of the lamp is increased by the burning away of
the carbons, whereupon the shunt electro magnet releases the feed mechanism as above
described.

page_text: I, JULIEN DULAIT of Charleroi Belgium, Engineer do hereby declare the nature
of this invention and in what manuer the same is to be performed to be particularly
described and ascertained in and by the following statement:-
This invention relates to an improved construction of electric arc lamps in which
the light from a fixed luminous point is thrown upward against a reflecting surface,
and in which the positive carbon is for this purpose placed at the bottom, the negative
carbon being directed upward, the two carbons being made to move at speeds propor-
tional to their rate of consumption, so as to maintain the luminous point always at the
same distance from the reflector, thus giving a constant angle of projection and a
uniformly reflected light.
This result is obtained by the construction of regulator, which I will describe with
reference to the accompanying drawings in which Fig. 1 shews a front view of the
lamp, Fig. 2 a side view, Figs. 3 to 14 detached details.
The regulator consists mainly of a frame composed of two circular horizontal
discs D B connected by vertical columns carrying the principal parts of the
mechanism, so that at the lower part of the lamp, i.e. that below the lower disc D
there are only the positive and negative holders, P P and N P¹ of which the former
receives an upward motion and the latter a downward motion in the proportions before
mentioned,
The motions are imparted by means of mechanism with an upper and lower screw
spindle VV rotated by the weight or pressure exerted on the thread of the lower
screw spindle V by a screw nut E, from which is suspended the descending negative
carbon holder, the rotation of whose screw spindle transmits the necessary motion at
the required relative speed to the upper spindle V₁ of the ascending lower carbon.
For this purpose the negative carbon holder is made proportionately very heavy,
being provided with a stem N made of cylindrical external form in order that it may
be guided in its descent in a corresponding cylindrical guide D² in which it passes
through the lower disc of the framing. On the upper end of the cylinder N is fixed
a laterally projecting screw nut E fitting on the lower screw spindle V.
This screw spindle turns on pivots on its upper and lower ends, carried in bearings
on the upper and lower cross pieces tt of a frame C the object of which will be
presently described. On the upper end of this screw spindle V is arranged a horizontal
toothed wheel which is held on the spindle between two insulating washers r r by a
screw nut e¹, this wheel being in gear with a pinion p fixed on the positive upper
screw spindle V', so that this is rotated at a proportionately quicker speed by the
lower spindle V.
The upper spindle V₁ also runs in bearings at its two ends, the lower one of which
is carried on a cross bar B of the frame, while the upper one is carried by the top
disc D thereof. The upper part of the positive carbon holder consists of a thin rod P
sliding in a guide on the lower disc D of the frame, being necessarily made as light
as possible as it receives an upward motion.

page_text: It has at its upper end a screw nut E¹ formed of two projecting thin arms b b fitting
with threaded holes on the upper screw spindle VI.
The two screw spindles have each several screw threads of the same quick pitch.
The weight of the positive carbon holder P P¹ may be partly counterbalanced by a
weight connected thereto by a cord passing over a pulley on the upper part of the
frame.
The two carbon holders have suitable clamping devices for holding the carbons, so
arranged that these are accurately in line with each other and in the axial line of the
lamp, in which is also situated the upper screw spindle V'. If the consumption of the
carbons is maintained in the proportion of two to one, the positive carbon will be
twice as long as the negative one, and the before mentioned toothed wheel and
pinion e p, are correspondingly proportioned.
If the proportions of the carbons are altered, the gearing is altered in a correspond-
ing manner.
From the above it will be seen that the downward pressure of the upper negative
carbon with it holder N P¹ rotates the lower screw spindle V which, in rotating the
upper spindle V at a proportionately quicker speed, causes the lower positive carbon to
be raised at the required increased speed for maintaining the luminous are at the same
point. These motions are regulated by a clockwork mechanism consisting of a
flanged disc T mounted on the upper end of the upper screw spindle V₁ to which it
is connected by a ratchet pawl c, Fig. 10, in such a manner that the rotation of the
screw spindle in one direction carries the disc T with it, but it can turn independently
thereof in the contrary direction. The disc T has a toothed flange gearing with a
pinion pl, Figs .8 and 9, on an axis a carrying a star wheel and a flyer v, the axis
being mounted on a slide M vertically adjustable on one of the pillars of the
frame D D.
The disc T being rotated by the screw spindle V₁ as this revolves in raising the
positive carbon holder, it imparts a corresponding motion to the star wheel and Hyer,
so that if the star wheel's motion is stopped, the motion of the screw spindles V Vi
is also stopped.
Below the star wheel is a horizontal looped lever L having its pivots V¹ mounted
in adjustable bearing S1, Figs. 4 and 5, and having on its one end a knife-edge c¹
which, when that end of the lever is raised, enters between the teeth of the star
wheel and stops its motion.
When the carbons are at the normal distance, an adjustable helical spring » ncts
on the other end of lever L drawing it down so as to raise the knife edge c¹ and thus
stop the feed mechanism.
When the distance of the carbons increases so as to increase the resistance of the
luminous arc, an increased current passes through the coils of an electromagnet E² on
a shunt circuit, and causes this to attract an armature A carried by the said lever L,
whereby the knife-edge end of this is drawn down in opposition to the spring ³, thus
freeing the star wheel and allowing the feed mechanism to act.
The upper end of the before mentioned frame C carrying the lower screw spindle V
carries the armature A¹ of an electro-magnet E³, the coils of which are of thick wire
and are included in the lamp circuit.
The said frame is suspended by springs R from a transverse bar S' of the frame
that carries the electromagnet E'; when the current passing through the lamp is
sufficiently powerful; the said frame C is held in a raised position by the electro-
magnet E, attracting its armature A'; when the electro magnet is not sufficiently
powerful, the frame C drops away gently by virtue of it spring suspension, and con-
sequently lowers the screw spindle V and negative carbon holder.
When the lamp is first put in action, the screw nut E₁ of the positive carbon
holder P is at the bottom of its screw spindle V', and the nut E of the negative carbon
holder N is at the top of its screw spindle V, the ends of the carbons being in contact.
As soon as the current passes through the lamp, the electro magnet E³ in the main
circuit attracts the armature of the frame carrying the lower screw spindle V,
which, being raised, causes the upper carbon to be raised in the contrary direction

page_text: to the feed motion, so as to separate it sufficiently from the lower carbon to produce
the arc, and the parts then continue in this position until the resistance of the lamp
is increased by the burning away of the carbons, whereupon the shunt electro-
magnet E in attracting the armature A releases the feed mechanism as above
described, and in thus setting in motion the screw spindles V V₁, the carbons are
made to approach each other until the normal length of arc is obtained.
In order to allow of the above mentioned vertical motion of the spindle V while V₁
remains stationary and while the wheels e, p, remain in gear, the pinion p is made of
a sufficiently greater width than e.
As the carbons are consumed in a definite proportion, it will be readily seen that
the luminous are will be maintained constantly at the same height, so that the angle at
which the light is projected will always remain the same.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. An electric arc lamp wherein the lower carbon holder is in connection with the
positive electrodo and the upper carbon holder with the negative electrode, such
carbon holders being so arranged and actuated as to maintain the luminous arc
practically at a fixed point, substantially as herein described.
2. An electric arc lamp wherein a lower ascending positive carbon holder and an
upper descending negative carbon holder, are respectively moved at a speed propor-
tionate to their consumption, by means of screw spindles V V₁ on which are screw
nuts E-E fixed respectively to the upper ends of the carbon holders N, P, the upper
carbon holder being made in descending by its weight, to rotate-the-screw spindle V,
the rotation of which is communicated by suitable gearing ep to, the screw spindle Vi
which causes the lower carbon holder to rise, such motion being regulated by a clock-
work mechanism Talv in combination with a knife edge C₁ on a lever L acted upon
by a spring and an electromagnet E³, substantially as herein described with refer-
ence to the drawings.
3. In an electric are lamp such as is referred to in the preceeding claim, mounting
the screw spindle V of the upper carbon holder in a frame C, the part A¹ of which
forms the armature of an electro magnet E' included in the lamps circuit, so that the
frame, screw spindle and upper carbon holder are raised on the passage of a current,
thereby raising the upper carbon so as to produce the arc, the frame C being suspended
from springs R R so as to cause a gentle descent of the frame and carbon holder when
the lamp current, ceases, substantially as herein described with reference to the
drawings.
Dated this 1st day of February 1889