Improvements in Electric Arc Lamps.
Year: 1894

page_text: Date of Application, 14th Feb., 1894
Complete Specification Left, 14th Nov., 1894-Accepted, 5th Jan., 1895
Improvements in Electric Arc Lamps.
HENRY FRANCIS JOEL 44 Lavender Grove, Dalston, London, Electrical
Engineer do hereby declare the nature of this invention to be as follows:-
My invention consists in improvements in the form of are lamps made on what is
known as the Pilsen-Joel type having coned or spindle shaped iron cores working
between two solenoids and balanced between them to make an arc of the required
length by the action of the electric current itself.
I make such lamps in a special and novel manner. For use with alternating
currents: I make the core of laminated iron such as soft iron wire, and build up
the cone shape by successive layers of iron wire decreasing in length towards the
end or butt of the cone, and in order to prevent the choking effect of the greater
mass of the iron, I place rings, or coils of copper, or other metal round the iron
core, so that the inductive and choking effect is gradually lessened in proportion to
the mass, whilst the magnetic balance due to the action of the increasing and
decreasing cones between the two coils is still maintained, thus enabling me to use
this core and construct an electrically adjusting lamp, acting in a similar way as
with continuous currents. I also make the core of a special taper having a long and
almost parallel end towards its point, and a blunt and comparatively quick taper at
it thickest end, or with two such unequal cones end to end, to make a spindle shaped
core. I also make an approximately spindle shaped, or double coned core, by
cutting it in the centre and separating the two halves, so that in lamps with the
coils in tandem, or end to end, the mass of iron is reduced to half in each solenoid
and thus the choking effect is decreased in each solenoid. I may also make an
unequal shaped double coned core, one end being a shorter and quicker cone than
the other, for a like purpose. In any of the constructions an important feature is
that the coils are wound on non-metallic bobbins and the core is not placed in a tube
as usual when made for continuous currents. To make such Pilsen-Joel lamps
work in parallel series, I arrange a rack and pinion with a paul and ratchet wheel
to work with the core, so that in one direction, say upwards, the coil is effectually
stopped from moving more than required distance to strike the arc. I have found
that such a check is necessary with this type of lamps to prevent their jumping,
and working one against the other, when joined in parallel series, such as two lamps
in series on a 100 volt circuit. I do this in several ways, one by using the flat
frame holding the core, and making ratchet shaped teeth on it, and gearing this
directly into a click or paul fixed to the frame of the lamp, another way is by
making cog teeth on the side of the flat frame and gearing same with a pinion and
then stopping the pinion by a ratchet wheel and paul or click, another way is by
means of two guide or two friction wheels mounted on a frame and so arranged that
by the movement of the flat frame, or a tube holding the core, in an upward
direction the two wheels are caused to act as a brake to bind the frame and hold
the core, this is adjustable, and a small movement is given to enable the carbons to
strike and make an arc and yet to allow the carbons in feeding to approach each
other.
1 construct the frame of my improved lamps of tubes with bridging pieces, and
make special provision that there is no electric connection between the carbons and
the metal of the frame, globe, or holder, or any external part of the lamps. I also

page_text: make special carbon holders, having a quick adjustment for alignments of the carbons
by means of a non-concentric ring holding the carbon, and I arrange a solenoid
cutout coil to make and break contacts when the lamps are joined in series so that
should the lamp go out, the circuit is maintained and a resistance is automatically
put in to compensate for the lamp. I also arrange a switch for the lamp, to act
automatically when the cover is moved down, or when the globe is lowered, say for
fresh carbons to be put in.
For lamps to burn in projectors or for photographic purposes, I arrange the
carbon holders to slide on guide rollers, so that the lamps may be used at au inclined
plane.
I also make a special arrangement of the suspending chains or cords used in the
lamps, which pass over pulleys to regulate the movement of the two carbons to, or
from each other; by fixing one end of the cords so that the top carbon travels only
one half the distance of the bottom carbon, and this I find useful in alternating
current arc lamps, as the iron cores do not go so far into the solenoid and the
choking effect is consequently much lessened, I also compensate the choking effect
and the loss of feeding power of the lamps by adding a graduated weight, such as
a metal chain attached direct, or through a pulley, or by discs of metal, which are
gradually added to the weight of the top carbon as it travels downwards, and I
effect the same object by winding the suspending chains or cords over a screw,
shaped, or fusee wheel which increases the weight power of the top carbon by
leverage, and in proportion reduces the weight power of the bottom carbon, and
thus assists the feeding and neutralizes the choking effect of the coils.
Dated this 14th day of February 1894.
snail
Hamps
HENRY FRANCIS JOEL of 44 Lavender Grove, Dalston, London, 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 :-
My invention consists of improvements in the form of arc lamps made on what
is known as the Pilsen-Joel type having coned or spindle shaped iron cores working
between two solenoids and balanced between them to make and maintain an arc of
the required length by the action of the electric current itself.
In the drawings illustrating my invention like letters indicate like parts.
I construct such lamps in a novel & special manner for use with alternating
currents. One type of lamp is shewn in Fig. 3, a front sectional elevation Fig. 4,
being a plan of the coil support or bridging pieces. In this type the coils are end
to end and the iron core is double coned or spindle shaped and is shewn in Fig. 1
and 2, a side & front elevation. The core is made of soft iron wire or soft iron
wire first covered with cotton, and is built up by successive layers of the iron wire,
to make the cone shape, each layer decreasing in length as shewn.
In order to prevent the choking effect of the greater mass of the iron core C,
I place rings or coils of copper R, R, R see Figs. 1, 2 & 3, or other metal round the
iron core C, so that the inductive and choking effect is gradually lessened in pro-
portion to the mass, whilst the magnetic balance due to the action of the coned
cores increasing in one solenoid and decreasing in the other is still compensated by
the greater and lesser pull respectively and I am thus enabled to use this core and
construct an electrically adjusting lamp to work with alternating currents of
electricity acting in a similar way as with continuous currents. In Fig. 3, M, is the
coil in the main circuit, and S, the shunt coil.

page_text: For other types of these lamps where the main coil M, and shunt coil S, are
placed side by side, I make the core C, in two halves, or simple cones and place
the rings R, R, in similar positions to those shewn in Figs. 1, and 2, the action
being practically the same as with the two coils end to end and double coned core
shewn in Fig. 3, this also applies to the lamps where the two coils are placed one
outside the other and a simple cone or half spindle shaped core is used.
In all these types of lamps an important feature is that the coils M, and S, are
wound on non-metallic bobbins and the core is not placed in a closed tube as is
usual when made for continuous currents.
To make such Pilsen-Joel lamps work in parallel series, I fix a special clamping
arrangement by which the core and carbon holders are effectually stopped from
moving more than the required distance apart to strike the arc. I have found that
such a check is necessary with this type of lamp to prevent their jumping and
working one against the other when joined in parallel series, such as two lamps in
series on a 100 volt circuit. I do this by means of two guide or two friction wheels,
Fig. 5, and 6, B, B, which are specially made non-concentric by being pivotted a
little out of centre, as shewn by the cross centre lines in Fig. 5, these wheels are
mounted on a frame A, or bridging piece shewn in Fig. 4, fixed on the underside
of the solenoid coil S, and so arranged that by the movement of the flat frame F,
which carries the core C, or a tube holding the core, in an upward direction,
the two wheels, which are weighted on the one side by the adjustable screws E, E,
are by their cam shape caused to move together and thus act as a brake to
bind the frame F, and hold the core C. A little play in the guide rollers B, B,
is given to allow a small movement to enable the carbons to strike and nake
an arc.
The movement of the frame F, downwards is perfectly free and allows the
carbons in feeding to approach each other. A pin D, on the side of the roller B,
prevents the roller from going too far round when the core frame F, is moving
down.
I construct the frame of my improved lamp Fig. 3, of tubes X, with bridging
pieces A, Fig. 4, and make special provision that there is no electric connection
between the carbons and the metal of the frame, globe, or holder, or any external
part of the lamp.
1 make a special carbon holder see Fig. 7, having a quick adjustment for align-
ment of the carbons by means of a non-concentric ring, or socket G, holding
the carbon H. The carbon is placed in the socket or ring G, and is quickly
put into line by twisting it round, and is then clamped by the ring I, and
Screw K.
I arrange a solenoid cut-out coil shewn at Fig. 8, to make and break contact
when the lamps are joined in series, so that should the lamp go out, the circuit
is maintained and a resistance is automatically put iu_to_compensate for the
lamp. The coil is shewn at L, and the iron core at O, with a resistance at T.
The contact is made at the screw U, and arm V. The current partly passes
through the coil L, this sucks in the core O, breaks the contact between U,
and V, and the current then passes through the arc. If the arc breaks the
spring forces the core O, out again and remakes contact between U and V, and
thus keeps the circuit intact for other lamps. The position of this cut-out coil
in the lamps is shewn in dotted lines at the top of the lamp Fig. 3.
I make a special arrangement of suspending chains or cords used in these
lamps, see Fig. 9, by fixing one end of the cords so that the top carbon travels only
one half the distance of the bottom carbon, and this I find useful in alternating
current arc lamps, as the iron cores do not go so far into the solenoid and the
choking effect is consequently much lessened.
In my former Patent No. 15898 of 1884 I described laminated iron cores for use
in this type of lamp, made of strips of sheet iron and bare iron wire therefore I
do not claim such construction in this Specification.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The construction of single or double cone shaped iron cores of alternating
current arc lamps, of iron wire covered with an insulating material, substantially as
shewn and described in reference to Figs. 1 and 2.
2. The construction of cores of alternating current arc lamps with metal rings
placed in suitable positions round the iron core for partly neutralizing the choking
effect of the iron core on the maiu and shunt coils, substantially as shewn and
described in reference to Figs. 1, 2 & 3.
3. The combination of the coned iron cores made of iron wires insulated with
cotton or other material, and the metal rings R, R, to form the cores of alternating
current arc lamps substantially as shewn and described in reference to Figs. 1,
.2 & 3.
4. The clamping device, substantially as shewn and described in reference to
Figs. 5 and 6.
5. The construction of the bye-pass or cut-out consisting of the combination of
the solenoid coil and core with the adjustable contacts substantially as shewn and
described in reference to Fig. 8.
Dated this 14th day of November 1894.
HENRY FRANCIS JOEL.