IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to Edward Laker Voice of 1 Francis Street Torrington
Square in the County of Middlesex for an invention of "IMPROVEMENTS IN
ELECTRIC LAMPS
"
PROVISIONAL SPECIFICATION left by the said Edward Laker Voice at
the Office of the Commissioners of Patents on the 16th May 1882.
EDWARD LAKER VOICE of 1 Francis Street Torrington Square in the County
of Middlesex IMPROVEMENTS IN ELECTRIC LAMPS
If two or more rods or bars of iron be placed in a hollow bobbin and magnetised
by a current of electricity they will have a tendency to place themselves are far
as possible from each other with a force proportional to the strength of the current,
by reason of the fact that the rods will be converted for the time being into
magnets with like poles joining or adjacent to each other, and in consequence
of the well known law that like poles repel each other the action is explained.
Now in my invention I utilise this principle in the construction of electric lamps
by placing the electrode or electrodes or carbon holder or holders in an iron core
of an electro magnet or magnets constructed of two or more rods of iron which are
made to surround the said electrode or holder
At the ends of the said iron rods or at a distance from their ends I cause them
to be hinged, the said hinge or hinges forming a fulcrum, instead of which the said
iron rods could be fixed to a brass socket having a pivot and extension pieces to
bite the electrode or carbon holder.
The weight of the said rods or core may be balanced and their movements
regulated by adjustable spiral or other springs.
I do not confine myself to the precise form of lamp as it is evident that my
invention can be applied in a variety of ways without departing from the nature
of the invention

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Laker Voice in the Great Seal Patent Office on the
16th November 1882.
EDWARD LAKER VOICE of 1 Francis Street.Torrington Square in the County
of Middlesex IMPROVEMENTS IN ELECTRIC LAMPS
If two or more rods or bars of iron be placed in a hollow bobbin and magnetized
by a current of electricity, they will have a tendency to place themselves as far as
possible from each other with a force proportional to the strength of the current,
by reason of the fact that for the time being they are converted into magnets with
like poles adjoining or adjacent to each other, and in consequence of the well known
law that like poles repel each other the action is explained.
Now I utilise this principle in the construction of electric lamps by placing the
electrode or electrodes or carbon holder or holders in an iron core of an electro-
magnet constructed of two or more rods of iron which are made to surround the
said electrode or carbon holder. At the ends of the iron rods or at a distance from
their ends I cause them to be hinged, the said hinge or hinges forming a fulcrum,
instead of which the said iron rods could be fixed to a brass socket having a pivot
and extension pieces to bite, or regulate the biting of the carbon holder. Figure 1
in the accompanying drawing shews the solenoid in section and the iron rods
forming the core, in elevation; A is the main circuit coil and B the shunt coil;
C, C are the iron rods forming the core; 0, O are the extension pieces which are
made to form part of, and are rigidly fixed to each iron rod respectively. These
said extension pieces may be of iron but preferably of brass, which in that case
would have small blocks of iron I, I, at or near their ends; the advantage of these
blocks will be presently explained. P. P are posts surrounded by spiral springs;
these posts are made to be adjustable, that is, they may be fixed at a greater or
lesser distance from the iron core; this is obtained by having an elongated hole
or slot in the frame F, a top view of which is shewn in Figure 3; S being the said
holes or slots. The said posts for supporting the springs are fixed by suitable
shoulderings and nuts. The fact of these posts being adjustable transversely
enables the biting power of the iron rods constituting the core, to be regulated,
owing to the upward pressure of the springs tending to counteract the repelling
force of the two iron rods, this force varying as the posts are closer to or farther
from the iron core. Fig 2 shews an elevation of one of the iron rods forming the
core of the magnet. Figure 4 is a sectional drawing of the bottom of the core and
Figure 5 a section across near the top.
The iron blocks I. I may be made to be adjustable on the extension pieces 0, 0,
but they are preferably fixed. If the lamp is placed in circuit the iron rods move
apart at the top and consequently bite the carbon holder at the bottom, at the
same time formning the arc. If however the lamps are working in series, the
varying resistance in the circuit which occurs on that account is compensated for
in the following manner. As soon as the arc gets too long, the increased resistance
causes the shunt coil B to convey more current whose increased magnetic effect
exerts an attractive power on the iron blocks I, I. while the core has a tendency
to drop, but that cannot happen without its first releasing the electrode, by reason
of the combined effect of the upward pressure of the springs and the increased
influence which the shunt coil B has on the blocks I. I.
Having now explained the nature of my invention and in what manner the
same may be carried into effect. I claim :-
Firstly
The use of a hinged divided core having extension pieces supported by adjustable

page_text: springs fitted on movable posts, whereby the biting power of the said divided
core may be regulated in the manner herein before explained with reference to
accompanying drawings
Secondly
The application of iron blocks to the said extension pieces, whereby the attractive
effect of the shunt coil facilitates the regulation of the feeding of the electrode
substantially as set forth-
Thirdly
The general arrangement and construction of electric lamps as set forth.
In witness whereof I the said Edward Laker Voice have hereunto set my
hand and seal this sixteenth day of November in the year of our Lord
Eighteen Hundred and eighty two
EDWARD LAKER VOICE (L.S.)
Witness
F A HARVEY