IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING
Year: 1879

page_text: LETTERS PATENT to Adam Fettiplace Blandy, of 41, Parliament Street, in the
City of Westminster, Civil Engineer, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR ELECTRIC LIGHTING."
Sealed the 14th November 1879, and dated the 23rd May 1879.
PROVISIONAL SPECIFICATION left by the said Adam Fettiplace Blandy at
the Office of the Commissioners of Patents on the 23rd May 1879.
ADAM FETTIPLACE BLANDY, of 41, Parliament Street, in the City of Westminster,
Civil Engineer. "IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING."
This Invention consists in the application of an electro magnetic governor for
regulating currents of electricity in the branches of a divided circuit, so as to permit
of serrin or other voltaic arc lamps being used in the said branches. This governor
is formed of an hollow cylinder of brass or other suitable material with a soft iron
core, such as are commonly used for electro magnets, induction coils, and the like
apparatus. Round the cylinder two or more insulated conducting wires are wound
together parallel to each other. The ends of those at which winding is begun
I call the "commencing," and the other ends the "finishing" ends, so that the wires
from commencing to finishing ends form solenoids coiled in the same direction
round the core; I utilize this for, say, two branches in the following manner :-
I take one branch and at any convenient distance from the point where it leaves
the main wire connect it with the "commencing" end of one of the governor wires.
The other branch I connect with the "finishing" end of the other wire of the
governor, the branches after traversing the governor being then continued separately
through their respective lamps, and so to the point where they again unite, and
thence to the generator. It will be seen from the foregoing that the two branch
currents traversing the governor pass round the core in opposite directions.
Supposing one branch and lamp with its arc to be at work, then upon bringing
the electrodes of the lamp in the other branch together so as to start an arc therein,
the current would naturally rush through the last branch and stop the arc in the
first, but owing to the form of governor the fact of making the circuit in one
branch sets up a momentary induced current in the other, keeping that are going
while the electrodes of the second lamp touch and separate.
The electro magnetic

page_text: governor may be of the simple straight form, or of the horse shoe or other con-
venient shape. The dimensions of core, wires, &c., will be according to the
magnitude of the currents.
I also propose to use an automating arrangement for withdrawing the iron
core when both branches are at work, and for replacing it when one branch
is broken or not in use, so as to be ready for starting it again. One method
of doing this is to place the coils in a vertical position, and attaching a cord,
chain, or similar appliance to the end of the core to pass said cord round
pulleys to a convenient position, and to attach it there to a weight sufficient just
to draw the core out of the cylinder when no current is passing. Then if only one
branch is at work the attraction of the coils will overcome the balance weight, and
will draw the core into the cylinder; but when both currents are at work, since one
tends to neutralize the other, the core will be released and will be lifted by the
balance weight, and so on.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Adam Fettiplace Blandy in the Great Seal Patent Office on the 20th
November 1879.
ADAM FETTIPLACE BLANDY, of 41, Parliament Street, in the City of Westminster,
Civil Engineer. "IMPROVEMENTS IN APPARATUS FOR ELECTRIC LIGHTING."
My Invention consists in the application of an electro magnetic governor for
regulating currents of electricity in the branches of a divided circuit, so as to permit
of electric lamps being used in the said branches. This governor is formed of a
piece of iron called the core round which two or more insulated wires are wound
together parallel to each other as represented in Figure 1.
"
If desired a thin layer of paper, varnish, brass, vulcanite, or other suitable
material may be interposed between the insulated wires and the said core, and such
material may be made in the form of a thin hollow cylinder fitting close to the
core, but into which the said core can be introduced, or out of which it can be
withdrawn at pleasure, in the manner common in electro magnets, induction coils,
and the like apparatus, provided always that whether with or without such inter-
posed material, the insulated wires are wound round the core in the manner above
described. The ends of these wires at which winding is begun I call the " com-
mencing," and the other ends the "finishing ends, so that the wires from
commencing to finishing ends form solenoids coiled in the same direction round the
core; I utilize this for, say, two branches in the manner represented in Figure 2
(that is to say), I take one branch (a) and at any convenient distance from the
point where it leaves the main conductor I connect it with the "commencing " end
of one of the governor wires. The other branch (b) I connect with the finishing
end of the other wire of the governor, the branches after traversing the governor
being then continued separately through their respective lamps, and so to the point
where they again unite, and thence to the generator. It will be seen from the
foregoing that the two branch currents (a and b) traversing the governor pass
round the core in opposite directions. Supposing one branch (a) and lamp with
its arc to be at work, then upon bringing the electrodes of the lamp in the other
branch (b) together so as to start an arc therein, the current would naturally rush
through the last branch and stop the arc in the first; but owing to the form of
governor the fact of "making" the circuit in one branch sets up a momentary
induced current in the other, keeping that are going while the electrodes of the
second lamp touch and separate. The electro magnetic governor may be of the
simple straight form, as represented in Fig. 1, or of the horse shoe or other
convenient shape. The dimensions of core wires, &c., will be according to the
magnitude of the currents.
For dividing an electric current of, say, 30 Webers per second, or thereabouts,
I use preferably a soft iron core in the form of a solid cylinder two feet in length
and two and a half inches in diameter, or thereabouts, round which are wound in
the manner before described two insulated copper wires, each of 125 yards in
length, and of the size known as No. 11, Birmingham wire gauge, or thereabouts.
I also propose in certain cases (but not in all) to use as an adjunct to said
governor an automatic arrangement for withdrawing the iron core when both
branches are at work, and for replacing it when one branch is broken or not in
use, so as to be ready for starting it again. One method of doing this is to place
the coils in a vertical position, and attaching a cord, chain, or similar appliance
to the end of the core to pass said cord round pulleys to a convenient position,
and to attach it there to a weight sufficient to draw the core partially out
of the coils when no current is passing. Then if only one branch is at work the
attraction of the coils will overcome the balance weight, and will draw the core
into the coils; but when both currents are at work, since one tends to neutralize

page_text: 2
the other, the core will be released and will be lifted by the balance weight, and
so on.
And having now described the nature of my said Invention, I declare that
I claim as my "Improvements in Apparatus for Electric Lighting,"
The construction and application of apparatus substantially as hereinbefore
described and represented in Figures 1 and 2 of the annexed Drawings for
regulating currents of electricity in the branches of a divided circuit.
In witness whereof, I, the said Adam Fettiplace Blandy, have hereunto set
my hand and seal, this Twentieth day of November, One thousand eight
hundred and seventy nine.
ADAM F. BLANDY. (L.S.)