IMPROVEMENTS IN ELECTRIC LIGHTING APPARATUS
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for au Invention
of "IMPROVEMENTS IN ELECTRIC LIGHTING APPARATUS." A communication
from abroad by Thomas Anthony Connolly, of Washington, District of
Columbia, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 23rd August 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltino, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC LIGHTING
APPARATUS." [A communication from abroad by Thomas Anthony Connolly,
of Washington, District of Columbia, United States of America.]
This Invention has relation to electric lighting and pertains specially to the
arc-light system in which two or more lamps are arranged in circuit and supplied
from a common dynamo-electric machine or generator.
The object of the said Invention is to provide means whereby, should the current
passing through any one of the lamps be interrupted, the circuit will still be
maintained through the other lamps without loss or obstruction.
The said Invention accordingly consists in the employment in connection with a
lamp in which the carbon-pencils (or one of the same) are fed by means of an
electro-magnet of an automatic switch, which while the arc is effective, allows the
circuit to be made entirely through the carbon pencils and their conducting
appliances, but which should the circuit through said pencils fail or become
ineffective, will divert the course of the current through the lamp-frame or through
a suitable conductor connected therewith.
In carrying the said Invention into practice, the frame-bars of the lamp are
attached to plates which support tubular magnets intended for feeding the positive
and negative carbon pencils respectively, the same passing through the hollow
centres of the magnets. The insulated wire of the upper magnet is in circuit with
the main conductor through a binding post and also with the iron of the magnet

page_text: or with any other suitable conducting medium which will lead the current from
said wire through the clamps into the positive or upper carbon pencil. The
shank of the aforesaid binding post sustains a pivoted L-shaped arm to which is
connected a retracting spring, which normally maintains said arm in contact with
a pin or stud connected with one of the metal frame-bars. A depending portion of
the arm is provided with an iron armature which I term a sub-armature, to
distinguish it from the main arınature of the magnet, and which when said magnet
is energized is attracted towards the side thereof, so as to cause a break of contact
between the arm and the pin or stud.
The main arinature of the said magnet consists of an annular disc or plate of
iron through the central opening in which the positive pencil passes and is fed.
Spring clamps rise from the surface of said armature so as to grasp the pencil
in the act of lifting the same after the current has been established.
A non-
magnetic metal plate is arranged below the main armature and supported from the
magnet by adjusting screws which pass through holes in the armature and are
encircled above said armature by cushioning springs. The plate is also provided
with clamps or conductors which depend therefrom and touch or embrace the
carbon near its point, so as to lead the current as near thereto as may be possible
or expedient.
The lower magnet, its armature and supporting plate, are substantially the same
as the upper magnet and its appurtenances. The upper magnet has however con-
ducting clamps above its top, and the current is led from the clamps into and
through the magnet wire, whence it is conducted to the other frame-bar. The
lower magnet is insulated from the frame-bars by à suitable collar.
A current entering the said binding post branches in two directions, one path
being through the wire of the upper magnet and thence into and through the
carbons, and the other through the L-shaped arm and the pin or stud, and thence
around through the lamp-frame. The exit for both currents is the same, i. e., through
another binding post. Now the upper magnet becomes sufficiently charged by the
current to attract the sub-armature on the L-shaped arm which breaks the circuit
through the stud and causes the entire current to pass into the magnet wire and
thence through the carbon pencile, which being in contact initiate the light.
Immediately the main armature is attracted by the magnet, and the clamps are
pressed.against the carbon pencil by the shoulders of the magnet, so that the pencil
is lifted a short distance to establish the arc. The lower magnet is also energized
at the same time, and the lower or megative pencil raised by the movement of the
armature and the action of the clamps, but owing to a difference in the adjustment
of the respective plates by which the play of the armatures is controlled the lower
pencil is lifted only about one half the distance moved by the upper pencil.
As soon as the distance between the pencils becomes too great to conduct the
current the armatures fall, the pencils come together, and the arm being retracted
touches the stud. Should there be any failure in re-establishing the arc from any
cause, the other lamps in the circuit are not put out or otherwise injuriously
affected, as the circuit is then made through the L-shaped arm as already stated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
23rd February 1882.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRIC-LIGHTING
APPARATUS." A communication from abroad by Thomas Anthony Connolly, of
Washington, District of Columbia, United States of America.
This Invention relates to improvements in electric lighting apparatus, and
pertains specially to the arc-light system, in which two or more lamps are arranged
in circuit and supplied from a common dynamo-electric machine or generator.
The main object of the said Invention is to provide means whereby, should
the current passing through any one of the lamps be interrupted, the circuit
will still be maintained through the other lamps without loss or obstruction.
The said Invention accordingly consists in the employment in connection with
a lamp in which the. carbon pencils (or one of the same) are fed by means of an
electro magnet of an automatic switch, which while the arc is effective allows the
circuit to be made entirely through the carbon pencils and their conducting
appliances, but which should the circuit through the said pencils fail or become
ineffective, will divert the course of the current through the lamp-frame or through
a suitable conductor connected therewith.
The said Invention is illustrated in the accompanying Drawing, which represents
a vertical central section of an arc-lamp provided with my improvements.
i
A, A¹, designate the frame-bars of the lamp attached to the plates B, B'; these
plates support the tubular magnets C, C³, intended for feeding the positive and
negative carbons, carbon-pencils D, D¹, which pass through the hollow centres of
the said magnets. The insulated wire d of the magnet C is in circuit with the
main conductor through the binding post o and also with the iron of the magnet
or with any other suitable conducting medium which will lead the current from
the said wire through the clamps g', g', into the positive or upper carbon pencil.
The shank of the binding post o sustains a pivoted L-shaped arm e to which is con-
nected a retracting spring e³ that normally maintains the said arm in contact with
a pin or stud f¹ connected with the metal frame-bar A. The depending portion
of the said arm e is provided with an iron armature f' which I term a sub-armature
to distinguish it from the main armature of the magnet C, and which, when the
said magnet is energized is attracted towards the side thereof so as to cause a
break of contact between the arm e and the pin or stud f'.
F is the main armature of the magnet C; this armature consists of an annular
disc or plate of iron through the centre opening in which the positive pencil D
passes and is fed. Spring-clamps 9, 9, extend upward from the surface of the said
armature so as to grasp the pencil in the act of lifting the same after the current
has been established. A non-magnetic metal plate H is arranged below the
armature F and is supported from the magnet by adjusting screws h¹, which pass
through holes in the armature and are encircled above the said armature by
cushioning springs h. The plate H is provided with the clamps or conductors g², g³,
which depend therefrom and touch or embrace the carbon near its point, so as to
lead the current as near thereto as may be possible or expedient. The magnet C',
its armature and supporting plate, are substantially the same as the magnet C and
its appurtenances, the magnet C¹ has however the conducting clamps g³, g², above
its top as shown, and the current is led from the clamps g' into and through the
magnet wire whence it is conducted to the frame-bar A¹. The lower magnet C¹
is insulated from the frame-bars A, A', by a suitable collar I.

page_text: The operation of the lamp is as follows, that is to say:-A current entering the
binding post o branches in two directions, one path being through the wire of the
magnet Ĉ and thence into and through the carbons, and the other through arm e
and the pin or stud f¹, and thence around through the lamp-frame. The exit for
both currents is the same, that is to say, through the binding post K; now the
magnet C becomes sufficiently charged by the current to attract the sub-armature
on the arm e, which breaks the circuit through the stud f¹ and causes the entire
current to pass into the magnet wire and thence through the carbon pencils, which
being in contact initiate the light.
Immediately the armature F is attracted by the magnet, the clamps 9, 9, are
pressed against the carbon pencil by the shoulders g³ of the magnet, so that the
pencil is lifted a short distance to establish the arc, the lower magnet C is also
energized at the same time and the lower or negative pencil raised by the
movement of the armature and the action of the clamps, but owing to a difference
in the adjustment of the respective plates H, L, by which the play of the armatures
is controlled, the lower pencil is lifted only about one half of the distance moved
by the upper pencil.
As soon as the distance between the pencils becomes too great to conduct the
current the armatures fall, the pencils come together, and the arm e being retracted
touches the stud f¹. Should there be any failure in re-establishing the arc from
any cause, the other lamps in the circuit are not put out or otherwise injuriously
affected, as the circuit is then made through the arm e, as already stated.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,-
First. In an electric arc-lamp, the combination with the magnet C through which
the arc is maintained of an automatic switch to continue the circuit or produce an
external path in case of the interruption or failure of the arc-circuit.
Second. The combination with the magnet C and its appurtenances for feeding
and supplying the carbon pencil of the sub-armature switch or arm e normally in
the branch circuit, and constructed and arranged substantially as described, so as
to provide an external circuit in case of the failure or interruption of the arc.
Third. The combination with the magnet C and its appurtenances for moving
and conducting the current to the carbon pencils of the automatic switch, con-
sisting of the pivoted arm e supporting a sub-armature, the pin or stud f¹ or its
equivalent, and the frame-bars or conductors A, A¹, substantially as and for the
purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty third of December, in the year of our
Lord One thousand eight hundred and eighty two.