Improvements in Electric Arc Lamps.
Year: 1892

page_text: Date of Application, 13th Apr., 1892
Complete Specification Left, 21st Oct., 1892-Accepted, 17th Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
We, JAMES SUGDEN of 99 Wyndham Road Camberwell London & WALLACE
JAMES LAMBERT SANDY of 41 Choumert Road Peckham London do hereby declare
the nature of this invention to be as follows:--
Our invention relates to improvements in the feeding or regulating mechanism of
electric arc lamps; & a means of preventing the carbon electrodes from approaching
each other too rapidly when the distance between such electrodes requires to be
regulated.
This is effected by attaching to the upper carbon a plunger or piston which is
free to slide in a tube or cylinder, sealed or partly scaled in such a way that it
retards any too sudden movement of the said plunger or piston.
Also to a brake or catch which, in combination with an electro-magnet or
magnets, acts directly on the carbons or rods carrying such carbons, and thus
prevents their approaching each other until the pressure is released by the
weakening of the said electro-magnet or magnets.
Dated this 12th day of April 1892.
JAMES SUGDEN.
WALLACE JAMES LAMBERT SANDY.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
We, JAMES SUGDEN, of 99 Wyndham Road, Camberwell, London, Electrician, and
WALLACE JAMES LAMBERT SANDY, of 41 Choumert Road, Peckham, Electrician,
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 :-
Our invention relates to the mechanism for automatically feeding the carbons or
other electrodes of electric arc lamps and regulating their distance, as we shall
describe referring to the accompanying drawing which is a vertical section partly
in elevation of a lamp according to our invention.
The lower carbon A is clamped by a setting screw A' in the socket head A³ of a
tube A³ which passes through the tubular core of an electro magnet A* having its
coil in the lamp circuit. To the underside of the socket A is fixed an iron
washer A constituting an armature which is attracted when the electro magnet A
is excited and is drawn down in opposition to a spring A, but when A is inert is
pushed up by the spring as far as permitted by a nut A7 acting as a stop. The
electromagnet A is itself carried by the rods B B which, with a casing C to which
they are secured in an insulated manner, constitute the framing of the lamp. The
upper carbon D is held in a split spring socket D' which is pivotted by a ball pressed
by a spring D within a hollow plunger or piston D³. This plunger or piston fits but
not tightly the interior of a tube D which is closed at the top. Spring blades D*
project down from the piston D3 and rub against the interior of the tube D' so as to
ensure conducting electrical contact therewith. One side of the carbon D bears against
the periphery of a grooved roller E; facing its other side is the end of a screw F
which by means of a milled nut F1 can be adjusted nearer to or farther from the
carbon. The screw F is held in one arm G₁ of a bell crank lever pivotted at G;
another arm G' carries an armature G₁ to an electro magnet H and has its upstroke

page_text: limited by an adjusting screw G³. The third arm G³ of the lever carries an
adjustable counterweight G*.
The coil of the electromagnet H, as well as that of A', is in the lamp circuit
which is so arranged with the parts suitably insulated that the current from
the one leading in wire passes through the coil of H to the casing C, tube D',
blades D' piston D' to the upper carbon D, then through the arc to the lower
carbon A, through the coil of A up one of the rods B to the other leading in wire.
The action of the lamp is as follows. The points of the two carbons A and D
being in contact, A being then held up by the spring A', when the lamp is put in
circuit, both the magnets A' and H are excited. The one A' attracts its
armature A lowering the lower carbon A while the other H attracts its arma-
ture G and thereby causes the point of the screw F to press against the upper
carbon D and to prevent it from descending; thus by the separation of the points of
the carbons the arc is struck. Afterwards when, owing to consumption of the
carbons, the resistance of the arc increases, the weight G overcomes the attraction
of the armature G and the point of F is withdrawn from the carbon D, which is
thus permitted to descend, but it can only descend very slowly, because it takes
time for air to leak past the piston D³ to the space above it in the tube D*. As
the upper carbon is thus permitted to approach the lower carbon, the resistance is
lessened, the armature G is again attracted and the carbon D is again held
stationary by the pressure of the screw F.
The electromagnet H may have its coil in a shunt to the lamp circuit, the lever
carrying the screw F being arranged to act in a reversed manner so that the carbon
is released when the armature G is attracted, owing to greater currer*
the shunt,
resulting from greater resistance of the arc.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we would have it understood
that we make no general claim to the fixing of the one carbon of an electric lamp
to the armature of an electromagnet for the purpose of striking the arc or to the
fixing of the other carbon to a piston or plunger moving in a tube closed at the top,
for the purpose of retarding the descent of the carbon, as each of these appliances
has been separately used or proposed, but what we claim is :-
In an electric arc lamp having its lower carbon attached to the spring armature
of an electro magnet, the upper carbon attached to a piston within a closed tube
and passed down between a roller and the arm of the armature lever of another
electromagnet, substantially as and for the purposes set forth.
Dated this 18th day of October 1892.
ABEL & IMRAY,
Agents for the Applicants.