Improvements in Arc Lamps for Alternating Current Circuits.
Year: 1896

page_text: Date of Application, 26th May, 1896-Accepted. 27th June, 1896
COMPLETE SPECIFICATION.
Improvements in Arc Lamps for Alternating Current Circuits.
A communication from abroad by ALEXANDER BARNHILL FERNALD, of Jersey
City, Hudson County, State of New Jersey, United States of America,
Mechanic, and JOHN HENRY HUBBELL, of the City of Yonkers, County of
Westchester, State of New York, Lawyer.
1, WILLIAM LLOYD WISE, of 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Chartered Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to performed to be
particularly described and ascertained in and by the following statement :-
This invention relates to electric arc lamps and particularly to feeding mechanism
therefor.
The object is to construct feeding mechanism in which the descent of the carbon
shall be so gradual that there will be no perceptible variation in the arc when once
struck.
This object is attained by what may be called a ball clutch in which the balls
provide a perfectly even movement for the carbon carrying rod and yet, when
necessary, serve to hold said rod against movement.
The invention consists in the construction, combination and arrangement of parts
hereinafter described and set forth in the claims.
In the accompanying drawings which form a part of this specification;
Fig. 1, represents so much of an arc lamp as is necessary to illustrate the
invention, the novel features being represented in full lines in vertical section and
the old features in dotted lines.
Fig. 2, represents in like manner in detail, on an enlarged scale, the invention in
operation.
A, indicates the base plate of the lamp from which depends, in the usual manner,
the frame for supporting the lower carbon, not shown in the drawings. Upon this
plate is mounted a frame as B, to which the feeding mechanism of the lamp is
secured and through ways in which the carbon-carrying rod C, moves. D, is the
feed magnet here shown as a solenoid with the core E.
The feeding mechanism operated by this magnet consists of what may be termed
an inclined ball seat namely, a collar or sleeve F, having a conical inner surface
and an exterior flange G, which rests upon stud rollers H, projecting inwardly
from the open lever 1, balls as K, which rest between the carbon-carrying rod and the
conical surface of the seat, a weight as L, M; surrounding the rod and resting upon
the balls, and a tripping device as N, surrounding the rod and extending up into
the seat. F, said device being preferably secured to the plate A. It is also well to
form this device as shown in the drawings, so that it may furnish a guide for the
carbon carrier, as it may be turned up and fitted to the rod much easier than the
plate A. The collar F, being mounted as shown, is free to move in any direction
upon the studs H, and so prevents the balls from wearing tracks in the rod.
The lamp mechanism as illustrated is intended for use in an alternating current
circuit and in it as illustrated, the lever I, is fulcrumed at J, in the frame B, which
fulcrum is sufficiently to one side of studs H, to provide for the elevation of the
rod and its carbon through the distance necessary to strike the arc.
In a lamp for use on direct current circuits this fulcrum would simply be placed
at the other side of studs H, as indicated in dotted lines at J', where the weight of
the core would overbalance the weight of the carbon rod, the magnet being in a

page_text: shunt or derived circuit. These changes and modifications incident upon converting
an alternating current lamp into one for. use on a direct current are understood by
electricians and will not be further dwelt upon here, suffice it to say that applicants
have successfully used their feeding mechanism in both forms of lamps.
The lever I, may be provided with a weight as at O, for adjusting the balance
of the parts. A dash-pot as P, may also be connected to the lever to steady the
movement thereof as is common in are lamps. By using the lever mechanism, as
shown, for operating upon the ball seat, a more effective and accurate feeding action
is obtained than can be had in any other way.
The weight resting upon the balls is shown divided_transversely into the
parts L, M, but it may obviously be formed in one part. The object in using two
portions shown is to facilitate assembling the parts of the feed mechanism. The
lower end of the weight and also the upper end of the tripping device are preferably
ground to fit the balls, though they may be plain. As shown in Fig. 2, the groove
in the weight inclines towards the rod C, so as to force the balls against the rod
thereby providing a quicker and firmer grip.
The plate Qhich serves as the upper guide for the carbon carrier also serves
as a stop to limit the pward movement of the lever I, while the shoulder X, R,
on the tripping device may serve as a stop for the downward movement of said
lever.
The brush for passing current to the carbon carrier is shown at S, in dotted
lines, as bearing thereon through an opening in the side of the tripping device.
As stated the lamp illustrated is designed for use on an alternating current
circuit and has its carbons touching when not in use.
Current being turned on, the magnet is energized, the lever I, tilted thereby, the
Its operation is as follows:-
ball seat carried upward which causes the balls to wedge in between the inclined
surface of the seat and the rod, thus clutching the rod and carrying it and its
carbon along until the arc is properly struck, the weight on the balls causing them
to more readily clutch the rod. Then as the arc lengthens the energy of the
magnet decreases and the rod will descend until the balls reach the upper end of
the collar N, where they will rest between it and the weight while the inclined
seat moves farther down thereby releasing the balls and allowing them to rotate
and permit the descent of the rod to such a point as will cause the current through
the magnet to again raise the seat and effect the clutching and lifting of the rod.
The balls being held between the weight and releasing device and against the rod,
a rolling friction is maintained between them and the rod, thereby insuring an
accurate and gradual descent of the rod and its carbon. These movements
subsequent to the striking of the are are almost imperceptible and recur at such
frequency as to cause practically a continuous descent of the carbon in compensation
for the combustion thereof.
Many changes may be made in the size, shape and formation of the parts and
mechanical expedients necessary to adapt the feeding mechanism to a direct
current circuit may be resorted to without departing from this invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. The combination with the carbon-carrying rod, of the ball seat, balls therein
resting between the seat and rod, a weight resting upon the balls and having a
groove for the balls inclined towards the rod, the feed magnet, a connection
between the ball seat and magnet by which the former is raised and lowered, and
a tripping device for loosening the grip of the balls upon the rod, as and for the
purpose set forth.
2. The combination with the feed magnet, of the lever operated thereby, the
clutch mechanism mounted to move freely and to rotate upon studs projecting from
said lever, and a fixed releasing device for the clutch mechanism, substantially as
set forth.

page_text: 3. The combination with the cylindrical carbon-carrying rod, of the inclined ball
seat surrounding it and provided with an exterior flange, balls resting between the
incline of the seat and the rod, a lever pivoted to the frame of the lamp and
controlled by the feed magnet, anti-friction rollers carried by said lever and
supporting the ball seat by its flange, and a releasing device for unseating the
balls to allow the carbon rod to feed downward.
4. The combination with the carbon-carrying rod and the feed magnet, of the
inclined ball seat controlled in its movements by said magnet, balls resting between
the incline and the rod, a weight resting upon the balls, and a tripping device for
lifting the balls from the incline, said weight and tripping device being so
constructed as to hold the balls between them: when .released from the seat, as and
for the purpose set forth.
Dated this 26th day of May 1896.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patut Agent.