Improvements in Multiple Carbon Arc Electric Lamps.
Year: 1893

page_text: Date of Application, 19th Jan., 1893
Complete Specification Left, 18th Oct., 1893-Accepted, 18th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Multiple Carbon Arc Electric Lamps.
I, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to the construction and arrangement of an arc electric
lamp so that a single regulating mechanism serves to control the movements
of two or three pairs of carbons, and that one of the pairs burns for a
certain time, such as an hour, that this pair is then extinguished, and
All the carbons thus
another of the pairs burns for a like time and so on.
become consumed by equal or approximately equal stages, the lamp continuing
to operate as long as if it bad a single pair of length equal to that of the two or
three pairs added together. For this purpose, when two pairs of carbons are
employed, I carry the upper carbons on the opposite arms of a horizontal lever
pivotted on a central rod which ascends and descends subject to the regulating
mechanism. The lever has a vertical arm which has a stud engaged in an undulating
groove formed in the face of a stationary vertical bar, so that, as the central rod
with its lever ascends and descends, the arm of the lever, according as its stud is in
one part or another of the undulating groove, is deflected to the one side or the
other, and thus the one or the other of the two carbons carried by the lever is held
in a relatively low position while the other is raised.
The lowered carbon continues to form the arc with the corresponding carbon
below it until the lever is deflected in the opposite direction whereupon this pair of
the carbons ceases to form the arc. the other pair now forming it and continuing to
maintain it until another deflection of the lever throws them out of operation and
the other pair again into operation.
For operating in this way, with three pairs of carbons, I carry them on three
cranks set at equal angles on a horizontal spindle, which can revolve in a bearing in
the central rod subject to the regulating mechanism.
On the crank spindle is fixed a pinion or ratchet operated by means of a fixed
vertical rack so that, as the regulating rod and spindle descend, the spindle is
caused to turn partly round, thus turning the cranks so as to make the three upper
carbons descend and ascend in succession. The movements may be rendered more
or less sudden by means of a tumbling weight or its equivalent, so that the revolu-
tion of the spindle is effected not gradually, but step by step.
The crank arrangement may obviously be applied to lamps having two pairs of
carbons.
Existing lamps constructed to consume two pairs of carbons, that is to say the
second pair after the first is consumed, can readily be altered so as to have the two
pairs consumed alternately by steps as above described, and each pair may be
duplicated so that four pairs of carbons can be thus operated.
Obviously the alternating movements may be imparted to the lower instead of the
upper carbons.
Dated this 10th day of January 1893.
ABEL & IMRAY,
Agents for the Applicant.

page_text: .
COMPLETE SPECIFICATION.
Improvements in Multiple Carbon Arc Electric Lamps.
I, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill in the County of
Surrey, Electrical Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to the construction and arrangement of an arc electric
lamp in such a manner that a single regulating mechanism serves to control the
movements of two pairs of carbons, one of which pairs burns for a certain time,
such as an hour, and is then extinguished, the other pair then burning for a like
time, and so on alternately. Both pairs of carbons thus become consumed by equal
or approximately equal stages, the lamp continuing to operate as long as if it had a
single pair of carbons of length equal to that of the two pairs added together.
For this purpose I construct the lamp as shewn in elevation by the accompanying
drawing.
I connect the two upper carbon holders A. A¹ to the equal opposite arms of a
horizontal lever B which is pivotted on a crosshead C. This crosshead is attached
to a rod D which ascends and descends subject to the regulating mechanism. This
mechanism may be of any known kind; as shewn in the drawing, it consists of a
solenoid E having its coil in the lamp circuit, and having its core arranged to hook
under a clutch washer F tilting it so as to grip and raise the rod D when the core
ascends, and releasing it when the core descends. The lever B has a vertical arm,
a stud G on which is engaged in an undulating groove H formed in the face of a
stationary vertical bar K, so that, as the crosshead C with the lever B ascends and
descends, the arm of the lever, according as its stud G is in one part or another of
the undulating groove H is deflected to the one side or the other, and thus the one
or the other of the two carbons carried by the lever is held in a relatively low
position while the other is raised. The carbon which for the time is the lower of
the two continues to form the arc with the carbon below it until the lever B becomes
deflected in the opposite direction.
As by this movement of the lever the pair of carbons forming the arc are
separated while the other pair are brought together, the arc between the former
pair ceases and an arc is struck between the other pair, which continue to maintain
the arc until another deflection of the lever throws them out of operation and brings
the other pair again into operation.
Many existing lamps are constructed to consume two pairs of carbons that is to
say the second pair after the first is consumed, but these have separate regulating
mechanisms such as solenoids, clutches or brakes for each pair. Such lamps can
readily be altered so as to have the two pairs consumed alternately in successive
stages according to this invention; only one set of regulating mechanism being
required as above described. Obviously, each of the pairs thus arranged might be
duplicated so that four pairs of carbons might be thus operated.
Instead of employing a rocking lever as above described, the two upper carbon
holders may be linked to two opposite cranks on a spindle journalled in a frame
carried by the regulating rod. This spindle having on it a pinion gearing with a
fixed rack is caused to revolve as it ascends and descends thus always raising the
one carbon and lowering the other.
The alternating movement, whether operated by a rocking lever or cranks, may
be applied to the lower carbon holders, the upper carbon holders being in that case
stationary.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described method of consuming two pairs of carbons in an electric

page_text: arc lamp, by giving one of each pair a reciprocating movement at intervals, so that
the two pairs are consumed by stages alternately.
2. For giving reciprocating movement such as is above referred to, to the carbons
of an electric arc lamp, the combination of the carbon holders, the rocking lever
5 and undulating groove, substantially as herein described.
Dated this 19th day of October 1893.
ABEL & IMRAY,
Agents for Applicant.