Improvements in Electric Arc Lamps.
Year: 1898

page_text: Date of Application, 26th Feb., 1898-Accepted, 3rd Sept.,
1898
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, West-
minster, S.W., Electrical Engineers, and FREDERICK BOOKER, of 19, Swallowfield
Road, Charlton, Kent, 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 ascertained in and by the following statement:-
In many electric arc lamps the movement of the carbons towards and from each
other is effected by means of a brake clutch wheel, which when it is moved by the
action of a solenoid in the one direction, separates the carbons, and when it is
moved in the other direction causes the carbons to approach.
This invention relates to the construction of a brake clutch for this purpose
which we shall describe referring to the accompanying drawings.
Fig. 1 is a front view and Fig. 2 is a plan partly sectional.
The brake wheel and clutch is in the form of a shallow cylindrical shell A on the
axis of which is loosely fitted a lever B and on this lever is pivotted at C another
lever D in front of B.
The hinder lever B has its one arm loaded by a weight E and its other arm
attached at 6 to one end of a circularly bent elastic wire or strip F (which may be
coated with indiarubber or other adhesive material) extending nearly round the
inner periphery of the brake wheel A, its other end being attached at d, to one
arm of the front lever D. The other arm of D is in position to be acted on by the
core of the regulating solenoid in the usual way.
From the loaded arm of the hinder lever projects a pin G which when the lamp is
not in action rests on a stop H. When the lever arm D is down as indicated by
the dotted lines D¹ the ends of the band' F are drawn together so that it does not
press on the inner periphery of the brake wheel A, which is thus left free allowing
the carbons to meet each other.
When the lamp is put into circuit the solenoid being thereby energised, its core
raises the lever D) and as the hinder lever B has its pin G held to the stop H by
the weight E the circularly bent band F having its two ends thus moved apart
is caused to expand and to press frictionally against the inner periphery of the brake
wheel A acting as a clutch so that, as the arm of the lever 1 is raised still further
it causes the brake wheel to turn partly round thereby separating the carbons and
striking the arc and at the same time raising the pin G of the lever E off the
stop H.
As the carbons become consumed the arm of lever D owing to the weakening of
the solenoid descends until the pin G rests again on the stop H.
As the arm of lever D descends still further it brings the ends of the band F
nearer together thereby lessening its diameter and relieving its frictional pressure
on the inner periphery of the brake wheel A which can then turn round in the
direction of the arrow moving the carbons closer together its movement being more
or less retarded by the frictional pressure of the circularly bent band F acting as
a brake

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
A brake clutch wheel for the regulating mechanism of an electric arc lamp,
constructed and operating substantially as described with reference to the
drawings.
D 11
1
1000