Improved Electric Arc Lamp.
Year: 1898

page_text: Date of Application, 21st Feb., 1898-Accepted, 28th May, 1898
COMPLETE DIECIFICATION.
Improved Electric Arc Lamp.
HENRY VINCENT JAMES, Westhill, Higher Broughton, Salford, Lancashire,
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:-
This invention relates to improvements in electric arc lamps of the focusing
type-in which the upper or positive carbon holder is connected by a chain riding
over a chain wheel, to the lower or negative carbon holder-both of which are
guided to or from one another by the usual guide rods. As the upper carbon
holder is of greater weight than the lower carbon holder, the upper carbon holder
tends to drop by gravity and in this manner lifts the lower carbon holder accord-
ingly. This invention consists of an improved method of striking and maintaining
the arc of constant current.
In an arc lamp made to this specification the carbon holders are connected
together by means of a chain passing over a sprocket wheel, which is fixed to the
side of a disc of greater diameter, riding upon centre pins carried by brackets
fixed to the top plate of the frame of the lamp. Near the periphery of the disc,
parallel to, and in horizontal line with its centre pins, I mount a shaft riding
in centre pins and carrying two cranks. At the base of the disc, I fit a slipper
brake having a rubbing surface of cotton belting. From both sides of one end
of this brake I fix flexible copper cords, the opposite ends of which I carry and
connect to two screws, screwed into the shaft between the cranks. From the other
end of this brake I lead another flexible copper cord & fix its other end to a spiral
spring the reverse end of this spring is fixed to a screwed brass pin, passed
through a fixed rod and secured by a nut. This nut is tightened or slackened
as more or less tension is required upon the spring. The cranks riding upon the
shaft are set in extreme opposite directions to one another, and at the extreme ends
of each crank is fixed the usual regulating solenoids. The lamp is regulated and.
adjusted by increasing or decreasing the tension upon the spring and by increasing
or decreasing a weight which may be mounted upon either crank.
Fig. I. & Fig. II. As the lamp is switched into an electrical circuit, the carbons
being together, the series wound coil A., pulls down its core B., which draws down
the crank C, & turns the crank shaft S, to which the cranks C, & C1, are fixed.
The brass slipper brake E, being coupled to the crank shaft S, by the flexible
cord connectors D & D 1, is pulled forward, at the same time a tension is put upon
the spiral spring F, to which the brake E, is connected by a flexible copper
cord D2. The tension upon the spring causes the brake E, to press upon the
periphery of the disc H, & in being pulled forward takes the disc H, round with
it & so strikes the arc between the carbons, through the lifting of the chain by
the sprocket wheel G. As the arc becomes long through the burning away of the
carbons, the shunt wound coil A 1, over powers the series wound coil A, and the
cranks C & C 1, are moved in the reverse direction. As the shunt core B2, draws
down the crank C1, and round with it the shaft S, the flexible copper cords D, D 1,

page_text: & D2, are slackened against the spring F, and in this manner the brake E is pulled
round to a point giving little or no pressure upon the periphery of the disc H,
which is then free to turn slowly and allow the carbons to come nearer together
by the chain wheel G, and the chain I. When the carbons are sufficiently near
for the normal resistance of the arc, the series coil A, pulls down its core B, and as
before described tightens the tension upon the brake E, which prevents then, the
carbons nearing further while the arc remains normal.
The top plate J, of the frame of the lamp is fixed to the lower plate J 1, by the
columns K1, & K2. The spiral spring F, has one end secured to a fixed pillar L,
by a screw & nut L1, & L2, respectively. The chain I, is guided to the upper
carbon holder over the guide pulley P.
Fig. 3 The flexible copper cord connectors D, & D1, are connected to the
shaft S, by screws N, & N4, & to brake E by the screws N 3, and N 5.
Fig. 4. The brass slipper brake E, has a brake wearing surface M, of pressed
cotton belting.
Fig. I. shows the mechanism in side elevation.
Fig. II. shows the top end elevation.
Fig. III. shows the method of applying & fixing the brake.
Fig. IIII. shows the brake slipper in section.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
I. A brass slipper brake fitted with a cotton belting wearing surface & sus-
pended against a disc upon flexible copper cords and moved in either direction by
the rotary motion of a crank shaft pulling against a fixed spring as before
shown.
II. The whole mounted and arranged in the particular manner aforesaid and
described, that the greatest freedom and travel may be taken by the regulating
cores with the smallest movement of the carbons.
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