IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1885

page_text: I JOHN GRICE STATTER of 37 High Street, Chelmsford, in the county of
Essex, Electrical Engineer do hereby declare the nature of my said invention for
"IMPROVEMENTS IN ELECTRIC ARC LAMPS " to be as follows:-
My invention relates to an improved method of disposing the magnetisable parts
under the influence of the helices used to supply the motive power to electric arc
lamps, and to the construction of band or flexible brakes, applied to a disc such as.
is referred to in my former Provisional Specification N° 17,008 of December 29th
1884.
In carrying out my present improvements a sheathing of iron is placed round
the solenoid and provides a more complete magnetic circuit-namely, through the
core to the magnetisable disc which may, or may not be toothed, and completing its
circuit by the sheathing, the air space traversed by the magnetic lines of force being
thereby very much diminished.
For preventing the disc from turning I employ a device consisting of a flexible
brake such as a cord or a thin band of metal hereinafter called "the band," which
passes round the periphery of the disc.
One end of this band is connected with the core of the solenoid; the band then
passes round part of the periphery of the disc and is kept upon it by suitable means
such as by a weight or a spring or by a weighted lever.
The band adheres to the periphery of the disc by friction except for certain
positions of the disc, when the pull of the weight or spring is relieved by contact
with a stop, or when the tension of the spring is less by reason of eccentric
attachment or when the moment of the weighted lever is less by reason of its
position-The friction of the band upon the disc is then so lessened that the
tendency of the rack to turn the disc overcomes it and a feed takes place.
The friction of the band upon the disc may be increased by the employment
of india rubber, gutta percha, or similar substances, or by grooving the disc with
one or more grooves, or by employing magnetisable metal for both band and disc.
More than one band may also be used.
When more than one rack rod and disc are used, and when, as is usual in this
class of mechanism, it is desired that one shall feed before the other-one stop is

page_text: placed in advance of the other-and a movement may be applied to the first rack
rod so that on completing its descent, it will actuate and remove the first stop and
thus allow the band to continue to adhere to the corresponding disc which is
geared to the first rack rod, thus allowing the system to turn and release the
second disc without removing the weight of the first rod from the system, or it can
cause the second stop to advance. The second rod on completing its travel can be
made in a similar manner to perform the same service for a third rod or to bring
its weight upon contact pieces such as those described in my said former Provisional
Specification.
If stops are not used, the movement prevents the brake from being released by
increasing the pull either of the spring or lever as the case may be."
I sometimes use this band brake upon a non-magnetisable disc or wheel and
actuate it by any known arrangement of helices used for supplying the motive
power for are lamps.

page_text: Improvements in Electric Arc Lamps.
I JOHN GRICE STATTER, of Middleton Road Works, Dalston, in the county of
Middlesex, 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 :—
My invention relates to an improved method of disposing the magnetisable parts
under the influence of the helices used to supply the motive power to electric arc
lamps and to the construction of band or flexible brakes applied to a disc or brake
wheel hereinafter called the brake wheel in an electric arc lamp.
In carrying out my improvements a sheathing. of iron is placed round the
solenoid and provides a more complete magnetic circuit for the magnetism.or
magnetic lines of force of the helices, namely through the core to the brake wheel
which can be made of iron (and which can be either smooth or toothed or milled)
and completing its circuit by the sheathing, the air space traversed by the magnetic
lines of force being thereby very much diminished.
For preventing the brake wheel from turning I employ a device consisting of a
flexible brake such as a cord or a thin band of metal or a chain hereinafter called
the band which passes round the periphery of the brake wheel.
One end of the band is connected to the core of the solenoid, the band then
passes round the whole or part of the periphery of the brake wheel (preferably in
a groove) and is kept tight upon it by a weight or by a spring or by a weighted
lever. The band acts as a brake upon the brake wheel except for certain positions
when by reason of the diminished tension exerted upon the band by the solenoid
the brake wheel is allowed to revolve carrying the band with it until the tension
of the weight or spring keeping the band tight upon the brake-wheel is diminished
by the contact of the herein before mentioned weight, a weighted lever with a stop
or by the then diminished tension of the spring, or the diminished moment of the
weighted lever when the grip of the band is lessened and the brake-wheel can turn
within it.
The rack can be geared direct to this break wheel and can turn the wheel by
reason of its gravitation when the tension exerted by the solenoid upon the band
is diminished as herein above described. In this manner it can feed the carbon.
The friction of the band upon the brake wheel may be increased by the
employment of india rubber, gutta percha or similar substances or by grooving
or milling the wheel, or by constructing both the wheel and the band of iron.
More than one band may also be used when more than one band, rack rod and
brake wheel are used and when as is usual in this class of mechanism it is desired
that one rack rod shall be fed in advance of the other the weight stop of the first
rack rod is placed in advance of the weight stop of the second rack rod and a
movement may be applied to the first rack rod that on completing its descent it
will actuate and remove the first stop and thus allow the-band of the brake wheel

page_text: •
of the first rod to remain tight and in this manner to carry the weight of the
first rod.
The second rod can then be released and fed without removing the weight of the
first from the system-or the second stop can be actuated by the descent of the
first rod to advance and release the second rod when it is required that this rod
should be fed. The second rod on completing its descent can be made in a similar
manner to perform the same service for a third rod or to bring its own weight
upon contact pieces.
גיי
If springs are used to supply the necessary tension to the band instead of
weights and stops the herein before described movement applied to the rods
increases the tension of the spring instead of removing the hereinbefore mentioned
stop. I do not however make any claim to these movements but merely describe
them as suitable devices to be used in connection with my improved flexible brako
when this is applied to a lamp having two or more rack rods.
I sometimes use this band brake upon a non-magnetisable brake wheel and
actuate it by any known arrangement of helices used for supplying the motive
power to arc lamp mechanism.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figures 1, 2, and 3
show diagrammatically my improved brake as applied to an arc lamp having only
one rack rod; figure 4, is a side elevation partly in section of a lamp constructed
according to my invention and having only one rack rod; figure 5 is a detached
edge view of the brake wheel and part of the band; figure 6 is a section of the
weight and its guide tube drawn to a larger scale. Similar letters in all the
figures represent similar parts.
In figure 1, the controlling mechanism consists of a solenoid S; B, is the band
passing round the brake wheel W and attached at its upper and lower ends
respectively to the core of the solenoid C and the weight X; O is the pinion
gearing with the rack rod R. In the position shewn in the figure the band is
drawn tightly upon the wheel by the weight X and the brake wheel is prevented
from turning. In order to feed the carbons, the core C of the solenoid S can
descend, the brake remaining tightly stretched upon the wheel until the weight X
is lowered to rest the whole or part of its weight upon the spring T whereupon
the band is slackened upon the brake wheel which can then revolve within it and
allow the rack rod to descend-In order to separate the carbons, the core C can
be drawn up within the solenoid S, lifting the weight X and again tightening the
band upon the brake wheel; any further upward motion of the core Ĕ then turns
the brake wheel W and raises the rack rod. The weight X is fitted to the tube M
after the manner of a piston and slides easily within it. It is provided with a
number of grooves as shewn, and with a valve V opening upwards; this serves to
prevent the weight being drawn up too rapidly by partially exhausting the air
behind it; it can descend freely the air escaping through the valve V. The
weight X may be replaced by a spring, the action being similar.
Figure 2 shews a similar arrangement in which the core S is provided with the
iron sheathing A. The band is drawn upon the wheel by the lever Y provided
with a weight X the moment of which decreases as the core C descends. The
point at which the band is loosened on the wheel is determined when the weight X
comes in contact with the screw J; its action is similar to that of figure 1.
Figure 3 shews the band so arranged that for an equal movement of the core C
the movement of the wheel will be twice as great as in figures 1 and 2. The core
is provided with a stirrup carrying two pulleys P arranged side by side; the band
is first attached to the framework of the lamp, passed over one of the pulleys P,
round the brake wheel W over the second pulley P and attached to the weight X
which slides upon the guide rod G; to release the brake wheel the core descends
until the stop T on the band rests against the stirrup carrying the pulleys P, and -
brings the weight X directly on to the core C; it will thus be evident that on any

page_text: further descent of the core the tension on that part of the band B gripping the
wheel W will be lessened and the wheel allowed to revolve. The solenoid S is of
the ordinary form.
Referring to figure 4, B is the band which is preferably a light steel chain; W, is
the brake wheel provided with a groove for the band B; the weight is contained
in the guide tube M. R is the rack rod gearing with the pinion O revolving with
the brake wheel. S is the solenoid wound differentially.
Figure 5 shews the band B lying in the groove of the brake wheel W-Figure 6
shews the details of the weight and its guide tube M which is the saine as that
described in connection with figure 1.
The arrangement for carrying out my invention as applied to a lamp having two
or more rack rods will be understood without further description.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be. performed I declare that what
I claim is :-
1. In electric are lamps the use of a flexible brake or brakes applied to a brake
wheel or brake wheels substantially as and for the purposes herein before described
and shewn in the accompanying drawing.
2. The improved electric arc lamp hereinbefore described and represented in
figures 4, 5 and 6 of the accompanying drawing.