Year: 1899

page_text: Date of Application, 17th Feb., 1899
Complete Specification Left, 28th Sept., 1899-Accepted, 6th Jan., 1900
I, HENRY BAGGETT, of 38, Siebert Road, Westcombe Hill, Blackheath, in the
County of Kent, Electrical Instrument Maker, do hereby declare the nature of
this invention to be as follows:
-
This invention relates to those electric arc lamps in which the carbons are
moved by two cords or strings wound round a common pulley in such a way
that when the pulley rotates in one direction the carbons are separated and when
the pulley is rotated in the other direction the carbons are brought together.
In such are lamps the movement of the pulley in the direction tending to
separate the carbons is commonly produced by the action of a solenoid whose
core is geared or linked to the pulley so that when the current in the said sole-
noid is too strong the pulley is turned round and the carbons are separated, and
when the current is too small the carbons are allowed to close up, their motion
being regulated by some form of brake.
In such arc lamps the brake hereinbefore mentioned is liable to jerk the car-
bons as they come together, and many devices have been designed with a view
to overcoming this objection. This invention has for its object principally to
provide a very delicate and sensitive brake for arc lamps of this class, and also
an improved means of controlling the movement of the pulley.
In carrying out my invention I provide a recess in the pulley, concentric with
the pulley and of an internal diameter slightly smaller than the diameter of the
pulley itself, within which I place two segments which may be made as herein-
after described. I take a disc whose thickness is slightly less than the depth of
the recess in the pulley, and which is provided with an aperture at its centre
large enough to allow the spindle of the pulley to pass through without touching
the disc. I make the diameter of the disc of such a size that the disc will exactly
fit into the recess and turn freely therein without touching the spindle. I now
cut the disc along two lines, one line being a diameter and the other line being
a chord at right angles to the said diameter and whose length is slightly less
than that of a diameter.
Of the four segments into which the disc is divided I make use for the purpose
of my invention of the two larger segments, each being slightly larger than a
quadrant of the original disc.
It will be seen that when these two segments are placed in the recess in the
pulley in the same relative positions which they occupy in the original disc,
they will take up a little more than half of the space in the recess, and that
there will be a clearance between the said segments and the spindle and a small
space between the adjacent sides of the two segments equal in amount to the
width of the cut.
I provide a thin metallic strip, such for instance as a straight steel spring,
of length slightly less than the aforesaid chord, and I fasten this in a suitable
manner to, those sides of the segment constituting the said chord.
The said

page_text: strip keeps the segments in place so that they may now be turned round inside
the recess without changing their relative position.
It will now be seen that any action tending to separate the adjacent faces of
the segments will have the effect of jamming the segments against the sides of
the recess.
I fix a lever on one of the segments acting in such a way that when pressed
in a certain direction it tends to separate the adjacent faces of the segments.
This may be done in any convenient manner. One way of doing so, which I
anticipate will give good results, is to fix two pins, one in each segment, at right
angles to the surfaces of the said segments. The lever may be pivoted on to
one of the said pins and shaped in such a way that when one end of it is pressed
the other end bears against the second pin so as to force the segments apart.
Instead of allowing the lever to bear directly on the second pin I may interpose
a spring fixed on the lever and bearing on the said pin.
It will now be seen that if the lever is pressed in a certain direction the seg-
ments will jam in the recess, and continued pressure on the lever will turn the
pulley in one direction. If however the lever is pressed in the contrary direc-
tion the segments will move inside the recess, and the pulley will be free to
rotate independently of the segments.
I place the pulley with the segments and the parts attached thereto so that
its plane of rotation is vertical, and I wind round the pulley two cords placed
in suitable grooves thereon. One end of each cord is fastened to the rim of the
pulley and the other end of each cord supports one of the carbon holders, so
that when the pulley is turned in, say, a right-handed direction the carbons are
separated, and when it is turned in a left-handed direction the carbons are
brought together.
I may connect the aforesaid lever by a link to the core of the solenoid through
which passes the current to the carbons, so that when the core is drawn into
the solenoid, the lever is pressed in a direction tending to jam the segments in
the recess and thereby to move the pulley in a direction that separates the car-
bons. By this means I provide a convenient method of striking the arc and
keeping it at its proper length.
I provide one of the segments with a stud projecting from the surface of the
said segment and engaging with a set screw fixed on the main frame of the
lamp, in such a way that the set screw stops the rotation of the segments in one
direction, the said segments being free to rotate in a direction away from the
said set screw.
I adjust the weights of the carbon holders so that the two carbons tend to
come together when they are not held. It will then be seen that supposing the
carbons to have been separated by any given distance, they will move towards
one another, during which time the friction of the inside surface of the recess
against the segments will tend to force the segments round and bring the afore-
said stud into contact with the set screw.
I shall now describe how my invention works in practice.
When the current is switched on to the lamp the core is sucked into the sole-
noid and presses on the lever through the medium of the link. The segments
are jammed in the recess and the pulley is turned round a short distance thereby
striking the arc. The strength of the current is thus diminished and the pres-
sure on the lever relieved, the weight of the carbon holders then turns the pulley,
which is now not held by the lever, and the carbons gradually feed together.
This process goes on while the carbons burn away. When the carbons come
too near one another the current will increase, the core of the solenoid will press
the link against the lever, and the segments will become jammed, thereby stop-
ping the feeding action of the pulley. When the carbons have burnt away so
that the current is again of normal strength, the pressure on the segments is
released and the pulley is free to rotate,

page_text: I may keep the segments in position by any suitable means, as for instance_
by a ring attached to the pulley. The shape of the segments may be modified
so long as their essential features herein before described are maintained. Thus
for instance it may be convenient to lighten them by perforations or apertures,
but such must not interfere with the working parts hereinbefore specified.
In some cases I make the metallic strip or spring herein before described,
which serves to keep the segments in place, of such a length that instead of
terminating as hereinbefore described, it may be made to embrace the segments
passing round the circular faces thereof and doubling in so as to grip closely the
whole or part of the adjacent faces of the said segments.
The said spring in such cases could be made in one continuous piece and a
groove could be provided around the periphery of the segments and so that the
pressure of the spring does not interfere with the fit of the segments in the
recess.
I desire it to be understood that I do not limit myself to the details of
construction herein described as it is obvious that these may be varied to an
indefinite extent without departing from the spirit of the invention.
T
1
A
1000
Applicants
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Norfolk House, Norfolk Street, London, W.C., Chartered Patent Agent.
I, HENRY BAGGETT, of 38, Siebert Road, Westcombe Hill, Blackheath, in the
County of Kent, Electrical Instrument Maker, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention relates to that type of electric are lamps in which the carbons
are moved by two cords or strings wound round a common pulley in such a way
that when the pulley is rotated in one direction the carbons are separated and
when the pulley is rotated in the other direction the carbons are brought towards
one another.
In such are lamps the movement of the pulley in the direction tending to
separate the carbons is commonly produced by the action of a solenoid whose
core is geared or linked to the pulley so that when the current in the said sole-
noid is too strong the pulley is turned round and the carbons are separated and
when the current is too small the carbons are allowed to close up, their motion
being controlled by some form of brake.
In such are lamps the brake hereinbefore mentioned is liable to convey shock
to the carbons as they come together, and many devices have been designed with
a view to overcoming this objection. This invention has for its object principally
to provide a very delicate and sensitive brake for arc lamps of this class, and
also an improved means for causing and regulating the movement of the pulley.
In addition to the brake I sometimes apply a loose drag on the periphery of
the pulley so arranged that the contact surfaces are respectively of rubber or
other similar material and metal.
In order that my invention may be more readily understood. I append draw-
ings hereto illustrating one form of my invention and certain modifications
thereof.

page_text: Figure 1, is an edge view (partly in section) of a pulley constructed in accord-
ance with my invention.
Figure 2, is a side elevation of the same.
Figure 3, is a detail view of the two segments hereinafter to be described.
Figure 4, and 4* illustrate a modified form of the parts shown in Figures 1
and 2.
Figure 5, and 5ª are further modifications.
Figure 6, is a diagrammatic view illustrating how a brake pulley constructed
in accordance with my invention may be connected with a double solenoid are
lamp's solenoids 20 and 20 by means of their cores 19 and 19" with the upper
and lower carbon holders.
Figure 7, is a view of a portion of an arc lamp fitted with a brake pulley and a
drag in which edge views of the pulley and drag are shown.
Figure 8, is a detail side view of the pulley and drag.
In carrying out my invention I provide a recess 1 in the pulley, concentric
with the said pulley and of an internal diameter slightly smaller than the
diameter of the pulley itself, within which I place two segments 2 and 3 which
may be made as hereinafter described. I take a disc whose thickness is slightly
less than the depth of the recess 1 in the pulley, and which is provided with
an aperture 4 at its centre large enough to allow the spindle 5 of the pulley to
pass through without touching the disc. I make the diameter of the disc of
such a size that the disc will exactly fit into the recess and turn freely therein
without touching the spindle. I now cut the disc along two lines, one line being
a diameter and the other line being a chord at right angles to the said diameter
and whose length is slightly less than that of a diameter.
Of the four segments into which the dise is now divided I make use for the
purpose of my invention of the two larger segments 2 and 3, each being slightly
larger than a quadrant of the original disc.
It will be seen that when these two segments are placed in the recess in the
pulley in the same relative positions which they occupy in the original disc,
they will take up a little more than half the space in the recess, and that there
will be a clearance between the said segments and the spindle and a small space
between the adjacent sides of the two segments equal in amount to the width
of the cut.
6
I provide a thin metallic strip 7 such for instance as a straight steel blade
spring, of length slightly less than the aforesaid chord, and I fasten this in a
suitable manner to those sides of the segments constituting the said chord. The
said strip keeps the segments in place so that they may now be turned round
inside the recess without changing their relative position.
It will now be seen that any action tending to separate the adjacent faces
of the segments will have the effect of jamming the segments against the sides
of the recess.
I fit a lever 10 on one of the segments acting in such a way that when pressed
in a certain direction it tends to separate the adjacent faces of the segments.
This may be done in any convenient manner. One way of doing so, which gives
good results, is to fix two pins 8 and 9 (Figures 1 and 2) one in each segment,
at right angles to the surfaces of the said segment. The lever 10 may be pivoted
on to one (8) of the said pins and shaped in such a way that when one end 11
of it is moved upwards the inclined face 12 of the other end bears against the
second pin 9 so as to force the segments apart.
It will now be seen that if the lever is moved in the direction of the arrow A
the segments 2 and 3 will separate and jam in the recess, and continued move-
ment of the lever will turn the pulley in the direction of arrow B. If how-
ever the lever is moved in the contrary direction the segments will move inside
the recess, and the pulley will be free to rotate independently of the segments.
I place the pulley with the segments and the parts attached thereto so that

page_text: its plane of rotation is vertical, and I wind round the pulley two cords 14 and
15, placed in suitable grooves 16 and 17. One end of each cord is fastened to
the rim of the pulley and the other end of each cord supports one of the carbon
holders, 31 and 32, (see Figure 6) so that when the pulley is turned in a clock-
wise direction the carbons 33 and 34 are separated, and when it is turned in a
contra-clockwise direction the carbons are brought together.
I may connect the aforesaid lever by a link 18 to the core 19 of the sole-
noid 20 through which latter passes the current to the carbons, so that when
the core 19 is drawn in to the solenoid 20 the lever 10 is moved in a direction
tending to jam the segments 2 and 3 in the recess, and thereby to move the
pulley 35 in a direction that separates the carbons. By this means I provide
a convenient method of striking the are 36 and keeping it at its proper length.
I provide one of the segments with the stud 21 projecting from the surface
of the said segment and adapted to engage with a set screw 22 fixed on the
main frame of the lamp, in such a way that the set screw stops the rotation of
the segments in one direction, the said segments being free to rotate in a direc-
tion away from the said set screw.
I adjust the weights of the carbon holders so that the two carbons tend to
come together when they are not held. It will then be seen that supposing the
carbons to have been separated by any given distance, they will move towards
one another, during which time the friction of the inside surface of the recess
against the segments will tend to force the segments round and bring the afore-
said stud 21 into contact with the set screw 22.
I shall now describe how my invention works in practice.
When the current is switched on to the lamp the core 19 is sucked into the
solenoid 20 and presses on the lever 10 through the medium of the lever 23 and
link 18. The segments 2 and 3 are jammed in the recess 1 and the pulley is
turned round a short distance thereby striking the arc. The strength of the
current is thus diminished and the pressure on the lever 10 relieved by the
stud 21 coming in contact with the set screw 22. The weight of the carbon
holders then turns the pulley, which is now not held by the lever 10, and the
carbons gradually feed together.
This process goes on while the carbons burn away. When the carbons come
too near one another the current will increase, the core of the solenoid will move
the link 18 against the lever 10, and the segments will become jammed, thereby
stopping the feeding action of the pulley. When the carbons have burnt away
so that the current is again of normal strength, the pressure on the segments
is released and the pulley is free to rotate.
I may keep the segments in position by any suitable means, as for instance
by a retaining ring 24 attached to the pulley for example by screws. The
shape of the segments may be modified so long as their essential features here-
inbefore described are maintained. Thus for instance it may be convenient to
lighten them by perforations or apertures.
In some cases I make the blade spring 7 which serves to keep the segments
in place, of such a length that instead of terminating as hereinbefore described,
it may be made to embrace one or both of the segments passing round the cir-
cular faces thereof and doubling in as at 25 (Figure 3) so as to grip closely the
whole or part of the periphery of the said segments.
The said spring 7 with its arc shaped prolongations 25 in such cases could be
made in one continuous piece and a groove 30 would be provided around the
periphery of the segments so that the pressure of the spring does not interfere
with the fit of the segments in the recess.
In Figures 4 and 4" the lever 10 consists of a disc 20 with a projection or
lug 27 on its face. The two segments are recessed at 28 and 29 to receive the
disc portion of the lever and the segments are cut away below the recess at 12
to form a face corresponding to the face 12 on the lever 10, Figure 2. The
lever 10 is pivoted to the segment 2 at 8 but instead of the segment 3 (Figure 2)

page_text: carrying the stud 9 it is fixed to the lever and bears against the face 12 which
the segment has been cut away to form.
In Figures 5 and 5" the lever 10, similar to that shown in Figures 1 and 2,
carries a pin 39 on its under surface which projects into a hole or slot 38 in
the segment 2. This pin is normally not in contact with the sides of the hole
or slot. When the pressure on the lever 10 is relieved should the segments for
any reason stick the pull of the fine wire solenoid 20" on the core 19 through
the connecting lever 23 (Figure 6) and link 18 draws the end. 11 of the lever
down and brings the pin 39 in contact with the bottom of the slot 38 in the
segment 2 and draws the segments together and releases the pulley.
In Figures 5 and 5" in lieu of the stud 21 and the set screw 22 I attach a
stop to the segment 3 and fit a stop piece 22, adjustable by a slot, on the
main frame of the lamp. I also show in Figures 5 and 5" a spiral spring 37
fitted in recesses in the adjacent sides of the segments and tending to keep
them apart and pressed slightly against the pulley though not sufficiently so to
act as a drag. This I do not claim as a part of my present invention.
Figures and 8 show one way in accordance with my invention in which I
apply a drag to the outer periphery of the pulley.
This drag consists of a block 40, faced with a piece of rubber 41, bearing on
the outer periphery of the pulley. The block is secured to the shaft 42 by a pin
43 passing through a hole in the said block of slightly greater diameter than
the pin so as to allow an angular movement, but not of any material longitudinal
movement on the shaft. The shaft 42 and drag are borne by a vertical rod 45
arranged to slide in the frame of the lamp, and the lower end of the rod is pro-
vided with means for the adjustment of its length, for example by a set screw
46 and lock nut 47.
The drag is held clear of the pulley by the action of the lamp solenoids which
operate through the connecting lever 23 on the lower end of the rod 45 as shown
in Figure 7. When the bar 23 is drawn away from the rod 45 the drag falls by
gravity so as to come in contact with the periphery of the pulley.
The
It will readily be seen on referring to the drawings that when the core 19
is drawn in by the solenoid 20 that the lever 23 is moved away from the lower
end of the rod 45 and that the drag will fall by gravity and come in contact with
the pulley 35 so that it rests on the pulley during the formation of the arc.
angular movement of the block prevents the drag impeding the striking of the
are; and after the arc is formed the drag acts on the pulley during the feeding
of the carbons. I find the drag useful in practice but not necessary: and I lay no
claim to it in the present application.
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 an arc lamp the employment of two segments substantially as and for the
purpose set forth.
2. The mechanism for feeding the carbons and striking the are substantially
as set forth.
3. The arrangement and combination of parts substantially as set forth.
Dated this 28th day of September 1899.
J. G. LORRAIN, M.I.E.E., M.I. Mech. E..
Norfolk House, Norfolk Street, London, W.C., Chartered Patent Agent.