Improvements in connection with Arc Lamps.
Year: 1893

page_text: Date of Application, 4th Dec., 1893
Complete Specification Left, 28th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in connection with Arc Lamps.
I FRANK MICHAEL LEWIS of 34 Leinster Gardens Hyde Park London
Electrical Engineer do hereby declare the nature of this invention to be as
follows:-
My invention refers to means for controlling the movement of the carbons, and
has for its object to ensure great regularity in the feed as the carbons are consumed,
to effect this with very small variation of the electromotive-force across the
terminal of the lamp, and to ensure greater certainty of the striking of the arc.
(ie. the movement of the carbons to the proper distance apart directly after
contact.
An arc lamp constructed in accordance with my invention comprises a rocking
beam or lever controlled by a solenoid acting ou a train of wheels as hereunder
described, preferably with an escapement arrangement to check the movement of.
the carbons. The motion of the carbons is caused, by the excess weight of the
upper carbon and carbon holder over that of the lower carbon and holder. The
chain connecting the two carbon holders passes over a disc chain wheel, mounted*
on an axis, one of the outer ends of which forms the fulcrum of the above
mentioned rocking beam. This wheel is provided with a small wheel fitted in a
slot, the axle of the small wheel being at right angles to the axle of the chain
wheel. This small (crown or bevel) wheel gears with two larger (crown or bevel),
wheels mounted loose on the main (that is the chain wheel) axle. One of these
wheels is cast with or attached to a ratchet wheel, and the other with or to a large
toothed wheel. This toothed wheel gears with a pinion on the escapement wheel.
axle. A ratchet pawl on the previously mentioned rocking beam engages with the
just mentioned ratchet wheel, and rotates this latter when the opposite (solenoid).
end of the rocking beam is depressed. A stop ratchet mounted on a stud fixed to
the corresponding side frame of the apparatus prevents the return of the ratchet,
A brake wheel.
wheel, when the rocking beam moves in the opposite direction.
attached to the previously mentioned large toothed wheel, or the corresponding.
crown or bevel wheel, is controlled by a brake stop or block fixed to a brake,
lever, mounted on an axle parallel to and conveniently placed vertically beneath,
the main axle. One end of the brake lever is connected to a spring fixed to the.
base of the apparatus, and the opposite end is provided with a stud or rod abutting
against the under side of the ratchet pawl end of the rocking beam, so that the
brake stop is placed in contact and withdrawn from the brake wheel by the move-.
ment of the before mentioned rocking beam. The stud or rod just mentioned may
perhaps more conveniently be attached to the rocking beam.
The checking of the feed of the carbons may be effected by the brake stop and
a dash pot in place of an escapement arrangement as above mentioned, or other
means of releasing the feed side of the train (above described) may be adopted..
It will be evident that the differential wheel arrangement, (that is the three crown
or bevel wheels and other attached wheels) causes the striking of the carbons to be.
effected from one side of the train, whilst the feed is effected by the opposite side
of the train. This arrangement causes the striking of the carbons to be effected.
more perfectly, since this movement takes place independently of the ordinary feed
movement.

page_text: It will be evident that my invention may also be applied to arc lamps in which
the feed is effected by rack and pinion mechanism.
Dated this 2nd day of December 1893.
J. CLARK JEFFERSON,
2, East Parade, Leeds, Agent for Applicant.
Improvements in connection with Arc Lamps.
I FRANK MICHAEL LEWIS of 34 Leinster Gardens Hyde Park London
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 refers to means for controlling the movement of the carbons, (or
one carbon only); and has for its object to ensure great regularity in the feed as
the carbons are consumed, to effect this with very small variation of the electro-
motive force across the terminals of the lamp, and to ensure greater certainty of
the striking of the arc, (i.e. the movement of the carbons to the proper distance
apart directly after contact.
My invention consists essentially in the introduction as part of the controlling
mechanism of a rocking arm connected to the solenoid plunger and a differential
or epicyclic train of wheels; in such a manner that the feed of the carbons towards
each other is effected from one side of the train, whilst the striking or moving
apart of the carbons is effected from the opposite side of the train, the said rocking
arm controlling the former (i.e. the feed) and operating the latter (i.e. the
striking).
As will be evident my invention is applicable to either focussing or non-focussing
arc lamps, but is hereinunder described only with reference to the latter.
An arc lamp constructed in accordance with my invention comprises a rocking
beam (single or double) mounted loose on the end (or ends) of the main axle of
the differential or epicyclic train, one end of the rocking beam being connected to
the plunger of the solenoid. The said axle is carried in bearings in vertical
standards attached to the base or frame from which the guide rods of the lamp are
suspended. On this axle between the 'standards is mounted the differential or
epicyclic train. This train consists of a central wheel or pulley, to and around'
which is attached and passed the chain, wire, or preferably the steel tape, by which
the carbon holder (or holders) is (or are) suspended. This centre wheel or pulley
carries a small crown or bevel wheel mounted on an axle at right angles to the main
axle, in bearings formed in a slot in said wheel or pulley. This small crown or
bevel wheel gears with two larger crown or bevel wheels mounted loose on the main
axle. One of these wheels is cast with or attached to a ratchet wheel, and the
other with or to a large toothed wheel. This toothed wheel gears directly, or by
means of a second pair of wheels on an intermediate axle, with a small pinion on an
escapement or fan axle. A ratchet pawl on the previously mentioned rocking beam
engages with the just mentioned ratchet wheel, and rotates this latter as the
opposite (or solenoid) end of the rocking beam is depressed. A stop or check ratchet
pawl mounted on a stud fixed to the corresponding side frame or standard, prevents
the return of the ratchet wheel when the rocking beam moves in the opposite
direction. A brake wheel attached to the previously mentioned large toothed
wheel, or the corresponding crown or bevel wheel, is controlled by a brake stop or
block fixed to a brake lever mounted on an axle parallel to and conveniently placed
vertically beneath the main axle. One end of the brake lever is connected to a
spring fixed to the base of the apparatus, and the opposite end is provided with a
stud or rod abutting against the under side of the ratchet pawl end of the rocking

page_text: beam, so that the brake stop is placed in contact with and withdrawn from the
brake wheel by the movement of the before mentioned rocking beam. The stud
or rod just mentioned may perhaps be more conveniently attached to the rocking
beam.
When a fan is used instead of an escapement, wheel and escapement, the following
arrangement may be employed in place of the just described arrangement of brake
wheel and brake stop. A catch is attached directly to the rocking beam in such a
manner, that it alternately comes in contact with and withdraws from or releases the
fan on the upward and downward motion of the solenoid plunger. A dash pot may
be used in connection with either of the above arrangements; also other means of
releasing the feed side of the train of wheels may be adopted.
It will be evident that the differential wheel arrangement in my invention may
consist of other well known differential gear than that above described, such for
example as are often used in connection with the driving gear of tricycles, in which
case the wheels may not be mounted coaxial and the rocking beam is pivotted to
suit viz. on the ratchet wheel axle. Also my invention may be applied when a
rack and pinion arrangement is employed instead of a pulley (chain or tape), the
pinion forming one of the wheels or being geared to one of the wheels of the
differential train.
Further my invention may be applied to lamps worked either with continuous or
alternating currents. When used for lamps in parallel, with little resistance in
series, I connect one side of the rocking beam to the piston or plunger of a dash
pot. With lamps run in series no dash pot is required.
And in order that my invention and the manner in which the same is to be
performed may be more readily and clearly understood I have annexed hereto the
accompanying sheets of drawings in which :-
Fig. 1 is a side elevation of a non-focussing arc lamp to which my invention is
applied, and in which the feed of the top carbon is caused by the weight of the
same and the holder, and which is checked by a fan and catch arrangement.
Fig. 2 is an elevation at right angles to Fig. 1.
Fig. 3 is a cross section on line X X Figs. 1 and 2.
In order to shew more distinctly the checking and regulating mechanism, I have
annexed hereto drawings of the same to a larger scale, in which a brake wheel and
brake stop arrangement are employed in connection with an escapement, Fig. 4
being a side elevation, Fig. 5 an end elevation and Fig. 6 a plan.
the corre
In all the views the same reference letter is used for the same or
sponding part.
A is the base from which the guide rods B are suspended, and on which the side
frames or standards C are mounted.
a is the rocking beam, mounted loose on the end or ends of the main axle d, the
latter being carried in bearings in the standards C. One end of the beam a is attached
to the plunger b of the solenoid D. On the axle d is mounted the differential or
epicyclic train of wheels. This consists of a central wheel or drum c, round which.
the wire tape or chain E to the top carbon holder (F Figs. 1 and 2) or to the guide
frame G (Fig. 4) is passed.
Figs. 4 to 6 represent a focussing arc lamp in which one end of the tape (or
chain) E is attached to the top carbon holder or guide frame, and the other end to
the bottom carbon holder or guide frame; i.e. as the top carbon descends, the
bottom carbon rises. In Figs.
to 3 the lamp is supposed to be non-focussing, the
steel tape E passing only to the top carbon holder.
The centre wheel or pulley c carries a small bevel (or crown) wheel e, which
gears with two larger bevel or crown wheels 9 and h mounted loose on the axle d.
The wheel g is cast with or attached to the ratchet wheel i, and the wheel with
or to the large toothed wheel k, all being loose on the axle d. This toothed
wheel k gears directly with the pinion n on the escapement wheel axle (see Fig. 5),
or may be geared indirectly by means of a pair of intermediate wheels on an
intermediate axle, as shewn in Fig. 1 in which n represents the fan axle.
"

page_text: The rocking beam a is provided with a pawl m, which engages with and moves the
ratchet wheel (so as to separate the carbons) when the, plunger of the solenoid
moves upwards in Figs. 1 to 3; and as the plunger b moves downwards, in
Figs. 4 to 6. A second pawl o prevents the return of the ratchet wheel i when the
rocking beam a and pawl m move in the opposite direction.
Intermediate and attached to both the wheels and k (Figs. 4 to 6) is provided
a brake wheel 1", which is controlled by a brake stop or block mounted on the
cross axle. The axle t is provided with a double armed lever s, one end of which
is drawn down by a spring i so as to cause the brake block r to press against the
brake wheel p; the opposite arm on the rise of the plunger being depressed by
the stud or rod attached to the rocking beam a, thus withdrawing the brake
block allowing the carbons to feed together.
In Figs. 1 to 3 where a fan a is used, the checking of the feed is effected by
means of the catch y (which is attached to the rocking beam a), coming in contact
with or in the way of the fan a.
is a dash pot, the plunger of which is attached to the rocking beam a by means
of a link having a slotted or drawn pin hole at its upper end.
In Figs. 1 to 3 the central wheel c is fixed or keyed to the main axle d, and on
the end of the same is provided a coiled spring H for the purpose of drawing up
the tape, when the carbon carrier is pushed up for recarboning.
It will be evident that owing to the striking and the feed being effected from
different sides of the differential or epicyclic train, the striking movement is
independant of the feed movement and is consequently more perfectly performed.
The operation of my lamp is as follows:-
Referring first to Figs. 1 to 3, in which case the solenoid winding is in the main
circuit when no current is passing through the lamp, the core 6 of the solenoid.
occupies its lowest position (see Fig. 1), the catch y being clear off the fan, so
that the feed gear is released and the weight of the top carbon and holder feeds:
until the carbons meet, or the strength of the current begins to raise the solenoid
core. During this time the catch o prevents the rotation of the ratchet wheel i.
Directly after the core 6 begins to rise, it raises the arm a so that the catch y stops
the fan and the feed side of the differential train, and at the same time the
catch m rotates the ratchet wheel i, thus raising the top carbon holder and
separating the carbons. When the arc grows too long, the core falls, the catch o
preventing a reverse movement of the ratchet wheel; and on the core descending
sufficiently far, the catch y again moves clear off the fan a and allows the lamp to
feed, until the current again raises the core b.
b
b
In Fig. 4 to 6, in which the solenoid winding is traversed by a shunt current
across the lamp circuit, when no current is passing, so that the core occupies its.
lowest position, the spring u is free to lock the feed side of the train through the
brake .
As soon as the current is switched on, the core b rises and moves the
arm a so as to take off the brake r, and allows the lamp to feed; the ratchet wheel i
being locked by the catch o. The solenoid D being in shunt, the current is
weakened as the carbons approach, until it allows the core to fall moving the
arm a, so as to allow the braker to stop the feed side of the train, whilst the
pawl m rotates the ratchet wheel i, so as to move the carbons apart. When the are
becomes too long, the increased strength of the current passing round the solenoid
again raises the core b, and as above explaiued releases the feed side of the
train.
I am aware that differential gear in connection with two separate electric con-
trolling devices have been proposed for are lamps and I do not therefore claim
differential gear broadly.
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 connection with are lamps having only. one electric controlling device, viz. :——

page_text: A solenoid and plunger, the introduction as part of the controlling mechanism of
differential or epicyclic gear in such a manner that the striking and feeding
movements are effected or permitted to take place independently of each other.
2. In connection with arc lamps having only one electric controlling device viz. :-
A solenoid and plunger, the introduction between the feeding and striking
mechanism of differential or epicyclic gear, so that the striking and feeding
mechanism act respectively through opposite sides of such gear.
3. In arc lamps the combination of a rocking arm connected at one end with the
plunger of a solenoid with (and mounted coaxial with) a differential or epicyclic
gear, the centre wheel of said gear carrying the suspension wire, cord or tape for
the carbon holder or holders, or geared to a rack (or racks) carrying the top (or
both) carbon holders, a ratchet wheel on one side of said gear acted upon by a
ratchet pawl connected to said rocking arm, a toothed wheel on opposite side of
said gear connected directly or indirectly with a fan, escapement, or other feed
checking or steadying device, and a stop or brake device acting on the feed gear,
such device or the feed gear being controlled by the movement of the said rocking
arm or of the solenoid plunger.
4. In arc lamps in which the feed of the carbon (or carbons) is due to gravity
and the regulation of the same is due to the movement of the plunger of a solenoid,
the introduction of a differential or epicyclic gear as part of the controlling
mechanism, one of the wheels of the said gear being controlled or operated by a
pawl on a rocking lever connected to the aforesaid plunger, a second wheel of said
gear carrying or geared with the wire, cord, or tape, or the rack or racks carrying
one or both carbon holders, and a third wheel of said gear connected directly or
indirectly with a fan, escapement, or other feed checking or steadying device, the
release and locking of such wheel or of such checking or steadying device being
controlled by the movement of the aforesaid rocking lever or the aforesaid solenoid
plunger.
5. In arc lamps the combination of a (single) solenoid D and plunger b, the
rocking lever a, the pawls m and o, a differential or epicyclic gear connected on the
one side to the ratchet wheel i and on the opposite side to the toothed wheel k and
by an intermediate wheel of said gear to the chain, cord or tape, or rack or racks
carrying one or both carbon holders, the fan or an escapement device, and the
catch y or the brake arrangement r, t, u, s, operated or controlled from the
rocking lever a or the solenoid plunger b, all substantially as herein set forth or
illustrated.
6. Arc lamps constructed substantially as illustrated in the accompanying
drawings or according to any modifications thereof herein set forth.
Dated this 24th day of August 1894.
J. CLARK JEFFERSON,
2, East Parade, Leeds, Agent for Applicant.