Improvements in Arc Electric Lamps.
Year: 1894

page_text: This Print is in accordance with the Original Specification as it stands after
Amendinent (under Section 18 of the Patents, &c. Act, 1883) as allowed
by the decision of the Comptroller General of the 21st day of June, 1897.
Date of Application, 12th Sept., 1894
Complete Specification Left, 11th June, 1895-Accepted, 13th July, 1895
Improvements in Arc Electric Lamps.
We, SAMUEL SEALY ALLIN, of 52 Woodstock Road Bedford Park London, W.
Manufacturer, and WILLIAM HENRY WOOD of 84 Foxberry Road Brockley,
London S.E. Foreman of Works, do hereby declare the nature of this invention to
be as follows:-
The objects of this invention are, to produce an improved method of striking
the arc without moving or interfering with the feed mechanism, and of feeding
together the carbons very gradually as they consume without breaking the
controlling circuit. To produce a lamp adjustable for working on either continuous
or alternating circuits, and with currents of largely varying volume, and capable of
working on very small currents.
The lamp consists of a base plate carrying the mechanism, and from which
descends the rod or rods which guide the carbon holders in their travel. The
carbon holders are connected by a chain passing over pullies. The arc is
struck by tilting one or both of these pullies, thus separating the carbons the
required distance, and this may be effected by connecting one or both of the
pullies, either to a rocking electro-magnet or to the rocking armature of a fixed
magnet. If a rocking magnet is used its poles are drawn, when the current is
switched on, to iron pole pieces suitably placed, and if the magnet is fixed, the pole
pieces in the armature are drawn to its poles, and the pulley or pullies similarly
tilted. The electro magnet is formed by passing round its core the required
number of turns either of the main circuit or of a shunt according to the movement
desired or, instead of an electro magnet a solenoid may be used connected to a
rocking frame carrying one of the chain pullies, preferably that of the lower
carbon holder and this latter arrangement we prefer, particularly for alternating
current lamps.
In this arrangement the feeding together of the carbons as they consume, which
is quite independent of the arrangement for striking the arc, is effected by gravity,
and is governed by a solenoid actuating through its core a brake, governing through
one or more wheels, a larger wheel on whose axis is a chain wheel with which gears
the chain connecting the carbon holders. This solenoid is preferably connected in
shunt across the carbons, but, mutatis mutandis it may also be in series with the main
circuit for lamps in parallel or wound partly in series and partly in shunt.
When the E.M.F. has risen in consequence of the consumption of the carbons,
the solenoid varies its force and removes, or permits the removal of the brake, and so
allows the large wheel to revolve, under the pull of the upper carbon holder, till the
carbons have sufficiently approached each other, when the brake is again applied.
In order to prevent too rapid a movement of the wheel we connect it with an
CD..
01

page_text: escapement, preferably a lever escapement governed by a balance. wheel, whose
oscillations are so controlled by a pin or otherwise, as to present no dead point.
In order to meet the varying strength of the magnets or solenoids when a lamp
is shifted from a continuous to an alternating circuit or vice versa, we provide a
means of regulating their force by regulating the opposing spring or balance
weight, and in order to enable the carbons to approach when no current is on, we
connect the brake lever with the rocking lever, armature, or magnet which strikes
the arc.
101 1
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1001
Improvements in Arc Electric Lamps.
We, SAMUEL SEALY ALLIN of 52 Woodstock Road, Bedford Park, London, W.,
Manufacturer, and WILLIAM HENRY WOOD, of 84 Foxberry Road, Brockley,
London, S.E. Foreman of Works, 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 :-
The objects of this invention are, to produce an improved method of striking
the arc without moving or interfering with the feed mechanism, and of feeding
together the carbons very gradually as they consume without breaking the
controlling circuit, to produce a lamp adjustable for working on either continuous
or alternating circuits, and with currents of largely varying volume, and capable
of working on very small currents.
The lamp consists of a base plate carrying the mechanism, and from this plate
descends the rod or rods which guide the carbon holders in their travel.
The carbon holders are connected by a chain passing over pullies. The arc is
struck by tilting one or both of these pullies, thus separating the carbons the
required distance, and this may be effected by connecting one or both of the pullies,
either to a rocking electro magnet or to the rocking armature of a fixed magnet.
If a rocking magnet is used its poles are drawn, when the current is switched on,
to iron pole pieces suitably placed, and if the magnet is fixed, the pole pieces in the
armature are drawn to its poles and the pulley or pullies similarly tilted. The
electro magnet is formed by passing round its core the required number of turns
either of the main circuit or of a shunt according to the movement desired or, instead
of an electro magnet a solenoid may be used having its core connected to a rocking
frame carrying one of the chain pullies, preferably that of the lower carbon holder and
this latter arrangement we prefer, particularly for alternating current lamps.
In this arrangement the feeding together of the carbons as they consume, which
is quite independent of the arrangement for striking the arc, is effected by gravity,
and is governed by a solenoid actuating through its core a brake, governing through
one or more wheels, a larger wheel on whose axis is a chain wheel with which
gears the chain connecting the carbon holders.
This solenoid is preferably connected in shunt across the carbons, but, mutatis
mutandis, it may also be in series with the main circuit for lamps in parallel or
wound partly in series and partly in shunt.
10
When the resistance has risen in consequence of the consumption of the carbons,
the solenoid varies its force and removes, or permits the removal of the brake, and
so allows the large wheel to revolve, under the pull of the upper carbon holder, till
the carbons have sufficiently approached each other, when the brake again
applied. In order to prevent too rapid a movement of the wheel we connect it with

page_text: an escapement, preferably a lever escapement governed by a balance wheel on
which the brake acts, and whose oscillations are so controlled by a pin or otherwise,
as to present no dead point.
In order to meet the varying strength of the magnets or solenoids when a lamp
is shifted from a continuous to an alternating circuit or vice versa, we provide a
means of regulating their force by regulating the opposing spring or balance
weight, and in order to enable the carbons to approach when no current is on, we
connect the brake lever with the rocking lever, armature, or magnet which strikes
the arc.
Our improved construction of lamp is shewn on the accompanying drawing in
which Fig. 1 is a side view, part of the top frame being broken away to shew the
escapement. Fig. 2 is a plan.
The upper and lower carbon holders A and B are connected by a chain C which
passes over guide pulleys D and E and a sprocket wheel F. Both carbon holders
are guided preferably by antifriction rollers as shewn along vertical tubes G G¹;
the upper carbon holder A is sufficiently heavy to overbalance the lower B so that
when the holders are free, the upper descends and the lower ascends till the carbons
meet. The guide pulley E is mounted at the one end of a double lever or frame H
which is pivotted at h and has connected to its other end a pair of links or cords
suspending the cores of a double solenoid S having its coil of low resistance in the
lamp circuit. On the axis of the chain wheel F is fixed a ratchet wheel with
which engages a spring pawl mounted on a toothed wheel K indicated in Fig. 1 by
dotted lines. This wheel gears with a pinion on the axis of an escapement wheel L
which by lever action causes a balance wheel M to oscillate, such oscillation being
limited by a pin m fixed to the framing. On the periphery of M a brake lever N
bears with a pressure resulting from a weight O, which can be adjusted nearer to
or farther from the fulcrum of the brake lever-or by a spring whose tension can
be adjusted; or, as shewn at Fig. 3 a spring lever N¹ bearing on the balance wheel
may be used with a counteracting spring O¹ whose tension can be adjusted by a
nut as shewn.
The arm of the lever N opposite to the brake is jointed to a link suspending the
core of a solenoid S¹ the coil of which is of high resistance in a shunt to the
lamp circuit. A lever P has its upper end inclined over the end of the brake
lever and its lower end bent to rest on the axis of the guide pulley E so that when
that pulley is raised the slope of P' acting on the end of the brake lever raises the
brake off the balance wheel. In order to prevent sudden movements of the
regulating mechanism I connect to the lever or frame H a dash pot cylinder Q
containing glycerine or other suitable fluid.
The electrical connections are from the post T to the insulated central part of
the holder A and also by wire t to the coil of the solenoid S¹; from the post T¹ to
the coils of the double solenoid S down the tube G¹ and thence to the insulated
central part of the holder B; there is also a connection t¹ to the coil of S¹. The
operation of the mechanism is as follows:--
When the lamp is out of circuit, the right end of the lever H is down, the guide
pulley E is up putting P in such position that the brake N is raised off the balance
wheel M the escapement being consequently free.
The holder A then descends and B ascends until the carbons meet and the
mechanism is stopped, in which condition the lamp remains until it is put in
circuit, whereupon the cores of S are attracted upwards allowing the right end of H
to rise lowering E and the lower holder B, thus separating the carbons and striking
the arc.
Should there be more than the normal resistance when the arc is struck,
or afterwards as the carbons are consumed, the solenoid S₁ attracts its core down,
reducing the pressure of the brake on the balance wheel, and thereupon the upper
carbon descends a little raising the lower carbon until the resistance of the arc
becomes norinal whereupon the brake comes to bear again with such pressure on
the balance wheel as to prevent farther movement of the carbons, until the resistance
of the arc again so far increases as to release again the balance wheel,

page_text: '
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an electric are lanp, the method of striking the arc by carrying the lower
carbon holder on a rocking lever or frame actuated by a solenoid or electromagnet
.so arranged that when the current is switched on the lower carbon drops away from
the upper one the required distance, substantially as described.
2. In an electric arc lamp controlling the feed of the carbons by means of a
.brake acting. on the balance wheel of an escapement in connection with the carbon
holders and operating substantially in the manner described.
3. In an electric arc lamp such as is above referred to, a connection from the
rocking lever or. frame to, the, brake lever, whereby the escapement is released from
the brake when the lamp is not in circuit, substantially as described.
4. In an electric. arc lamp the combination of a lower carbon holder and a
heavier upper holder connected by a chain passing over guide pullies and a sprocket
wheel, the pulley from which the chain is led to the lower holder being mounted on
a rocking lever or frame connected to the cores of solenoids having their coil in
the lamp circuit and the sprocket wheel being geared to an escapement, on the
balance wheel of which bears a brake lever connected to the core of a solenoid
having its coil in a shunt to the lamp circuit, arranged and operating, substantially
as described. .