Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 7th May, 1896
Complete Specification Left, 8th Feb., 1897-Accepted, 5th June, 1897
Electric Arc Lamps.
I, WILLIAM Fox of 4 Bramley Street, Broughton, Manchester in the County
of Lancashire, Electrician do hereby declare the nature of this invention to be as
follows:-
An automatic electric arc lamp for alternating or direct currents, with brake
wheel feed, the lamp being differential wound and self-focussing, with flat solenoids
and laminated moveable cores arranged horizontally, suitable holders for the carbon
electrodes being formed of two rigid claws and a third vertical spring claw, the
carbon rod being pressed against the rigid claws by the spring claw. The carbon
holders are carried by suitable frames, working on guide-rods, said guide-rods being
connected together at the top and bottom of the lamp and forming a frame for the
entire mechanism. The arc is struck, and the feed of the carbons regulated by
two flat solenoids of insulated wire of any suitable metal, one solenoid being in
"series," and the other being in "shunt," with the arc. These solenoids have
moveable fat cores of any suitable magnetic material, preferably made up of thin
plates insulated one from the other, the entire core having small rollers on the
under side to reduce friction in sliding in and out of the solenoids.
The cores are connected by means of metal or other links, chains or cords to
crank arms on a small shaft pivotted in front of the solenoids in such manner that,
on one of the cores advancing the other recedes, and vice versa.
Another crank
arm on the same shaft is connected by similar means to a tail piece on a pivotted
block carried by a strap piece working on the same centres as a grooved brake-
wheel, the block having a flexible cord of metal, or other suitable material,
fastened at opposite sides of its pivot by the ends and passing round the brake-
wheel in its groove, so that, on the tail-piece being lifted by the links, etc.,
aforesaid, the flexible brake carries the brake-wheel round with it, the brake being
released by a retrograde motion of the tail-piece, and the strap catching on a stop
suitably arranged so as to ease the grip of the flexible brake and allow the brake-
wheel to turn freely round. The brake-wheel carries a toothed pinion, or wheel,
engaging with a rack or chain connected at one end to the upper carbon holder,
and at the other end, by means of an insulator, to the lower carbon holder in such way
that, on the wheel being revolved by the movable brake, the upper carbon holder
is raised and the lower depressed.
The action of the lamp is as follows, On the current flowing through the lamp,
the series solenoid is exited, drawing in its core and separating the carbons by
raising the block, and, revolving the wheel by means of the flexible brake, until
the arc is struck and the current reduced to the normal working quantity.
On the arc becoming too long through the carbons burning away, the current
in the shunt solenoid increases, and the core of this solenoid is drawn in, and,
acting in the reverse manner to the series side, brings the carbons together until
the balance is again established between the two solenoids, and, as the carbons
further burn, the shunt solenoid continues its action until the brake strap-piece is
brought to the stop and, slightly releasing the brake, allows the wheel to slip and
the carbons to approach by gravity, any undue approach being checked by the
series solenoid acting in opposition. A dashpot is provided to check sudden changes
and violent action in the lamp.
Dated this Sixth day of May 1896.
WILLIAM FOX.

page_text: Electric Are Damps.
I, WILLIAM Fox of 4 Bramley Street, Lower Broughton, Salford, in the
County of Lancaster, Electrician, 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 electric are lamps, and consists first of automatic
mechanism for regulating the feed of the carbons, and secondly, of improved
holders or sockets for holding the respective carbons.
And in order that my said invention may be the more readily understood I have
bereunto annexed a sheet of drawings, and will now proceed to describe the same
with the figures and letters of reference marked thereon.
Fig. 1 is a perspective view of an electric arc lamp (partly broken away)
constructed in accordance with my improvements.
Figs. 2 to 5 illustrate details.
In accordance with my invention I employ a wheel (A) (hereafter called the
brake wheel) which is mounted upon the axis (B), supported in bearings (C) on
the lamp top. Upon the side of this brake wheel, or keyed upon the same axis is
the chain wheel (D), over which passes the chain (E) with its ends connected
respectively to the upper and lower carbon holder carriers (F) and (G) (see
Fig. 1).
Around the brake wheel (A), and in groove (H) of its periphery, a band of
fine wires or similar flexible material (1) (hereinafter called the brake-strap) is
passed, which is connected at one end to the link (J) on the upper side, and at
the other end to the link (K) on the underside, of the swivelling block (L).
This block swivels on central pin (M) carried by the arms or cranks (N) on
shaft (B), and the effect of its movement on such central pin is to tighten or
slacken the aforesaid flexible brake strap (1) around the brake wheel. This brake-
strap by its friction or grip on the brake wheel serves to sustain the carbon holder
carriers (F), (G), and on being slackened to allow them to be respectively raised
and lowered. It will therefore be seen that by regulating the tension or grip of
the said brake-strap upon the brake wheel an even and regular feed may be given
to the carbon points.
To effect this desirable adjustment automatically I employ two flat solenoids of
insulated wire (O), (P), one in series' and the other in shunt' with the are.
These solenoids have movable cores (Q), (R) of any suitable magnetic material,
preferably thin strips of metal insulated one from the other, and the entire core
capable of moving in and out of the solenoid upon small rollers or runners to reduce
friction. These cores are connected by links (R'), (R2) to the cranks or arms (R³)
and (R) of a shaft (T) cominon to both cores. This shaft is pivotted between
bearings (R) and screw points (R) and the relative positions of the cranks or
arms (R), (R) are such that as the shaft (T) is rotated the core (Q) is caused
to retire into the solenoid (0) whilst the other core (R) advances out of the
solenoid (P), or vice-versa.
Another crank or arm (S) on the same shaft is connected by link (S') to the
tail piece (U) of the swivelling block (L), and it will now be seen that as the shaft
is turned in the direction of the arrow (a) the action of the crank (S) through
link (S) on the tail-piece (U) will be to swivel the block (L) on its central pin (M),
and by depressing the upper end of the flexible brake strap connected to link (J),
and elevating the lower end connected to link (K) the said strap will be tightened
upon the brake wheel as shewn in Fig. 4. Likewise, by the further movement of
shaft (T) the friction or grip of said strap (1) will serve to raise the arms (N), & turn

page_text: the brake-wheel (A) and with it the chain wheel (D) which thereby separates the
carbon points.
The action of the lamp is as follows:-
On the current flowing through the lamp the 'series solenoid (P) is excited,.
drawing in its core (R) and separating the carbons (Y) through the movement of
the brake wheel under the action of the brake-strap, as aforesaid until the .rc is.
struck and the current reduced to the normal working quantity. On the are
becoming too long through the carbons burning away, the current in the 'shunt"
solenoid (O) increases, and the core of this solenoid is then drawn in and acting in the
reverse manner to the 'series' core upon the arms (N) and brake strap (I),.
serves to reverse the moment of the chain wheel (D) and so bring the carbon.
points together until the balance is again established between the two solenoids,..
and as the carbons further burn the 'shunt' solenoid (0) continues its action until
tle brake strap (1) is cased or its grip relaxed by the stop (V) coming against
the top of the lamp, when it allows the brake wheel to slip and the two carbons to.
approach by gravity.
Any undue approach is checked by the series solenoid acting in opposition..
A 'dash-pot' is provided at (W) to check sudden changes and violent action in
the lamp.
In accordance with the further features of my invention I form the carbon.
holders of three claws (1), (2) and (3), two rigid (1), (2), and, by preference, cast
in one piece, and the third (3) of spring metal, and secured to the others by a
clamping screw (4) for the lower electrode, and arranged and fixed as shewn in.
Fig. 5 for the upper electrode. This construction of holder enables the carbons.
to quickly and easily be fixed and removed. In the case of the lower holder the
Fase of the two rigid claws is cast or formed with a 'ball' (Z) fitting in a socket' in the
carrier (G), and cl: n ped there by parts (5). The said holder thereby allows for
the carbons to be held in line with each other. The said carbon holder carriers.
are guided by the rods (6), which are coupled by cross stay (7) and form a complete
framing for the mechanism.
Having thus particularly described and ascertained the nature of my said inven--
tion, I wish it to be understood that I do not confine myself to the precise
arrangement of mechanism for conveying the movements of the solenoid cores, or of
tightening the brake strap, since the same may be varied without departing from
my invention, and what I claim and desire to secure by Letters Patent is :-
1. In electric arc lamps, the use of a 'brake' and brake strap acting under the
influences of solenoids (in 'series' and 'shunt' respectively with the arc) and.
movable cores, as and for the purposes described.
2. In an electric arc lamp, the automatic feed mechanism hereinbefore desired.
and illustrated in the accompanying drawings.
3. The brake wheel (A), flexible brake-strap (1), block (L), cranks or arms (N),
shaft (T), cranks or arms (R3), (R), (S) and (W), link (S'), links (R') (R2) or
their equivalent, coupled to cores (Q) & (R), (mounted on anti-friction rollers),
solenoids (O) and (P), constructed, arranged and operating separately or
collectively as and for the purposes set forth and illustrated.
4. A holder for holding the carbon electrodes of an are lamp composed of two.
rigid claws and one spring or elastic claw as set forth.
Dated this 6th day of February 1897.
WILLIAM FOX,
By John G. Wilson & Co.,
Agents.