IMPROVEMENTS IN ELECTRIC LAMPS OR REGULATORS
Year: 1881

page_text: LETTERS PATENT to Alexander Leslie Fyfe, of Maidenhead Court, Aldersgate
Street, in the City of London, and John Main, of Brixton, in the County of
Surrey, for an Invention of "IMPROVEMENTS IN ELECTRIC LAMPS OR
REGULATORS."
PROVISIONAL SPECIFICATION left by the said Alexander Leslie Fyfe
and John Main at the Office of the Commissioners of Patents on the 2nd
September 1881.
ALEXANDER LESLIE FYFE, of Maidenhead Court, Aldersgate Street, in the City
of London, and JOHN MAIN, of Brixton, in the County of Surrey. "IMPROVE-
MENTS IN ELECTRIC LAMPS OR REGULATORS."
Our Invention relates to an improved construction of electric lamp or regulator
on the arc system, in which the feeding up of the carbon is automatically effected
in a very gradual and progressive manner, the action of the feed mechanism being
controlled by the current itself, responds to the slightest fluctuations in the
strength of the current, so that the interval between the two carbons is maintained
constant, and great steadiness of the light is ensured.
The Invention consists in the following combination, arrangement, and operation
of the mechanism.
The upper carbon holder is provided with rack teeth, and is supported by gearing
with pinion and wheel. A ratchet or break wheel is pressed by a detent or break
lever in order to arrest descent of the carbon holder; the gearing is mounted in a
frame or cage fitted to slide up and down a short distance within the fixed frame
of the regulator, and which is held up therein by the action of one or more
solenoids or electro-magnets mounted upon the fixed frame and placed in the
circuit. The core or armature of the solenoid or electro-magnet may act either
directly upon the cage or through the intervention of levers, and it carries an arm
in position to act on the brake lever, whereby to release the brake and permit the
gradual descent of the carbon whenever by the weakening of the current in the
solenoid the weight of the cage and carbon holder overcomes the attraction of the
solenoid or electro-magnet. Should the carbon descend too low, the power of the
solenoid becomes sufficient to raise the cage with the carbon until the proper
interval to form the arc is attained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Leslie Fyfe and John Main in the Great Seal Patent
Office on the 2nd March 1882.
ALEXANDER LESLIE FYFE, of Maidenhead Court, Aldersgate Street, in the City
of London, and JOHN MAIN, of Brixton, in the County of Surrey. " IMPROVE-
MENTS IN ELECTRIC LAMPS OR REGULATORS."
Our Invention relates to an improved construction of electric lamp or regulator
in which the feeding of the carbons is automatically effected in a very gradual and
progressive manner, the action of the feed mechanism being controlled by the
current and responding to the slightest fluctuations thereof, so that the interval
between the carbons is inaintained constant, and great steadiness of the light is
ensured.
<. The Invention consists in a combination of mechanism wherein the upper carbon
holder is supported by being geared with a brake controlled train of wheels and
.pinions, the holder and train being capable of receiving from a solenoid or electro-
magnet in the main circuit a slight longitudinal movement bodily in the lamp
frame, whereby they are raised for the purpose of separating the carbons and
establishing the arc, and the brake being actuated by another solenoid or electro
magnet to permit the descent of the carbon holder independently of the train for
feeding the carbon as it wastes away.
In order that the Invention may be more readily understood, we have illustrated
it in the accompanying Drawings, and will proceed to describe it with reference
thereto; Figure 1 is a vertical section through the mechanism of the regulator;
Figure 2 shows a modification of the shunt solenoid.
The lamp frame consists of top and bottom plates A, A¹, connected by pillars,
and from the lower plate depends the usual frame supporting the lower carbon
holder;
B is a square rack rod to which the upper carbon holder is attached, said
rod passing freely through plates A, A', and gearing with the first wheel c of a train
of any suitable number of wheels and pinions contained in a cage C fitted to slide
longitudinally a short distance between plates A, A', upon guide pins a fixed
thereto. A-bracket-G-on-the-cage-embraces-the-rack-rod-and-holds-it-in-gear-
with the wheel; the bracket may carry a roller to lessen the friction between it and
the rack rod. The cage C is suspended by a link from the short arm of a lever D
pivoted in a bracket d fixed to top plate A. The other arın of the lever D carries
an adjustable counterweight D¹, and is connected by a link to the core E' of a
solenoid E fixed upon the lower plate A¹. The solenoid E is connected in the main
_circuit of the lamp as shown, and when the current is passing it attracts its core
and raises the cage C and with it the rack rod B, thus separating the carbons and
establishing the arc. When however the current in the solenoid becomes weak or
ceases altogether, the cage drops, the counterweight and core being insufficient to
balance it.
The last wheelf of the train is a brake wheel and has preferably a smooth rim,
against which a light brass spring brake or detent f¹ bears by its own unbalanced
weight. This brake f¹ is pivoted at f³ and carries a light armature g; the brake
.and armature being partially counterbalanced by a weight f2 adjustable to enable
the mechanism to work as delicately and sensitively as may be desired; G is an
electro-magnet, or it may be a solenoid, wound with fine wire, and which in the
example illustrated in Figure 1 is an electro magnet mounted in the cage Cand
placed in a shunt circuit bridging the arc in the usual way, one end being connected
to the frame K, and the other to frame A or to the positive terminal I; R is a
resistance placed in the shunt circuit. The magnet or solenoid G is carried by a
bracket secured adjustably to the side of frame C to enable it to be adjusted at the

page_text: y
proper distance from the armature. Instead of being carried by the movable
cage C it might be affixed to the frame A, in which case it would be horizontal and
the armature g vertical, so as to make its action independent of the movements of
the cage C; L is a stop fixed to the main frame A which meets the armature
only when the cage C is allowed to descend to its lowest point by the total
cessation of the main current in the solenoid E, whereby the brake is released and
the upper carbon is allowed to run down until it meets the lower carbon in
readiness for relighting.
To enable the rack rod B to be raised for the insertion of a fresh carbon, the
second wheel c² of the train turns loose on its arbor in one direction, being con-
nected thereto by a spring click engaging with a ratchet wheel c¹ fast with the
pinion.on the arbor.
Figure 2 shows the brake actuated by a solenoid G, the descent of whose core g¹
is limited by a stop 7³. This core is provided with a lifting stud g*, which passes
through a slot in and takes under the armature g and raises it when the core rises
a certain distance.
The action of the lamp is as follows:-The main current enters at the positive
terminal I, passes round the solenoid E through the frame A to the rack rod B and
upper carbon, thence to the lower carbon, returning by frame K which supports
the lower carbon holder and is insulated from the frame A¹ to the negative
terminal H. The attraction of the solenoid E for its core raises cage C and rack
rod B carrying the upper carbon, thus forming the arc. When the arc is at its
normal length, practically none of the current passes through the shunt solenoid
or magnet, but when by the consumption of the carbons the resistance of the arc
exceeds that of the shunt circuit, sufficient current passes through the latter to
excite the magnet or solenoid G, and so gradually lift the brake f¹, thus allowing
the rack Band upper carbon to descend by their own weight until the resistance
of the arc is again less than that of the shunt circuit. The magnet G then ceases
to attract its armature, and the brake is again applied and prevents the further
descent of the rack B. Should the rack descend too far, the strength of the
solenoid E is so much increased as to still further raise the cage C and separate
the carbons to the proper distance.
The lamp above described is adapted to work in series. In the case of a single
lamp in the circuit, the solenoid G would be in the main circuit and fixed upon the
plate A' of the main frame, and its core would carry an arm, which, when the core
rises, acts on and releases the brake, the core being raised by a counterweight
overcoming the attraction of the solenoid when the current is weakened by the
increased resistance of the arc. When it is desired to keep the arc in the same
focus, the lower carbon instead of being fixed to the frame K would be fed
upwards at the proper speed by cords and pulleys or other gear, operated by the
weight of the rack rod B in any of the usual ways.
It is to be understood that the lamp may be arranged to work in other than a
vertical position.
Having described the nature of the said Invention, and the manner of performing
the same, we declare that what we claim as our Invention to be protected by the
hereinbefore in part recited Letters Patent is,―
1st. The improved electric lamp or regulator_constructed and operating, sub-
stantially as herein described and shown in the Drawings.
2nd. In an electric lamp or regulator, the upper carbon holder supported by a
rack gearing with brake-controlled mechanism mounted in a longitudinally movable
cage, in combination with a solenoid in the main circuit for raising the cage and
carbon holder to establish the arc, and with another solenoid or electro magnet in
a shunt or in the main circuit for releasing the brake to permit the descent of the
carbon, the whole combined to operate substantially as herein specified.
3rd. In an electric lamp or regulator in which the upper carbon holder is
supported by a rack in gear with brake controlled mechanism in a longitudinally
movable cage, the combination of the cage, the lever by which it is suspended, and

page_text: the solenoid E, operating substantially as herein described and shown in the
Drawings.
4th. In an electric lamp or regulator in which the upper carbon holder is
supported by a rack in gear with mechanism controlled by any suitable means to
regulate the feed of the carbon, the making the said mechanism together with the
rack and holder movable bodily in a longitudinal direction for the purpose of
separating the carbons to establish the arc, the two movements being independent
of one another, substantially as specified.
In witness whereof, we, the said Alexander Leslie Fyfe and John Main, have
hereunto set our hands and seals, this Second day of March, A.D. 1882.