IMPROVEMENTS IN ELECTRIC ARC LAMPS
Year: 1883

page_text: LETTERS PATENT to Frederick Mori of Leeds in the County of York
Electrician for an Invention of "IMPROVEMENTS IN ELECTRIC ARC LAMPS.”
PROVISIONAL SPECIFICATION left by the said Frederick Mori at the
Office of the Commissioners of Patents on the 19th January 1883.
FREDERICK MORI of Leeds in the county of York Electrician "IMPROVEMENTS
IN ELECTRIC ARC LAMPS
"
This invention relates to lamps in which two carbons are employed one being
fixed and the other movable and the object of my improvements is to feed the
movable carbon at such a rate as shall compensate for the consumption at the two
points and thereby render the light as even as possible. In order to effect this the
movable carbon is attached to the bottom end of a vertical rack which gears with
a toothed pinion the carbon and rack descending by their own weight subject to
the controlling action of escapement mechanism which releases the rack or checks
the same in its descent according to the strength of the current.
The mechanism of the lamp consists of the rack and pinion above mentioned the
latter being loose on a spindle mounted in a frame balanced between two pillars or
uprights fixed to the bed plate of the lamp. The equilibrium of the frame is
maintained by means of the action of a solonoid on a bar of iron attached to one
side of the frame and passing down into the hollow core of the coil. On the same
spindle as the pinion are a ratchet wheel and worm wheel the ratchet wheel being
fast to the pinion and the worm wheel fast on the spindle. On the face of the
worm wheel is a catch which gears with the ratchet wheel. The worm wheel gears
with a worm or helix formed on a spindle mounted in the same frame which
spindle also carries a plain wheel or disc. The construction of the parts is such
that the weight of the rack and carbon acting through the medium of the pinion
and ratchet wheel upon the worm wheel is sufficient to cause the worm to revolve
and thereby allow the rack and carbon to descend slowly but by applying a brake
to the brake wheel on the worm spindle the motion is instantly arrested.
Supposing the current to be broken the solonoid will cease to preserve the
[Price 6d 1

page_text: equilibrium of the frame which carries the mechanism which will descend slightly
and in so doing liberate the brake wheel and allow the carbon to descend until the
points meet whereby the current will be established. The solonoid will then exert
its influence upon the iron bar attracting it and raising the mechanism and
bringing the brake wheel in contact with the lever or other check piece which
serves to stop the rotation thereof at the same time separating the carbons
sufficiently to form the electric arc. As the combined weight of the carbon and
rack will decrease as the carbon is consumed I cause the pinion to gear with a
barrel containing a tape spring the tension of the spring opposing the rotation of
the pinion and decreasing in proportion to the consumption of the carbon.
When coupling the lamps in series I employ a small solonoid in each lamp
which provides a secondary or "shunt" circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick Mori in the Great Seal Patent Office on the 19th July
1883.
FREDERICK MORI of Leeds in the County of York, Electrician
IN ELECTRIC ARC LAMPS
"
"IMPROVEMENTS
This Invention relates to electric arc lamps, the object of my Improvements
being to regulate the feed of the carbons at a rate proportionate to the consumption
thereof so as to maintain a uniform length of ". arc and also to provide means
for the re-establishment of the current when the same has been completely
interrupted.
In order that my Invention may be more clearly understood I have hereto
annexed two sheets of Drawings illustrative thereof. Two forms of lamp are
shewn which are identical in principle and differ only in what may be termed the
escapement motion or that part of the apparatus which governs the feeding
mechanism. Figs 1, 2 and 3 represent the simplest form of lamp which is
constructed as follows. A is a metal plate to the underside of which are attached
two arms B connected by a cross bar C which supports the lower carbon D. Upon
the plate A is a layer of vulcanite or other insulating material E which supports
the mechanism of the lamp. F and G are metal plates connected by pillars H
(see plan view Fig 4).
The parts marked J constitute the framework which is attached to the lever K,
the said lever being supported upon the pivots or fulcrums a. Upon the spindle b
are mounted a worm wheel c, a ratchet wheel d and a pinion e, the worm wheel
being fast upon the shaft whilst the ratchet wheel and pinion are loose. On the
face of the wheel c is a catch which is pressed into the ratchet wheel by a spring
as shewn in Fig 5. The rack L gears with the pinion e and to the bottom of this
rack the positive carbon or electrode is attached, the negative electrode being
supported by the cross bar C. The worm wheel c gears with a worm ƒ on the
spindle which also carries,a wheel upon the top of which rests a brake lever j.
M is a solenoid in the interior of which is a metal core N to the bottom of which
is fixed a piston O fitting accurately within the cylinder of the solenoid and thus
forming an air valve.
g
.
The core N is connected at the top to the lever K which supports the framework.
of the lamp. The positive conducting wire is attached to the terminal P, the
negative wire being secured to the terminal Q and the solenoid wire is connected
to the lamp at and L. When the circuit is complete the attraction of the
solenoid counterbalances the weight of the carbon and framework of lamp, and
preserves the requisite length of arc, but, when owing to the consumption of the
carbons the current becomes weaker the weight of the rack and framework over-
comes the attractive power of the solenoid and descends, thus bringing the carbon
points closer together. As soon as the descent of the framework commences, the
brake comes in contact with the rod and the pressure thereof is removed fro:n
the wheel h. The weight of the rack and carbon acting on the worm wheol c is
sufficient to cause the worm to revolve and thereby allow the rack to descend
until the current is re-established, when the solenoid again commences to act upon
the core, and the framework is again raised and the carbon points seperated so as
to give the requisite length of arc.
As soon as the framework is raised the brake j rests upon the wheel hand
arrests the revolution of the worm f. When the lamp is in operation the feed of
the carbon requires to be very gradual and for this reason I employ two brakes for
the wheel the second one m being placed underneath, as shewn in detail Fig 6.

page_text: The extent of motion allowed to the wheel his consequently very slight, as no
sooner does the frame begin to descend than the revolution of the worm is arrested
by the brake m. If however the current be completely interrupted the framework
will descend until the carbon points come into contact and the screw n will press
upon the brake m and remove it from contact with the wheel. The current being
re-established the framework will rise without seperating the carbons until the
brake m again presses against the wheel, when the rotation of the worm f will be
stopped and the rack will be drawn up along with the framework and the carbons
seperated to the required extent.
In Figs 7 and 8 I have shewn a lamp similar in principle to the one above
described with certain additions thereto. In this case the framework is balanced
by two solenoids, that marked R being composed of very fine wire whilst the one
marked M is of wire of much larger diameter. Attached to the framework is an
electro magnet S the armature r of which is fixed to the end of a lever s mounted
on a pillar T. Attached to the bracket or support t is a spring contact maker t¹,
and another contact maker is attached to the pillar U which is in connection with
the bottom plate A. V is a resistance coil, one end of which is connected to the
plate F and the other to the coil of the electro magnet, the other end of the magnet
wire being secured to the insulated bracket u. When the current becomes weak
and the framework begins to descend, the contact makers t' touch each other and a
current passes through the electro magnet attracting the armaturor and causing
the screw to raise the brakej and thus leave the wheel h free to revolve and
allow the rack to descend to compensate for the consumption of the carbons.
In order to facilitate the adjustment of the carbons point to point I attach the
top one to the rack L by means of a double ball and socket joint as shewn in
Fig 9.
Having thus described the nature of my said Invention, and shewn by drawings
how the same is to be performed or carried into practical effect I would have it
understood that I do not confine myself to the precise details of construction
herein shewn and described as the same may be varied, but what I claim as my
Invention and consider to be new is. Firstly. The construction of electric arc
lamps in which the feed of the carbon shall be regulated by means of a wheel c.
and worm f so disposed that the wheel shall act upon the worin whenever the
strength of the current is diminished sufficiently to effect the release of the wheel /
from the control of the brake or other equivalent escapement mechanism.
Secondly. The construction of electric arc lamps in manner substantially as
herein shewn and described
In witness whereof I the said Frederick Mori have hereunto set my hand and
seal this eighteenth day of July, in the year of our Lord, one thousand eight
hundred and eighty three.
FREDRICK
MORI