Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said William Jeffery at the Office
of the Commissioners of Patents on the 31st March 1882.
WILLIAM JEFFERY of North Woolwich in the County of Kent
IN ELECTRIC ARC LAMPS"
"IMPROVEMENTS
My invention chiefly refers to the arrangements for regulating the arc. For
this purpose I make the lower or negative carbon a fixture;, the upper or positive
carbon or the wood or other rod to which it is clamped is free to slide through a
tube or guide; to this a flexible loop or ring say of India rubber is connected
through which the positive carbon or positive carbon holder passes, the opposite
side of this loop or ring is connected to the armature of an electro magnet, for
instance by a lever which is jointed at its other end to another piece or lever
having its fulcrum on a bridge, tlie opposite end of this lever is provided with an
armature which is acted on by an adjacent electro magnet or solenoid; when the
armature is attracted by the magnet the elastic ring is tightened and the carbon
thereby gripped and lifted the required distance to produce the arc; the armature
released the elastic ring contracts and the carbon is free to slide through saime.
The loop or ring is by preference placed in a slanting position. A series of carbons
arranged in the manner before described may be fitted along side one another in a
ring or as desired in one and the same lamp.
Should the armature of the electro magnet get hung up from any cause, in order
to obviate the other lamps in the same circuit being extinguished I provide a
shunt whereby the current when not going to the positive carbon goes to the
adjacent lamp by the said shunt.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Jeffery in the Great Seal Patent Office on the
30th September 1882.
WILLIAM JEFFERY of North Woolwich in the County of Kent
IN ELECTRIC ARC LAMPS
"
"IMPROVEMENTS
The object of my Invention is the providing of simple and improved means of
regulating the arc for the production of the electric light and the invention chiefly
refers to the arrangements for regulating the arc. For this purpose I make the
lower or negative carbon a fixture, the upper or positive carbon or the wood or
other rod to which it is clamped is free to slide through a tube or guide, to this a
flexible loop or ring say of india-rubber is connected through which the positive
carbon or positive carbon holder passes, the opposite side of this loop or ring is
connected to the armature of an electro-magnet, for instance by a lever which is
jointed at its other end to another piece or lever having its fulcrum on a bridge,
the opposite end of this lever is provided with an armature which is acted on by
an adjacent electro magnet or solenoid; when the armature is attracted by the
magnet the elastic ring is tightened and the carbon thereby gripped and lifted the
required distance to produce the arc; the armature released the elastic ring
contracts and the carbon is free to slide through same. The loop or ring is by
preference placed in a slanting position. A series of carbons arranged in the
manner before described may be fitted alongside one another in a ring or as desired
in one and the same lamp.
Should the carbon of the electro-magnet get hung up from any cause, in order
to obviate the other lamps in the same circuit being extinguished I provide a
shunt whereby the current when not going to the positive carbon goes to the
adjacent lamp by the said shunt.
In order that my Invention may be more completely and fully understood I will
now proceed to describe the same with the aid of the accompanying drawings.
Figure 1 is a front view of a single carbon lamp with coils and apparatus complete
constructed according to my invention; Figure 2 is an end view and Figure 3 is a
plan of same; Figure 4 shews detached the arrangement of shunt coil and spring
for closing the circuit; Figure 5 is a diagram showing a modification of apparatus
for cutting out of circuit; Figure 6 shews a lamp constructed according to my
Invention for carrying two pairs of carbon rods, which can be arranged either for
burning both together, or singly, or one after the other; Figure 7 is an end view
of same; Figure 8 shews an arrangement of lamp, by which both upper carbons
(positive) feed by gravity and the lower one (negative) is controlled by solenoid
coil and elastic ring, counterbalanced by a weight. By this arrangement as the
upper carbons burn faster than the lower one, and are fed by gravity, the adjust-
ment of the lower carbon takes place at longer intervals.
Similar letters of reference refer to like parts in all the Figures.
a is one terminal connected direct to the metal frame p carrying the lower
carbon b. The other terminal c is connected to one end of a thick coil, of wire
wound round the solenoid d, the iron core or cores e of which is or are attached to
a lever that carries the upper carbon rod. This lever f is so arranged that the
outer arm can be shortened or lengthened according to circumstances for example
according to the amount of current passing through the solenoid coil d or according
to the machine that is employed, or the number of lamps that may be in the
circuit. This may for example be accomplished by means of the set screws fifi.
The solenoid coil d is wound with fine wire of a suitable high resistance in the

page_text: opposite direction to the large wire, so as to divert a certain part of the current
passing through the solenoid or electro-magnet. The lever fhas its fulerum on
the bridge piece g; and a strong adjustable spring his in connection with the arm
or lever by means of connecting link i so that in a state of rest the iron core e is
withdrawn a suitable distance from the centre of the solenoid coil d and the carbon:
rods are then placed in contact with each other. The end of the lever f by means
of the connecting link i carries the upper carbon rod k which it holds-by means of
an elastic loop or ring of india-rubber or any other suitable elastic or flexible
material. This loop or ring is attached to the connecting link or lever i at one
end by pins or clips and the loop or ring is of such a size that the carbon rod k
will slide through the said loop or ring by its own weight, when the tension of
the loop or ring diminishes, by the current ceasing, or diminishing by the increasing
resistance as the arc becomes longer. This loop or ring is held at its other end
by the bent arm l' the position of which latter is adjusted by the set nuts r r.
These lamps may carry one, two or more pairs of carbon rods by having one or
more levers attached to the iron core of the solenoid or the armature of an electro
magnet. For example at Figures 6 and 7 I have shown a lamp with two pairs of
carbons and at Figure 8 I have shown a lamp having three carbons, two upper and
one lower the lower carbon in this case being the adjustable carbon
.
The lamps are made to work in series, or singly as required. s is a table on
which the apparatus is supported.
I have guarded against an accident happening to one lamp and so extinguishing
all lamps in the same circuit by having a shunt coil added as shown more
particularly at Figures 4 and 5 one end of the shunt coil is attached to the negative
pole and the other to an insulated support in such a manner that when the
current cannot pass between the carbon points, the iron core of the solenoid or the
armature of an electro magnet on being released instantly closes the shunt circuit,
and as the resistance of the shunt circuit is about the same as the lamp circuit no
difference will be made in the other lamps by alterations in the resistance of the
total circuit; qq are rings by which the lamp is suspended from any desired
position according to circumstances
The operation of the lamp is as follows:-
When no current is passing, the carbon rods are in contact. The current passing
round the solenoid coils d draws down the iron core e, and by that means the
other end of the lever f is lifted. The elastic ring which is attached to this
lever by link is thereby tightened and grips the carbon or carbon holder and
lifts it the required distance for the arc. As the carbon rods are consumed, and
the resistance of the arc increases, the force which the lever f exerts on the elastic
ring or band decreases and the india-rubber ring contracts, which allows the
carbon rod / to feed forward or downward till the required distance is reached,
when the elastic ring or band is again tightened by the iron core e being attracted
by the solenoid coil d. By the employment of this elastic ring a great improve-
ment is effected as after the first lighting the carbons do not again come into
contact unless all current ceases. It will therefore be seen that the employment of
this elastic loop or ring, as it expands or contracts, according to the amount of
current passing through the lamp, allows the carbon rod to feed forward either
quickly or slowly according to the amount of tension the lever exerts on the ring,
and so automatically keeps the carbons the proper distance apart for the display
of the electric arc, and thereby avoids all that flickering that is generally noticeable
in most other arc lamps.
The distance of arc required can be easily adjusted. The spring / on the lever f
which acts in opposition to the solenoid coil d can also be arranged for amount of
current or machine employed. The shunt coil o shown more particularly at
Figure 4 is very simple and acts instantly the iron core e of the solenoid coil (or
armature of electro-magnet) is released and the shunt coil being about the same
resistance as the arc, the other lamps are unaffected. The shunt coil being separate
and having no maguetic influence on the solenoid, if the lamp re-arranges itself or

page_text: the carbons are renewed the lamp will immediately relight, without any difference,
being observed in the other lamps in the same circuit.. A modification of above
mentioned method of cutting out of circuit is shown at Figure 5 in which I employ.
a rod m' pendant from the lever which rod m as the lever f descends dips into or.
is lifted out of a cup n containing mercury.
'
Having now described the nature. of my said Invention and in what manner
the same is to be performed I declare that I claim
.
First. In an electric lamp burning one or more sets of carbons and provided.
with a solenoid or electro-magnet for separating and controlling the said carbons.
the application of an india-rubber or any other elastic or flexible ring or loop
acting with the said solenoid or electromagnet substantially as hereinbefore
described and illustrated with reference to the accompanying drawings.
Second. The combination with a lamp constructed as hereinbefore described of
cut out or shunt coil in which the circuit is closed by the action of the core of the
solenoid coil or armature of electro-magnet on being released by the ceasing of
current or accident to lamp, so that the low resistance circuit is not affected all
substantially as herein before set forth.
Third. The combination of parts forming the improved electric arc lamps, as.
shown on the accompanying drawings.
In Witness whereof I the said William Jeffery have hereunto set my hand
and seal this Twentyninth day of September in the year of our Lord
One thousand eight hundred and eighty two.