IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to John Henry Johnson of 47 Lincoln's Inn Fields in the
County of Middlesex Gentleman for an invention of " IMPROVEMENTS IN
ELECTRIC LAMPS" A. communication from abroad by Jean Marie Anatole
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 6th May 1882.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN ELECTRIC LAMPS a communication from abroad
by Jean Marie Anatole Gérard-Lescuyer of Paris in the Republic of France
Engineer
3
This Invention relates to Electric lamps and consists of a peculiar method of
arranging and supporting the carbons or candles as hereinafter described.
In carrying out this Invention as applied to a lamp provided with one pair of
carbons, for example, one of the carbons is rigidly fixed in a socket or holder
formed on a conducting plate or base The other carbon is carried in a socket or
holder attached to a horizontal plate supported by a pair of legs or pivots the
lower extremities of which are immersed in mercury contained in two cups provided
on a second conducting plate or base in such a manner that this carbon is capable
of oscillating in a vertical plane passing through the entire of the fixed carbon.
The extent of motion allotted to the oscillating carbon is limited on the one hand
by contact with the fixed carbon and on the other side by means of a set screw
bearing against the oscillating socket and working in a support or bracket attached
to the second base plate:
When no current is passing in the lamp the two carbons are in contact the
moveable carbon being so balanced on its legs or pivots as to have a tendency by
reason of its weight to lean against the fixed Carbon and thus facilitates the first
formation of the arc. When the carbons are placed in a circuit the current passes
up one of the carbons and descends by the other and as, two parallel currents in
77

page_text: opposite directions repel one another this repulsion suffices to cause the oscillating
carbon to move away from the fixed carbon and thus establish the arc.
The lower extremities of the legs or pivots are pointed and take their bearing in
hollow cones filled with mercury forming the bottoms of the cups herein before
referred to thus ensuring great lightness and good contacts:
The sockets or carbon holders are arranged in tension upon the circuit and the
carbons are arranged in quantity upon the same circuit so that one of the carbons
of each pair thus presents a positive pole whilst the other carbon presents a
negative pole.
Any number of carbons may be arranged on the plate supporting the fixed
carbon or carbons in order to obtain a continuous illumination during any desired
period of time. The base of the lamp is capable of being accurately adjusted in a
horizontal position by means of set screws.
The arrangement of the carbons herein before described may be inverted the
arrangement of the parts in this case being similar to that herein before described
it is unnecessary to repeat the description. The repulsion is sufficient to maintain
the are at the points notwithstanding the inverted position. Morcover the arc
may be controlled if required by the means for which I have already obtained
Letters Patent Nod 1552 A.D. 1880.
The carbons employed in combination with the repulsion arrangement herein-
before described may be arranged with the moveable carbon in the centre of a
hollow or tubular fixed carbon the arc being produced in the space between the
hollow carbon and the internal or central carbon which is removeable or according
to another arrangement three or more carbons of cylindrical or angular form are
employed being arranged in the form of a ring surrounding a central carbon.
One of the principal advantages of the carbon arrangement herein before described
is that the point of contact between the carbons of each lamp is so small that it
may almost be regarded as a geometrical point and the derivation is reduced to a
minimum on account of the great resistance opposed to the current of this part:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Henry Johnson in the Great Seal Patent Office on the
1st November 1882.
JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN ELECTRIC LAMPS" a communication from abroad
by Jean Marie Anatole Gérard-Lescuyer of Paris in the Republic of France,
Engineer
This Invention relates to Electric Lamps and consists of a peculiar method of
arranging and supporting the Carbons or candles as hereinafter described.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 is an elevation of part of a lamp provided with one pair of carbons and
Figure 2 is a corresponding plan.
Figure 3 illustrates a similar arrangement inverted.
Figures 4, 5 and 6 represent various different arrangements of carbons.
One of the carbons a of each pair is rigidly fixed in a socket or holder b formed
on a conducting plate or base c. Two cylindrical cups & containing mercury are
provided upon another conducting plate c' the said cups being formed with conical
bottoms as shown by dotted lines in figure 1. The other carbon his carried in a
socket or holdere attached to a horizontal plate supported by a pair of legs or
pivots g the lower extremities of which are immersed in the mercury in the cups d
in such a manner that this carbon is capable of oscillating in a vertical plane
passing through the centre of the fixed carbon. The extent of motion allotted to
the oscillating carbon is limited on the one side by contact with the fixed
carbon a and on the other side by means of a set screw i bearing against the
oscillating socket, e and working in a support or bracket attached to the base
plate c¹.
When no current is passing in the lamp the two carbons u and h are in contact
the moveable carbon h being so balanced on its legs or pivots g as to have a
tendency by reason of its weight to lean against the fixed carbon a and thus
facilitates the lighting or first formation of the arc. When the carbons a and h
are placed in a circuit the current passes up one of the carbons and descends by
the other and the two parallel currents in opposite directions repel one another
this repulsion sufficing to cause the oscillating carbon to move away from the
fixed carbon a and thus establish the arc.
The lower extremities of the legs or pivots g being pointed and taking their
bearing in the hollow conical bottoms of the cups & filled with mercury great
lightness and good contacts are insured.
The sockets or carbon holders are arranged in tension upon the circuit and the
carbons are arranged in quantity upon the same circuit so that one of the carbons
of each pair thus presents a positive pole whilst the other carbon presents a
negative pole.
Any number of carbons may be arranged on the plate c in order to obtain
continuous illumination during any desired period The base of the lamp is capable
of being accurately adjusted in a horizontal position by means of screws l.
The arrangement of the carbons a and h hereinbefore described may be inverted
as represented in Figure 3 the arrangement of the parts in this case being similar
to that hereinbefore described it is unnecessary to repeat the description. The

page_text: repulsion is sufficient to maintain the arc at the points notwithstanding the
inverted position moreover the are may be controlled if required by the means
described in the Specification of Letters Patent 1552 A.D. 1880.
Figures 4, 5 and 6 represent various arrangements of carbons which may be
employed in combination with the repulsion arrangement hereinbefore described.
In Figure 4 the central movable carbon x is arranged in the centre of a hollow
or tubular fixed carbon y and the arc is produced in the space between the hollow
carbony and the internal or central carbon x which is moveable.
In Figure 5 three cylindrical carbons are shewn arranged in the form of a ring
surrounding the central carbon and figure 6 illustrates a similar arrangement
with the surrounding carbons z of rectangular section. The carbons may be of
other section and the surrounding carbons may be in other number than three.
One of the principal advantages of the carbon arrangement hereinbefore described
is that the point of contact between the carbons of each lamp is so small that it
may almost be regarded as a geometrical point and the derivation is reduced to a
minimum on account of the great resistance opposed to the current at this part.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is :-
The Improvements in Electric Lamps consisting in supporting and arranging
the carbons substantially as hereinbefore described and illustrated in the
accompanying drawings.
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this twenty fifth day of October One
thousand eight hundred and eighty two.
TORO זוח
TONICONT
7
J. HE
HENRY JOHNSON. (L.S.)