IMPROVE- MENTS IN ELECTRIC LAMPS
Year: 1880

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN ELECTRIC LAMPS." A communication from abroad by the Compagnie
Générale d'Eclairage Electrique of Paris, France, an Incorporated Company.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 16th April 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS." [A communi-
cation from abroad by the Compagnie Générale d'Eclairage Electrique of Paris,
France, an Incorporated Company.]
In the Specification to Letters Patent granted to me on the 4th March 1879,
No. 863, for an Invention communicated to me from abroad by J. C. Jamin, was
described a form of electric lamp in which the two carbons are placed side by side
at a little distance apart within an electrical loop, so that the voltaic arc is formed
between their points. The present Invention relates to electric lamps of this
kind, and consists in providing means whereby such a lamp is kindled when it
is brought into circuit, and becomes excluded from the circuit when its carbons are
consumed, also when there are several sets of carbons in a lamp, those of one pair
become kindled, and when they are consumed those of another pair become
kindled, and so on successively, and when the circuit in the lamp itself is broken
by accidental extinction or otherwise, the general circuit is nevertheless maintained
without affecting other lamps with which it may be connected. For this purpose
one of each pair of carbons is held in a socket hinged to the framing, and so loaded
that when left free the carbon becomes inclined till its point bears against the
point of the other carbon permitting passage of electricity, so as to kindle the
carbons; but the electrical loop within which the carbons are enclosed, as described
in the Specification above referred to, is according to the present Invention enclosed
in an iron sheath, so that when the electricity passes through the lamp, this
sheath becomes magnetic and attracts a spring armature, a stud on which bearing.
against the moveable carbon pushes it away from the other carbon to the distance
suitable for maintaining the voltaic are between the points of the two carbons.
Both carbons may be gradually advanced by clock work as they are consumed, so

page_text: as to keep the are between their luminous points stationary. When there are a
number of pairs of carbons arranged in one lamp they are brought successively
into action in the following manner:-One carbon of each pair is pressed by a
spring against a stud of fusible metal near its root. The other carbon of each
pair is jointed to a lever connected to the armature of an electro-magnet in the
lamp circuit, which magnet may be an iron sheath covering part of the electrical
loop surrounding the carbons. When the lamp is out of circuit, the armature
being then free, all the carbons connected to it bear with their points each against
the point of its neighbouring carbon. When the lamp is put in circuit, one or other
of the pairs of carbons becomes kindled, and immediately the armature is attracted
so that the carbons are all separated each from the other of its pair. The carbons
of the one pair kindled go on burning, the other pairs all remaining inert, and
when the are of the burning pair approaches their root, the fusible stud against
which one of them bears is melted, and the spring then pushes the carbon away
from the other, so that the electrical circuit is broken. The armature thereupon
leaving the electro-magnet again brings all the remaining pairs of carbons into
contact at their points, and thus another of the pairs becomes kindled. The
carbons of this pair when consumed are in their turn separated, those of another
pair are kindled, and so on successively till all the carbons are consumed. The
successive extinctions and rekindlings above described being almost instantaneous,
the light is practically continuous. When several lamps are in the same circuit,
the conductors to them are so arranged that if one should be extinguished the
general circuit will nevertheless be maintained in the following manner:-The
main conductor instead of being led directly to each lamp divides into two branches.
One branch passes through the coil of an electro-magnet through the lamp and
back to the main conductor beyond the magnet. The other branch passes through
the armature of the electro-magnet, a contact, a resistance about equivalent to that
of the lamp and back to the main conductor. When the lamp is in action all the
electricity passes through it and the coil of the electromagnet, the armature of the
latter being attracted away from the contact, so that none of the electricity passes
through the resistance; but should the lamp be extinguished so that no electricity
can pass through the coil of the electro-magnet; the armaturo being left free makes
contact so that the electricity passes through the resistance to the main conductor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 24th
July 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. " IMPROVEMENTS IN ELECTRIC LAMPS." A communi-
cation from abroad by the Compagnie Générale d'Eclairage Electrique of Paris,
Franco, an Incorporated Company.
In the Specification to Letters Patent granted to me on the 4th March 1879,
No. S63, for an Invention communicated to me from abroad by J. C. Jamin,
was described a form of electric lamp in which the two carbons are placed
side by side at a little distance apart within an electrical loop, so that the voltaic
are is formed between their points. The present Invention relates to electric lamps
of this kind, and consists in providing means whereby such a lamp is kindled when
it is brought into circuit, and becomes excluded from the circuit when its carbons
are consumed, also when there are several sets of carbons in a lamp, those of one
pair become kindled, and when they are consumed those of another pair become
kindled, and so on successively, and when the circuit in the lamp itself is broken by
accidental extinction or otherwise, the general circuit is nevertheless maintained
without affecting other lamps with which it may be connected. For this purpose
one of each pair of carbons is held in a socket hinged to the framing and so loaded
that when left free the carbon becomes inclined till its point bears against the
point of the other carbon, permitting passage of electricity so as to kindle the
carbons; but the electrical loop within which the carbons are enclosed, as described.
in the Specification above referred to, is according to the present Invention enclosed
in an iron sheath, so that when the electricity passes through the lamp this sheath
becomes magnetic and attracts a spring armature, a stud on which bearing against
the moveable carbon pushes it away from the other carbon to the distance suitablo
for maintaining the voltaic are between the points of the two carbons. Both
carbons may be gradually advanced by clock work as they are consumed, so as to
keep the arc between their luminous points stationary. When there are a number of
pairs of carbons arranged in one lamp they are brought successively into action in
the following manner:- -One carbon of each pair is pressed by a spring against a
stud (which may be of fusible metal) near its root. The other carbon of each pair
is jointed to a lever connected to the armature of an electro-magnet in the lamp
circuit, which magnet may be an iron sheath, covering part of the electrical loop
surrounding the carbons. When the lamp is out of circuit, the armature being
then free, all the carbons connected to it bear with their points each against the
point of its neighbouring carbon. When the lamp is put in circuit, one or other of
the pairs of carbons becomes kindled and immediately the armature is attracted, so
that the carbons are all separated each from the other of its pair. The carbons of
the one pair kindled go on burning, the other pairs all remaining inert, and when
the arc of the burning pair approaches their root, the stud against which one of
them bears ceases to support it, and the spring then pushes the carbon away from
the other, so that the electrical circuit is broken. The armature thereupon leaving
the electro-magnet again brings all the remaining pairs of carbons into contact at
their points, and thus another of the pairs becomes kindled. The carbons of this
pair when consumed are in their turn separated, those of another pair kindled,
and so on successively, till all the carbons are consumed. The successive extinctions
and rekindlings above described being almost instantaneous, the light is practically
continuous. When several lamps are in the same circuit, the conductors to them
are so arranged that if one should be extinguished the general circuit will never-
theless be maintained in the following manner :-The main conductor instead of
being led directly to each lamp, divides into two branches. One branch passes
3

page_text: through the coil of an electro-magnet, through the lamp and back to the main
conductor beyond the magnet. The other branch passes through the armature of
the electro-magnet, a contact, a resistance about equivalent to that of the lamp and
back to the main conductor. When the lamp is in action, all the electricity passes
through it, and the coil of the electro-magnet, the armature of the latter being 5
attracted away from the contact, so that none of the electricity passes through the
resistance; but should the lamp be extinguished so that no electricity can pass
through the coil of the electro-magnet, the armature being left free makes contact
so that the electricity passes through the resistance to the main conductor.
Abel's Improvements in Electric Lamps.
through the coil of an electro-magnet, through the lamp and back to the main
conductor beyond the magnet. The other branch passes through the armature of
the electro-magnet, a contact, a resistance about equivalent to that of the lamp and
back to the main conductor. When the lamp is in action, all the electricity passes
through it, and the coil of the electro-magnet, the armature of the latter being
attracted away from the contact, so that none of the electricity passes through the
resistance; but should the lamp be extinguished so that no electricity can pass
through the coil of the electro-magnet, the armature being left free makes contact
so that the electricity passes through the resistance to the main conductor.
DESCRIPTION OF THE DRAWINGS.
Fig. 4 shews an arrangement for kindling a pair of carbons y, y', and then
separating them so that they hang parallel with the voltaic are at their points.
F, G, H, is an iron sheath containing the directing electrical coil, and having
at its side a spring armature K, L, from which a stud L, M, extends to the
carbon y. The carbons are held in sockets E which may be suspended within a
framing A, B, C, D, from a barrel H¹ governed by clock work, so that the carbons
descend as they are consumed maintaining the arc at their points in nearly a
constant position. Before the lamp is put in circuit the carbons hang, as shewn,
with their points in contact, and when a current is sent through them the arc is
started at their points. The current at the same time renders the sheath F, G, H,
magnetic, the armature K, L, is attracted, and the stud L, M, pushes the carbon y¹
away from y to take a position parallel to it. The arc is afterwards retained at the
points of the carbons by the directing influence of the coil within the sheath. Fig. 5
shews a similar arrangement applied to two pairs of carbons, one of each of which
is held in a socket C, D, pivotted at O.
·
Figs. 1, 2, and 3, shew respectively a side view, a vertical cross section, and a
plan of a lamp having a number of pairs of carbons (three pairs being shewn)
arranged so that one or other of the pairs shall be kindled, and when that pair is
consumed another pair shall be kindled, and so on successively. The directing loop
consisting of a number of convolutions of insulated wire or thin metal_strip is
enclosed in a sheath F, G, H, and at its upper part there is an iron sheath T. The
carbons y, y, are held in sockets, one of each pair y having its socket a pivotted
at b to a metal plate N fixed to a non conducting base O. The other carbon y' of
each pair has its sockot e pivotted to a plate above O, and its socket extends
upwards and is attached by a pin to a bar foxtending horizontally from the arm g
of a bell crank levor, the other arm h of which is the armature to the electro-
magnet T. A spring acting against a pin on the socket a of each carbon y
presses it against a stud c on a bar & projecting down from the plate N. While the
lamp is out of circuit the carbons hang as shewn, meeting at their points. When
the lamp is put in circuit the voltaic arc will be started at the points of one or
other of the pairs, and immediately the sheath T becoming magnetic will attract
its armature h, which pushing the bar f to the right will cause the carbons y¹ to
separate from the carbons y. Tho are started on one of the pairs of carbons will be
maintained at their points by the directing influence of the loop, and as the other
carbons are kept apart no are will be started on them. When a pair of carbons
are so far consumed that the stud c (which may be of fusible metal) no longer
supports the carbon y which bears against it, that carbon is pressed aside by the
spring r, as shown in respect of the right hand carbon in Fig. 1. The current being
thus interrupted the armature will descend, permitting the carbons of the
remaining pairs to meet again at their points, whereupon a fresh are will be started,
and so on successively till all the carbons are consumed.
When several lamps aro in one circuit the arrangement shewn at Fig. 6 is
employed to prevent interruption of the current through the general circuit when
it is interrupted by the oxtinction of any one of the lamps. R and S are two
points in the general conductor; L, wires connecting it to one of the lamps; Q is

page_text: an electro-magnet having an armature & resting on a contact U, which is connected
to S through a resistance equivalent to that of a lamp. When a current is
transmitted through R part goes through k, U to S, and part through the coil of Q
to the lamp and back to S; but the armature being immediately attracted breaks
contact at U, so that the whole current goes to the lamp. Should the current of
the lamp be stopped, the armature k being no longer attracted will drop making
contact at U, and the current then passes directly to S and through the general
circuit.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondents, I
claim in respect of electric lamps,-
First. Effecting the separation of the carbon points after kindling by means of
an armature attracted to an iron sheathing of the directing coil, which is rendered
magnetic by the passage of the lamp current, substantially as herein described.
Second. Effecting separation of the carbons when they are nearly consumed by
pressing one of them against a stud near its root, so that when it is no longer
supported by the stud it is pushed away from the other carbon, substantially as
herein described with reference to Figs. 1 and 3 of the accompanying Drawings.
Third. The arrangement described with reference to Fig. 6 for maintaining the
O general circuit when there is a breach of circuit through any lamp connected to the
general circuit.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Twenty fourth day of July, in the year of our Lord One
thousand eight hundred and e