IMPROVEMENTS IN AND CONNECTED WITH ELECTRIC LIGHT APPARATUS OR LAMPS
Year: 1879

page_text: LETTERS PATENT to Alfred Longsdon, of Queen Victoria Street, in the City of
25
London, for the Invention of IMPROVEMENTS IN AND CONNECTED WITH
ELECTRIC LIGHT APPARATUS OR LAMPS." A communication from abroad by
Alfred Krupp, of Essen, in the Empire of Germany, Cast Steel Manufacturer.
PROVISIONAL SPECIFICATION left by the said Alfred Longsdon at the
Office of the Commissioners of Patents on the 16th May 1879.
"
ALFRED LONGSDON, of Queen Victoria Street, in the City of London. IM-
PROVEMENTS IN AND CONNECTED WITH ELECTRIC LIGHT APPARATUS OR LAMPS." (A
communication from abroad by Alfred Krupp, of Essen, in the Empire of Germany,
Cast Steel Manufacturer.)
The main object of this Invention is to ensure a suitable automatic periodical
regulation of the distance of the carbon points or other electrodes used in electric
lamps. The regulation according to this Invention is such that the upper carbon
descends while the lower carbon ascends, so that the voltaic arc keeps the same
position, all as hereinafter described.
The core of an electro magnet is connected to a lever which is connected to the
lower carbon holder, and also by rod or other connections to a clamping or pinching
appliance or holder for the upper carbon. A spring in connection with the lever is
so arranged as to counteract the force of the electro magnet. When the circuit is
complete and the carbon points close together the lower carbon is by the electro
magnet drawn down and the upper carbon held fast by its clamp or holder, which
may be an electro magnet or an incline piece acting against a peg, or cam, or piece
which presses against the upper carbon or its holder, a helical spring tending to
force the peg back. The voltaic light are now appears in its full power, but as the
carbons are consumed the current is weakened; the spring at last becomes more
powerful than the electro magnet, and lifts the lever with the lower carbon, at the

page_text: same time the grip on the upper carbon or its holder is released, so that the carbon
drops upon the lower carbon; the current is thereby again strengthened, so that the
electro magnet overpowers the spring and draws the lower carbon down, at the same
time gripping the upper carbon or its holder.
This arrangement can be used for any kind of currents, and several of these
lamps can be placed in one circuit. The regulation takes place about every three
minutes, and is so quick that it is imperceptible. Not only is the regulation itself
imperceptible to the human eye, but in the intervals between each regulation the
light remains practically the same, though the electric current is weakened as the
carbons are consumed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Longsdon in the Great Seal Patent Office on the 15th
November 1879..
"IM-
ALFRED LONGSDON, of Queen Victoria Street, in the City of London.
PROVEMENTS IN AND CONNECTED WITH ELECTRIC LIGHT APPARATUS OR LAMPS." (A
communication from abroad by Alfred. Krupp, of Essen, in the. Empire of Germany,
Cast Steel Manufacturer.)
The main object of this Invention is to ensure a suitable automatic periodical
regulation of the distance of the carbon points or other electrodes used in electric
lamps. The regulation according to this Invention is such that the upper carbon
descends while the lower carbon ascends, so that the voltaic arc keeps the same
position, all as hereinafter described.
The core of an electro magnet is connected to a lever which is connected to the
lower carbon holder, and also by rod or other connections to a clamping or pinching
appliance or holder for the upper carbon. A spring in connection with the lever is
so arranged as to counteract the force of the electro-magnet. When the circuit is
complete and the carbon points close together the lower carbon is by the electro-
magnet drawn down and the upper carbon held fast by its clamp or holder, which
may be an electro-magnet or an incline piece acting against a peg, or cam, or piece
which presses against the upper carbon or its holder, a helical spring tending to
force the peg back. The voltaic light are now appears in its full power, but as the
carbons are consumed the current is weakened; the spring at last becomes more
powerful than the electro-magnet, and lifts the lever with the lower carbon, at the
same time the grip on the upper carbon or its holder is released, so that the carbon
drops upon the lower carbon; the current is thereby again strengthened so that the
electro-magnet overpowers the spring and draws the lower carbon down, at the same
time gripping the upper carbon or its holder.
This arrangement can be used for any kind of currents, and several of these
lamps can be placed in one circuit. The regulation takes place about every three
minutes, and is so quick that it is imperceptible. Not only is the regulation itself
imperceptible to the human eye, but in the intervals between each regulation the
light remains practically the same, though the electric current is weakened as the
carbons are consumed.
And in order that this Invention may be more fully understood I will proceed to
describe the same with reference to the accompanying Drawings.
In Figure 1 d is the core of an electro-magnet c; it is jointed to the lever e, which
has its fulcrum in the casing A, and is held by a short link e' connected to the
holder b for the lower carbon; the lever e is by the rod n connected to a clamp o in
connection with the holder a for the upper carbon; the clamp o with one inclined
side acts on a peg 9, when it is pulled down by the rod n, the spring holding it
against the peg 9; this action takes place when the circuit is complete, and the
carbon points within a very short distance of each other, the electro-magnet c
attracting the core d and pulling down the rod n. The voltaic are now appears, but
as the carbons are consumed the current is weakened so much that the spring / at
last becomes stronger than the electro-magnet, and pushes the lever e and rod n up;
the helical spring under the head of the peg q will then push the said peg away
from the upper carbon, allowing it to drop; the current will now be strengthened
again, so that the electro-magnet overpowers the spring h, and pulls the lower
carbon down, whereby the lever e, rod n, and clamp o will be pulled down also, and
the clamp o grip the upper carbon again.
Figure 2 shows another arrangement of parts in which an electro-magnet o
forms the clamping appliance. As long as the current is strong enough the arma-
ture levert will be attracted by the electro-magnet o, and the peg 9 hold the

page_text: upper carbon, but when the current becomes weakened by the burning away of
the carbon points the spring p will pull the lever t away from the electro-magnet,
and the peg q will release its hold on the upper carbon, and allow the same to
drop.
Figure 3 shows another kind of holder for the upper, carbon; it consists of four
guide rollers set in a frame; the clamping appliance is a peg q, as before, which may
be actuated in one of the two modes above described.
Figure 4 shews a clamping peg p jointed to a cam p³, or piece having its fulcrum
at the other end.
And having thus described and ascertained the nature of this Invention, I declare
that I claim,-
Arranging an electro-magnet core in combination with a lever connected to the
lower carbon or carbon holder for retaining the latter and a spring for raising it, the
upper carbon or carbon holder being simultaneously retained by a clamping appliance
or released therefrom, substantially as described and shown.
In witness whereof, I, the said Alfred Longsdon, have hereunto set my hand
and seal, this 30th day of October, in the year of our Lord One thousand
eight hundred and seventy nine.
ALFRED LONGSDON. (L.S.)