IMPROVEMENTS IN ELECTRIC LIGHT APPARATUS
Year: 1878

page_text: LETTERS PATENT to Alfred Longsdon, of Queen Victoria Street, in the City of
London, England, but temporarily of Paris, France, for the Invention of
IMPROVEMENTS IN ELECTRIC LIGHT APPARATUS." A communication by
Alfred Krupp, of Essen, Germany.
Sealed the 10th December 1878, and dated the 28th September 1878.
PROVISIONAL SPECIFICATION left by the said Alfred Longsdon at the
Office of the Commissioners of Patents on the 28th September 1878.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, England, but
temporarily of Paris, France. "IMPROVEMENTS IN ELECTRIC LIGHT APPARATUS."
(A communication from Alfred Krupp, of Essen, Germany).
The primary object of this Invention is to automatically regulate the position of
the carbons of an electric light apparatus without abandoning the generally
acknowledged conditions on which the precision of motion of the single parts
depend.
The Invention refers to,-
First. The application of a brake for the self-acting regulation of the distance
between the two carbons.
Second. The application of a flying pinion revolving in quicksilver for regulating
the motion of the carbon holders as a substitute for wheelwork.
Third. The application of a magnetic spiral with an iron casing and iron bottom
for the purpose of moving a brake.
Fourth. The application of parts as hereafter described to an electric lamp in
combination with fixed lower carbon holder.
The carbon holders are each suspended by chains or cords from a disc. The
disc from which the upper positive carbon holder hangs is twice as large as the
other disc of the negative holder. The chains or cords are applied to the discs in
such a manner that when the upper holder goes down by its weight the lower
holder is thereby caused to rise, and as the latter only rises half the way the other
is descending, it results that the light always occupies the same spot in the room.
rD...All

page_text: This
As the weight of the upper holder in order to prevent the motion of samo from
being easily influenced by dust and so forth must not be too small, it is necessary
to provide an appliance for regulating and slackening the course of this bar.
is obtained through a flyer wheel revolving in quicksilver or some other suitable
liquid; on the axis of the flyer is a wheel which gears into a cog wheel on the axis
of the discs. In order to prevent the flyer making also a retrograde movement when
new carbons are put in, the cog wheel is provided with a ratchet wheel. The
fixing and regulating of the right distance of the carbons is done in the following
manner :-
On the axis of the discs aforesaid and the cog wheel there is another disc, and on
this latter acts a peculiarly constructed brake; this consists of two parts which are
connected by a link. In the lower part which turns on the common axis is bored
a hole in which a pin takes, a certain amount of play being allowed for same,
thus
limiting the retrograde movement of that part of the brake. At the upper arm of
the brake is applied a brake block, and at the other end an anchor of an electro-
magnetic spiral hangs down on a brass bar. If the lamp is put to work the anchor
is drawn into the spiral whereby the brake block is pressed on the brake disc, and
in its further advance drives same backwards as far as the regulating screw permits.
By this means the upper carbon is raised and the lower one lowered, and the light
appears. The carbon is gradually consumed, the current grows weaker and its
effect on the electro-magnet gradually relaxes. The brake assisted by its spring
(the action of which can be regulated through lever and regulating screw in
accordance with the power of the current), and through the weight of the carbon
holders slowly moves backwards, causing thereby the brake disc to move forward
and the carbon holders to approach each other. This movement being completed
thus far, as the brake disc has been previously turned back, the lower part of the
brake bears against its pin, in consequence of which, if the current continues
growing weaker, the brake turns in the link, the brake block releases the brake
disc, and the carbons approach each other; the current is thereby strengthened and
the brake again takes on to the brake disc, either holding same fast if the carbons
are in the right position, or fetching it back if they stand too near each other. If
the carbons are to be exchanged for new ones the brake is fixed by the regulating
screw and the work is stopped thereby.
The electro-magnetic spiral stands on the iron bed plate of the lamp and is
surrounded by an iron cylinder, increasing thereby its attraction on the anchor.
The advantage of this lamp over such of other construction consists in its
simplicity and consequently also in its cheapness. It has no wheelwork, no con-
tacts, is not subject to wear, and so regulates the position of the carbons that they
always produce the greatest possible effect of light without allowing sanie to fluc-
tuate. As in many cases the electric lamp is used without a concave mirror, and
it is therefore unnecessary to keep the point of light always in the same spot, the
lamp can be so simplified that the movable parts of the lower carbon holder are
left out and the latter thus made immovable.

page_text: 1879.
ALFRED LONGSDON, of Queen Victoria Street, in the City of London, England,
but temporarily of Paris, France. "IMPROVEMENTS IN ELECTRIC LIGHT APPARATUS."
A. communication from Alfred Krupp, of Essen, Germany.
The main object of this Invention is to automatically regulate the positions of
the carbons of an electric lamp in a simpler manner than heretofore without
abandoning the generally acknowledged conditions on which the precision of motion
of the single parts depend.
The Invention refers to,-
The application of a brake appliance for the automatic regulation of the distance
between the two carbon points.
The application of a fan or fly revolving in quicksilver or other liquid for
regulating the motion of the carbon holder as a substitute for clockwork.
The application of a magnet coil with iron casing and iron bottom for the motion
of the brake appliance, and
The application of the above-named parts in an electric lamp with stationary
lower carbon holder.
· And in order that the Invention may be fully understood I will now proceed
to describe the same with reference to the accompanying Sheet of Drawings, of
which Figure 1 is a side elevation, and Figure 2 a front elevation of an electric
lamp constructed according to this Invention.
a is the holder for the upper positive carbon, and b the holder for the lower
negative carbon. The holder a is by a jointed chain or a wire attached to and
suspended from a disc or pulley c, and the holder 6 similarly to a disc or pulley d;
the disc d is half the size of the disc c. The chains or wires are so passed round
the pulleys that when the holder a descends a certain distance by its weight the
other holder b ascends to half the distance. Hereby the result is obtained that the
light from the electric arc formed between the carbon points always occupies the
same place in the room or other space..
As the weight of the upper holder a must not be too small because its motion
would then be easily influenced by dust and dirt, it is neesssary to have an
appliance for retarding and regulating its course or travel.
For this purpose a fly or fan e is applied which revolves in mercury or other
liquid; on the spindle of this fly there is a pinion f which gears with a tooth wheel
g on the spindle x of the aforesaid chain pulleys c and d..
In order that the fly e by the insertion of a fresh carbon should not have to
revolve backwards, the tooth wheel g is fitted with a pawl wheel h. The setting and
regulating of the proper distance between the carbon points is done in the following
manner- -On the same spindle x as the pulleys c and d and tooth wheeled g, there is
a disc i as shewn in the separate view, Figure 3. Figure 4 is a separate view of a
brake of a peculiar form acting on this disc i. The brake consists of two parts k
and m, which are jointed together at ; the lower part m can turn on the spindle
x, and has a hole m¹ in which is inserted a small peg n, Figures 1 and 2; the peg
n has much play in the hole, and the backward motion of the brake is limited
thereby o is a brake block on the upper part k of the brake; p is the keeper for
an electro-magnetic coil q; this keeper is by a brass rod suspended from the other
end of the part k.
When the lamp is in action the keeper p is drawn into the coil q, whereby the
brake block o is pressed against the disc i, turning the latter in its further move-
ment downwards, that is, so far as the set screw r, Figure 1, will allow. Hereby the
upper carbon points will be raised and the lower carbon points lowered, and the
electric are then makes its appearance. The carbon points now gradually consume

page_text: away, the current becomes weaker, and its effect on the electro-magnet q is lessened.
The brake k supported by the spring s (the action of which can be suitably
regulated in proportion to the strength of the current by means of the lever u and
set screw v), and by the weight of the carbon holder moves slowly back, and
thereby the brake disc i is enabled to turn forward and the carbon points can
approach each other. When this movement has proceeded as far as the brake
disc i moved back before, then the lower part of the brake comes to bear against
the peg n; by the further weakening of the current the brake will now turn in its
joint at 1, the brake block' o releases the disc i, and the carbon points move towards
each other, thereby the current is strengthened and the brake is again applied to
the disc either simply to hold it when the carbon points are in their right position,
or to pull it back when the carbon points are too close together.
When inserting new carbons the brake is fixed by the set screw w, and the work
is arrested thereby.
The electro-magnetic coil q rests on the bed plate t of the lamp and is surrounded
by an iron casing, whereby its power of attraction to the keeper is increased.
The advantages of this lamp as compared with others are comprised in its
simplicity, and hence cheapness, there are neither wheelwork nor contacts, it is
not exposed to wear, and the carbon points are so regulated that the greatest light
is obtained constantly and without fluctuation.
As in many cases the electric lamp is used without concave mirror reflector, and
it is then not requisite always to keep the light in the same place, the lamp may
be simplified by leaving out the moving parts for the lower carbon holder, making
it fixed instead of movable.
Having now described the nature of the said Invention and in what manner the
same is to be performed, I declare that I claim as the aforesaid improvements in
electric light apparatus,-
Firstly. The application of a brake appliance for the automatic regulation of
the distance between the carbon points, substantially as herein described and
shewn.
Secondly. The application of a fan revolving in mercury or other liquid for
regulating the movement of the carbon holder as a substitute for clockwork,
substantially as set forth.
Thirdly. The application for moving the brake appliance of an electro-magnet
arranged and constructed, substantially as herein described and shewn, and
Fourthly. The application of parts herein-before claimed in an electric lamp with
stationary lower carbon holder.
In witness whereof, I, the said Alfred Longsdon, have hereunto set my hand and
seal, this Fifth day of February, in the year of our Lord One thousand
eight hundred and seventy-nine.
ALFRED LONGSDON. (L.S.)