IMPROVEMENT IN ELECTRIC ARC LAMPS
Year: 1885

page_text: I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said invention for IMPROVEMENT IN
ELECTRIC ARC LAMPS, a communication to me from abroad by Richard Walther
and Bernhard Hugo Walther, Manufacturers, of Werdau, in the German Empire,
to be as follows:-
This improvement relates to electric arc lamps and has for its object the simple
and effective regulation of the carbons.
The carbons are regulated directly by the main current and so, that one or two
solenoid cores are influenced by the current, so as to be more or less attracted and
thereby recede more or less into the bobbin or protrude from the same for the
purpose of acting by this movement on a lever mechanism, which lifts or lowers
the carbon holder by friction.
Beside this lever, influenced by the solenoids, the latter are armed with a
magnetic brake, serving to prevent the solenoid cores from falling out too easily.
This brake consists of two iron pieces, placed at a small distance from the
solenoid cores for the purpose of retarding the motion in a certain degree by
magnetic attraction.
The iron pieces can be put more or less close to the solenoid cores by means of a
suitable adjusting device, so as to cause the magnetic brake to act with more or
less power. The two branches of the main current pass through the solenoids, are
subsequently united and let through the carbon holder rod to the upper carbon,
where the current leaps over to the lower carbon and then leaves the lamp. The
current effects the regulation of the arc by attracting the solenoid cores and moving
a link or lever, acting in combination with the magnetic brake, which acts, by the
more or less strong attractive force of the solenoid cores on the iron pieces
mentioned above.
When the lamp is lighted, the carbon points are at first in contact with cach
other; by the current, acting on the solenoid cores, these are pulled into the
bobbins and, by means of the suspended link, mentioned above, acting on a hinged
tongue of the brake lever, the upper carbon holder is lifted by clipping, until the
carbon points have normal distance from each other.

page_text: By the carbons being consumed and the current diminished, the solenoid cores
fall down; the tongue releases the carbon holder, so that the latter drops downward.
This successive sinking takes place imperceptibly.
The solenoid cores move freely in the bobbin, and their downward motion is
effected by the adjustable brake in such a manner, that the attraction of the cores
by the current is exactly proportional to the normal strength of current.
The current, which may either pass through one bobbin only, or be divided into
two branches, acting on two bobbins, therefore regulates the arc surely and correctly
without the use of a shunt current. The lamp may be constructed for various
purposes with a stationary or changeable focus.
The upper carbon is thus clipped between a pair of tongues, one of which is
hinged to the free end of the brake lever and influenced by the link, suspended
from the armature of the solenoid or solenoids, while the other is pivoted on the
axis of the brake lever, so that the two tongues are nearly symmetrical to the
carbon holder, and their free ends in contact with the same.
I, HERBERT JOHN HADDAN of 67 Strand in the County of Middlesex Civil
Engineer do hereby declare the nature of this invention, a communication to me
from abroad by Richard Walther and Bernhard Hugo Walther, of Werdau, in the
German Empire, Manufacturers and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
This improvement relates to arc lamps and has for its object the simple and
effective regulation of the carbons.
For this purpose, as shown by the annexed drawings Figs. 1 to 6. The carbons
are regulated directly by the main current by means of one or two solonoid cores
which are influenced by the current, so as to be more or less attracted, and thereby
recede more or less into the bobbin or protrude from the same for the purpose of
acting by this movement on a lever mechanism h. i. k. which lifts or lowers the
carbon holder by clipping friction..
In this lever mechanism the upper carbon is clipped between a pair of
tongues i one of which i is hinged to the free end of the brake lever. and
influenced by the link suspended from the armature of the solenoid or solenoids,
while the other k is pivoted on the axis of the brake lever, so that the two tongues
are nearly symmetrical to the carbon holder and their free ends in contact with
the same,

page_text: . Besides this lever influenced by the solenoids, the latter are armed with a
magnetic brake E serving to prevent the solenoid cores from falling out too easily.
This brake consists of two iron pieces e and f. placed at a small distance from the
solenoid cores a and b for the purpose of retarding their motion to a certain degree
by magnetic attraction.
The iron pieces can be put more or less close to the solenoid cores by means of a
suitable adjusting device so as to cause the magnetic brake to act with more or
less power. The two branches of the main current pass through the solenoids A. B.
and are subsequently united at d and led through the carbon holder rod C to the
upper carbon where the current leaps over to the lower carbon and then leaves the
lamp at g.
The current effects the regulation of the arc by attracting the solenoid cores and
moving the link or lever acting in combination with the magnetic brake, which
acts by the more or less strong attracting force of the solenoid cores a. b on the
iron pieces e. f.
When the lamp is lighted the carbon points are at first in contact with each
other; by the current acting on the solenoid cores, the latter are pulled into the
bobbins and by means of the suspended link h acting on the hinged tongue i of
the lever the upper carbon holder is lifted by clipping until the carbon points
have attained a normal distance from each other.
As the carbons are consumed and the current diminished, the solenoid cores fall
down; the tongue i releases the carbon holder c so that the latter drops downward.
This successive sinking takes place smoothly and imperceptibly.
The solenoid cores move freely in the bobbin and their downward motion is
effected by the adjustable brake E in such a manner that the attraction of the
cores by the current is exactly proportional to the normal strength of current.
The current which may either pass through one bobbin only, or be divided into
two branches acting on two bobbins, therefore regulates the arc surely and correctly,
without the use of a shunt current.
The lamp may be constructed for various purposes, with a stationary or
changeable light focus.
With this lamp, however, if it is constructed for stationary carbon arcs the
inconvenience arises that when the carbons are completely burned away the current
proceeds directly to the lower carbon holder without being utilized which is very
detrimental to the lamp.
To obviate this drawback an arrangement shown by figs. 5 and 6 serves to
automatically exclude the lamp from the circuit when the lower carbon has nearly
burned down.
The lower carbon is contained in a tube in which is placed the helical spring m
which raises the carbon by means of the rod n, as required The rod n is furnished
with a collar o which when the lower carbon is burned down to a very short piece
turns the two-armed lever p. p' about its fulcrum g. into the position shown in
Fig. 6.
The longer arm p¹ of the lever, is in its normal state in contact with the
spring r.
After the current has entered the upper part of the lamp and proceeded from the
upper to the lower carbon it passes through the lower carbon holder to the.
lever p. p whence it continues through the spring r fixed to the support 8, from
which spring the current leaves the lamp through a suitable conducting device.
When the spring ? is disconnected from the lever p. p¹ by turning the lever into
the position shown in fig. 6., the curcuit is interrupted and the lamp extinguished
until fresh carbons are introduced when the lever p. p' is again raised.
The lower carbon holder is secured to the lamp plate by the support s but is
insulated therefrom.
To allow the lamp to be made smaller for use in low rooms, or the like in this
construction the lever system h. i. k. for regulating the carbon are act directly on
the upper carbon, which is moved downward thereby in a tube.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is;
1.) In electric are lamps the device for regulating the movement of the carbon
points by means of the main current, consisting of one or more solenoids A. B
traversed by the main current, and serving to attract the cores a. b provided with
the magnetic brake E-e. f., and thereby control a lever mechanism consisting of
lever k tongue i for the purpose of automatically causing the carbon points to
approach to, or recede from each other as required.
2.) The regulating magnetic brake consisting of adjustable iron pieces e. f. which
serve by the current in the solenoids to restrain more or less, the movement of the
cores a. b.
3.) In an electric arc lamp, the automatic isolating or current breaking device,
consisting of a rod n provided with collar o and raised by a helical spring m, which
when the carbon is perfectly burnt down, brings the lever p p¹ out of contact with
a spring r and thus breaks the electrical circuit.