Improvements in Automatic Cut-outs for Arc Electric Lamps.
Year: 1898

page_text: Date of Application, 21st Feb., 1898
Complete Specification Left, 21st Nov., 1898-Accepted, 11th Feb., 1899
Improvements in Automatic Cut-outs for Arc Electric Lamps.
We, GUSTAV BYNG, of 69-71-88, Queen Victoria Street, in the City and County of
London, Electrical Engineer, and ARTHUR ERNEST ANGOLD, of Peel Works, Salford, in
the County of Lancaster, Electrician, do hereby declare the nature of this invention
to be as follows:-
Our invention relates to an automatic cut out for are electric lamps, and has for
its object the safe-guarding of the shunt coils and carbon holders when said lamps
are worked upon circuits having a higher electro motive force than the shunt coils
will stand without being overheated. The ordinary carbons are not uniform in the
rate of consumption, and therefore it is necessary to protect a series of lamps
individually, so that the first having the carbons consumed does not have the fuil
E.M.F. maintained across its shunt coil. When arc electric lamps are placed in a
circuit of an E.M.F. exceeding 150 volts the are flares considerably before it breaks,
and unless the stumps of the carbons are long, the holders will be damaged by the
excessive heat.
Our invention consists of an automatic switch actuated by the regulating mechanism
of the lamp and is arranged to break the circuit through the shunt coil when an
excessive EM.F. is maintained between the carbons. The same action also short
circuits the arc, and by reducing the voltage across the terminals, puts it out. These
movements of the cut out device take place while the armature of the regulating
mechanism is below the feeding point, and do not interfere with the working of the
lamp. To ensure a quick "make" and "break" we affix an insulated carbon con-
tact on an arm or lever which is pivotted near to its lower extremity, and is
sufficiently free upon its axis as to fall in either direction so as to engage with either
one of two fixed contacts. One of said contacts is fixed to and electrically connected
to the lamp frame, and the other is insulated and connected to the end of the shunt
coil. A flexible wire, or like conductor connects the pivotted switch arın to one of
the lamp terminals. In its normal position the carbon contact upon the pivotted
lever rests upon the terminal end of the shunt coil. Upon the pivot or spindle of the
switch or contact arm, a counterweight is fixed, and also a crank or like connection
coupling it with the feeding mechanism of the lamp, so that the contact between
said switch arın and the end of the shunt coil is broken when the E.M F. across the
shunt coil becomes large enough to endanger it. The saine movement causes the
contact to be transferred to the lamp frame, thus cutting out the shunt coils, carbon
holders, and all other parts subject to damage. This, however, is only a momentary
action, because the armature of the lamp being relieved of its downward pull, at once
rises, and replaces the switch arm. The momentary shorting" of the arc reduces
its voltage sufficiently to break it, and when the switch arm is thrown back by the
armature the circuit is entirely broken by reason of a pivotted catch actuated by the
series coil, said catch being magnetically withdrawn when the main armature is at or
above its feeding point. When the carbons are replenished, and the action of the
series coil withdraws the catch, the switch arm again establishes the shunt circuit
and the mechanism is under normal conditions. The counter weight and switch arm

page_text: are arranged so that they are only moved over the dead point in each action, in order
to get a quick make and break.
We may also place in close proximity to a coil or conductor on the main circuit,
a fuse strip of bismuth alloy or the like, in which the degree of fusion is lower than
that of the coils of the arc lamp, lamps or dynamo within the same circuit. We
may term this a "temperature fuse" since it is not actuated by an electrical current
passing through it, but by contiguity with a coil or conductor. The temperature
affects the fuse by radiation, and therefore is not sufficiently sensitive to break the
circuit with a momentary impulse or increase of current, unless this is sustained for
an appreciable length of time, the circuit being broken by rupture of the fuse before
the dynamo or other apparatus could be damaged.
Dated this 18th day of lubruary 1808
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicants.
Improvements in Automatic Cut-outs for Arc Electric Lamps.
We, GUSTAV BYNG, of 69-71-83, Queen Victoria Street, in the City and County
of London, Electrical Engineer, and ARTHUR ERNEST ANGOLD, of Peel Works,
Salford, in the County of Lancaster, Electrician, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our invention relates to an automatic cut out for are electric lamps, and has for
its object the safe guarding of the shunt coils and carbon holders when said lamps
are worked upon eircuits having a higher potential than the shunt coils will stand
without being overheated. The ordinary carbons are not uniform in the rate of con-
sumption and therefore it is necessary to protect a group of lamps in series, indi-
vidually, so that the first having the carbon consumed does not have the full E.M.F.
maintained through its shunt coils. When arc electric lamps are placed in a circuit
having an E.M.F. exceeding 150 volts, the are "flares" considerably before it breaks
and unless the stumps of the carbons are long, the holders will be damaged by the
excessive heat.
Our invention consists of an automatic switch directly actuated by the regulating
mechanism of the lamp, of whatsoever type that may be, and is arranged to break
the circuit through the shunt coil when an excessive E.M.F. is maintained between
the carbons. The same action also shortcircuits the arc, and by reducing the voltage
across the terminals, puts it out. These movements of the cutout device take place,
while the armature of the regulating mechanism (of any type) is below the feeding
point, and do not interfere with the working of the lamp.
In order that our invention may be clearly understood we have, appended the
accompanying two sheets of drawings in which Figure 1 is an elevation of the
switch device, and Figure 2 an end view of the same with contact B removed, and
contact Cnot shown, for clearness. Figures 3 and 4, Sheet 2, are diagrams illus-
trating the circuits through the lamp under varying conditions. Similar letters of
reference indicate corresponding parts in the several views, and in the diagrams
Sheet 2 where appplicable.
In carrying our invention into effect we attach an insulated double carbon con-
tact D to an arm or lever pivotted to the base or frame of the lamp at its lower
extremity and is sufficiently free upon its axis to fall in either direction from the
centre line, so as to engage with either one of the two fixed contacts B and C.

page_text: The contact C is fixed upon and electrically connected to the frame F, the wire or
lead g representing a connection shown upon the diagrams Figures 3 and 4 Sheet 2.
The contact B is insulated froin the frame F and connected to one end of the shunt
coil & by a wire or the like i. A flexible wire or conductor connects the pivotted
switch arm D to one of the lamp terminals ;-the + terminal in the present instance.
In its normal position the carbon contact D, upon the pivotted lever or switch arm
rests upon the insulated contact B connected to the shunt coil as aforesaid. Upon
the spindle f of the switch D a loose counterweight is fitted, A, of elliptical shape,
with the centre of gravity arranged to place the weight upon the normal position
of the lever carrying D, and said counterweight A is loosely suspended upon the axis f.
Also that of the lever D, hereinafter called the switch lever. A pine projects there-
from which engages with the lower end of a crank or lever E attached to a spindle a
forming part of the feeding mechanisin of the lamp, which is not shown, since it
forms no part of the present invention, and may be of any type or form.
1
―
A catch or pawl G, pivotted at c and working within the range of a slot and guide
pin b holds the switch arm D in its central or neutral position shown by the diagram
Figure 4; this being taken up by the further advancement of E, when the pawl G
engages with the pin d, drawing D back with it, and holding it momentarily in this
neutral position. Said pawl G, by reason of the slotted pin guide 6 releases D when
raised above the feeding point of the regulating device controlling E which forms no
part of our invention, and therefore is not shown or described. The end of the lever E
striking the pin e, alters the centre of gravity of the counterweight A, thus relieving
the switch arm D of its influence. Thus the shunt coil is broken when the E.M.F. is
sufficiently high to endanger it, the path of the circuit then being according to the
diagram Figure 4, viz., from the + terminal a through to the + carbon m, and
froin the terminal y through the series coil S and frame F to the carbon n the shunt
coils & being shortcircuitel or cut out, and the dotted outline shows the momentary
position of D, when the contact is transferred to the lamp frame F through C. The
shunt coils and carbon holders are thus preserved from damage. The position of D
shown by the dotted outline, Figure 4, is momentary, since the armature of the lamp
mechanism being relieved of its downward pull, at once rises, the butt end of the
catch G then replacing the switch arin D in the normal position shown by the
diagram Figure 3. The action of the series coil raises the carriage or slide of what-
ever type of regulating mechanism the invention is applied to, which brings the pawl
portion of the catch C out of its engagement with the pin d, and by releasing the
unequally pivotted counterweight A allows D to establish the shunt coil circuit as
shown by Figure 3. The balance of A enables a quick make and break to be
performed in the movement of the switch arm D.
We may also place in close proximity to either the shunt or series coil, and in series
with the circuit or any part of the conductors thereof, a fusible strip of bismuth or like
alloy in which the degree of fusion is less than the destructive heating temperature of
said coils. We may term this, a "temperature fuse" since it is not actuated by a
direct electric current pissing through it, but by the radiation of heat from such coil
or conductor. The fuse is not sufficiently sensitive to break the circuit by a
momentary impulse or increase of current, unless this is sustained for an appreciable
length of time, said circuit being broken before the generator or any part of the circuit
is damaged by overheating.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
First. An automatic cut out for are electric lamps having an insulated contact D on
a pivotted switch arm, in combination with a "shorting" contact C and a shunt
contact B, with a counterweight A crank arın E and catch G substantially as and for
the purpose set forth, and as described and shown by the appended drawings.
Second. In an automatic cutout for are electric lamps as referred to in the pre-

page_text: ceding claim, the arrangement of the series and shunt coil circuits relatively,
substantially as and for the purposes herein described with reference to the diagrams
Figures 3 and 4, Sheet 2.
Dated this 10th day of Novembar 1900
FREDK. WALKER,
73, St. Stephens Road, Upton Park, London, E.,
Agent for the Applicant.