Improvements in Automatic Cut-outs for Electrical Circuits.
Year: 1889

page_text: Date of Application, 22nd May, 1889
Complete Specification Left, 22nd Feb., 1890-Accepted, 22nd Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Automatic Cut-outs for Electrical Circuits.
I, WILLIAM JOSEPH STARKEY BARBER-STARKEY, of Aldenham Park Bridgnorth in
the County of Salop, Barrister, do hereby declare the nature of this invention to be as
follows:-
This Invention relates to automatic cut-outs for electrical circuits.
An automatic cut-out constructed and arranged according to these Improvements
is intended to open a circuit when the pressure therein exceeds or is in defect of a
predetermined range of voltage.
In carrying out my Invention I include a small dynamo or magneto electric motor
in a high resistance shunt from the dynamo or mains. By means of stops or other
devices I limit the possible angular motion of the armature of this electro motor so
that it may not rotate continuously whilst its circuit is closed. The spindle of the
armature is geared or connected with a switch or device such as a mercury or brushi
contact, for opening and closing the main circuit. There may also be arranged with
the motor, a device for opposing its rotation by means of springs or weights. If it is
required that the apparatus shall close a circuit as soon as the pressure reaches a
certain amount, the force which opposes the rotation of the armature is regulated so
that the armature can move only when that pressure is reached. If it is desired that
the circuit should be opened as soon as the current reaches a predetermined pressure,
the force opposing the rotation of the armature is regulated so that the armature will
not move until that pressure is reached; in this case the main circuit is already closed
and the apparatus operates to open it, in the former case the reverse happens, that is
to say the circuit is already open and the apparatus closes it.
When the armature of the motor moves in consequence of the pressure having
reached a determined amount, the motion of the armature is communicated by the
connecting device to the switch or contacts so as to open or close the circuit as herein-
before described. When it is desired to open the circuit if more than a determined
pressure exists in the main, the motor may have one or more coils of thick wire
included in the main circuit.
Dated this 20th dose of Mar A T 1980
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Automatic Cut-outs for Electrical Circuits.
I, WILLIAM JOSEPH STARKEY BARBER-STARKEY of Aldenham Park Bridgnorth in
the County of Salop, Barrister, 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:—
This Invention relates to automatic cut-outs or devices and apparatus for opening
and closing electric circuits when the pressure therein is in excess or in defect of a
predetermined range of voltage.
In carrying out my Invention I include a small magneto- or electro-motor in a high
resistance shunt from the dynamo or mains, or, when it is desired to open the circuit
only, I may include a low resistance motor in the main circuit. By means of stops or
equivalent devices I limit the possible angular motion of the arinature of the motor so
that it may not rotate continuously when its circuit is closed. The spindle of the
armature is geared or connected with a switch or similar suitable device such as a
D

page_text: mercury or brush contact for opening and closing the main circuit. There may
also be combined and arranged with the motor a device such as a weight spring or
brake for the purpose of resisting or tending to resist the rotation of the armature as
hereinafter more fully described.
If it be desired that the apparatus shall close a circuit as soon as the pressure therein
reaches or exceeds a certain range of voltage, the weight spring or similar device
which tends to oppose the rotation of the armature is adjusted so that the armature
can move only when that pressure is reached. If it be required that the circuit
should be opened as soon as the current reaches a predetermined pressure, the weight
spring or equivalent device opposing the movement of the armature is adjusted or
regulated so that the armature will not move until that pressure is reached; in this
case the main circuit is already closed and the apparatus operates to open it, and the
motor may be in series instead of in shunt; in the former case the circuit is already
open and the apparatus operates to close it and the motor is in a high resistance
shunt.
When the armature of the motor moves in consequence of the pressure in the main
circuit having reached a certain amount, the motion of the armature is communicated
by means of a lever, by gearing, or by similar and suitable means to a switch or
contacts as hereinafter described.
I will now proceed to describe in what manner my invention may be carried into
practical effect with reference to the accompanying drawings. Fig. 1 shows in
elevation and Fig. 2 in plan, an apparatus constructed according to these Improve-
ments. Fig. 3 indicates approximately the position of the armature when at rest.
Figs. 4 and 5 represent diagramatically two methods of connecting the apparatus in
circuit. Fig. 6 shows an arrangement for preventing volatilisation of the mercury
contact by sparking when contact is broken, and Figs. 7 and 8 represent respectively
a sectional elevation and a plan of the apparatus arranged as a cut-out in the main
circuit.
In the apparatus represented in Figs. 1 and 2 the motor may be wound in a shunt
and it may have a permanent magnetic instead of an electro-magnetic field. The
electro-field magnets and armatures should be wound in shunt with high resistance
wire so as to employ only as much of the current as will be effective for the
operation of the motor at the determined pressure. A lever L is connected with
the spindle of the armature which is carried in suitable bearings. One end of the
lever L carries two prongs N N which may be constructed so that their lengths may
be adjusted by screws as indicated in the drawings Figs. 1 and 2. On the other
end of the lever there is carried a weight W which may be adjusted at any desired
part of the lever between the motor and the end of the lever. Instead of the sliding
weight W an adjustable spiral spring having one end connected to the base of the
apparatus and the other end to the end of the lever L or other equivalent device such
as a friction brake for opposing the motion of the armature may be employed.
The weighted end of the lever L falls, when the armature moves, upon the head of
the adjustable stop E and its motion is thus limited.
The angular position of the armature relatively to that of the lever L may he
adjusted and secured by means of the screw G which enters a tapped hole in the
disc H fixed on the armature spindle and passes through the concentric slot formed
in the disc I which is parallel with the disc H and is loose on the armature spindle.
The lever is secured to the outer disc I and it follows from the construction, that the
relative positions of the disc and therefore of the lever and armature may be altered
and secured by means of the screw G.
The mercury cups C Care insulated from each other and are respectively electrically
connected with the two terminals T T which are in turn electrically connected with
the two ends of the main cable or conductor which is to be opened or closed by the
apparatus.
Assuming that the terminals T T are connected with the main circuit and the
terminals T T are connected with the shunt circuit to which also the motor circuit

page_text: is connected, and that the lever rests with its weighted end on the stop E with the
prongs N N out of the mercury cups. When the e.m.f. in the dynamo circuit M M
reaches a predetermined amount, the intensity of the magnetic field just suffices to
enable the armature to rotate in opposition to the tendency of the weight W, and the
movement of rotation once commenced, it increases rapidly, and the electrically
connected prongs
N N are forced downwards into the mercury cups thus completing
the main circuit.
The exact point at which the movement of the armature, commences may be
determined by an adjustment of the angular position of the armature with respect to
the lever L so as to bring it into a more or less advantageous position with reference
to the lines of force, or it may be determined by an adjustment of the position
of the weight W or of the tension of the equivalent spring. An adjustment
of the vertical position of the stop E will practically be equivalent to an adjustinent
of the position of the armature relatively to that of the lever L. When the main
circuit has been closed by the prongs entering the mercury cups, the force requisite
to keep the circuit closed is less than that originally required to originate the move-
ment of the armature, since the armature now lios in a more advantageous position
relatively to the lines of force. Consequently, the weight W (or the equivalent
spring) will not overcome the magnetic force until a lower e.m.f. exists in the
main circuit, when the weight (or spring) will operate to move the armature in
the opposite direction and thus break the circuit. The exact pressure at which the
circuit is thus opened will depend upon the position of the armature, of the weight,
or of the stop as hereinbefore described. The range of pressure within which the
apparatus may operate may vary within wide limits but in actual practise a range of
20 volts is found easy to obtain and to be sufficient for most purposes.
In order to promote quickness of break in opening the main circuit by means of
the apparatus, a spring K may be arranged below the lever on the contact side of
the motor or above the lever on the opposite side. The same or a similar result
may be obtained by the use of the apparatus illustrated in Fig. 6. In this arrange-
ment a disc constructed of a metal which will not be prejudicially affected by the
mercury, is floated on the surface of the mercury and is supported below by a
suitable spring P which may surround a stem formed on the under side of the disc.
The flotative power of the disc may be increased by making it partly hollow or by
the aid of cork or wood. The strength of the spring or the flotative power is adjusted
so that when the disc is depressed by the prong N on the closing of the circuit, the
disc will be submerged partly or entirely in the mercury. So soon as the e.m.f.
falls to a certain point, the disc rises, and when the circuit is finally broken there will
be an accelerated motion of the armature and the slight consequent spark will occur
between the solid metal surfaces of the disc and prong and no volatilisation of the
mercury will take place. The spring P may be dispensed with if the disc is
sufficiently flotative without it.
The position of the motor armature when the apparatus is constructed as herein-
before described, and when the weighted end of the lever L is resting on the stop,
(the circuit being open) will be approximately as represented in Fig. 3.
The apparatus may be joined up as represented diagramatically in Figs. 4 and 5.
In Fig. 4 it is joined in shunt to the dynamo terminals and in this case the e.m.f.
actuating the apparatus is that of the dynamo D. In Fig. 5 one of the terminals of
the apparatus is joined to one of the poles of the dynamo D and the other to the
corresponding pole of the secondary battery or accumulator B which is being charged
or is in circuit with the dynamo. In this case the e.m.f. actuating the apparatus is
that due to the difference between the e.m.f. of the dynamo and that of the battery,
and I preferably employ a permanent magnetic field for the motor and include a
switch in the circuit between the dynamo and battery to provide a means for
breaking the circuit and preventing the battery discharging through the dynamo
when the latter is at rest.
When the apparatus is desired to be employed as a main circuit cut-out it is

page_text: preferred to employ the construction and arrangement illustrated in Figs. 7 and 8.
The armature is wound with a conductor having a sufficient cross section to carry
the main current safely. The current enters at the terminal T traverses the field
magnet coil the mercury cup c, the armature coils, the mercury cup c¹, and the two
mercury contact cups CC to the terminal T¹. The lever L, the prongs N N and the
mercury cups CC may be constructed and arranged as described with reference to
Figs. 1 and 2. If the current exceeds a certain pre-determined amount, the motion
of the armature breaks the main circuit. In order to prevent the re-closing of the
circuit which might occur from the lever falling back again after the opening of
the circuit, a small catch may be arranged to engage with the lever as soon as it
has moved far enough to break the circuit and to hold it securely until released by
hand. It may also be arranged that the motion of the lever in breaking the circuit
may close an electric bell circuit, and thus call attention to the fact that the cut-out
has acted. Alternatively, there may be mounted upon the armature spindle at a
small angle from the perpendicular a weighted arm, the weight W being adjustable.
By this arrangement as soon as the armature commences to move, its motion rapidly
increases until the weight W has passed over the centre when the lever will be
held in open circuit until replaced by hand to re-establish the circuit. A second
weight. W may be employed on the lever L to give greater stability.
The circuit through the armature coils is completed by the ends of its coil dipping
into the two mercury cups c e' so that the motion of the armature may be perfectly
free of the restraint of a solid metallic connection, it may however be completed by
a rubbing metallic contact or equivalent device.
I desire it to be understood that I do not limit myself to the precise arrangements
and constructions of the apparatus represented by the accompanying drawings as
these are intended to be merely typical, and these Improvements may obviously be
very considerably modified. For example the motion of the armature may be opposed
by a brake or friction device and instead of communicating the motion of the
armature to the switch by the lever L it may be communicated by pulleys and cords
or gearing; also, instead of the mercury contact cups, a double brush or other
suitably constructed switch may be employed, but I prefer to employ the construction
and arrangement hereinbefore described and illustrated by the accompanying
drawings.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, 1 declare that what
I claim is.
(1) An apparatus for closing an electric circuit by means of an electro-motor
included in a shunt from the main circuit when the e.m.f. in that circuit reaches a
predetermined amount, constructed arranged and operated substantially as herein-
before described and as illustrated by the accompanying drawings.
(2) An apparatus for automatically opening an electric circuit by means of an
electro-motor included in series with or in shunt from the main circuit, when the
e.m.f. in that circuit exceeds a predetermined amount, constructed arranged and
operated substantially as and for the purpose hereinbefore described and as illustrated
by the accompanying drawings.
(3) In an apparatus for closing an electric circuit when the e.m.f. tberein
reaches a predetermined amount operating the switch or circuit closing device by the
motion of the armature of an electro-motor included in a shunt from the circuit,
substantially as and for the means herein before described.
(4) In an apparatus for opening an electric circuit when the current therein
exceeds a pre-determined pressure, operating the switch or circuit opening device by
means of the motion of an electro-motor energised by or from the current in the
circuit, substantially as and by the means hereinbefore described.
(5) In an apparatus for opening an electric circuit, the combination and arrangement
with the switch or circuit opening device, of an electro-motor energised by or from

page_text: the main circuit, a weight spring or similar device for opposing the motion of the
motor armature, a stop or stops for limiting its motion, and means for communicating
the motion to the switch, substantially as herein before described.
(6) In an apparatus for closing an electric circuit, the combination and arrange-
ment with the switch or circuit closing device of an electro-motor energised from
the main circuit, a weight spring or similar device for opposing the motion of the
motor armature, a stop or stops for limiting its motion, and means for communicating
the motion to the switch, substantially as herein before described.
(7) In an apparatus for opening and closing an electric circuit, the combination
and arrangement with a mercury contact of a metallic float, substantially as and for
the purpose hereinbefore described and as illustrated by the accompanying drawings.
Dated this 20th day of February A.D. 1890.
WILLIAM E. HEYS,
Agent for the Applicant.