An Improved Method and Electro-magnetic Cut-out for Automati- cally Disconnecting Charged Conductors in the event of Breakage or Short Circuit, applicable to Overhead Systems of Electric Traction and the like.
Year: 1898

page_text: Date of Application, 14th Jan., 1898
Complete Specification Left, 14th Oct., 1898-Accepted, 14th Jan., 1899
PROVISIONAL SPECIFICATION..
An Improved Method and Electro-magnetic Cut-out for Automati-
cally Disconnecting Charged Conductors in the event of Breakage
or Short Circuit, applicable to Overhead Systems of Electric
Traction and the like.
I, ROBERT CORNELIUS QUIN, of Ambleside, Palatine Road, Blackpool, in the
County of Lancaster, Borough Electrical and Tramway Engineer, do hereby declare
the nature of this invention to be as follows:-
Í take a switch controlled either by a spring or weight in such a way that the
spring or weight act to release the switch. To this switch I affix a rocking bar
or lever, pivoted at or near its centre and to the extremities of which lever I
attach pieces of soft iron or other magnetic metal.
Close to the one end of the lever fix a coil or winding of wire having a
magnetic core. One terminal of this coil I connect either to earth or to the return
or negative conductor. The opposite end I connect either through a suitable
resistance or direct to the extreme end of the line which is to be protected. This
said coil to be attached to the base of the switch or in any other convenient
position:
At the opposite end of this lever and close to the corresponding magnetic end
of the rocking bar or lever I attach another coil or winding of wire of low resist-
ance and of sufficient section to carry the maximum current required for the
normal working of the line to be protected. One end of this latter main circuit
coil I connect to the positive terminal of the source of supply, the other I connect
to the aforesaid main circuit switch, or I connect this main circuit coil and main
circuit switch, and the line to be protected in such a way that they are placed
electrically in series.
To the rocking bar or lever I also attach or fix an indent or other suitable form
of catch in such a way that when this rocking bar is attracted and held in posi-
tion by the first named shunt circuit coil the switch will be held closed and the
line therefore charged. That when the rocking bar is attracted by the main
circuit coil the said catch or indent is raised allowing the weight or spring con-
trolling the action of the main circuit switch, to release the said switch and thus
disconnect the line.
Further, preferably to the end of the aforesaid rocking bar I attach a spring or
weight suitably controlling its action, the said weight or spring being adjustable
so as to increase or lessen the force opposing the magnetic attraction of the said
shunt circuit coil.
The action of the said apparatus and method is as follows: —
The switch being closed on the line and being connected to the source of supply
the line or conductor becomes charged as also does the shunt circuit coil, this
latter acting to hold the main circuit switch in position and to maintain the line
charged.
It will be seen that this shunt circuit coil is charges only so long as there is
electrical continuity in the line, but should the line break or otherwise its electrical

page_text: continuity be disturbed the magnetic attraction of this shunt circuit coil upon
the rocking bar or lever ceases releasing the indent attached to the rocking bar,
and allowing the spring or weight attached to the main circuit switch to operate
the same to disconnect the line.
Further in the event of the current taken from the line exceeding the normal
of that for which the action of the main circuit coil was adjusted this main circuit
coil by attracting the magnetic material attached to its end of the rocking bar or
lever raises the indent and thus disconnects the line.
The use of this main circuit coil is optional and can if necessary be replaced
by a length of fusible metal generally termed fusible cut-out.
Dated this 12th day of January 1898.
An Improved Method and Electro-magnetic Cut-out for Automati-
cally Disconnecting Charged Conductors in the event of Breakage
or Short Circuit, applicable to Overhead Systems of Electric
Traction and the like.
I, ROBERT CORNELIUS QUIN, of Ambleside, Palatine Road, Blackpool, in the
County of Lancaster, Borough Electrical and Tramway Engineer, 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 has reference to the controlling or governing of electric mains
or lines for overhead systems of electricity supply for traction purposes, and
other similar or equivalent purposes; and it has for its object and effect the
accomplishment of the ends or results-amongst others-hereafter set forth. The
invention is hereafter fully described with the aid of the accompanying drawings,
which illustrate the method according to which the controlling or governing
action is effected, and one form of automatic electro-magnetic cut-out mechanism,
according to the invention, for carrying out the method.
In the drawings, Figure 1 is a diagrammatic view, illustrating the method
according to this invention, of controlling electricity service systems.
Figures 2 and 3 are, respectively, side elevation, and front elevation, shew-
ing an automatic electro-magnetic cut-out, according to the invention.
According to this invention, in electric service systems, such as those employed
for electric traction on the overhead system, in which the line is divided up into
a series of sections of certain lengths, there is employed a switch (such as illus-
trated in the drawings), cr an equivalent device, comprising a shunt coil
electro-magnet, which is connected with the end of the line or section of the
line; and, in the case of a breach of the line, or its electrical continuity being
disturbed, this coil is caused to control it, and make it dead. In the diagram-
matic view in Figure 1, there is shewn a section of an electrical line or main,
of which a is the main conductor, and which is fed from a general electrical
service line or main, through a switch device, generally designated b. c is a
shunt magnet on the switch, and d is a supplementary wire, which connects the
end of the line a with the shunt magnet. This magnet operates or controls
the switch in the case of a breach or disturbance of electrical continuity any-
where between the points and y of the line a, and disconnects it from the
source of electricity or feeding line.
Regarding this apparatus, illustrated in Figures 2 to 4, there is shewn in

page_text: this the electro-magnetic cut-out for automatically disconnecting or opening
circuits in the event of the breaking of the line, or short circuiting, in electricity
supply systems, such as referred to. In this apparatus, in the case of the
breakage or disturbance of continuity in a section of a line or conductor, this
section or conductor is automatically disconnected or cut out by the shunt
coil magnet c, herein before referred to with reference to Figure 1; while, in
addition to this shunt magnet, there is another electro magnet i, having a
winding of wire of low resistance, and of sufficient section to carry the maximum
current required for the normal working of the line; and which, with the main
circuit switch, and the line to be protected, is placed electrically in series. This
magnet serves to disconnect or open the circuit automatically in case of an
excess of current through a short circuit, or otherwise, taking place in the
line.
In this switch apparatus, f f are two weights on the end of the levers f¹,
which are adapted to so act that the switch is opened when freed by the magnetic
devices, and the line disconnected; and this freeing or releasing of the weights
is effected, and the action of the weight is controlled by the shunt magnet c
and series magnet i, through a rocking lever g, hinged at g¹, and having at its
lower and upper ends soft iron armatures 92.
The weight arms f¹ are hinged on, and rock about the hinges f2; and they
operate the actual contact arms, h, which are also pivotted at f, and are kept
in the spring contacts j (the construction of which is shewn in Figure 4), so
long as the weights are held in the upper position, as shewn in the drawings;
but are removed therefrom when the weights fall.
In connection with the rocking lever g, there is provided a spring k, a
variable tension on which is obtained by an adjusting milled nut k¹, which
screws on and off the threaded rod on the end of k, which passes through g.
By this spring, the force tending to move the lever away from the shunt
magnet d, and to release the weights, is increased or lessened, as desired.
The levers f¹ of the switches are normally held up in position as shewn in
the drawing, by a catch or detent on the bar g, on which a roller f³ on the
.bar f' connecting the two weight levers f¹ together, rests.
With regard to the electrical connections, e is the wire, by which current from
the feeder or source of supply to the section main passes. This is connected up!
with the switch device by the binding screw 7 of one of the spring contacts j,
and so, through the arms h and frame thereof, the current passes to the other
contact, and thence to the series magnet i; and from here to the binding
screw fitting m, whence it passes to the main line or conductor.
With regard to the shunt coil c, current is supplied to it directly from the
main line, through the supplementary wire d, the binding screw device n, and
the toils of the magnet; and it passes away, by the binding screws n¹, to earth,
or to the return or negative conductor. Or, in lieu of the current passing directly
to this coil, it may first pass through a resistance (shewn diagrammatically
at o Figure 1) on the wire d.
All the above parts, together with wooden buffer blocks 2, and rubber
cushions p¹, are secured onto the base or slab r, which is of suitable material.
The action of the mechanism or apparatus shewn, and the operation of the
method according to the invention, are as follows: -In the normal condition
of parts, ie., when the line is in normal work, the switch bars h are in contact
with the contact devices j, and the weight levers f¹ and weights f are held up
by the cross bar f4, as shewn in the drawing, by the detent or catch g³, on which
the roller f³ of the bar f rests, this detent being held in this position by the
attraction of the shunt coil magnet 6 on the rocking bar g. With this position
of the parts, current flows through the contacts j, and contact arms, and magnet i,
to the line, or section of the line on which the switch apparatus is placed.
In the case of the line or section becoming broken, or its continuity disturbed,
the shunt magnet c will have no potential, as its connection with the line a

page_text: is broken, and therefore, the armature 92 of the rocking bar a will cease to be
pulled. or attracted; while. the other end of this bar will be pulled away from
the cross bar f by the spring k, and the detent g³ will be withdrawn from, this
cross bar; whereupon, the weights f, being released,, will fall, and will move
the levers f, and so the contact arms h, out of the contacts:j, and so disconnect
the line from the feeder or source of supply. In this position, of course, the
weights of the arms f¹ will rest on the buffers p¹.
"
In the case of a short circuit taking place, the abnormal current flowing
through the line, and the series magnet i, causes the rocking lever 9g to be
pulled towards it, by its attraction on the armature gl. Thus this excess of
current pulls the detent g away from cross bar f*, and so allows the weights
to drop and pull the switch arms out of the contacts j, as in the other case,
and disconnect the line.
In some cases, if desired, the main circuit magnet or coil i is dispensed with,
and there is substituted a length of fusible metal between the contacts and
the line in which case, the disconnection of the line, or a section of line, will
be effected, in the case of the passage of an excess of current; by the melting
of the fusible metal; while in the case of the line being broken or its continuity
disturbed, the disconnecting of the section of the line will be effected by the
switch arms and contacts, and the shunt coil c, owing to the absence of potential
in this coil. Thus it will be seen, that this shunt circuit coil c is charged only
so long as there is electrical continuity in the line, and that should the line
break, or otherwise, its electrical continuity be disturbed; there will be an absence
of potential in the coil, and the magnetic attraction of it upon the rocking bar g
ceases, with the effect above described.
Having now particularly described and ascertained the nature of this in-
vention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The herein described improvement in the controlling of electric circuits
for overhead electric traction supply systems, and analogous or equivalent
circuits, consisting in causing the line, or section of a line, to be disconnected.
automatically by means of electro-magnetic devices, so connected with, or opera-
ting in connection with the said line or section, that when it-the line or section
-is broken, or its electric continuity disturbed the magnet or magnets cease to
possess potential, and the circuit or line becomes disconnected from the service
or source of supply; for the purposes described.
2. In electric circuits for overhead electric traction, and analogous or equi-
valent purposes, such as referred to, an automatic cut-out mechanism at the
end of the line at which the circuit is fed to it; a shunt coil magnet and switch
or contact mechanism adapted to be operated thereby; and a supplementary
wire or connection connecting the other end of the line with said shunt magnet;
operating substantially as in the manner, and for the purposes set forth.
3. An automatic, electric disconnecting or cut-out mechanism for overhead
electric traction supply systems, and analogous or equivalent purposes, having
shunt and series electro-magnets, a weighted or spring pressed switch. mech-
anism, and retaining and releasing means connected with said switch mechanism,
by which the switch is automatically moved, and the line disconnected, in case
of either an excess of current passing through same, and the series magnet
therein, or the absence of potential in the other magnet; substantially as set
forth.
4. An automatic electric disconnecting or cut-out mechanism for overhead
electric traction supply systems, and analogous or equivalent purposes, compris-
ing a shunt coil magnet; a series coil magnet; an armature lever adapted to be
operated by said magnets; and a weighted or spring-pressed switch lever or
levers, adapted to be held and released by said magnets; and a spring or weight
operating in connection with said armature lever, adapted to release said weighted

page_text: or spring-pressed switch levers when there is an absence of potential in the
shunt coil; substantially as described.
5. An automatic electro-magnetic cut-out mechanism for purposes as described,
comprising the parts arranged and adapted to operate particularly as set forth
with reference to and shewn in the drawings.
Dated 1941. day of October 1000
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.