Improvements connected with the Controlling of Electrical Circuits.
Year: 1898

page_text: Date of Application, 27th Sept., 1898
Complete Specification Left, 27th June, 1899-Accepted, 23rd Sept., 1899
PROVISIONAL DEPUITICATION,
Improvements connected with the Controlling of Electrical
Circuits.
I, ARTHUR BROMLEY HOLMES, of 36, Prince's Avenue, Prince's Road, Liverpool,
in the County of Lancaster, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention has reference to the controlling of electrical circuits, such as
those of electric light and power service systems, and it has more particularly
for its object to provide a mode of controlling such circuits, by which, when a
short circuit or overload arises, the abnormal current so caused shall be reduced.
and the circuit automatically restored to the normal condition when the cause of
overload has been removed.
According to this invention (in the case of a short circuit or overload taking
place in the circuit), the object and effect referred to are attained, by causing, by
a controlling mechanism, operating and arranged as hereafter described, the
normal circuit to be broken, and the current to be passed through a secondary
connection, or branch of the main circuit, in which a resistance is employed. In
the carrying out of this mode of controlling the circuit, there is employed a
mechanism of an automatic kind, so arranged that when an excess of current takes
place, it causes the main circuit or line to be broken, and the current to be
passed through the secondary connection containing the resistance, and it keeps
the main line of circuit broken until the short circuit or overload is rectified.
According to one arrangement, or mechanism, operated as described, there is
employed a circuit opening and closing device, say mercury cups on two terminals
in the main line, at the point where the circuit is to be opened and closed, with
a contact fork, dipping normally into them; and a solenoid forming part of the
main line, the fork and the core of the solenoid being suitably mounted, say, upon
a balanced lever. In connection with this solenoid and device, there is a second
coil or solenoid, forming part of a secondary or branch circuit or connection, and
so arranged that it only acts upon the core when such core has first been moved
to come under its active influence by the main line coil, that is, at the moment
of existence of an excess of current. The action of these two coils of the main
line and the secondary connection or circuit is that when a fault in the circuit
takes place, and an excess of current passes through the main line, the solenoid
core and device are moved, and the main circuit opened, and the core brought into
the influence of the secondary coil, through which the current will then pass; and
the connecting fork having thus been taken out of the mercury cups and the core
moved and brought under the action of the second coil, it will be held there, and
will keep the main line circuit open.
To render complete action of the mechanism automatic, so that the main line
circuit shall be reclosed, when the fault or overload has been removed, there is
used in connection with the mechanism a weight, which when the main line is
closed, exercises a given degree of pressure or movement on the device, tending
to keep the fork in the mercury cups and the line closed, but which, when the
fork is lifted out of the cups by the solenoid, is so moved, that its moment on the
fork is diminished, and the pull on the core by the current passing through the

page_text: coil of the secondary line connection, is sufficient to hold the weight up and the
fork out of the mercury. But when this secondary current is reduced, by the
rectification of the short circuit or overload, the power and pull of the secondary
solenoid coil on the device, is reduced below that of the weight, and consequently
the weight presses the fork again into its cups, and the normal main line circuit
is restored.
This invention may be usefully applied to circuits supplied by accumulators;
the feeders of electric railways, or the connection of sections of a line of electric
railway; the feeders for electric light or power of an electricity supply station.
or the protection of a number of dynamos working in parallel; and similar or
analogous applications.
Dated this 26th day of Sentember 1898
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.
COMPLETE SPECIFICATION.
Improvements connected with the Controlling of Electrical
Circuits.
I, ARTHUR BROMLEY HOLMES, of 36, Prince's Avenue, Prince's Road, Liverpool.
in the County of Lancaster, Electrical Engineer, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:·
This invention has reference to the controlling of electrical circuits, such as
those of electric light and power service systems, and it has more particularly
for its object to provide a mode of controlling such circuits, by which, when a
.short circuit or overload arises, the abnormal current so caused shall be reduced.
and the circuit automatically restored to the normal condition when the cause of
overload has been removed.
According to this invention (in the case of a short circuit or overload taking
place in the circuit), the object and effect referred to are attained, by causing, by
a controlling mechanism, operating and arranged as hereafter described, the
normal circuit to be broken, and the current to be passed through a secondary
connection, or branch of the main circuit, in which a resistance is employed. In
the carrying out of this mode of controlling the circuit, there is employed a
mechanism of an automatic kind, so arranged that when an excess of current takes
place, it causes the main circuit or line to be broken, and the current to be
passed through the secondary connection containing the resistance, and it keeps
the main line of circuit broken until the short circuit or overload is rectified.
According to one arrangement, or mechanism, operated as described, there is
employed a circuit opening and closing device, say mercury cups on two terminals
in the main line, at the point where the circuit is to be opened and closed, with
a contact fork, dipping normally into them; and a solenoid forming part of the
main line, the fork and the core of the solenoid being suitably mounted, say, upon
a balanced lever. In connection with this solenoid and device, there is a second
coil or solenoid, forming part of a secondary or branch circuit or connection, and
so arranged that it only acts upon the core when such core has first been moved
to come under its active influence by the main line coil, that is, at the moment
of existence of an excess of current. The action of these two coils of the main
line, and the secondary connection or circuit, is that when the fault in the circuit
takes place, and an excess of current passes through the main line; the solenoid
core and device are moved, and the main circuit opened, and the core brought into
the influence of the secondary, coil, through which the current will then pass; and

page_text: the connecting fork having thus been taken out of the mercury cups, and the core
moved and brought under the action of the second coil, it will be held there, and
will keep the main line circuit open.
To render complete action of the mechanism automatic, so that the main line
circuit shall be reclosed, when the fault or overload has been removed, there is
used in connection with the mechanism a weight, which when the main line is
closed, exercises a given degree of pressure or movement on the device, tending
to keep the fork in the mercury cups and the line closed, but which, when the
fork is lifted out of the cups by the solenoid, is so moved, that its moment on the
fork is diminished, and the pull on the core by the current passing through the
coil of the secondary line connection is sufficient to hold the weight up and the
fork out of the mercury. But when this secondary current is reduced, by the
rectification of the short circuit or overload, the power and pull of the secondary
solenoid coil on the device, is reduced below that of the weight, and consequently
the weight presses the fork again into its cups, and the normal main line circuit is
restored.
This invention may be usefully applied to circuits supplied by accumulators;
the feeders of electric railways, or the connection of sections of a line of electric
railway; the feeders for electric light or power of an electricity supply station,
or the protection of a number of dynamos working in parallel; and similar or
analogous applications.
The diagrammatic drawing hereto annexed illustrates the invention. In this
drawing, the lines a and b may represent two conductors, namely, the supply and
return, of a circuit supplying electrical energy to lamps 1, or a motor m, or other
mechanism or thing absorbing electrical energy. may represent the source of
the electrical supply.
The automatic electrical device for opening and closing the main circuit con-
ductor a,
in circumstances such as referred to, consists of a solenoids forming part
of the circuit, and through which the whole current passes; two cups c containing
mercury, forming the terminals at the point of opening and closing the circuit
on the line a; a contact fork f working in connection with the mercury cups c;
a core operated by the solenoid s; and a lever d, fulcrummed at e, and sus-
pending, from one arm, the core k, and from the other, the fork f.
The lever d will be approximately balanced by the adjustable weight w on one
arm of the lever d.
.
The weight wo on the arm w³ tends always to keep the fork f in the mercury
in the cups c, and the core k out of the solenoid s, so that there is always a
moment on the side of the lever fulcrum e acting against the core k.
The secondary or branch circuit--designated o-connects the two parts of the
circuit line a terminating in the two cups c. This branch circuit has a resistancer
in it, and a solenoids directly under the solenoid s, such solenoid being so
arranged in relation to the solenoids and the core k, that it acts upon the core
when such core has first been moved down to come under its active influence,
by the main line solenoid s, that is, whenever an excessive current, from causes
'as specified, has taken place.
In action, when a fault in the circuit takes place, say, a short circuit, and an
excess of current passes through the main conductor a, the solenoid core k is
drawn down by the solenoid s, and the fork f is withdrawn from the mercury in
the cups c against the weight w¹, and, consequently, the direct main current
line a is opened. As the fork f leaves the mercury terminals, the current will
pass by way of the branch circuit o, and the core k having been brought under the
action of the second solenoid s¹, it will be held by this second or branch circuit
solenoid, and will keep the main line circuit, by way of the terminal cups c, open;
and it holds the weight w¹ up in the position shewn in dotted lines against a stop n.
This condition will exist so long as an excess of current is passing.
Of course the resistance r, or its equivalent, in the branch circuit o, prevents

page_text: the line, or section of a line, on which the apparatus is used, being damaged. and
the lamps, motors, or what-not, used in the circuit, are thus protected from injury.
When the fault or overload in the circuit has been removed, the circuit through
the main line a, by way of the cups c and fork f, is restored by this automatic
mechanism, through the weight wl; namely, as soon as the normal current passes
through the circuit, the force of the solenoid on the core k becomes less than the
moment of the weight w¹, and consequently, the arm of the lever carrying the
fork is moved down, and the fork enters the mercury in the cups c, and the
normal or main circuit by way of these cups and fork, is re-established.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. An electric circuit having a circuit opening and closing device adapted
automatically to close and keep closed the main circuit; and an electro-magnetic
device connected with the said opening and closing device, operated by the current
passing through the main circuit wires, and adapted to operate the opening and
closing device, and open the main circuit when an excess of current takes place;
and a branch circuit having a resistance therein connecting the ends of the line
on either side of the point at which the circuit is closed and broken, through
which the current is passed when the said main circuit line is opened; and an
electro-magnetic device connected with and operated by the current passed through
the said branch circuit, and connected with the said circuit opening and closing
device in the main circuit conductor, and adapted to keep the main circuit open
whilst an excess of current continues.
2. In an electric circuit, a branch circuit having a resistance; an opening and
closing device on the main circuit; and electro-magnetic devices operated by the
current passing through the main circuit and through the branch circuit, sub-
stantially as in the manner and for the purposes herein set forth.
3. In an electric circuit, comprising supply and return conductors a and b, an
electricity supply source x, and an electricity consuming apparatusas 1 m--
on the said circuit; a circuit opening and closing device on the conductor a; a
solenoids on the conductor a between the source and said opening and closing
device; a core k connected with said opening and closing device, and operated by
the solenoids, and adapted to open the said circuit; a branch circuit o connect-
ing the two parts of the main conductor a on either side of the terminals of the
opening and closing device; a resistance r on the branch circuit o; a solenoid s¹
on said circuit, adapted to influence the core k; and a weight or spring connected
with the opening and closing device, and acting in a contrary direction to the
solenoids, and normally adapted to close the said circuit and keep it closes;
substantially as set forth.
4. The combination in the main conductors a and b of an electric circuit, of the
solenoids on the conductor a; contact terminals c; connecting and disconnect-
ing device working in connection with c; a core working in connection with
the solenoids; a lever d connecting the core & and contact device f; a weight w¹
tending normally to operate the connecting device f, and to close the circuit; the
branch circuit o; a resistance r thereon; and solenoid sa adapted to operate on the
core k, as set forth.
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.