IMPROVEMENTS IN APPARATUS FOR CONTROLLING INDICATING AND ARRESTING THE FLOW OF ELECTRIC CURRENT
Year: 1883

page_text: LETTERS PATENT to William Morris Mordey of Putney, in the County of
Surrey for an Invention of IMPROVEMENTS IN APPARATUS FOR CONTROLLING
INDICATING AND ARRESTING THE FLOW OF ELECTRIC CURRENT
PROVISIONAL SPECIFICATION left by the said William Morris Mordoy at
the Office of the Commissioners of Patents on the 10th January 1883.
WILLIAM MORRIS MORDEY of Putney in the County of Surrey, "IMPROVE-
MENTS IN APPARATUS FOR CONTROLLING, INDICATING AND ARRESTING THE FLOW
OF ELECTRIC CURRENT
"
•
This invention relates more particularly to controlling the current passing from
a source of electricity, such as a dynamo machine, into accumulators or secondary
batteries, into electro depositing apparatus, and into systems of electric mains and
the like. It is also in part applicable to switches and other instruments whereby
an electric circuit may be broken.
In charging accumulators or secondary batteries if the electromotive force of
the source fall, from any cause, below that already acquired by the accumulator,
a reverso current is set up in the opposite direction to the charging current, and
part, or the whole, of the stored up energy is discharged through the source. When
the source of current is a dynamo machine this effect may result from the following
causes amongst others ;-
Temporary or permanent slowing of the engine driving the dynamo machine;
or from slipping, stretching, or breaking of the belt, or failure of the gearing; or
from the accumulator becoming fully charged, or at least charged to such a degree
as to enable it to send a current back to the dynamo machine; or from the machine
being stopped.
Under any of those circumstances the accumulator, unless disconnected from
the charging source, will discharge, to a greater or less extent, through the latter.
In electro depositing apparatus a reverse current may also be set up, with; in

page_text: the case of a series dynamo, that is, one in which the field magnet coils are in
series with the main circuit, the additional effect of reversing the polarity of the
field and the direction of the current.
In systems of electric mains in which a constant difference of potential is sought
to be maintained between the main leads by more than one dynamo machine
or other source of electricity, a generator whose electromotive force was less
than the said difference would offer a path through which a part of the current
would flow and be for practical purposes lost.
The object of this invention is to disconnect the source of electricity from the
conductor or apparatus into which the current flows, when the current from any
cause become reversed, and, in some cases, to reconnect the two when sufficient
difference of electromotive forces has been reestablished. This is effected by
breaking the main circuit. In the case of shunt machines the field coils may, if
found desirable, be simultaneously short circuited through a greater or less
resistance, or may be disconnected; and separately excited machines may have
their excited circuits disconnected. Simultaneously with the disconnection of
the circuit a visual or aural signal may be given to apprise the attendant of
the fact.
One form of apparatus, according to my invention, consists of two electro-
magnetic sucking coils in each of which bangs a soft iron bar or core; under
these coils is fixed a permanent magnet, so placed that its poles are opposite the
lower ends of the two cores. The said cores are suspended from opposite ends of
a rocking lever or beam supported at its centre on a bracket or bridge, and having
at or near one end (which I will call the left-hand end) an inverted metallic fork
or U piece, insulated from the beam, and so placed that when the beam is depressed
at that end the prongs of the U piece dip into two mercury cups, making a con-
nection between them. At the other end (the right hand end) of the beam aro
two similar forks or U pieces placed preferably on opposite sides of the beam, and
so arranged that when that end of the beam is depressed they dip into and make
connection respectively with two similar pairs of mercury cups.
The beam is so arranged by means of its greater weight at the right hand end,
or by a spring, or some other suitable arrangement that it shall be depressed at
that end, so that in its ordinary position when at rest, the four mercury cups
are respectively connected together in two groups of two each by means of the
U pieces.
The electro magnetic sucking coils are placed in the main circuit between the
accumulator and the charging dynamo or other source of electricity, being con-
nected either in series or in parallel circuit, as may be found most suitable; one
end of the coiled conductor is connected to the accumulator, main or the like, and
the other end to the source of electricity by means of one pair of the right hand
mercury cups and the U piece connecting them. The coils are so wound or so
connected that the current from the dynamo or other source of electricity, when it
is passing in the proper direction and is charging the accumulator, mains or the
like, produces similar poles at the lower ends of the cores; the poles of the
perinanent magnet being so relatively placed that the core in one coil shall be
attracted by one pole of the permanent magnet, and the core in the other coil shall
be repelled by the other pole of the magnet, so that the right hand end of the beam
remains depressed.
But if, from any of the causes enumerated above, the direction of the current
become reversed, the polarity of the cores will likewise be reversed, and the one
formerly attracted by the permanent magnet will be repelled and vice versa. The
cores in their motion rock the beam and break the connections at the two pairs of
mercury cups; one of these as already explained, being connected in the main
circuit between the dynamo or other source of current and the accumulator; this
circuit is thereby broken and the accumulator is prevented from discharging
through the dynamo. If the other pair of mercury cups and their connecting
U piece be in the field magnet circuit, that circuit is thereby also broken.

page_text: If it is for any reason preferable to short-circuit the field magnet circuit instead
of disconnecting it, the terminals of this circuit may be connected to a pair of
mercury cups at the left hand end of the beam, and the depression of the beam
at that end by plunging the U piece into these cups will short-circuit the fields.
Thus the pair of mercury cups at the left hand end, and one pair at the right hand
end of the beam are alternatives for producing cessation of excitation in the field
magnet coils; the former pair being connected up and used when it is required to
short-circuit or bridge across the field magnet terminals; the latter when it is
wanted to break or disconnect the field magnet circuit.
In order to reduce sparking to a minimum and to prevent the formation of arcs
at the point or points of contact breaking, a thin slab or shutter of suitable
refractory substance such as slato, is automatically interposed between the U pieces
and the mercury cups, at the same time that contact is broken. This is accom-
plished in this form of the apparatus by a.connecting rod and bell crank lever
operated by the beam. A slab or shutter of slate or other suitable refractory
substance extends across mercury cups. When the right hand end of the beam is
raised by a reversal of current the slub or shutter is inserted between the cups and
the U pieces, thus preventing the formation of arcs at these points of contact-
breaking.
The shutter is automatically withdrawn when the beam is again depressed at
that end.
This mode of preventing or reducing sparking is applicable to many forms of
contact breakers.
To give warning that the current is reversed and the charging no longer pro-
ceeding an electric bell, or other audible signal may be operated by means of a
contact piece on the left hand end of the beain which completes a subsidiary circuit
in which an electric bell or audible signal is included
If it be desired to give notice of the reversal of current without breaking the
circuit the first U piece at the right hand end of the beam may be lengthened, so
that contact is not broken at the mercury cups in the main circuit. The electric
bell circuit will thus be completed without disturbing the other arrangements. In
this use of the instrument it would act simply as an alarum for current reversal
and the connections to field magnet circuit may be dispensed with.
In order to remake the connection between the dynamo or other source of
current, and the accumulator or system of mains, when the relation between their
electromotive forces has become such that the dynamo is again capable of adding
to the charge of the accumulator, or of supplying current to the mains the following
device is employed ;-
After the main circuit is broken the left hand end of the beam is held down by
a pawl which catches an arm, which projects from the axis of the said beam. This
pawl is attached by a rocking shaft and connecting rod to a second rocking lever,
at the ends of which are suspended two iron cores. These cores hang in two coils.
or solenoids similar to those above mentioned but wound with fine wire so as to
have a high resistance. When the right hand end of the lever is depressed it brings
two contact pieces into contact with two terminals and thereby connects the
terminals of the accumulator, mains or the like, through one coil or solenoid, and
the terminals of the dynamo or other source of electricity through the other coil or
solenoid.
In this way the solenoids or coils being respectively placed between the accumu-
lator terminals and the dynamo terminals, the lever will be actuated by the
difference of the strength of the currents from these two sources-The pawl will
be lifted when the electro motive force of the machine or other source exceeds that
of the accumulator. The amount of excess may be regulated by a spring or sliding
weight on the lever.
The main beam thus released will fall at the left hand end and remake the
connection between the accumulator and dynamo or other source of current, at the

page_text: same time will break the electric bell circuit, and the circuits of the two fine wire
solenoids, as they are no longer required
When this arrangement for releasing the pawl is used the field circuit would not
require to be broken or short circuited and the corresponding terminals and mercury
cups would not be used.
The apparatus is susceptible of many variations, without departure from the
principles of my invention; for instance, in place of the main solenoids, olectro-
magnets, acting on one or more permanent magnets, may be used. Or, a permanent
magnet or permanent magnets may be suspended in the solenoids, and be attracted
or repelled by a change in the direction of the current ;-or the solenoids may be
wound on the cores; or the permanent magnet may be the moving part, and the
cores fixed; or ono solonoid (electromagnet, or equivalent arrangement) may be
employed instead of two.
In another form the beam may be made of iron, and be wholly or in part
surrounded by the main circuit coils; the polarity of the iron bar determining its
attraction to or repulsion from a permanent magnet or permanent magnets placed in
its vicinity. The solenoids may be fixed to the bar and made to move with it; or
they may be fixed and hollow, and constructed so as to allow of the motion of the
bar within them. To release the pawl the differential coils may be replaced by
electro magnets of ordinary form acting on soft iron keepers or armatures. Or, the
two wires may bo wound on one bobbin, or round one core, either together (parallel)
over one another; or on different portions of the same so as to act differentially
on one or inore soft iron keepers, armatures, or entering cores. Or, the use of iron
or steel may be dispensed with, and coils of wire acting on one another may be
employed to produce tho required motion. Or, in place of employing a differential
electric arrangement, such as above described, one solenoid or electro magnet only
may be used, connected to the terminals of the dynamo or other source of current ;
and the armature, keeper, or other moving part or parts may be adjusted by a counter-
balance or sliding weight, or by an antagonistic spring, so as to respond and releaso
the pawl when the electro motive force had attained a given amount
U pieces or forks aro used in the above described apparatus to avoid the
employment of flexible conductors, and to give a double break, but they are not
essential
If found desirable the number of contact breaking points may be increased by
giving the forks a greater number of prongs or projecting pieces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Morris Mordoy in the Great Seal Patent Office on the
10th July 1883.
WILLIAM MORRIS MORDEY of Putney in the County of Surrey IMPROVE-
MENTS IN APPARATUS FOR CONTROLLING INDICATING AND ARRESTING THE FLOW
OF ELECTRIC CURRENT
This invention relates more particularly to controlling the current passing from
a source of electricity, such as a dynamo machine into accumulators or secondary
batteries, into electro depositing apparatus and into systems of electric mains and
the like. It is also in part applicable to switches and other instruments whereby
an electric circuit may be broken.
In charging accumulators or secondary batteries if the electromotive force of the
source fall, from any cause below that already acquired by the accumulator, a
reverse current is set up in the opposite direction to the charging current, and part
or the whole, of the stored up energy is discharged through the source. When the
source of current is a dynamo machine this effect may result from the following
causes amongst others.
Temporary or permanent slowing of the engine driving the dynamo machine; or
from slipping stretching, or breaking of the belt, or failure of the gearing or from
tho accumulator becoming fully charged, or at least charged to such a degree as to
enable it to send a current back to the dynamo machine; or from the machine
being stopped.
Under any of these circumstances the accumulator unless disconnected from tho
charging source, will discharge to a greater or less extent, through the latter.
In electro depositing apparatus a reverse current may also be set up within the
case of a series dynamo, that is, one in which the field magnet coils are in series
with the main circuit, with the additional effect of reversing the polarity of tho
field and the direction of the current.
In systems of electric mains in which a constant difference of potential is sought
to be maintained between the main leads by more than one dynamo machine or
other source of electricity, a generator whose electro motive force was less than the
said difference would offer a path through which a part of the current would flow
and be for practical purposes lost.
The object of this invention is to disconnect the source of electricity from the
conductor or apparatus into which the current flows, when the current from any
cause becomes reversed, and, in some cases, to reconnect the two when sufficient
difference of electro motive forces has been reestablished. This is effected by
breaking the main circuit. In the caso of shunt machines the field coils may, if
found desirable bo simultaneously short circuited through a greater or less
resistance or may be disconnected; and separately excited machines may have their
excited circuits disconnected. Simultaneously with the disconnection of the circuit
a visual or aural signal may be given to apprise the attendant of the fact.
One form of apparatus which I call an Automatic Switch, according to my
invention is shewn in plan Fig. 1 in side elevation Fig. 2 in end elevation Fig 3.
A A² aro two electro magnetic sucking coils in each of which hangs a soft iron
bar or core a a².
Under these coils is fixed a permanent magnet M, so placed that its poles are
opposite the lower ends of the two cores a a¹. The cores a a² are suspended from
a rocking lever or beam B, B' supported on a bracket or bridge C, and having at or
near one end B an inverted fork or U piece of copper U insulated from the beam

page_text: and so placed that when the beam is depressed at the end B, the prongs of the
U piece dip into two mercury cups d d making a connection between them. At
the other end B₁ of the beam are two similar forks or U pieces U₁U" placed
preferably on opposite sides of the beam and so arranged that when the end B' of
the beam is depressed they dip into and make connection respectively with two
similar pairs of mercury cups d' d' d¹¹ d'—The beam is so arranged by means of
its greater weight at the end B' or by a spring or some other suitable means that
in its ordinary position when at rest the four mercury cups dd dd" are
respectively connected together in two groups of two each by means of the
U pieces UU". The electro magnetic sucking coils A A¹ are placed in the main
circuit between the accumulators and the charging dynamo, being connected either
in series or in parallel circuit, as may be found most suitable.
One end of the coiled conductor is connected by the terminal T to the
accumulators, main, or the like, and the other end by means of one pair of mercury
cups d'd, and the U piece U¹ joining them to the terminal T' which is connected
to one pole of the dynamo.
The other poles of the accumulators and dynamo are respectively connected to
the terminals T" T; the coils are so wound or so connected that the current from
the dynamo or other source of electricity when it is passed in the proper direction
and is charging the accumulators, mains or the like produces similar poles at the
lower ends of the cores a a', the poles of the permanent magnet being so relatively
placed that the core a¹ in one coil A¹ shall be attracted by one pole of the
permanent magnet M, and the core a in the coil A shall be repelled by the other
pole of the magnet, so that the end of the beam B¹ remains depressed. But if from
any of the causes enumerated above, the direction of the current becomes reversed
the polarity of the cores a, a¹ is reversed, a being attracted and a repelled by tho
permanent magnet M.
The cores in their motion rock the beam B B¹, and break the connections at the
two pairs of mercury cups d' d¹¹.
One of these d¹ as already explained being connected in the main circuit between
the dynamo, and accumulators, this circuit is thereby broken and the accumulators
are prevented from discharging through the dynamo. If the other pair of mercury
cups d" and their connecting U piece U¹ be in the field magnet circuit, by way of
the terminals t t (the dynamo being shunt wound) the circuit is thereby also
broken.
If it is for any reason preferable to short circuit the field magnet circuit instead
of disconnecting it, the terminals of this circuit may be connected to the mercury
cups & at the end B of the beam, and the depression of the beam at that end by
plunging the U piece U into these cups will short circuit the fields. Thus the
pair of mercury cups at the end B and one pair d" at the end B¹ of the beam are
alternatives for producing cessation of excitation in the field magnets the former
when it is required to short circuit the field magnets the latter when it is wanted
to break or disconnect the field magnet circuit. In order to reduce sparking to a
minimum and to prevent the formation of arcs at the point or points of contact
breaking, a thin slab or shutter of slate or other suitable refractory non conducting
substance is automatically interposed between the U pieces and the inercury
cups d'd at the time the contact is broken. This is accomplished in this form of
apparatus by a connecting rod E and bell crank lever L operated by the beam B B'.
The thin slab of slate or other suitable substance extends across the mercury.
When the end B' of the beam is raised by a reversal of current the slate or
shutter c is inserted between the cups and the U pieces, thus preventing the
formation of arcs at these points of contact breaking.
It will be seen that the shutter is automatically withdrawn when the beam is
again depressed at the end B'. This mode of preventing or reducing sparking is
applicable to many forms of contact breaking switches.
To give warning that the current is reversed and the charging no longer pro-
ceeding an electric bell is operated by means of a contact piece on B which coming

page_text: in contact with the spring e completes a subsidiary circuit connected to
terminals G, G¹ in which an electric bell or other signal is included. If it is desired
to give notice of the reversal of current without breaking the circuit the U piece U'
at the end B' of the beam may be lengthened so that contact is not broken at the
mercury cups. The electric bell circuit would thus be completed without dis-
turbing the other arrangements. In this use of the instrument it would act simply
as an alarum for current reversal and the connections to field magnet circuit may
be dispensed with. In order to remake the connection between the dynamo or
other source of current and the accumulators or system of mains when the relation
between their Electro Motive Forces has become such that the dynamo is again
capable of adding to the charge of the accumulators or of supplying current to the
mains, the following device is employed. After the main current is broken the
end B of the beam is held down by a pawl y which catches an arm / projecting
from the axis of the said beam, by a rocking shaft i. The pawl is connected by a
rodj to a second rocking lever H at the ends of which are suspended two iron
cores K K' which hang in two coils II' similar to A A¹ but wound with fine wire
so as to have a high resistance. When the end B of the lever B B' is depressed it
brings two studs m m¹ into contact with two contact pieces ff' and thereby
connects the coil I to the accumulators or main, and the coil I' to the terminals of
the dynamo or other source of electricity.
In this way the solenoids or coils I I¹ being respectively connected to the
accumulators and to the dynamo the lever will be actuated by the difference of the
strength of the currents from the two sources. The pawl will be lifted when the
Electro Motive Force of the machine sufficiently exceeds that of the accumulators
(the amount of difference necessary to liberate the pawl being regulated by a
spring or sliding weight) The main beam B B' thus released will fall at the
end B and remake the connection between the accumulators and dynamo or other
source of current and at the same time will break the electric bell circuit and the
circuits of the two fine wire solenoids I I. When this arrangement for releasing
the pawl is used the field circuit would not require to be broken or short circuited
and the corresponding terminals and mercury cups would be dispensed with.
The apparatus is susceptible of many variations without departure from the
principles of my invention; for instance in place of the main solenoids, electro-
magnets acting on one or more permanent magnets may be used, Or a permanent
magnet or permanent magnets may be suspended in the solenoids, and be attracted
or repelled by a change in the direction of the current; or the solenoids may be
wound on the cores; or the permanent magnet may be the moving part and the
cores fixed; or one solenoid (electro magnet or equivalent arrangement) may bo
employed instead of two.
In another form the beam may be made of iron, and be wholly or in part
surrounded by the main circuit coils; the polarity of the iron bar determining its
attraction to or repulsion from a permanent magnet or permanent magnets placed
in its vicinity. The solenoids may be fixed to the bar and made to move with it;
or they may be fixed and hollow, and constructed so as to allow of the motion of
the bar within them. To release the pawl the differential coils may be replaced by
electro magnets of ordinary form acting on soft iron keopers or armaturos. Or,
the two wires may be wound on one bobbin, or round one core, either together
(parallel) over one another; or on different portions of the same so as to act
differentially on one or more soft iron keepers, armatures, or entering cores.
the use of iron or steel may be dispensed with, and coils of wire acting on one
another may be employed to produce the required motion. Or, in place of
employing a differential electric arrangement, such as above described, one solenoid
or electro magnet only may be used, connected to the terminals of the dynamo or
other source of current, and the armature, keeper, or other moving part or parts
may be adjusted by a counterbalance or sliding weight, or by an antagonistic
spring so as to respond and release the pawl when the electro motive force had
attained a given amount.
Or

page_text: U pieces or forks are used in the above described apparatus to avoid the
employment of flexiblo conductors, and to give a double break, but they are not
essential.
If found desirable the number of contact breaking points may be increased by
giving the forks a greater number of prongs or projecting pieces.
Having described the nature of my said invention and the manner in which the
same may be carried into practical effect I would have it understood that what I
consider to be novel and original and therefore claim as secured to me by the
herein before in part recited Letters patent is.
1, The use for the purpose of controlling indicating and arresting the flow of
electric current of apparatus arranged and operating substantially as hereinabove
described.
2. Causing the connection between a dynamo electric machine or other source of
current and an accumulator or system of mains to be automatically broken when
the electro motive force of the latter acquires an excess over that of the former
by the use in conjunction with a lever or beam and contact making devices of
electro-magnetic sucking coils or their equivalent and a permanent magnet or its
equivalent the arrangement being such that the reverso current flowing from the
accumulator or system of mains to the dynamo or other charging source shall cause.
the lever or beam to be rocked so as to break contact substantially as described.
3. The use in conjunction with apparatus for making and breaking an electric
circuit of an isolating devico such as a slab or shutter of non conducting material
and means for causing the same to be interposed between the points at which the
electric circuit is broken at the time of its being broken to reduce sparking and to
prevent the formation of an are substantially as described.
4. The use for the purpose of remaking the connection between the dynamo or
other source of current and the accumulator or system of mains in apparatus for
controlling and arresting the flow of electric current of differentially acting apparatus
substantially as described
In Witness whereof I the said William Morris Morday have hereunto set my
and and seal this tenth day of July AD 1883