AUTOMATIC ELECTRIC COUPLER
Year: 1885

page_text: I, JOHN SMITH RAWORTH of No 24, Brazenose Street, Manchester in the county
of Lancaster, Electrical Engineer, do hereby declare the nature of my invention for
AUTOMATIC ELECTRIC COUPLER " to be as follows:-
This invention relates to an improved method of coupling a dynamo-electric
machine (or other variable source of electric energy) with the main leading wires
in cases where two or more machines are working parallel or where one or more
machines are working parallel with primary or secondary batteries, and the object
of this invention is to effect the connecting or coupling of the machine with the leads
automatically so soon as the difference of potential at the terminals of the machine
become slightly higher than in the adjacent portions of the main leads, and to
break the connection whenever the electromotive force of the machine falls so low
that current ceases to flow from the machine to the main leads, thus, preventing,
the magnetism of the machine from being reversed by current passing through it.
in the wrong direction.
The automatic coupler consists of a magnet or electromagnet, balanced on pivots
and influenced by three solenoids; two of high resistance are shunts between the
main leads and between the machine terminals respectively, and are arranged to
have opposing influences upon the magnet, so that when the strengths of currents
in the two solenoids are equal, the magnet will not move, but if the current due to
the machine preponderates, the magnet will turn in one direction on its pivots and
make the connection between the machine and the leads. As soon as this
connection is made, the currents in the two shunt solenoids become equalised, and
the magnet would lose its bias if it were not for the third solenoid which is of low
resistance and carries either the whole or an adequate portion of the main current.
The magnet is weighted on one side so that it will break connection with the main
leads whenever the current ceases to flow through the solenoid of low resistance.
If it should fail to act and current should commence to come back through the
machine, this reverse current will instantly move the magnet and break the
connection.
I prefer to make these automatic couplers with electro-magnets excited by two
coils, each being in series with one of the above mentioned high resistance
solenoids, but these exciting coils act in unison and are not opposed in their effect,
seeing that they have no tendency to move the magnet but only to make it
susceptible to the influence of the solenoids.
...J

page_text: The arrangement which I prefer to adopt is the same which I have described in
my Patent Specification No 76684 for "Electric Meter," wherein a magnet is
supported on pivots within a solenoid and excited by coils of wire around the axis
which connects the pole pieces. I have also found advantage in forming extensions.
on the ends of the pole pieces at right angles thereto, that is to say, parallel with
the axis. The actual connection between the machine and the leads is made by
copper forks dipping into troughs of mercury which forks are moved in either
direction by the above described magnet.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.
'
I, JOHN SMITH RAWORTH, of No 24 Brazenose Street, Manchester in the County
of Lancaster, Electrical Engineer, do hereby declare the nature of my invention for
"AUTOMATIC ELECTRIC COUPLER" and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to an improved method of coupling a dynamo-electric
machine (or other variable source of electric energy) with the main leading wires
in cases where two or more machines are working parallel or where one or more
machines are working parallel with primary or secondary batteries, and the object
of this invention is to effect the connecting or coupling of the machine with the
leads automatically so soon as the difference of potential at the terminals of the
machine become slightly higher than in the adjacent portions of the main leads, and
to break the connection whenever the electromotive force of the machine falls so
low that current ceases to flow from the machine to the main leads, thus preventing
the magnetism of the machine from being reversed by current passing through it in
the wrong direction.
.
The automatic coupler consists of a magnet or electromagnet, balanced on pivots
and influenced by three solenoids; two of high resistance are shunts between the
main leads and between the machine terminals respectively, and are arranged to
have opposing influences upon the magnet, so that when the strengths of currents
in the two solenoids are equal, the magnet will not move, but if the current due to
the machine preponderates, the magnet will turn in one direction on its pivots and
make the connection between the machine and the leads. As soon as this con-
nection is made, the currents in the two shunt solenoids become equalised, and the
i

page_text: magnet would lose its bias if it were not for the third solenoid which is of low
resistance and carries either the whole or an adequate portion of the main current.
The magnet is weighted on one side so that it will break connection with the main
leads whenever the current ceases to flow through the solenoid of low resistance.
If it should fail to act and current should commence to come back through the
machine, this reverse current will instantly move the magnet and break the
connection.
I prefer to make these automatic couplers with electro-magnets excited by two
coils, each being in series with one of the above mentioned high resistance solenoids,
but these exciting coils act in unison and are not opposed in their effect, seeing that
they have no tendency to move the magnet but only to make it susceptible to the
influence of the solenoids.
The arrangement which I prefer to adopt is the same which I have described in
my Patent Specification N° 76688 for "Electric Meter" wherein a magnet is
supported on pivots within a solenoid and excited by coils of wire around the axis
which connects the pole pieces. I have also found advantage in forming extensions
on the ends of the pole pieces at right angles thereto, that is to say, parallel with
the axis. The actual connection between the machine and the leads is made by
copper forks dipping into troughs of mercury which forks are moved in either
direction by the above described magnet.
Fig. 1 of the accompanying drawings is a front elevation, Fig. 2 a side elevation
partly in section and Fig. 3 a plan of an automatic electric coupler according to my
invention; Fig. 4 is a diagram shewing the electric connections.
In all the figures similar parts are indicated by similar letters.
a is a table and b a base made of any strong insulating material such as wood,
slate, ebonite or the like; c is a frame carried by four pillars d standing up from
the base b. This frame c carries two screw centres e e supporting the pivots of the
balanced electro magnets f which is free to turn on its pivots through a considerable
angle and is connected by a link g to a copper dipper k. According as the magnet f
turns in the one direction or the other it causes the dipper k to become immersed
into or to rise out of mercury in two cups m¹ and m³.
The positive conductor from the machine to which the coupler is applied is fixed
to the terminal n¹ and the main leading wire of the outer circuit is connected by a
wire with the binding screw n², consequently when the dipper k enters the mercury
the machine is in direct communication with the outer circuit.
The return wire from the outer circuit is permanently connected with the
negative conductors of the dynamo machines or other sources of electric energy.
The instrument contains one circuit of low resistance and two circuits of high
resistance.
The low resistance circuit carries the full current of the dynamo machine from
the terminal n 1, to the terminal n 2 through the copper band o which is for the
most part wrapped round the two bobbins or frames p1 p 2 which carry part of the
fine wire of the two circuits of high resistance.
The first circuit of high resistance starts from the terminal n 1 and after making
a great number of convolutions round the bobbin or frame p 1 crosses over to the
central bobbin p 3 which surrounds the axis of the electromagnet f, and after
making a great number of turns round it finally joins the main negative conductor
at q. The second high resistance circuit starts from the terminal n 2 and after
making a great number of convolutions round the bobbin or frame p 2 crosses over
to the central bobbin p 3 which surrounds the axis of the electromagnet f and
after making a great number of turns round it finally joins the main negative
conductor at q.
The difference between the two circuits of high resistance consists in their being
wound in opposite directions on the deflecting bobbins p 1 p 2 whilst they are wound
in the same direction round the magnetising bobbin p 3. They therefore both tend
to produce similar polarity in the electromagnet f, but their deflecting actions are
opposed to each other. Thus the current which passes from the main positive

page_text: '
conductor to the main negative conductor through the coil wound on the bobbin p 2
constantly tends to hold the dipper k out of the mercury whilst the current which
passes from the positive pole of the dynamo machine through the coil wound on
the bobbin p 2 constantly tends to immerse the dipper k in the mercury. So long,
therefore, as the difference of potential in the main leads exceeds that at the
terminals of the dynamo machine, the dipper k cannot enter the mercury and the
machine is kept out of circuit. But a rise of one or two volts in favour of
the dynamo machine is sufficient to cause the dipper to enter the mercury and
so to establish the connection between the dynamo and the leads.
The main current from the dynamo then flows through the circuit of low
resistance, following the copper band o which is arranged to incline the dipper k
to remain immersed in the mercury cup as long as any current continues to pass
from the dynamo machine to the leads.
Small resistance coils included in one of the circuits of high resistance serve
to adjust those resistances so that the dipper may enter the mercury when the
potential in the dynamo machine exceeds that in the leads by any prearranged
number of volts.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The construction of automatic electric coupler for connecting and disconnecting
a dynamo machine and a circuit by the movement of a magnet subject to opposing
influence of two highly resisting shunt coils connecting respectively the terminals of
the machine and those of the circuit substantially as herein described.
2. In an electric coupler of the kind referred to in the preceding claim, in
combination with the magnet and the two shunt coils, a low resistance coil, which,
according to the direction of current through it, assists the one or the other of the
shunt coils in its action on the magnet, substantially as and for the purpose set
forth.