A Self-acting Electro-magnetic Combined Switch and Cut-out.
Year: 1886

page_text: Date of Application, 1st Nov., 1886.
Complete Left, 1st Sept:, 1887.
Complete Accepted, 4th Oct., 1887.
PROVISIONAL SPECIFICATION.
A Self-acting Electro-magnetic Combined Switch and Cut-out.
I, JULIAN MONEY VERNON KENT, of Connaught Mansions, Westminster, in the
county of Middlesex, Electrical Engineer, do hereby declare the nature of my
invention to be as follows:-
This invention relates to au apparatus to be used on an electric circuit wherein one
or more electromotive forces vary, or tend to vary, with respect to each other, as for
instance when a dynamo or primary battery is either employed to charge a secondary
battery or is being used on the same circuit as the secondary battery.
One form of this apparatus substantially consists of an electromagnet wound with a
coil of high resistance which is connected in shunt upon one or more of the sources of
electromotive force, which electromotive force I hereinafter call the prime resultant
electromotive force; near this electro-magnet is a bar of soft iron, capable of
movement about any fixed point in the base of the apparatus to which it is attached
in a suitable manner by means of a pivot, spring, or otherwise. This bar may have
any suitable shape. Upon this bar is wound a coil of low resistance and connected at
one end with the source or sources of prime resultant electromotive force, and at the
other end with an external circuit.
At one end of this bar is placed an adjustable weight, and the other end makes or
breaks the circuit aforesaid in any suitable manner such as by prongs dipping in and
out of mercury cups and the like. Hereinafter this iron bar is called the armature.
The polarities of the armature and of the shunt coil are so arranged and the weight
so adjusted that when the prime resultant electromotive force is as great or greater
than the resultant electromotive force due to the other electromotive forces the circuit
is closed by the movement of the armature; but when this latter resultant electro-
motive force is as great or greater than the prime resultant electromotive force the
polarity of the armature being thereby reversed the polarity of the shunt remaining
the same the circuit is immediately opened by the movement of the armature.
It is sometimes desirable to have more than one high resistance coil in connection
with the apparatus, which coils may be connected in shunt upon any of the electro-

page_text: motive forces acting or tending to act upon the circuit, or they may be connected in
shunt upon any other independant electromotive force such as a local battery and the
like, moreover the current going round any such coil or coils may also be made to go
round the armature.
The coils may be wound in any manner necessary to effect the above described
movement of the armature, and it is not necessary to wind them or more than two
cores though it may be done. The coil may be wound differentially.
Polarization may be effected by means of a permanent magnet.
It is obvious that in any form of the apparatus the armature may be fixed while the
other parts of the apparatus are capable of movement.
COMPLETE SPECIFICATION.
A Self Acting Electro-magnetic Combined Switch and Cut Out.
I JULIAN MONEY VERNON KENT of Connaught Mansions, Westminster in the
county of Middlesex, Electrical Engineer, do hereby declare the nature of my
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 an apparatus to be used on an electric circuit wherein one
or more electromotive forces vary, or tend to vary with respect to each other, as for
instance when a dynamo or primary battery is either employed to charge a secondary
battery or is being used on the same circuit as the secondary battery.
One form of this apparatus substantially consists of an electro-magnet wound with
a coil of high resistance which is connected in shunt upon one or more of the sources
of electro-motive force, which electro motive force I hereinafter call the prime
resultant electro-motive force, near this electro-magnet is a bar of soft iron capable
of movement about any fixed point in the base of the apparatus to which it is attached
in a suitable manner by means of a pivot, spring, or otherwise. This bar may have
any suitable shape. Upon this bar is wound a coil of low resistance and connected at
one end with the source or sources of prime resultant electromotive force and at the
other end with an external circuit. At one end of this bar is placed an adjustable
weight, and the other end makes or breaks the circuit aforesaid in any suitable
manner such as by prongs dipping in and out of mercury cups and the like. Herein-
after this bar is called the armature.

page_text: The polarities of the armature and of the shunt coil are so arranged and the weight
so adjusted that when the prime resultant electro-motive force is as great or greater
than the resultant electro-motive force due to the other electro-motive forces. The
circuit is closed by the movement of the armature but when this latter resultant
electromotive force is as great or greater than the prime resultant electro-motive force.
The polarity of the armature being thereby reversed the polarity of the shunt
remaining the same; the circuit is immediately opened by the movement of the
armature.
I have illustrated in figures 1 and 2 of the accompanying drawings the general
construction and arrangement of an apparatus constructed as first above described for
use when charging batteries by means of a dynamo or other generator, and in
figures 3, 4, 5 and 6 I have illustrated diagrammatically certain modifications of
construction and some of the various modes of connection by which the objects may
be efficiently and conveniently attained. In all the figures similar letters refer to
similar parts.
a is an upright electro magnet wound with a high resistance coil and this is
connected as a shunt upon the dynamo or generator, the connection being made for
convenience at the terminals t t. By this connection the polarity of the electro
magnet a is independent of the direction of the current in the main circuit. B is a
movable armature consisting of a soft iron bar pivotted or hinged at b so as to be
capable of free vibratory motion.
The armature B is wound with a low resistance coil C of sufficient section to carry
the whole current without heating connected to the main circuit preferably by the
connections shown consisting of mercury cups d d into which the ends of the coil
dip and oscillate but never break connection thus allowing free vibration of the
armature; the cup d is connected in the usual way to the main circuit.
The armature B is provided with an adjustable weight and its angular motion
inay be regulated by the adjustable stop b². On the other end of the armature B an
arm F provided with a pair of prongs ff. adapted to make and break circuit through
the mercury cups e e' the former of which is connected to the battery and the latter to
the aforesaid cup d'.
The action is as follows:-
When the electro-motive force of the dynamo exceeds that of the battery, the
magnet a attracts the armature B and so completes the circuit through the cups e e¹.
The main current then traverses the armature coil in such direction as to make the
pole P north, the pole P¹ being south. If then the current reverses or tends to
reverse the pole P is reversed and being repelled by pole P¹ the circuit is broken and
the battery automatically cut out.
In the foregoing description and reference to figures 1 and 2 I have set forth
certain connections which I have found to be efficient it is however obvious that many
modified arrangements and connections may be substituted.
I have illustrated in the diagrams 3, 4, 5, and 6 different methods of accomplishing
the same object.
In that shown in figure 3 there is the addition of a high resistance coil also wound
upon the armature B and placed as a shunt between the positive terminal of the
dynamo and the positive terminal of the battery, and is such that when the current
flows from the dynamo it makes the pole P unlike pole P¹ and vice versa, also when
the main current is interrupted a current still traverses the armature coil by which its
magnetism is maintained.
The arrangement shown in figure 4 differs from that of Figure 3 only in respect of
the connections of the electro magnet a which is a shunt upon the battery when the
main circuit is open.
Figure 5 illustrates the use of a permanent magnet for the armature and two
upright electro-magnets a a¹ placed one at each end thereof each being wound with
coils of high and low resistance. The two electro-magnets a a¹ are connected with
one another in parallel or series as desired. The high resistance coils are connected
in all other respects as in figures 3 or 4 the low resistance coils being connected as

page_text: before described. By this arrangement the armature tends to cling to the left or
right hand magnet according as the current is flowing out or into the battery.
In figures 3, 4 and 5 it is obvious that when the main current is flowing the high
resistance coil shunted between the positive terminal of the dynamo and the positive
terminal of the battery is practically short circuited and only comes into operation
when the main circuit is broken.
Figure 6 represents an arrangement in which the armature B is wound with a
coil of high resistance only and placed as a shunt upon the dynamo or battery and the
upright electro-magnets a a¹ are wound respectively with coils of low and high
resistance the former being in the main circuit as before described and the latter a
shunt between the positive terminal of the dynamo and the positive terminal of the
battery as described in reference to figures 3, 4 and 5.
I have now set for such arrangements and connections as I have found to be
efficient but I do not bind myself to the use only of the particular arrangements
specified as it will be obvious that many modifications may be made whereby the
same or similar results will be attained. I also find it sometimes desirable to utilize
the movement of the armature to vary the resistances of any of the coils or to cut
them in or out of circuit.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is
1. The hereinbefore described construction of self acting electro magnetic combined
switch and cut out consisting essentially of fixed and movable electro magnets so
disposed and connected with the various electromotive forces acting upon them as to
operate substantially at the times and for the purposes setforth.
2. In an electro magnetic combined switch and cut out the arrangement and dis-
position of electro magnets or permanent magnets or both (one of which is necessarily
capable of motion) in such a manner as to automatically operate and be operated
substantially as and for the purposes hereinbefore set forth."
Dated this First day of September 1887.