IMPROVEMENTS IN AUTOMATIC SWITCHES FOR USE IN CHARGING SECONDARY BATTERIES OR ACCUMULATORS
Year: 1885

page_text: We THOMAS JOHN JONES of 12 Princes Street Hanover Square in the County
of Middlesex, Electrician and REGINALD BELFIELD of Lyndally Palace Road Tulse
Hill Park in the County of Surrey, Electrical Engineer, do hereby declare the
nature of our invention for "IMPROVEMENTS IN AUTOMATIC SWITCHES FOR USE IN
CHARGING SECONDARY BATTERIES OR ACCUMULATORS," and in what manner the
saine is to be performed, to be particularly described and ascertained in and by the
following statement :-
.
Our Invention relates to automatic switches to be used when charging secondary
batteries or accumulators by means of a dynamo electric machine for the purpose
of protecting the dynamo from injury from a discharge of the battery in case the
electro-motive force of the dynamo shall fall below that of the battery; and also
for the purpose of providing against charging the battery in the wrong direction
in consequence of a reversal of the polarity or leads of the dynamo from any cause.
The action of this switch is such as to automatically cut off the battery from the
dynamo when the electro-motive force of the latter falls, and at same time
throw into the circuit of the latter a permanent resistance, and to automatically
throw the battery again into the circuit of the dynamo when the electro-motive
force of the latter shall have sufficiently increased; also to rectify the direction of
the charging current in case the poles or leads of the dynamo should be changed
by any means, and so insure the charging of the battery still in the same direction.
The switch consists, essentially, in the combination of an electro-magnet or
magnets or a solenoid, a permanent magnet attached to one or more rocking
frames carrying contact arms, mercurial or other contacts, and a resistance, Bo
connected and arranged as to cause the battery to be switched out of, and the
resistance to be switched into, the circuit of the dynamo and vice versa, without
breaking the current, and also to rectify the direction of the charging current in
case of reversal of polarity of the source as above mentioned.
Various forms and arrangements of the protector switch may be adopted of
which we have illustrated several examples in the accompanying drawings forming
part of this specification and we will proceed to describe the same with reference
thereto.
Figure 1, is a plan of an elementary form of protector switch by which the
princinlo man bo rodillained

page_text: Figure 2, is an elevation and Figure 3 a plan of a practical form of the
instrument.
Figure 4, is a part elevation of a modification of the instrument.
Figure 5, is an elevation of an instrument similar to that shown in figures 2
and 3 in which the mercury cups move in the opposite direction to the contact
arms. Figures 6. 7. 8 et seq are further modifications as hereinafter described.
Referring to figure 1, M is a permanent magnet pivoted at m. A A¹ are a pair
of arms attached to but insulated from the magnet and making contact with one
pair at a time, of five contact pieces C numbered from C¹ to C³, the pair with which
they make contact being dependent on the position of the magnet, that shown
being the normal position to which the magnet tends to return by the action of
springs a or of gravity. E E¹ are a pair of electro-magnets placed opposite the ends
of the permanent magnet M these electro-magnets being so wound as to present
like poles to the opposite ends of the magnet M whereby there will be produced at
one end of the magnet M attraction, and at the other end repulsion, the magnet
being thereby deflected to the right or left as the case may be according to the
direction of the current traversing the electro-magnets.
D D', are the terminals of the dynamo, B B¹ the battery terminals, and R R¹ the
resistance terminals, the connections being made as follows:-
One end of each electro magnet is connected via the spring to one arm and
the other to the corresponding terminal of the dynamo. Contacts C¹ and C³ are
connected together and to the one terminal of the battery to be charged, the other
battery terminal being connected to contact C³. Contacts C² C' are connected to
the resistance terminals R R¹,
The switch being in its normal position the course of the current is as follows:-
+pole D of dynamo, electrio magnet E, arm A, contact C'; Resistance, contact C",
arm A, electro-magnet E¹,-pole D¹.
When the dynamo has attained sufficient electro-motive force to cause the
electro magnets E E' to deflect the magnet A (the point at which this occurs being
determined by the resistance) the arms are brought into contact with C¹ and C³
whereby the battery is thrown into circuit in lieu of the resistance. Should now,
the electro-motive force of the source fall to or below that of the battery the
electro magnets, lose their magnetism, the magnet A returns to its normal position
cutting off the battery and substituting the resistance which remains in circuit
until the electro-motive force of the dynamo again exceeds that of the battery.
Even should the maguet A fail to be returned to its normal position by the action
of the springs or gravity it would be forced to do so by the reversal of polarity of
the electro-magnets by the battery current.
Should the polarity of the dynamo become changed by any means the action
would be as follows:-
=
The arms A A¹ would be thrown on to contacts C³ and C5 and the path of the
current would be; + pole D¹, electro-magnet E¹, arm A¹, contact C³, + pole B of
battery, pole B', arm A, electro-magnet E,-pole D, the direction of the current
through the battery remaining unchanged. In this case, the effect of a fall of the
electro-motive force of the dynamo is the same as before and needs no further
description.
Referring now to figures 2 and 3, the magnet M is fixed on a rock shaft m on
which are fixed two metallic bosses a a² insulated from each other and from the
axis, each boss carrying three arms A¹ A² A³, A* A³ Aº, two on one side and one on
the other of each boss there being three arms, in all, at each side of the axis.
These arms are bent and dip at the ends into corresponding mercury
cups C1 C2 C3, C4 C5 C6 and are at such heights that in the normal position two
arins, viz those A¹ and A', are immersed, their corresponding cups C² C* being
respectively connected to the resistance terininals R R¹.
The magnet A plays between dissimilar poles of the electro-magnets E E¹ so
that when it is attracted by the one and repelled by the other electro-magnet, the
rocking frame is oscillated to one side until all the arms on one side are immersed

page_text: in, and the others lifted out of the mercury. The bosses A A¹ being connected via
the electro magnets E E¹ with the respective terminals D D₁ of the dynamo, while
the two mercury cups C2 C3 being connected with the one pole B¹, and the
cups C³ C with the other pole B of the battery, the same effects are produced in
like circumstances as previously described in reference to figure 1.
In order to increase the range of motion of the rocking frame whilst reducing
the play of the magnet, the latter may be pivoted at its opposite end m as in
figure 4 and connected by a slot and pin with a crank arm a² on the axis a³ of the
rocking frame.
Instead of fixed mercury cups as in figures 2 and 3, the motion may be divided
between the arms and the cups by mounting the latter on a frame c rocking on an
axis c (parallel to that of the rocking frame described in figures 2 and 3) and
provided with a crank arm c³ so connected by pin and slot with the permanent
magnet as shown in figure 5, that the contact arms and cups move in opposite
directions.
Instead of the two sets of arms being carried on the same rock shaft and moving
together they may be worked separately by cams on the rock shaft as in figure 15
so that the one set is raised when the other is lowered.
Instead of a pair of electro magnets and a bar permanent magnet we may use a
horse-shoe permanent magnet and a bar electro-magnet wound with a consequent
point and provided with poles at the ends and middle, between which the
horseshoe magnet plays as in figure 6.
Or we may use a horseshoe permanent magnet with a bar electro magnet
between its limbs as in figure 7, the permanent magnet in both figures 6 and 7
being fixed to the axis of the rocking frame carrying the contact arms, while the
electro magnet in figure 6 is fixed, and in figure 7 may be fixed or made to rock on
a centre below; the electro magnet in this case carrying the mercury cups on a
rocking frame as in figure 5. Or the electro magnet may be fixed on a sleeve
loose on the axis of the permanent magnet, said sleeve carrying the cam working
one of the frames as in figure 15 the axis carrying the other cam and the
permanent magnet being either rocking or fixed.
Instead of an electro magnet, we may use a solenoid S having a consequent
point at its centre traversed by a bar permanent magnet M as in figure 8, the
permanent magnet being hung by a sort of parallel, motion of which one member
is an arm fixed to the axis of the rocking fraine carrying the contact arms arranged
as in figures 2 and 3; or instead of the solenoid we may use a bar electro magnet
wound with a consequent point placed below or above a bar permanent magnet as
in figures 9 and 10 respectively either the electro-magnet or the permanent magnet
being hung in the parallel motion and the other fixed as the case may be.
Instead of a single rocking frame the two sets of contact arms may be carried
by separate axes parallel to one another; each axis having an arm fixed to it at
about right angles to the rocking frame, to which arms, forming members of the
parallel motion, are jointed the opposite ends of the permanent magnet (as in
figures 11 and 12) or of the permanent magnet, or of the electro-magnet as the case
may be, if either of the arrangements shown in figures 9 and 10 are used.
In the arrangement shown in elevation and plan in figures 11 and 12 the
contact arms of the rocking frames project towards one another so that when their
axes are rocked by the motion of the permanent magnet in one direction the one
set of arms is raised and the other lowered as shown in dotted lines in figure 11.
Each set consists of a pair of arms 'A' A³, A³ A' the two pairs dipping in the
same mercury cups C¹ C'.
One arm of each pair has a third arm A³ A dipping in separate mercury
cups C C the connections and operation being as follows:-
A¹ and A are connected together and to one pole of the machine via the
solenoid while A2 and A² are also connected together and to the other pole; the
cups CC are connected to either pole of the battery to be charged. In the
normal position only the arms A³ A° are in mercury and these being connected to

page_text: the poles of the machine send the current through the resistance. On the change
taking place one of these latter arms is lifted out and the pair on the opposite
shaft immersed. thus cutting the resistance out of, and putting the battery into,
circuit; the direction of the charging current decides as in the former cases which
pair of arms shall be immersed.
In figures 13 and 14 the two rocking frames worked in the manner above
described in reference to figures 11 and 12 have each one arm A, A¹ each arm
terminating in a set of four contact points the two sets dipping in the same four
mercury cups C¹ 0 C3 C4 arranged in a square, the one set being so arranged as to
connect the cups C¹ C3, C2 C diagonally and the other set to connect the
cups C¹ C³, C³ C³ the poles of the battery being respectively connected to the
cups CCs and the poles of the dynamo to the other two cups C¹ C³ the connection
being via the coil or electro magnet in the case of C¹. Each arm A A¹ also carries
a fifth contact point dipping in an extra mercury cup said cups C5 C6 being
respectively connected with the terminals of the resistance. The contact points
are of different lengths such that in the normal position the points a³, a², and a³, a
only are immersed in the mercury and the dynamo circuit is closed through the
resistance. By the oscillation of the rocking frames the principal mercury
cups C C C C are connected diagonally or otherwise according as the one or
other set is immersed the effect being to throw the battery into the circuit, the
reversal of polarity of the dynamo being guarded against in the manner previously
described.
In all the arrangements herein described an indicator may be attached to the axis
of the rocking frame or one of them to show at a glance the position of the switch.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is
The various combinations of parts constituting a switch for the purposes
hereinbefore specified constructed and operating substantially in the manner herein
described and illustrated in the respective figures of the drawings.
Dated the 28th day of March 1885.
T. J. JONES.
REGINALD BELFIELD.
By their Agents, A. M. & Wm Clark,
53, Chancery Lane, London, W.C.