An Improved Apparatus for Controlling Electric Currents, especially applicable for Charging Secondary Batteries or Accumulators.
Year: 1899

page_text: Date of Application, 29th May, 1899
Complete Specification Left, 6th Mar., 1900-Accepted, 29th May, 1900
An Improved Apparatus for Controlling Electric Currents, especially
applicable for Charging Secondary Batteries or Accumulators.
We, VERITYS LIMITED, Electrical Engineers, of Plume Works, Aston, in
the County of Warwick, and LOUIS JOHN STEELE, Electrician, of 14, Clarendon
Road, Holland Park, in the City of London, do hereby declare the nature of
this invention to be as follows:-
:-
Electric current controlling apparatuses of the type to which this invention
refers are well known in the art, and are extensively used when charging
secondary batteries or accumulators for safe dealing with any opposing electro-
motive force, in excess of that of the charging circuit or dynamo, which may
for a time prevail in the secondary battery or secondary circuit, until such time
as the electro-motive force of the primary current or dynamo is sufficiently high
to resist and overcome the opposing force referred to. Such a lowering of
the electro-motive force of the primary circuit is of frequent occurrence in
dynamos, wherein speed varies and belts often break or slip.
This invention has for its object an improved apparatus of the kind above
referred to in which the objects to be attained are accomplished in a more
efficient manner than hitherto, there being no waste of power in the shunt coil
of the apparatus while the charging is taking place, but a universal adjustment
of the whole of the material parts of the apparatus in relation to each other.
The apparatus constructed according to this invention comprises the follow-
ing parts: An oscillating carrier, preferably of a ring formation, has fitted
to it so as to be longitudinally adjustable a permanent magnet or equivalent
device the one end of which projects from the carrier and moves pendulum-like
between the curved poles of an electro-magnet constructed as hereinafter
described. This carrier is fulcrummed by a knife edged pivot pin within a
suitable bracket attached to the supporting slab or base of the apparatus, and
on opposite sides of it are connected two copper contact pieces so as to be in-
sulated from the said carrier, the said contact pieces having an adjustment in
two directions viz.:-vertical and transverse. The said contact pieces are pre-
ferably carried upon the carrier by forming bosses on the carrier sides through
which holders for the contacts adjustably pass, the said holders being locked
within the said bosses after adjustment. The said contact pieces are also
adjustable within the holders, preferably by set pins. A flexible connection from
the main current wire is taken to each of these contact pieces, one in the circuit
at front of the apparatus and one at the back of the apparatus. The permanent
magnet is connected to the ring carrier by two simple clamping pins passing
through slots in either of the parts.
An electro-magnet, as before referred to, is disposed below the projecting
active face of the permanent magnet, before described, so that its pole pieces,
which are adjustable upon the core and curved to the radaii of the active face
of the permanent magnet, are separated sufficient to admit of the oscillation of

page_text: the carrier, as aforesaid, bringing the end of the permanent magnet in the
field of either of its poles, the said permanent magnet being attracted or repelled
by the effect of the said pole pieces. The core of this electro-magnet is wound
with series and shunt coils, each connected to a terminal in the main circuit
and to a mercury cup adjustably fitted to the slab or base of the apparatus
adjacent to the contacts of the ring carrier before referred to, and with which
said mercury cups the said contacts alternately engage. The connections of the
series and shunt coils are such that there is no waste of power in the apparatus
so long as the electro motive force of the dynamo exceeds that of the secondary
battery the circuit of the shunt coil being at the time opened, (the shunt coil
not short-circuited).
When working with the EM F of the dynamo the greatest, the current
from the dynamo passes from the main into the series coil of the electro-magnet,
whose poles are thereby excited so as to respectively attract and repel the per-
manent magnet in a direction which will rock the ring carrier and dip the con-
tact piece into the mercury cup of the series coil circuit, at the same time with.
drawing the contact from the mercury cup of the shunt coil's circuit. If at any
time the opposing electro motive force of the secondary battery overcomes that
of the dynamo the polarity of the electro-magnet is instantly changed and the
permanent magnet caused to oscillate over to the opposite pole piece, which
automatically opens the main or charging circuit and closes the shunt circuit,
the effect of which is that the permanent magnet would be held by the electro-
magnet under the influence of the shunt circuit until such time as the EM F
of the dynamo again exceeds that of the battery.
The distance between the pole pieces of the electro-magnet, and the amount
of air gap between their curved faces, and the permanent magnet, can be adjusted
to any nicety by the simple operation of screw pins or similar devices which
connect the parts to their carriers, and the permanent magnet can easily be
disconnected from its carrier-ring, as also can the contact pieces, for refitting,
the construction of the apparatus and the fitting of its parts being of special
importance as regards adjustment and the ease with which the whole can be
taken apart, refitted, and put together, especially having regard to packing for
transit.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Patent Agents for the Applicants.
An Improved Apparatus for Controlling Electric Currents, especially
applicable for Charging Secondary Batteries or Accumulators.
We, VERITYS LIMITED, Electrical Engineers, of Plume Works, Aston, in
the County of Warwick, and LOUIS JOHN STEELE, Electrician, of 14, Clarendon
Road, Holland Park, in the City of London, 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:
Apparatus of the type to which this invention refers is well known in the
art for controlling electric currents in a particular way, and is extensively used
in the charging of electrical accumulators or secondary batteries for safe deal-
ing with any opposing electro-motive force in excess of that of the charging
circuit or dynamo which may for a time prevail in the secondary battery or

page_text: secondary circuit, the said apparatus being such that the excess electro-motive
force referred to is passed to a safety circuit until such a time as the EM F
of the primary current or the dynamo has risen sufficiently in voltage to again
resist and overcome the opposing force referred to. The lowering of the E F
of the primary circuit below that of the secondary circuit is a common occurrence
when dynamos are used for charging accumulators, in consequence of the speed
of the dynamo varying and driving belts slipping and in some cases breaking,
in which case the apparatus deals safely with the return current. This inven-
tion comprises an improved apparatus of the kind hereinbefore referred to in
which the objects to be attained are accomplished in a more efficient manner
than in apparatus hitherto, there being no waste of power in the high resistance
coil or circuit of the apparatus while the charging of the secondary battery is
taking place. In the apparatus according to this invention a universal adjust-
ment of the whole of the material parts in relation to each other is attained,
and the construction of the apparatus as a whole and the fitting of its parts is
such that portions of it can be easily refitted and taken apart for package in
transit. Further, the general design is substantial and the apparatus is free
from all delicately fitted parts which would be likely to get out of order quickly.
An apparatus constructed and having its parts arranged according to this inven-
tion is illustrated in the accompanying sheet of drawings. In this sheet Fig. 1
is a front elevation with some of the parts in section, and Fig. 2 a transverse
vertical section with some of the parts in elevation, the material parts of the
apparatus being supported in these views upon the usual base or slab. Fig. 3
is an elevation of a portion of the back Fig. 2. Figs. 4 and 5 are modifications
of adjustments of some of the parts Figs. 1 and 2.
In these figs. an oscillating carrier c of a ring formation has fitted to it,
preferably so as to be longitudinally adjustable, a permanent magnet d, the
one end d of which projects from the carrier and moves pendulum-like between
the curved poles e, e³, of an electro-magnet e, constructed and provided in the
manner hereinafter described. The carrier c is fulcrummed by a knife edged
pivot pin f within a bracket g attached to the supporting slab or base board a
of the apparatus, and on opposite sides of it carry two copper contact pieces h, h³,
which have an adjustment in a longitudinal direction. The said contact pieces
are carried upon extensions or ears h³, h, projecting from the boundary of
the carrier, and their adjustability within the said ears are controlled by set
pins h5, 6. In Fig. 5 a contact piece is adjustably fitted to the ear h, in
the same way as in Fig. 1, but the said ear is adjustably connected to the
carrier by a screwed shank, h, thereon taking through a boss on the carrier
and being fitted with lock nuts h³, h.
The permanent magnet d has between it and the carrier c, a copper strip i,
which is in electrical communication with the pivot pin f. The latter is knife-
edged at the parts f2, f³, where it engages the bracket g. The bracket g is of
an open box construction which will allow of a free oscillating movement of
the magnet d and the carrier c (which move as one piece), and it is connected
to the base board or supporting slab a by screw pins a², a³. A flexible con-
nection, (Figs. 2 and 3) from the main or charging current terminal, m, is
taken to the contact pieces h, h2, through the pivot pin f, copper strip i, and
carrier c; the necessary connection for this being indicated in Fig. 1 by a dotted
line, which latter is used in the drawings to indicate the main circuit of the
apparatus. The magnet d, whose end is represented as being a north pole, is
connected to the ring carrier by two simple clamping pins c³, c.
The electro magnet e as before referred to, is disposed on the supporting slab
or base a, below the end d of the permanent magnet in a position so that its
pole pieces e, e, which are curved, are separated sufficient to admit of the
oscillation of the carrier c bringing the end d² of the permanent magnet within
the field of either the one or the other of the said pole-pieces; the said per-
manent magnet being attracted or repelled by the effect of the said pole pièces,

page_text: and the move-
ment of the contact pieces h, h, is brought about. The core of the electro-
magnet is wound with low and high resistance coils o, o², respectively con-
nected to a terminal in the main circuit and to a mercury cup r,, adjustably
fitted to the slab or base of the apparatus adjacent to the contact pieces h, h³,
the said contact pieces alternately engaging the said mercury cups. The coil o
is connected with the terminals m, n, and the mercury cup r, and the low
resistance coil is connected up to the terminal, and the mercury cup ², so
that the latter coil under ordinary conditions of working of the apparatus,
viz. When the electro motive force of the dynamo exceeds that of the secondary
battery or accumulator, or, in other words, the EMF of the charging circuit
exceeds that of the charged circuit, is out of the circuit entirely (not short
circuited), so that no waste of power takes place therein.
and, as a consequence the oscillation or rocking of the carrier
In the drawings a chain line represents the connection of the low resistance
circuit of the apparatus. The voltage required for actuating the coil of this
circuit is the measure of difference between the EMF of the dynamos and
the EMF of the battery necessary to bring the apparatus into action for safe
guarding the charging circuit.
One of the pole pieces of the electro magnet e is shown adjustable by the
modification Fig. 4. This adjustability allows of the distance between the two
pole pieces and the consequent air gap being varied.
Fig. 3 shows the flexible connection Fig. 2 leading from the terminal m
to the pivot pin f.
ACTION OF APPARATUS.
When working with the dynamo EMF exceeding that of the battery, the
current from the dynamo passes to the terminal m and from thence to the
carrier c, mercury connection h, r, and low resistance coil o, after which it
passes to the terminal of the apparatus and from thence to secondary battery
or accumulator. When this takes place the pole pieces e², e', are so excited
as to hold the permanent magnet d upon the pole piece e, and keep the mer-
cury connection h², r, active. If at any time the EMF of the dynamo drops
sufficiently low to cause an opposing MF from the secondary battery or
charged circuit, the polarity of the electro magnet e is instantly changed and
has a reverse action upon the permanent magnet d to cause it to oscillate over
onto the opposite pole piece, which automatically opens the charging circuit
by breaking the mercury connection h, r, and closes the high resistance circuit
by making the mercury connection h, ; the effect being that the permanent
magnet would be held by the electio magnet under the influence of the high
resistance circuit until such time as the EMF of the dynamo again exceeds
that of the battery.
The windings of the electro magnet are preferably mounted upon a solid
copper tube or spool w (as shown in the drawing in rig. 1) so that when the
high resistance circuit is broken the risk of breaking down its insulation owing
to its self-induction is reduced to a minimum. The mercury cups r, r, can
be replaced by flexible rubbing metal contacts if desired.
It is claimed for the apparatus as aforesaid that it is of simple construction,
has no delicate parts, is compact, and its action sensitive and certain, whilst
the saving of power is the result of arranging the high resistance circuit in
such a manner as to be cut out when the parts of the apparatus are in a working
position as shown in the drawings.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is: -
Winet An annaratus
ot the kind described. distinguished by an electro-

page_text: magnet having its windings or coils arranged to affect its pole pieces in the
manner described, in combination with the mercury connections or contacts or
their equivalents h, r², and h², r, controlling low and high resistance circuits,
and an oscillating carrier c carrying a permanent magnet and parts of the
mercury contacts as aforesaid, the whole electrically connected to the primary
and secondary circuits to operate in the manner described.
Second. An apparatus of the kind described consisting of an electro-magnet e
wound so as to influence its pole pieces in the manner described, an oscillating
carrier c moving on a knife-edged fulcrum upon the base or slab a and carry-
ing contact pieces h, h2, and a permanent magnet d (the latter working over
the pole pieces and the electro-magnet e) mercury cups r, r², into which con-
tact pieces h, h², alternately dip, and flexible connection /, all arranged to
work in the manner described.
Third. In an apparatus of the kind described, the combination of an electro-
magnet having its windings or coils arranged to affect its pole pieces in the
manner described in combination with mercury connections or contacts h, r2,
and h³, r, a permanent magnet d, and a flexible connection, substantially as
described and set forth.
Fourth. An apparatus of the kind described constructed and having its parts
arranged to operate in the manner described and set forth in Figs. 1 to 3.
Fifth. In an apparatus of the kind described, making the contact pieces of
the mercury connection and the pole pieces of the electro-magnet adjustable for
the purposes described and in the manner set forth.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also at Liverpool, London, and Manchester,
Patent Agents for the Applicant.