Automatic Arrangement for Switching Accumulators in or out of Circuit.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Automatic Arrangement for Switching Accumulators in or out of
Circuit.
We, BERNARD MERVYN DRAKE and JOHN MARSHALL GORHAM both of No. 2
Princes Mansions, Victoria Street Westminster in the County of Middlesex Electrical
Engineers do hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide a reliable means for cutting off the
charging current of accumulators when they are full and putting them into the
charging circuit again when they are exhausted.
For this purpose we suspend the cell of the accumulator by means of a double
ended lever and counterbalance and we provide on the lever a sliding or rolling
weight running on guides. It will thus be seen that as the weight of the plates
increases owing to the formation of sulphate of lead while at the same time there is
a corresponding decrease in the weight of the solution, the plates will in time over-
balance the counter-weight and the sliding or rolling weight, causing the lever to be
tilted beyond the horizontal line, whereupon the weight will slide down to the end of
the lever and the battery is then kept in circuit until the reverse action has taken
place and the counterbalance draws the lever in the opposite direction in consequence
of the lightness of the cells.
The above described appliance we make use of for the purpose of putting the
batteries in or out of the charging circuit by connecting with the lever a suitable
device whereby in its motion in one direction or the other it is caused to make or
break or reverse the necessary contacts for this purpose.
Thus according to one arrangement we provide two solenoids the coils of which
are so connected with the battery, through a series of contacts operated by an arm
on the before mentioned lever, that according as this is made to couple up the
solenoids in one way or the other, these are made to actuate a core in one direction
or the other, which core is made to move a contact switch so as to reverse the battery
connections.
Each end of the core has a rod extending beyond the two solenoids, which rods,
when the core has been moved over in one direction or the other, is made to bear

page_text: against a weighted pivotted contact piece that establishes the contact between the
battery and the solenoid coil, so as to break this contact and render the solenoid
inoperative as soon as it has moved the switch over. As soon as the core is moved
in the opposite direction by the other solenoid the weighted contact piece falls back
into its original position, closing the circuit again.
The sliding weight on the balance lever is capable of being increased and decreased
so that by varying it, the degree to which the cell is to be exhausted before it is
again included in the charging circuit may be correspondingly varied. In cases
where a number of cells are charged in series, it is necessary to add a sparking
contact, which may consist of a spring arm fixed on the before mentioned reversing
switch and carrying a contact stud, which as the switch is moved to the one side or
the other, makes contact with the one or other of two blocks connected to leads from
either pole of the battery.
The spring arm is made sufficiently flexible to enable the contacts of the switch to
be brought home without any risk of the switch being drawn out by the action of
the spring.
In many cases it would be required to run the accumulators in conjunction with
the dynamo whenever a certain number of lamps were in use, independently_of
whether the cells were charged or not, so as to avoid the loss in conversion. For
this purpose we carry the lamp circuit through a solenoid which acts on the lever
carrying the accumulator in opposition to the balance weight and tends to connect
the accumulator with the charging circuit.
The extent of this pull could of course be regulated as desired.

page_text: COMPLETE SPECIFICATION.
Automatic Arrangement for Switching Accumulators in or out of
Circuit.
We, BERNARD MERVYN DRAKE, and JOHN MARSHALL GORHAM both of No. 2
Princes Mansions, Victoria Street, Westminster, in the County of Middlesex,
Electrical Engineers, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement:—
The object of this invention is to provide reliable means for cutting off the charging
current of accumulator batteries when they are fully charged, and putting them into
the charging circuit when they are exhausted.
For this purpose, we employ apparatus such as we shall describe referring to the
accompanying drawings. Fig. 1 shews the automatic charging arrangement applied
in the case where an accumulator is charged from a primary battery. Fig. 2 shews
the arrangement in cases where the accumulator is charged from conductors supplied
from a central station.
Referring first to Fig. 1, A is the primary and B is the secondary battery. C is
a cell, which we may term a master cell, corresponding with one of the secondary.
cells B, or it may be one of these cells, and having its plates hanging from one end
of a lever D which is suitably counterweighted and has a rolling weight d applied
to it.
For this rolling weight may be substituted a tumbling weight on a vertical arm of
the lever, or the lever itself may be bent.
The lever arm is extended to carry a Ụ conductor E, the limbs of which dip into
mercury cups. As shewn in the figure, there is a complete circuit from the poles of
the battery A through the mercury contacts E, through mercury in cups F through C
and through the cells B.
When by charging the accumulator, including the cell C, its liquid becomes
heavier and its plates lighter, the counterweight raises the plates of C, breaking
contact at E but not at F. Again when the accumulator is exhausted, the plates
of C, having gained weight while the liquid has become lighter, descend, making
contact again at E and thus bringing the accumulator into circuit with the primary.
In Fig. 2, B represents the accumulator battery and C one of its cells arranged as
above described as a master cell, its lever D carrying on a vertical arm a contact
piece G which as the lever oscillates from the one position to the other makes contact
of either of two pairs of springs g or g'. H and H are two solenoids with their
cores coupled and jointed to a lever K which can make contact with either of two
sets of contact springs k k¹, and which, besides, makes subsidiary spark contacts
at or . There are also two contact levers M M¹, one in the circuit of each of the
solenoid coils. P and N being the main charging leads, when the parts are in the
condition shown in the figure, the circuit is completed from P through the accumulator
cells B and C, through k and K to N. A secondary circuit through g the coil

page_text: of H and M which existed before the parts attained the position shewn and con-
sequently excited the solenoid H causing the core to move to the left, became
opened at M by the last part of the stroke of the core, thus throwing the solenoid H
out of circuit, and allowing a contact to be made by M', which however does not close
another secondary circuit because there is not contact at g'.
When the accumulator is charged, the plates of Cascend causing G to break
contact with y and to make contact with g¹. The solenoid H' is thus excited drawing
the core h towards the right and so moving the lever K, causing it to break contact
at k and to make contact at k³, and also by the last part of the stroke breaking the
contact M. By the break of contact at k the accumulator is cut out of circuit, but
there is continuity of circuit from P through k¹ and K to N.
The movement of the core h to the right having allowed M to make contact, when,
owing to the discharge of the accumulator, the plates of C descend again, G breaks
the contact with g' and makes contact with g completing the circuit through the coil
of H causing movement of h and K. and restoring the parts to the condition shewn
in the figure. As by the arrangement shewn there remains continuity of circuit
from P to N notwithstanding that the accumulator is thrown out of circuit, obviously
the leads P N can serve for charging other accumulators or for other electrical
purposes.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. For automatically switching an accumulator battery into or out of circuit with
its charging source of electricity, utilising the change of gravity of the accumulator
plates and liquid, due to the charge and discharge of the accumulator, for moving
contacts whereby the accumulator circuit is opened and closed, substantially as
described.
2. The automatic switch arrangement consisting of a master cell having its plates
connected to a counterpoised lever to which a contact is connected, substantially as
described with reference to Fig. 1.
3. In combination with the switch arrangement referred to in the preceding claim,
a pair of solenoids having their cores connected to a switch lever with contacts
arranged and operating substantially as described with reference to Fig. 2.
Dated this 10th day of April 1889.
ABEL & IMRAY,
Agents for the Applicants.