Improvements relating to Secondary Batteries.
Year: 1890

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by PHŒEBUS HARRY ALEXANDER, of 510, West 23rd
Street, New York, United States of America, General Manager of a Company.]
Improvements relating to Secondary Batteries.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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:-
This invention relates to secondary batteries, and consists in means for cutting the
said batteries out of circuit, the operation of which is made to depend upon the
condition of the liquid or fluid in the cells as determined by the current which is
passing through or from the said battery.
It is desirable and generally necessary to the preservation of a secondary battery, to
interrupt the circuit in which it is contained or to shunt the current charging it around
the battery when it is being charged or discharged too rapidly or when it is fully
charged and the charging current continues to flow. Such conditions are always
accompanied by either a rise of temperature of the exciting solution, or the evolution
therefrom of gas, or both, and the present invention provides means which will be
brought into action or operation by the occurrence of such conditions to interrupt the
battery circuit or to complete a shunt around the same as the case may be.
The object of the first part of the invention is to take advantage of the increase or
rise of temperature which occurs in a secondary battery, when charged too rapidly or
heavily, to operate a thermostatic device by means of which the charging current may
be interrupted or diverted. This may be accomplished in a great variety of ways.
The simplest and most effective way of carrying out the invention, however, is to
employ a box or cell for the battery composed of a substance having a comparatively
high coefficient of expansion, and to utilize this expansion for imparting movement to
one or more contacts arranged to constitute a cut-out or shunting device. This is
readily accomplished by securing to the side of the cell a metal strip slightly bowed
out from the side and fastened at its ends by screws or clamps. Under the centre or
bowed portion of this strip is a contact strip or plate, and the two strips, normally
insulated from one another, are connected respectively to the opposite poles of the
battery.
By such an arrangement it is obvious that the expansion of the side or wall of the
cell will draw down the bowed strip in contact with the other strip or plate and thus
short-circuit the battery. Fusible safety strips may be used to interrupt the battery
and dynamo circuit when this occurs, or other well understood provisions made for
arresting the operation of the battery and dynamo.
It is, of course necessary either that the said bowed strip have a smaller coefficient
of expansion than the material of the cell or else be in such position that it is not
affected to the same degree by the heat of the battery fluid.
It is well known that when a secondary battery has been acted upon by a current
for a certain time it becomes what is known as charged, after which the further action
of the current results merely in the evolution of gas from the solution. At such times
therefore, or whenever through any abnormal conditions gas is given off, it is desirable
to cut-out the battery from the circuit.
The second part of the invention consists in the combination with devices capable
of arresting the charging or action of the battery, as by closing a circuit either
directly or indirectly, and thereby disconnecting the battery from its charging or
working circuit, of a receptacle or body containing a fluid which is capable of being
displaced by the gas evolved from the solution of the battery so that the body will
rise and operate the cut-out devices.
The simplest form of apparatus for this purpose is a simple U-shaped glass tube

page_text: which is filled with any suitable fluid, such as the solution used in the battery cell, and
which is supported with its open ends extending downward into the solution of the
battery.
Above this tube is arranged any suitable form of device which being encountered
by an upward movement of the tube will operate to cut-out the battery.
With a device of this kind when a certain amount of gas passes up into the tube
displacing the liquid therein, the tube rises and operates the cut-out.
These improvements are illustrated in the accompanying drawing in which
Figure 1 is a perspective view of a battery provided with one of the cut-outs, above
described, and
Figure 2, is a perspective view of a battery showing the mode of attachment of the
other form of cut-out.
A is the containing cell or box for any ordinary form of secondary battery.
B, B, are the battery-plates which are immersed in a suitable fluid or solution, and
C, D, are the battery terminals or poles.
The material of the cell or case À should be of hard rubber or other similar material
having a relatively high coefficient of expansion. To one side or outer wall of the cell
or box A, is secured a metal strip E bent or bowed slightly so that under ordinary.
circumstances its centre is raised from contact with the side of the cell sufficiently to
permit the insertion under it of a contact terminal F. The strip E is conveniently
secured to the cell by screws G passing through holes in the strip near the opposite
edges of the side of the cell so as to take advantage of as much of the expansible wall
of the cell as possible.
The strip E is electrically connected to one of the battery terminals, as D, and the
contact plate or strip F is similarly connected with the other terminal C. Between
the battery terminal D and the binding post H, by means of which the charging
current is conducted to the cell, is inserted a fusible safety strip K. A similar
strip L is inserted between the binding-post H and the opposite battery terminals C,
as for instance at a convenient point in the strip F.
Whenever in the use of or process of charging or forming this battery, the fluid
therein becomes heated a condition well known to be extremely detrimental to the
battery, the increasing temperature expands the side wall of the cell so that the strip E
is drawn down into contact with the plate or strip F. The first effect of this action
will be to short-circuit the battery and to fuse the strip K which is to be made smaller
or more easily fused than the strip L. The battery is thus cut-out and the charging
circuit then interrupted by the fusing of the strip L.
Each cell of a series of batteries may be provided with one of these cut-outs so that
any local defect or improper action may be at once detected.
It is obvious that the object of the invention is or may be accomplished the instant
that the two contact strips are brought together by the expansion produced by the
heating of the battery fluid. For this movement, once obtained, may be utilized in a
variety of ways, as for instance, to sound an alarm either electrically or mechanically,
to operate an indicator or annunciator, or to shunt or cut-out the battery by many
well known forms of apparatus.
In the modified form of cut-out above referred to and which is illustrated in
Figure 2, T represents a metal strip secured to the side of the cell A and electrically
connected with one of the binding-posts. S is a second metallic strip having a
flexible portion which extends under the first.
I, is a shaped glass tube which is to be filled with any desired liquid, preferably
the same as is used for the battery solution, and is hung over the edge of one
of the plates B with its open ends extending down into the solution of the
battery. As long as the tube is filled with liquid, it has no tendency to rise,
but if gas is evolved from the battery solution, some of the ascending bubbles
enter the open ends of the tube displacing the liquid therein. This causes the
tube to rise, and at a predetermined point, it encounters the flexible strip S which is
normally out of contact with the strip T and raises it until it touches the said
strip T.

page_text: The battery by this means is short-circuited, and the safety strips K, L, of which
the latter is made more sensitive than the former, are at once fused, thus interrupting
the charging circuit and that through the battery.
The devices employed in connection with the tube or body for cutting out the
battery or for interrupting the charging or working circuit, may be very greatly
varied, and any of the well known devices may be employed for this purpose provided
they are capable of being operated directly or indirectly by the movement of the said
tube.
The special devices shown are merely given in illustration of the principle of the
operation.
The movement of the tube I, may be employed not only for effecting in the manner
set forth the disconnection of the battery from the circuit, it may be used for indicating
directly or indirectly by an suitable means when the battery is charged.
Both of the above described devices may be associated with the same cell, but for
the sake of illustration they are shown as applied to different cells.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First. A Thermostatic cut out combined and associated with a secondary battery in
substantially the manner set forth and adapted to be operated by the heat of the
battery fluid when the temperature of the same rises to a given point as set forth.
Second. The combination with a secondary battery, of a cut-out attached to a part
of the battery capable of expansion as the result of a rise of temperature of the
battery fluid and adapted to be operated by such expansion as herein set forth.
Third. The combination with a secondary battery, of a band or strip having a
different coefficient of expansion under varying temperatures from the material com-
posing the jar or cell and secured to said cell so as to be moved by the expansion of
the same by the heating of the battery fluid, and a contact plate arranged to be
encountered by the said strip or band, these parts being constructed as a circuit-closer
or cut-out to divert the charging current from the battery when the fluid therein
becomes heated.
Fourth. The combination with the expansible cell or case of a secondary battery,
of a bent or bowed metal strip E secured to the side of the cell at two points, the
contact strip F extending under the same, an electrical connection between the poles
of the battery and the said strips whereby the contact of the two strips will shunt
the battery, as herein set forth.
Fifth. The combination with a secondary battery of a body or receptacle containing
a liquid and supported in the solution in such position that the liquid therein will be
displaced by gas evolved from the solution, and a cut-out device adapted to be operated
by the movement of said body due to the displacement of liquid by the ascending gas,
as set forth.
Sixth. The combination with a secondary battery, of a receptacle containing liquid
open at one end and supported in an inverted position in the battery solution and a
cut-out device in position to be encountered and adapted to be operated by the said
receptacle when movement is imparted thereto by the displacement of the liquid by
gas evolved from the solution, as set forth.
Seventh. The combination with a secondary battery of a U-shaped tube filled with
liquid and supported in an inverted position in the solution, and contact terminals of
a cut-out device in position to be brought into engagement by an upward movemeent
of the tube due to the displacement of liquid therefrom by gas evolved from the
solution, as set forth.
711 1
T
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.