Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND AND OBJECTS OF THE INVENTION
The present invention concerns an electrical accumulator
cell intended for connection with a liquid filling or charging
system common to several cells. The system is intended for
the replenishment of the electrolyte with water and also serves
as a ventilation system for gas formed in the cell.
The invention is intended primarily to be applied to
lead accumulator cells and will be described below in connec-
tion therewith. The invention is applicable, however, to all
types of accumulator cells in which electrolyte is used.
The use of electrolyte in accumulator cells varies to
a high degree with the application range of the cells. Batteries
which are subjected to constant charges and discharges, as,
- for example, in electric-powered trucks, consume large amounts
,s of electrolyte. The same is true of batteries which are
exposed to strong and long-lasting over-charging. In such
cases the control and filling-up of electrolyte may be
required as often as once every twenty-four hours. In other
cases, where the operating conditions are not hard on the
battery, it may be sufficient to control and fill-up the
electrolyte a few times during the year.
- The consumption of electrolyte is also affected by
such factors as the composition of the lead-base alloy in
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'he electrode grid and the age and general condition of
the battery. It is not unusual for electric trucks to
have batteries with up to 50 cells. In larger enterprises
employing many trucks, the daily control and filling-up of
electrolyte in the cells therefore represents a task of
extensive proportions. During the control and filling-up
process the plug or fuse screwed into the venthole may be
removed, the liquid level must be controlled, and the ;~
filling-up must be carried out, whereupon the plug is
replaced. In order to facilitate this task, certain
batteries are provided with a plug having a level-indicating
device and with an aperture for the filling-up that can be
quickly opened and closed. Such measures have reduced the
maintenance problems, but each cell continues to require
individual checking.
The present invention concerns a cell for connection
with a common liquid filling system. This means that by
feeding the liquid at a single point one obtains a filling-up
to the controlled level in several cells at the same time.
Normally, a single filling point should be sufficient for the
entire battery.
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A common liquid filling system and the cells connected
with it must meet certain requirements. The system must be
easy to mani~ulate and make possible the quick filling of
all the cells. Depending on the size of the battery, a dura-
tion of from S to 10 minutes can be accepted. The system
must also be independent of the position of the cells, at
least to a certain extent; that is, it must function even
when the cells for some reason or other are on different
planes or at different angles. Furthermore, it must operate
'~ 10 automatically, i.e., no supervision or measure must be neces-
sary while the filling takes place. The system, moreover, must
~ be safe in operation, and in case of possible disturbances,
,' overfilling must be avoided.
BRIEF SUMMARY OF THE INVENTION
These objects are achieved by apparatus for delivering
liquid to the interior of an accumulator cell. The apparatus
comprises a liquid inflow conduit communicating with the
interior of the cell to conduct liquid thereto from an outside
source. A liquid outflow conduit communicates with the interior
of the cell. A float is arranged within the cell to follow a
rising and dropping level,of liquid within the cell. A liquid
conductor is connected to the float so as to be movable, in
response to raising and lowering of the liquid level, between
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a liquid supply position and a liquid non-supply position.
In the liquid supply position, liquid from the inflow
conduit combines with liquid in the cell, when liquid in
the cell is below a given level. In the liquid non-supply
position, liquid is conducted by the conductor from the
inflow conduit to the outflow conduit, when liquid in the
cell is above the given level.
THE DRAWING
' ~ Other advances of the present invention will become
apparent from the following detailed description of a pre-
ferred embodiment thereof in connection with the accompanying
drawings in which like numerals designate like elements and
in which:
- Figure 1 shows schematically the upper part of a
cell according to the invention;
Figure 2 shows schematically a detail of the cell
of Figure 1 having a lower electrolyte level; and
Figures 3 and 4 are cross-sectional views of top
portions of cells of different embodiments of the invention.
Figures 1, 2 and 4 illustrate the basic concept of the
invention while Figure 3 shows in greater detail a preferred
form of cell for carrying out the invention.
7~3~7
DETAILED DESCRIPTION OF PREFERRED
EMBODIMENTS OF THE INVENTION
Figure 1 shows the upper part of an electrical
accmulator cell according to the invention. Within the
cell container 1 there are disposed electrodes 2, which
are joined to pole taps or plugs 3 and 4. In the container
there is also disposed electrolyte 5, the surface of which
; 16 is here shown at the highest level desired. On the
,,
~i~ electrolyte there is a float 6 which is kept in place by
a lever arm 12, connected with the cell container's cover
by a link 13. On the upper side of the float there is a
bowl-like container 7. Conduit pipes for the inflow 10 and
the outflow 11 of the liquid are attached to the upper side
of the cell by means of a holder 9.
The liquid is conveyed to and away from the cell by
the tubes or hoses 15 and 14. The flow direction of the
` liquid is indicated by arrows in the figure. Figure 2 shows
the details essential for the filling-up function in the same
cell. In Figure 2 the cell with the surface 16 of the elec-
trolyte is shown at such a low level that an additional supply
of liquid is desirable. By way of the tubes 14 and 15 the cell
can be coupled together with other such cells, and it has proved
possible to connect in series up to 10 cells, and also to con-
nect pairs of lines 14, 15 in parallel to a common main line.
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If now it is assumed that the system is to be exempli-
fied by the cell shown in the figure, the tube or hose 15 is
joined to a water reservoir and tube 14 is joined to a suction
mechanism such as a
- The latter makes it possible to obtain a low pressure, so
that the pressure difference between the inflow 10 and the
outflow 11 is about 1 kPa. Water then flows through the
tube 15 and the inflow 10 into the cell. If thé electrolyte
level in the cell is too low, as is the case in Figure 2, then
the liquid flows down into the bowl of the float and from the
latter down into the cell. When the desired level has been
reached, as is the case in Figure 1, the inlet end of the
outflow tube enters the liquid,via the upwardly open end of
the bowl and is able to suck liquid therefrom. Thus, liquid
is collected in the bowl and sucked out again vla the outflow
11 and the tube 14. Thus, the bowl 7 serves as a conductor
to transfer liquid directly from the inflow conduit to the
outflow conduit, when the bowl is in the liquid non-supply
position of Figure 1.
The function of the embodiments shown in Figures 3 and
4 is the same as described above. The difference lies in the
control of the float, which according to Figure 3 is carried
out by two pins or pegs 20, 21 which stick up in the inflow
pipe and the outflow pipe.
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In Figure 4 control is carried out by a pin 25.
This pin serves as a level indicator and is therefore
enclosed in a transparent covering 27. In order to prevent
the float and the guiding pin from sinking too far down, the
upper end of the pin has been provided with a broadening or
widening part 26 which engages a stop.
The embodiment shown in Figure 3.is provided with a bow-
shaped piece or ring 19 for retaining the float, which thus
is guided or controlled by the pins 20 and 21. The ring 19
is fixed in a holder 23 having a circular outer cross-section,
wherein the inflow and outflow channels 10 and 11 are bored
or drilled and provided with connection nipples 17 and 18.
The holder is movably attached to the fastener 22 and is
fixed tightly against it by means of an O-ring 24. The
fastener 22 is fitted in the usual manner in the top of the
container by means of a screw thread. Because the holder 23
is movable in the fastener 22, the holder can be adjusted in
such a way that the suitable position is obtained for the tube
or hose couplings 17 and 18.
Openings can also be made in the cover of the container
for the control of the temperature and the density of the
electrolyte. It is important, however, that these openings
be provided with tightly fitting plugs and that also the cell
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be completely tight, for example, in the seam or groove
between the container and the cover. To control this, the
cell is subjected to an overpressure of about 20 kPa, whereby
a pressure drop of at the most 4 kPa is permitted during a
period of 10 seconds.
In order to safeguard the liquid flow, the ends of
-~ the inflow and outflow tubes can be cut obliquely or on the
bias, as is shown in Figures 3 and 4. One can also use
other arrangements to prevent the openings of the tubes from
becoming wholly or partly blocked by the bottom of the bowl.
Of course, other realizations of the invention than
those described are also possible. For example, the bowl in
which the inflow and outflow tubes terminate may be placed
elsewhere than dlrectly on the upper side of the float, and
the control and placing of the float may also be different
from the description given above.
Although the invention has been described in connec-
tion with a preferred embodiment thereof, it will be appre-
ciated by those skilled in the art that additions, modifications,
substitutions and deletions not specifically describ-d may be
made without departing from the spirit and scope of the inven-
tion as defined in the appended claims.
