Improvements in and relating to Secondary Batteries.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Secondary Batteries.
I, WALTER AMBROSE CROWDUS, of 5227, Woodlawn Avenue, Chicago, in the
County of Cook, State of Illinois, United States of America, Electrician, do
hereby declare the nature of this invention to be as follows:-
This invention relates to secondary batteries of the kind in which the elements
are formed by applying lead salts to conducting supports, and is designed to
provide a secondary battery suitable for use with vehicles, that is to say, to be
carried by vehicles for the storage of electricity to be used either as motive
power for propelling such vehicles or for lighting or other purposes.
The chief objects of my invention are to provide means for preventing or
diminishing the agitation or "wash" of the battery fluid and for preventing the
gradual removal of the active material from the plates by reason of this agitation.
Around each plate or element of my improved secondary battery I arrange a
flexible porous wrapper or envelope of a suitable material, preferably sulphite
paper. This wrapper prevents the agitation or washing of the battery fluid from
removing the active material of the plate, and it also assists in retaining said
active material in position on the supporting plate.
In order to separate and maintain the plates or elements of the battery at the
requisite distance from each other and to further control and prevent any move-
ment of the battery fluid, I insert between each two adjacent plates a sheet or
sheets of perforated porous material, said sheets being preferably formed of wood
pulp fibre. These sheets serve to entangle and hold the battery fluid, and they
are also adapted to completely fill the space between the adjacent plates and to
hold the aforesaid envelopes in contact with the plates enclosed by them. The
perforations in the said sheets reduce the internal resistance of the battery below
that which would be offered by an imperforate sheet, and moreover each individual
perforation forms as it were a separate cell holding its own complement of battery
fluid, and stratification of such fluid is thus prevented.
1
1731
1000

page_text: 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 of the kind in which the elements
are formed by applying lead salts to conducting supports, and is designed to
provide a secondary battery suitable for use with vehicles, that is to say, to be
carried by vehicles for the storage of electricity to be used either as motive
power for propelling such vehicles or for lighting or other purposes.
66
"
One of the chief objects of my invention is to provide means for preventing
or diminishing the agitation or wash of the battery liquid. Another object
is to provide means for preventing the gradual removal of the active material
from the plates by reason of the agitation or shaking to which the battery is
subjected.
According to my invention I arrange around each plate or element, or around
the positive plates only, of the battery, a porous wrapper or envelope of a suitable
material or materials, preferably the material known as sulphite pulp" or
"sulphite paper "which consists chiefly of wood pulp treated with sulphuric
acid and rolled into sheets. I also arrange between each two adjacent plates a sheet
or sheets of perforated porous or absorbent material, said sheets being preferably
formed of wood pulp fibre. These sheets serve to entangle and hold the battery
fluid, and they are also adapted to completely fill the space between adjacent
plates and to hold the aforesaid wrappers in contact with the plates enclosed by
them.
In order that my invention may be clearly understood and readily carried into
effect I will describe the same more fully with reference to the accompanying
drawings in which:
Figure 1 is a sectional elevation of a battery constructed according to my
invention showing the envelope and separating sheet partially broken away from
one of the plates or elements.
Figure 2 is a horizontal section on the line A-B of Figure 1; and
Figure 3 is a vertical transverse section of two adjacent plates on the line C-D
of Figure 1.
I may employ any suitable form of plate or element in my improved battery,
but I prefer to use a plate a constructed in accordance with the Specification of
my prior Patent No. 1628 granted to me on the 20th January 1898.
bis the flexible porous wrapper formed of a thin strip or sheet of sulphite
paper and wrapped longitudinally around the plate so as to practically enclose the
same. The ends of the strip overlap slightly as will be seen in Figure 3. If
the said wrapper were utilized to cover the vertical edges of the plate it would
be liable to be abraided by the sides of the battery case, and for protecting and
enclosing said vertical edges I therefore employ channelling strips c of hard
rubber or other appropriate insulating material. The wrapper 6 and two of the
strips c constitute a complete envelope for the plate; and practically prevent
all detrimental effects due to any agitation or washing of the fluid. Moreover,
should there be any tendency for the active material of the element, as it becomes
disintegrated, to fall or settle toward the bottom of the battery, such falling or
settling will be prevented by the said envelope, the life and the maximum
efficiency of the battery being thus greatly prolonged.
To still further assist in properly insulating the plates and keeping them at
equal distances from each other, as is necessary in all batteries of this type, I
provide a sheet of perforated material d formed of wood pulp. This perforated
sheet is placed against the above described wrapper and between the plates, and
is of such thickness as to be capable, when it absorbs the battery liquid, of com-
pletely filling the space between the opposing elements of the battery and keeping
the aforesaid wrapper in contact with the plate. The perforations form little
cells which hold the battery liquid and reduce the internal resistance of the cell

page_text: below what it would be were the said sheet not perforated. A further advantage
of these cells is that each cell holds its own complement of liquid, and thus acts
to prevent stratification of the electrolyte, which entails more or less serious
consequences.
If desired I may make both the wrapper and separator of sulphite paper or of
wood pulp fibre; or I may use other appropriate material or materials.
In placing the various parts of the battery in position, the edges of the separat-
ing sheets & are slipped into the channels of the strips c, the thickness of said
sheets, when dry, readily admitting of this. The subsequent swelling of said
sheets as they absorb the battery liquid, acts to hold all the parts firmly and
prevent their relative movement.
In the drawings I have shown the positive (or lead oxide) plates or elements
only as enclosed by a wrapper, since the active material of the negative (or spongy
metal) plates is not liable to become disintegrated and to fall or settle toward
the bottom of the battery. Obviously, however, both negative and positive plates
may be provided with a wrapper such as b.
As will be apparent from the drawings the positive and negative elements are
arranged in intermeshing sets and all the positive elements are connected together
at one side of the battery and all the negative elements are connected together at
the other side thereof, in the manner set forth in the specification of my aforesaid
prior patent.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
-
1. The combination with a secondary battery element of a flexible porous
wrapper and a perforated separator for the purposes specified.
2. A secondary battery having its parts constructed arranged and combined
to operate substantially as described with reference to the accompanying drawings
for the purposes specified.
Dated this 15th day of Iul 1890
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.