Improvements in Packets or Pads for Electric Cells.
Year: 1891

page_text: Date of Application, 18th Dec., 1891-Accepted, 23rd Jan., 1892
COMPLETE SPECIFICATION.
Improvements in Packets or Pads for Electric Cells.
I, LEWIS HOPKINS ROGERS of Brookline, in the County of Norfolk, State of
Massachusetts, United States of America, Electrician, 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 improvements in packets or pads to be used in a galvanic
cell to produce the electrolyte or active part of the cell. It consists in enclosing
an electrolytic chemical within a casing or envelope made of suitable absorbent or
porous material, which is to be kept in a dry state until the cell is to be charged
and used, when it is to be moistened to dissolve the chemical and bring the
electrolytic solution thus produced into contact with the positive and negative
elements of the cell, which preferably rests against the casing of the pad so as to
generate an electric current.
It further consists in means to retard the polarization of the cell caused by the
electrolytic chemical coming into too close contact with either of the elements of
the cell. Also, in means to accelerate the starting of the action of the cell, and in
minor details of construction, as will be fully set forth in the Specification and
claims.
The invention is carried out as follows, reference being had to the accompanying
drawings, whereon:
Fig. 1 represents a plan view of one of the forms of my improved packet or pad.
Fig. 2 represents a central longitudinal section of the same.
Fig. 3 represents a similar section of the packet, showing the means employed to
retard the polarization of the cell.
Fig. 4 represents a plan view of a second or modified form of the packet
or pad.
Figs. 5 and 6 represent central longitudinal sections of other modified forms of
the same.
Fig. 7 represents a perspective view, partly in section of an electric cell, con-
sisting of a positive element, a negative element, and one of my improved packets
or pads interposed between said elements and resting against them.
Fig. 8 represents a perspective view, partly in section, of an electric cell, con-
sisting of a positive element, a negative element, one of my improved packets or
pads introduced between said elements and resting against them both, the electrode
of the negative element projecting through perforations in the pad and in the
positive element and showing the complete cell resting within a box or case.
Similar letters refer to similar parts on the different parts of the drawings.
The sulphate of copper, or other electrolytic chemical a, in a dry state, is
enclosed within a casing or envelope made of sheets of blotting paper bb or other
suitable absorbent or porous material, preferably sewed together at their edges as
shown at 6 in Figs. 1, 2, 3 and 4.
This constitutes a very neat and convenient form in which to transport the
electrolytic chemical, and allows the amount of the chemical contained within the
packet to be previously weighed or measured, and varied according to the variations
in the time it is desired to have the cell generate an electric current the various
amounts required having been predetermined by experiments, and if so desired, the
packet may be suitably marked to indicate the time during which it will generate a
current within the cell.
In Figs. 7 and 8, Z represents the positive element of an electric cell, having
the terminal z, which element is preferably made of zinc, and in said figures

page_text: C represents the negative element of the cell, having the terminal c, which element
is preferably made of copper. The packet or pad containing the electrolytic
chemical is moistened and placed between the elements Z and C, resting against
them both when the cell is generating an electric current, as shown in said figures.
In Fig. 8 the elements forming the cell are shown as placed within a box or case A,
and having the terminal c of the negative element passing upward through
perforations in the packet or pad and in the positive element Z as described
hereinafter.
If it is desired to introduce a resistance between either the positive or negative
elements of the battery and the electrolytic chemical, to retard the polarization of
the battery, I increase the thickness of the absorbent material on the side of the
packet or pad which is to rest against said element, either by increasing the number
of sheets of absorbent material, or using one sheet of greater thickness, or increasing
both the thickness and the number of sheets used on that side of the packet or pad.
In Fig. 3, I have shown this resistance as consisting of an increased number of the
sheets bb, but I do not wish to confine myself to the construction shown in said
figure, as it may be varied as above described without departing from the spirit of
this portion of my invention.
To prevent the enclosed chemical from being shaken into any one place in the
packet or pad and to retain it more evenly distributed over the entire packet or
pad, the same may be quilted as shown at 6 in Fig. 4, but this is not necessary to
the working of the packet, although it may be desirable in some places.
When the packet or pad is to be used in a cell in which the terminal of one of
the clements of the cell is to pass through said packet, I prefer to perforate the
packet and provide such perforation with an eyelet 63 or with a row of stitching or
other binding on the packet around such perforation, as shown in Fig. 8, but it is
not essential to use the packet in such cells alone, as it is equally well adapted to
be used in other forms of cells, as shown in Fig. 7.
If so desired, the packet may be supplied with a binding e as shown in Fig. 5,
which binding is sewed on the outer edges of the packet to strengthen the same, or
it may be supplied with a metal binding d as shown in Fig. 6 adapted to hold the
chemical within the packet by clamping the sheets of absorbent or porous materials
together, or the same may be cemented or glued together in any suitable manner.
I do not wish to confine myself to the exact form of casing or envelope shown in
the drawings, as the same may be made in various forms, as for instance in the form
of bags, envelopes, etc. Nor do I wish to confine myself to the use of blotting
paper as the material within which the electrolytic chemical is to be enclosed, as
felt and various kinds of cloth, or other well known absorbent or porous materials
might be used to equal advantage without departing from my invention; also the
chemical used to produce the electrolytic solution may be varied according to the
kind of material used to form the positive and negative elements of the cell.
To use my improved packet or pad we proceed as follows: If we use a cell
having a sheet of copper for one element and a sheet of zinc for the other or
opposite element, and a packet containing a quantity of sulphate of copper for an
electrolyte, one of the elements of the cell, as for instance the sheet of copper,-
is placed within the cell; the packet is then placed against the sheet of copper and
having the increased thickness of absorbent material opposite to the side resting
against the copper; a sufficient quantity of water to dampen the entire packet is
then poured upon the packet, and the other element of the cell, as for instance the
sheet of zinc, is placed within the cell so as to rest against the thickest part of the
absorbent material of the packet, as shown in Figs. 7 and 8. If the sheets of
copper and zinc are then connected by a metallic connection an electric current
will then be generated within the cell. It is not essential that the packet or pad
should be dampened after it is placed within the cell as it may to equal advantage
be dampened just before it is to be introduced within the cell."
It will be seen that the increased thickness of the absorbent or porous material
on one side of the packet or pad will act in a similar manner and accomplish the

page_text: same result as the porous earthenware pot used in the cell known as the "Daniells"
cell.
It is not essential that the absorbent material should be increased in thickness as
described, to retard polarization, for the same result would be obtained if the
chemical was encased within an envelope made of absorbent or porous material of
even thickness throughout, and the resistance produced by the introduction of a
suitable number of extra and independent sheets of absorbent or porous material
between the proper elements of the cell and the packet or pad.
To accelerate the starting of the action of an electric cell in which one of my
improved packets or pads is used to form the electrolyte, I prefer to use absorbent
or porous material which has been previously saturated with a solution of the
chemical formed by the action of the cell, as for instance, in the cell above
described, composed of sheets of copper and zinc with a packet containing sulphate
of copper for the electrolytic chemical, I would saturate the absorbent material
which is to rest against the zinc with a solution of sulphate of zinc, and dry such
absorbent material before encasing the sulphate of copper within it. This causes
the cell to generate an electric current as soon as the copper, zinc and moistened
packet have been brought together and the metallic circuit has been closed between
the copper and zinc, without having to wait for sufficient sulphate of zinc to be
formed by the decomposition of the sulphate of copper and consequent production
of sulphate of zinc. The chemical used to saturate the absorbent or porous
material depends upon the materials used in forming the different elements of the
cell, and may be varied accordingly without departing from my invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is -
1. The herein described packet or pad for an electric cell, consisting of an
electrolytic chemical, and a casing or envelope of absorbent or porous material,
containing said chemical, adapted to be moistened to form the active material of
the cell, substantially as set forth and described.
2. The herein described packet or pad for an electric cell, consisting of a casing
or envelope of absorbent material, adapted to be placed between and to rest against,
both the positive and negative elements of the cell, said casing containing a charge
of electrolytic chemical, which chemical dissolves and forms the active material of
the cell when the pad moistened, substantially as set forth and described.
3. The herein described packet or pad for an electric cell, consisting of sheets of
blotting paper joined together at their edges, forming an envelope or casing, and a
charge of an electrolytic chemical contained between said sheets of blotting paper,
said pad being adapted to be placed between and to rest against, both the positive
and negative elements of the cell, to form the active material when said pad is
moistened, as set forth and described.
4. A packet or pad for an electric cell, consisting of an electrolytic chemical, a
casing or envelope of absorbent or porous material containing said chemical, and a
perforation in said packet having an eyelet or other binding, for the purpose as set
forth.
5. A packet or pad for an electric cell, consisting of an electrolytic chemical, a
casing or envelope of absorbent or porous material, containing said chemical, and a
perforation in said packet having an eyelet or other binding, for the purpose as set
forth.
6. An electric cell consisting of a positive element, a negative element, and a
packet or pad consisting of an electrolytic chemical, a casing or envelope of
absorbent or porous material encasing said chemical, placed between the elements
of the cell and adapted to form the electrolyte by moistening said packet, as set
forth and described.
7. An electric cell, consisting of a positive element, a negative element, and a
packet or pad introduced between the two elements consisting of an electrolytic

page_text: chemical encased within a casing or envelope of absorbent or porous material, said
casing being of an increased thickness on one side to retard polarization of the cell,
as set forth and described.
8. A packet or pad for an electric cell, consisting of an electrolytic chemical, a
casing or envelope containing said chemical, made of absorbent or porous material,
said casing having been previously saturated with a solution of the resulting chemical,
produced by the electrolysis of the enclosed chemical, whereby the starting of the
action of the cell is accelerated, as set forth and described.
Dated this 18th day of December 1891.
LEWIS HOPKINS ROGERS.
Herbert & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.