Improvements in Supports for the Active-material of Accumulator- electrodes.
Year: 1899

page_text: Date of Application, 20th Jan., 1899-Accepted, 25th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Supports for the Active-material of Accumulator-
electrodes.
We, FLORIS WÜSTE, FRIEDRICH VON RUPPRECHT, and CARL VON RUPPRECHT, of
the Firm Accumulatoren-Fabrik Wüste und Rupprecht, of Baden und Wien, in
the Empire of Austria, 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:-
In the construction of an accumulator-plate or electrode, the high requirements
which have to be fulfilled both with respect to capacity as well as to durability,
involve the reconciliation of the most heterogeneous conditions. Whilst on the
one hand, much active material must be employed in order to give the plate a
high capacity, on the other hand it is not advantageous in the interest of the
strength and stability of the plate to unduly diminish the weight of the support.
Whilst, on the one hand, in order to obtain a large surface of contact between the
electrolyte and the active material and to protect the support from being attacked
by the electrolyte, the active material should surround the support; on the other
hand, in order to obviate untimely falling off of the active material it is necessary
to enclose the active material as much as practicable by the support. In order to
preserve the strength of the plate as a whole, the frame must be as rigid and stiff
as practicable, whilst on the other hand the unavoidable increase in volume of the
active material during the use of the accumulator, especially of the positive plate,
causes the support, if it cannot yield, to be broken or the active material therein
shattered. Finally it is advantageous that the active material, where possible, of
the whole plate shall form a rigid coherent mass in itself, whilst again to obtain
good conduction of the current from and to the badly-conducting active material,
as large a contact surface as practicable is necessary between the said active
material and the support, which cannot be well effected without cutting up and
subdividing the
the said active material.
To satisfy these requirements, which oppose each other in many respects, as
completely as practicable, is the object of the present invention, which relates to a
special construction of support for the active material of accumulator-electrodes.
In Figures 1 to 4 of the accompanying drawing are shown several forms or
modifications of our improved supports for the active material, in each case in
elevation and in transverse section. Figure 5 is a side elevation partly in section,
illustrating a further modification of our invention.
The improved support consists essentially of two or more grids a and b arranged
parallel to each other and enclosing the active material at the side, and consisting
of bars either running parallel, Figure 2, or intersecting each other at suitable
angles, Figures 1, 3 and 4. The bars of the several grids are displaced relatively
to or cross each other, whereby as good a distribution as practicable of the metal
in the active material and therefore as good a conduction of the current as
practicable to and from the badly-conducting active material are obtained.
It is to be noted that the two grids neither touch each other anywhere, nor are

page_text: they connected together in any way; except at the edge c of the plate where the
two grids are united to form one cast piece. On the bars of each grid (in the case
of a grid having crossing bars, preferably at the intersecting parts thereof) and
formed in one piece therewith, there are arranged small cylindrical or otherwise
suitably formed rods perpendicular to the plane of the grid and completely
penetrating the active material of the plate.
By means of these small rods a firm connection is made between the support and
the active material, and a large contact surface obtained without deteriorating the
solidity of the body of active material. On the other hand, by means of the grids,
fall of the active material is effectually prevented without too much reduction of
the contact surface between the active material and the electrolyte, since each grid
itself is to some degree anchored in the mass of active material, and thus can be
made fairly slight, wherewith again a reduction in the dead weight of the support
is effected. Finally, from the circumstance that the two grids are in no way
stiffened relatively to each other, an elasticity or capacity of yielding of the supports
is afforded so as to permit of the alterations in volume of the active material.
Figure 5 illustrates a modification of our invention wherein several of the above
described supports are united as panels to form a larger support consisting of one
cast piece.
The manufacture of the supports for the active material above described is
effected by casting the metal around the active material moulded in special
moulds, which active material, so to speak, forms the core. If desired, also, a
false core can be employed which is then removed and the active material
afterwards introduced.
Having now particularly described and ascertained the nature. of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A support for the active material of accumulator-electrodes, wherein two or
more grids are cast around active material suitably moulded to form a core, or
around a false core, parallel to and opposite each other, and neither touch nor are
in connection with each other except at their edges with which they form a single
cast piece, and the bars thereof are displaced relatively to each other and are
provided with rods extending through the active material, all for the purpose of
obtaining as great a capacity as practicable by good distribution of the metal in
the active material and at the same time ensuring a good hold therefor without
preventing expansion thereof, substantially as hereinbefore described.
2. A support for the active material of accumulator-electrodes consisting of
several of the supports hereinbefore described united as separate panels into one
cast piece, as set forth.
Dated the 20th day of January 1800
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicants.