An Improved Method of and Apparatus for Stamping Electrode Plates.
Year: 1899

page_text: Date of Application, 28th July, 1899-Accepted, 30th Sept., 1899
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Stamping Electrode
Plates.
We, CARL TIEFENTHAL, Junior, Manufacturer, KARL MEYER, Modeller, and
FRIEDRICH NEBLUNG, Stamp Maker, all of Velbert, Rhineland, Germany, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
Up to the present time the various attempts to stamp indented electrode plates
instead of rolling or moulding them have not attained the success desired. By
the processes already known it has been possible to perforate the plates completely
through and through, but, when this is done, there is, on the one hand, a con-
siderable loss occasioned by the punched out. pieces of lead, and, on the other
hand, the strength of the plate is reduced whilst its effective surface is but very
slightly increased.
The present invention has for its object an improved method and apparatus
whereby accumulator plates can be impressed with indentations to a certain speci-
fied depth simultaneously on both sides of the plate. A central web or thickness
of metal is left between the indentations at each side with the result that the
plate possesses considerable strength or stiffness whilst its effective surface is very
considerably increased in comparison with the small increase in weight of the
plate when compared with completely perforated plates.
In order to carry out the invention it is essential that the usual method of
indenting the plate on only one side at a time be abandoned, and, as already
stated, that the indentations be made on both sides simultaneously and in direct
line with one another.
The advantages of stamping the indentations on both sides simultaneously are
self evident; for, besides the rational mode of operation and the economy effected
by it, the displacement of the material of the electrode plate is rendered homo-
geneous whilst the web remaining at the centre of the plate can be increased or
diminished in thickness as desired.
The drawing annexed shows, by way of example, a convenient mode of con-
structing an apparatus for carrying out the invention.
The electrode plate a which is to be operated upon is surrounded by a frame
in the usual manner and beyond which it cannot extend when subjected to pres-
sure. The so called strikers or plates f, g, are arranged above and below the
frame b and are bound to each other and to the frame 6 by means of the screws d
and are also held in place on the bed of the machine by means of guide bolts c.
The upper plate f projects over a little at each side as shown on the drawing. A
number of vertical holes e are made in each striker and through the
holes e of the bottom striker g pins project upwards said pins being
held rigidly in place by means of the bottom plate k. In line with the
pins i are pins which are secured to the movable stamp-head m and pass through
the holes e of the upper striker f. Screwed into the plates are guide pins no

page_text: round which spiral springs are fitted said springs, which are of a certain speci-
fied strength, bear at their upper ends against the projections of the plate f.
If the stamp head m is moved downwards the pins act upon the plate a and
force it along with the frame b and strikers f and g downwards against the action
of the springs 2. This downward movement of the plate a causes the fixed pins i
to indent the plate at the underside whilst at the same time the moving pins
indent it at the upper side. The movement of the stamp head is so regulated in
conjunction with the action of the springs that the plate a is only indented to a
certain depth at each side.
The stamp head is subsequently caused to ascend with the result that the pins /
are withdrawn from their indentations in the plate a, whereupon the springs
acting upon the strikers f, g, force the plate a up sufficiently to free the indenta-
tions on its underside from the pins . The plate properly indented on both sides
now lies within its frame b and is not warped, bent, or damaged in any manner
and can be easily withdrawn.
Under this method of stamping it is possible to use cylindrical shaped stamps
without tapered or conical points so that the indentations made are of a cylin-
drical form which is a matter of great importance as such shaped indentations
hold the active material securely in place without danger of falling out.
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 consider novel and desire to claim is: -
1. The method of manufacturing indented electrode plates wherein the lead
plate is by means of two sets of stamps simultaneously indented on both sides
with indentations in line with one another a central web of the material being
left between the indentations which web is regulated in thickness by the aid of a
spring or equivalent arrangement, substantially as set forth.
2. An apparatus for stamping electrode plates simultaneously with indenta-
tions on both sides made substantially as hereinbefore described with reference
to the drawings annexed.
Doted this 27th dow of Tul, 1900
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.