Improvements in the Art of Making Plates for Electric Battery Purposes.
Year: 1898

page_text: Date of Application, 3rd May, 1898-Accepted, 18th June, 1898
COMPLETE SPECIFICATION.
Improvements in the Art of Making Plates for Electric Battery
Purposes.
I, ALFRED CARENO CROFTAN, a Citizen of the United States of America, resid-
ing at No. 103, State Street, Chicago, Cook County, Illinois, United States of
America, Gentleman, 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;-
My invention relates to certain improvements in the art of manufacturing
spongy lead plates, the special purpose being to produce suitable plates for stor-
age batteries. To such end it consists in a certain new and improved method
and in a certain new and improved spongy lead plate, both of which will be fully
described below and the essential features of which will be pointed out in the
appended claims.
In the drawing furnished herewith I have shown in Figure 1 a simple form
of apparatus to illustrate my improved method, and have also shown in Figures 2
and the preferred form of my improved lead plate or battery grid.
"lead" to cover
In this specification, for convenience I have used the term
any metals which are commonly used for this purpose, as for instance, lead, zinc,
antimony, or other metal.
Describing first the improved method, the apparatus shown to carry out the
same consists of an air compressor, A, connected by means of a pipe, B, with a
Said retort is
retort, C, in the bottom of which are a series of small orifices, c.
arranged above a suitable support, D, upon which is a receiving plate, E, pro-
vided with a handle, F, by means of which it can be moved about upon the
support, D.
The
In practising the method the retort, C, is supplied with lead which is melted
by the application of heat and an air pressure maintained in the retort by means
of the compressor, A, sufficient to crowd the lead out through the orifices, c.
distance between the retort, C, and the receiving plate, E, is such that the metal
as it falls from the retort reaches the receiving plate in a semi-solid form; that
is to say, it is cooled down sufficiently to prevent it from running together into
a solid mass, and yet it is still in a sufficiently plastic condition to weld together
as the particles pile up one upon another. These particles are of a stringy
nature and the receiving plate, E, is vibrated back and forth and from side to
side so as to pile up the stringy particles into a spongy mass, the portions of
which are welded together at their points of contact.
The plate thus obtained is comparatively light and exceedingly porous because
of the stringy form or shape of the particles of lead, the interstices between said
particles being much larger than if the lead were in the form of globules of finely
divided dust, which would result from blowing or showering it in the same semi-
solid condition into a chilling receptacle.
The spongy lead plate thus formed is next subjected to pressure upon certain
portions to form comparatively solid strengthening ribs or frames. This may be

page_text: done by means of suitable presses and dies or rolls, which it is not thought neces-
sary to illustrate in the drawings. The completed plate is shown in Figures 2
and 3, the spongy portions, G, being made up of the stringy lead particles welded
together and the comparatively solid portions, G₁, forming ribs or a strengthen-
ing frame welded to the spongy portions.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what
I claim is —
1 The improved method of forming spongy lead plates, which consists in
forcing molten lead through a series of small orifices and allowing it to pile up
just before solidifying upon a horizontally vibrating surface; substantially as
described.
2: The method of forming spongy lead plates, which consist in forcing the
lead in a molten condition through a series of small orifices, receiving it at a
temperature intermediate between a running and a congealing temperature upon
a horizontally vibrating support and afterwards compressing certain portions of
the spongy mass thus formed to produce comparatively solid strengthening ribs
or frames; substantially as described.
1000
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62, St. Vincent Street, Glasgow, Agents for the Applicant.