An Improvement in the Construction of Elements for Secondary Batteries or Accumulators.
Year: 1886

page_text: Date of Application, 5th June, 1886.
Complete Left, 7th Mar., 1887.
Complete Accepted, 7th Apr., 1887.
PROVISIONAL SPECIFICATION.
An Improvement in the Construction of Elements for Secondary
Batteries or Accumulators.
I JAMES PITKIN of 56 Red Lion Street Clerkenwell in the County of Middlesex
Philosophical Instrument Maker do hereby declare the nature of this invention to be
as follows:-
My Invention relates to improvements in secondary batteries or accumulators, and
it has for its object to provide improved means of retaining the active material in
contact with the supporting plate whereby I am enabled to avoid the use of covering
sheets or plates of non-conducting material which increase the internal resistance
of the battery and are otherwise objectionable and whereby the whole area of the
supporting plate except its edge flanges is available for active material.
According to my Invention, the supporting plate of lead is cast with side flanges
around all four sides and also with projecting studs at suitable intervals over both
faces of the plate to afford the desired hold for the active material. The studs and
flanges are cast taper to draw readily from the mould and to cause them to key the
material to the support, the studs are hammered down so as to burr or enlarge their
outer ends, and at same time depress them below the level of the side flanges.
The flanges also are bent inwards by means of a suitable tool or otherwise undercut
on their inner sides to assist in holding the active material which when filled into the
cavity of the plate covers over the studs and is securely keyed to the plate by the said
studs and flanges. I also cast a tang or tangs in one with the supporting plate of a
suitable form for suspending the element in position and for coupling it with other
elements.
Dated this 5th day of June 1905
J. PITKIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
An Improvement in the Construction of Elements for Secondary
Batteries or Accumulators.
I JAMES PITKIN of 56 Red Lion Street, Clerkenwell, in the County of Middlesex,
Philosophical Instrument Maker, 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 improvements in secondary batteries or accumulators, and
it has for its object to provide improved means of retaining the active material in contact
with the supporting plate whereby I am enabled to avoid the use of covering sheets or
plates of non-conducting material which increase the internal resistance of the battery
and are otherwise objectionable, and whereby the whole area of the supporting plate
except its edge flanges (where such are used) is available for active material.
According to my invention, the supporting plate of lead, is cast with projecting
studs (of round, square, triangular or other form) at suitable intervals over both faces
of the plate, and in addition thereto, it may or may not, also be cast with flanges along
all or any of its four sides, said flanges, if used, projecting from both faces of the plate.
The studs (and flanges if any) are cast taper, so as to draw readily from the mould
and in order to cause the studs to key the active material to the supporting plate, it is
necessary that this tapered form should be reversed, and this I accomplish by hammering
or pressing the studs so as to burr or enlarge their outer ends. The flanges (if any)
are also made to assist in keying the active material to the supporting plate, and this is
accomplished by bending the flanges inwards by means of a suitable tool, or their
inner sides may be undercut by means of a suitable graver or tool such as is used for
cutting sheet zinc or brass. The active material when filled into the cavity of the
plate, covers its whole area, except the tops of the pins and flanges, the active material
being securely keyed to the plate by the said studs and flanges, and protected by the
latter from accidental injury. The active material is preferably red lead applied to
the plate in a pasty condition, but litharge in a similar condition may be used for the
negative element, although, I prefer red lead. I also cast a tang or tangs in one with
the supporting plate of a suitable form for suspending the element in position and for
coupling it with other elements.
Reference is to be had to the accompanying drawings forming part of this specifica-
tion, wherein figure 1 is a face view and figure 2 a vertical cross-section on line 1-1
figure 1, of a supporting plate as cast. Figure 3 shows a similar section on a larger
scale, of a portion of the plate after the studs have been burred down and the flanges
bent inwards.
The same letters of reference indicate the same parts in all the figures.
a is the lead plate, are the studs placed as close together as may be necessary,
over the whole surface of the plate in rows or otherwise, and (say) at a distance apart
from centre to centre of about twice their diameter or rather more, the studs being

page_text: more or less numerous according to the rate of discharge desired. c are the flanges
and d are the tangs cast on the top edge of the plate for suspending and coupling the
element in the battery in the usual way.
Having now particularly described and ascertained the nature the said invention
and in what manner the same is to be performed, I declare that what I claim is :—
1. A supporting plate of lead for the active material of an element of a secondary
battery, having projecting studs which are cast upon its surface and burred over, or
enlarged at their outer ends, as and for the purpose specified.
2. A supporting plate of lead for the active material of an element of a secondary
battery, having studs which are cast upon its surface and burred over or enlarged at
their outer ends, and baving also flanges which are bent inwards or undercut, as and
for the purpose specified.
3. An element for a secondary battery consisting of a supporting plate of lead
having projecting studs cast upon its surfaces and flanges around its edges, the studs
being burred over or enlarged at their outer ends and the flanges being bent inwards
or undercut, and of active material filling the cavities of the plate and covering over
the studs, substantially as specified.
J. PITKIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agonts.