Improvements in the Manufacture of Screens or Sieves for Use in Stamp-batteries and otherwise for the Separation of Ore and other Substances.
Year: 1893

page_text: Date of Application, 20th Sept., 1893
Complete Specification Left, 20th June, 1894-Accepted, 21st July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Screens or Sieves for Use in
Stamp-batteries and otherwise for the Separation of Ore and
other Substances.
I, CHARLES RALEIGH, of Johannesburg, in the South African Republic,
Milling Engineer, do hereby declare the nature of this invention to be
follows:
:-
as
This invention relates to the manufacture of screens or sieves for use in stamp-
batteries and otherwise; its principal object being to increase the durability of the
screening material.
In stamp-batteries the screening material ordinarily employed consists of wire
gauze woven with the warp and weft at right angles to one another and respectively
arrauged horizontally and vertically. The working of the stamps subjects the
screens to a pulsatory movement and in a short time produces "bagging." Constant
flexion and reflexion of the gauze then canses some of the warp threads or wires to
open out from one another, thereby not only increasing the size of the meshes at
that part, but weakening the gauze along that line and inducing excessive local
bending of the weft threads, rupture shortly ensuing.
In the manufacture of screens according to my improved method, I cause the
weft threads or wires to assume a position oblique to that of the warp threads or
wires, so that, when in position over the outlet from what is known as the
mortar-
box"
of a stamp-battery, the warp threads or wires are horizontal and the weft
threads or wires diagonal. Or the weft may be horizontal and the warp diagonal
when the screen is in position; the width woven being varied accordingly.
According to another variation, two opposite margins of the fabric are bounded by
selvage wires, whilst the whole of the intermediate wires are diagonal, the latter
being arranged in two series crossing one another at right angles or thereabouts.
It will be obvious that if a screen of rectangular shape be cut obliquely from
wire or other gauze of ordinary manufacture, both warp and weft threads that is,
those composing the body of the fabric-would run diagonally in relation to the
screen-frame. Such a practice would, however, entail considerable waste of
material, and would, moreover, afford no selvage on any one of the four sides of the
material comprising the screen.
Dated the 19th day of September 1893.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Screens or Sieves for Use in
Stamp-batteries and otherwise for the Separation of Ore and
other Substances.
I, CHARLES RALEIGH, of Johannesburg, in the South African Republic,
Milling Engineer, 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 the manufacture of screens or sieves for use in stamp-

page_text: batteries and otherwise; its principal object being to increase the durability of the
screening material.
In stamp-batteries the screening material ordinarily employed consists of wire
gauze woven with the warp and weft at right angles to one another and respectively
arranged horizontally and vertically. The working of the stamps subjects the
screens to a pulsatury movement, and in a short time produces "bagging." Constant
flexion and reflexion of the gauze then causes some of the warp threads or wires to
open out from one another, thereby not only increasing the size of the meshes at
that part, but weakening the gauze along that line and inducing excessive local
bending of the weft threads, rupture shortly ensuing.
The accompanying diagrams represents screens or sieves manufactured according
to my improved method.
In Fig. 1, the welt threads or wires a have been caused to assume a position
oblique to that of the warp threads or wires b, so that, when in place over the outlet
from what is known as the "mortar-box" of a stamp-battery, the warp threads or
wires are horizontal or parallel with the side of the screen or sieve and the weft
threads or wires a diagonal. Or the weft may be horizontal and the warp
diagonal; the width woven being varied accordingly.
According to the variation illustrated in Fig. 2, the opposite margins of the
fabric are bounded by selvage wires c and c', whilst the whole of the intermediate
wires a and b are diagonal; the latter being arranged in two series crossing one
another at right angles or thereabouts.
It will be obvious that if a screen of rectangular shape be cut obliquely from
wire or other gauze of ordinary manufacture, both warp and weft threads that is,
those composing the body of the fabric-would run diagonally in relation to the
screen-frame. Such a practice would, however, entail considerable waste of
material, and would, moreover, afford no selvage on any of the four sides of the
material comprising the screen.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be perforined, I claim :-
1. For use in stamp-batteries or otherwise, the improved manufacture of
screening material substantially as described with reference to the accompanying
diagrams.
2. The employment in a stamp-battery or otherwise of a screen or sieve in which
the warp (or weft) is parallel with the side of the screen and the weft (or warp)
oblique thereto.
3. The employment in a stamp-battery or otherwise of a screen or sieve in which
both the warp and the weft are oblique to the selvage.
Dated the 20th day of June 1894.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.