Improvements in or relating to Sieve Cleaning Devices.
Year: 1895

page_text: Date of Application, 27th Mar., 1895-Accepted, 11th May, 1895
Improvements in or relating to Sieve Cleaning Devices.
A communication from FR. BRANDSTAEDTER, Engineer and Mill Manager, of
Louvain, Kingdom of Belgium.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 an apparatus for cleaning the gauze of sieves of bolting
or sifting machines for coarse meal and finings where the sieves move horizontally
to and fro, or oscillate in circular ares. It consists principally of a movable frame R
placed beneath the sieve, as shown in longitudinal section in Figure 1 carrying
scrapers a arranged separately, at determinate distances, across the direction of
motion. These scrapers are pressed automatically but gently from beneath against
the gauze of the sieve or screen A, and are so placed that reciprocating with the
frame R, the under side of the entire sifting surface of the gauze may be touched
by them at the same time giving the material to be sifted a free passage through
the gauze.
The scrapers a may vary both as to form and arrangement, and are preferably
in the form of indiarubber bands, or ribbons strained across from one bar to the
other in the scraper-frame R as shown in Figure 2, and are equidistantly separated
in such a manner that if, for instance the longitudinal to and fro movement of the
frame R is, say, 2 centimetres, the interval between the scraper only equals
2 centimetres.
Instead of bands or ribbons as above described, wire brushes or the like may be
employed; but in that case it would be necessary to employ, in lieu of indiarubber
some other flexible material suitable for the purpose.
The approximation of the scrapers to the under side of the gauze, so that they
may exert thereon a gentle upward pressure, may, be effected, as shown in Figure 1,
by means of springs S carrying a guide-bar P on which the scraper-frame R rests
and slides to and fro. It is however possible to obtain the necessary effect by
flexion of the gauze of the sieve itself in which case the weight of the material to
be sifted presses down the gauze in such manner that the springs S can be dispensed
with.
The scraper-frame is of such length that a space is left in the sieve-box or
chest K to allow of the displacement of the end-faces r, Figures 1 and 2. From
the reciprocating or to and fro movement of the sieve-box K, the frame R receives
a counter-effect and moves backwards and forwards an amount corresponding to
the open space at each end face due to the difference of length of the frame and
sieve box thereby causing an automatic cleansing of the sifting surfaces.
One sieve-box is divided practically, into four longitudinal divisions so that
four scraper frames R may be arranged in a horizontal plane, side by side,
(see Figure 2); while the flat sieve above them has only two longitudinal
divisions B B Figure 3. Hence this advantage that the gauze of the sieve in one
division B finds a horizontal central support on the separation wall of the
collecting box beneath.
Figure 1 shows a flat sieve reciprocating horizontally with the improved cleansing
arrangement or device.
scillating sieres
The arrangement however is equally applicable to

page_text: In Figure 1 T indicates the sloping bottom of the collecting box down which
glides the sifted material from one end to the other.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated
to me by my foreign correspondent, I declare that what 1 claim is :-
1. In machines for bolting or sifting coarse or fine meal with sieves either
reciprocating horizontally or oscillating in circular arcs an arrangement or device
for cleansing the gauze of the sieve composed of a frame such as R beneath the said
gauze provided with scrapers such as a to press elastically against the under surface
of the gauze and be sufficiently displaced to and fro by the reciprocation of the
frame R as to scrape the sifting surface of the gauze of the sieve while the sifted
material falls between them such scrapers being formed of ribbons bands cords
wires brushes or the like of indiarubber or other suitable flexible material
substantially as described and illustrated in the accompanying drawings.
2. In machines for bolting or sifting meal the combination with a sieve of a
reciprocating frame carrying scrapers substantially as and for the purpose described
and illustrated in the accompanying drawings.
Dated this 27th day of March 1895.
BOULT & WADE,
Agents for the Applicant.