Improvements in or relating to Apparatus for Screening and Sifting Coal, Ore, and other Materials.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Apparatus for Screening and Sifting
Coal, Ore, and other Materials.
We, ANTON OBEREGGER, of Fohnsdorf, Styria, Austria, Engineer, and EDWARD
CARR GREAVES, of 3, Herbert Road, Nether Edge, Sheffield, Traveller, do hereby
declare the nature of our said invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The object of our invention is to effect improvements in apparatus for screening
and sifting coal, ore and other materials, whereby the substances to be screened
or sifted are suitably agitated, and the material is economically and rapidly
delivered to the respective receptacles without being smashed or pulverised.
According to our invention we make use of one or more sieve or sieves mounted
in suitable framing, in an inclined position, and operated in such a manner that
the sieves partake of tranverse and longitudinal reciprocating motions by reason
of their connection with revolving cranks or eccentrices, such motions being in
some cases applied to a greater extent to one end of the sieve or screen than to the
other end.
And in order that our said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which
similar figures of reference indicate corresponding parts.
Fig. 1 is a plan view illustrating one method of communicating motion to a
sieve 14, by means of a revolving crank at or near the receiving end 15, such
motion being reduced transversely and progressing by a series of oval curves to
an ultimate reciprocating longitudinal motion at the delivery end 16.
Fig. 2 is a longitudinal vertical section of a double screen apparatus.
Fig. 3 is a plan and Fig. 4 a sectional elevation, showing three superposed
screens.
Fig. 5 is an elevation of the driving gear end of Fig. 4, showing also the ball
bearings (omitted in Fig. 4 for greater clearness).
Fig. 6 is a plan showing an arrangement for operating four sieves or screens
simultaneously.
Fig. 7 is a sectional elevation on the line ab of Fig. 6.
Fig. 8 is a sectional elevation on the line c, d of Fig. 6.
Fig. 9 is a sectional elevation on the line e, f of Fig. 6.
Fig. 10 is an elevation showing an arrangement of sieves or screens placed
spirally. Fig 11 is a plan of the same, and Fig. 12 is an extended detail view of
the screens shown in Figs. 10 and 11.
Fig. 13 is a plan of an arrangement of sieves of trapezoidal forms.
Referring to Fig. 2-14 is the upper sieve, having a delivery shoot 17. 18 is
the lower sieve, the two sieves being coupled together. 19 is a portion of the
frame. 20, 20, are the side walls of the screens or sieves. 21, 21, are additional
plates for protecting the walls 20 from wear and tear of the materials. 22, 22,
017

page_text: are angle irons joining the frames together. 23, 23, are suspension rods, chains,
or ropes for suspending the sieves at each end, and reducing friction. Additional
supports are sometimes provided in case those shown should break. Other forms
of support may be used, if preferred. In some cases ball bearings 29, as shown in
Fig. 1, are fitted to the supports between horizontal plates. 25 is a vertical
driving shaft carrying a crank pin 26, and fitted with a balance wheel 27 carrying
a block 28 to balance the crank and ensure smoothness in working. 30 is the
delivery opening or shoot for the dust, the screened material passing out of the
sieves by the shoots 17 and 24.
Figs. 3, 4, and 5 illustrate another arrangement in which the two sieves 14 and
18 are coupled together and operated by the crank 26", and the lower sieve 31
is separately mounted and operated by the crank 26. The cranks 26 and 20ª
are arranged in opposite positions, at angles of 180° apart, whereby the motions,
are balanced, and the wheel 27 and weight 28, shown in Fig. 2, are dispensed
with. The method of applying ball bearings to the frames is shown at 29 in
Fig. 5.
Figs. 6, 7, 8 and 9, illustrate the application of our invention to four sieves
united together so as to be operated simultaneously by one eccentric, or ran
equivalent crank motion.
These sieves are rectangular in plan, and are partly superposed and placed at
right angles to each other, as shown in Fig. 6.
They are also set at suitable inclinations respectively, as shown in Figs. 7, 8
and 9.
Thus the material falling from the screen 32 is partly received by the solid
plate 36, and thereby conducted with the remaining material from 32 to the
sieve 33. In like manner the material falling through the sieve 33 is received
by the sieve 34; and that from the sieve 34 is in like manner received by the
sieve 35. Each of these sieves is provided with a delivery shoot for the sifted
material, as shown in the drawings.
The four sieves are fitted to one frame, which is suspended by four (or more)
rods 23, attached to supports in any suitable manner. 37 is an eccentric fast on
the shaft 25, the ring of the eccentric being attached to another ring 38 carrying
four blocks as shown in plan view in Fig. 6, and in section in Fig. 9.
method of driving and working, which will be readily understood from the
drawings.
The
Figs. 10 and 11 illustrate a modification of our invention, in which the sieves
are spirally arranged, and in which they may be formed with straight sides,
angularly arranged, or with curved sides as shown in Fig. 11. In this arrange-
ment the solid plates 36 are dispensed with, but instead thereof and for a similar
purpose the screens are made of different lengths, as shown (in extended form)
in Fig. 12. In Figs. 10, 11 and 12 the sieves are numbered 39, 40, 41 and 42.
Fig. 13 illustrates an analogous arrangement to that shown in Figs. 10, 11
and 12, the only difference being that the sieves are trapezoidal.
It will be obvious that the number and relative positions of the sieves may be
varied, and superposed sieves may be separately worked by three cranks or
eccentrics set at angles of 120 degrees apart, or four cranks or eccentrices at
angles of 90 degrees apart. Also two or more sets of sieves may be radially
arranged over those shown in Fig. 6, with separate cranks or eccentrics to each
The throw of the cranks or eccentrics may be varied, as required.
set.
In arranging the inclination of the sieves, we find it advantageous to increase
the angles vertically for the finer materials; thus a three-screen apparatus would
have the upper screen, for the coarser material, inclined from the horizontal
6 degrees; the second screen 8 degrees, and the lowest screen 10 degrees at the
outlet, or thereabouts. Also the usual reticulated material may be used for sifting
fine materials, and perforated plates or bar or channel iron for heavy and coarse
materials.
The improved method of mounting and working screens and sieves described

page_text: reduces friction to a minimum, and thus effects a great saving in motive power,
and but little lubrication is required.
Also the sieves are readily accessible without removal for clearing and supplying
either wet or dry materials, and for other usual operations.
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 claim is :-
1. The improved apparatus for screening and sifting coal, ore, and other
materials, substantially as described.
2. The improved method of operating a sieve or screen substantially as herein
before described and illustrated by Fig. 1 of the drawings.
3. The improved method of mounting, combining, and operating two or more
sieves or screens, substantially as herein before described and illustrated by the
drawings.
4. In apparatus for screening and sifting coal, ore, and other materials, the
application and use of suspension rods, chains or ropes substantially as and for
the purposes herein before described and illustrated by the drawings.
5. In apparatus for screening and sifting coal, ore, and other, materials, the
application and use of ball bearings, substantially as and for the purposes herein
before described and illustrated by the drawings.
Dated 8th March 1908
GEORGE DOWNING & SONS,
8, Quality Court, London, W.C., Agents.