Improvements in Grain Screens or Sifters.
Year: 1897

page_text: Improvements in Grain Screens or Sifters.
I, GEORG WAGNER, of 6, Hofstallstrasse, Darmstadt, in the German Empire
Works Director, do hereby declare the nature of this invention to be as follows:-
This invention relates to machines for sifting grain and has for its object to
effect by a machine, which occupies practically no more space than machines now
generally employed, a quicker sifting of the grain than with such machines as
hitherto manufactured.
This result is obtained :-
By separating, by means of rotating distributing discs, the specifically heavy
grain from the lighter impurities by means of centrifugal force.
By conveying the impurities more quickly to the screen gutters or passages
than the grain itself by the employment of so called "draw wings" arranged on
the underside of the distributing discs, and,
By effecting the passage of the grain through the meshes of a silk sifter and
conveying the cleaned grain to the outlet from the machine by, means of brushes
arranged under the silk sifter and which move simultaneously in a circular and
in a zig-zag path.
The screen or sifter which is suspended so as to oscillate upon movable rods
is caused to oscillate or swing by means of a vertical shaft which passes through
the screen or sifter and which is cranked at its upper and lower ends and movably
connected with the screen or sifter at these two points.
At the part of the shaft which is not cranked there are arranged at suitable
distances one above the other a series of discs between which there is provided a
second series of discs which carry concentric rings and extend from the periphery
of the screen or sifter to near the centre of the same. The discs of the second
series are covered with silk which is carried by the rings so that spaces are pro-
vided which are divided into annular divisions by the rings.
The grain to be treated passes from the inlet, hopper or chute on to a flat tray
and slides from this upon the upper of the distributing or first series of discs
rotated by the shaft. The said upper disc then conveys the grain by centrifugal
force towards the periphery of the screen or sifter in such a manner that the
cleaner, specifically heavier, parts are carried further outwards than the impure,
specifically lighter, parts which upon leaving the said distributing disc fall
directly upon the silk disc stretched underneath the same so that a partial sifting
or separation is already effected.
The grain is then conveyed from the periphery of the screen or sifter towards
the centre of the same by means of the wings, which are arranged upon the
underside of the rotating distributing discs and consist of two crossed parts, in
such a manner that the upper lighter and impure portion of the layer of grain
upon the silk is more quickly conveyed towards the centre of the screen or sifter

page_text: by means of the upper part of the wing than the lower heavier and purer portion.
During the movement of the grain over the silk a portion of it falls through
upon a plate placed thereunder. In order to prevent the perforations in the
silk from becoming blocked up by the grain there are arranged in each division
of the spaces which remain between the silk and the plate brushes upon frames
which brushes as a result of the concentric shape of their bearing surfaces and
of the oscillating or swinging motion of the screen or sifter are moved forwards
simultaneously in a circular and in a zig-zag path from the outer surface of
the inner ring to the inner surface of the next ring and back again so as to clear
the meshes of the silk from the grain adhering thereto and to convey forwards the
grain which has fallen through the silk on to the plate.
A sector shaped portion of the said plate is perforated. As soon, therefore,
as the grain is conveyed to this portion by the brushes it drops through the per-
forations into a tray shaped passage arranged underneath the same, by means
of which passage this portion of the grain is then conveyed to a sack outside the
apparatus.
The portion of the grain which remains behind upon the upper face of the
silk is conveyed by means of the lower part of the wing towards the centre of
the screen or sifter and reaches the distributing disc underneath the same and
so on until all of the grain that can be utilized is conveyed away and the impurities
finally removed from the apparatus through outlets in the bottom of the same.
In order to avoid the shocks arising from the swinging or oscillating motion
of the screen or sifter I provide in the middle of the same on the shaft a balanced
fly wheel which can at the same time serve as a distributing disc by causing the
grain to drop from the silk disc above it on to its surface from which it is caused
to pass to a silk disc arranged underneath it, by centrifugal force.
By a suitable arrangement of slides or valves the above described apparatus
can be separated into two or more parts which can then be independently
employed for treating different kinds of grain at the same time. In this case
it is only necessary to provide separate air passages and trays for the different
divisions of the screen or sifter and also for the upper divisions of the apparatus
separate outlets for the impurities besides the above named slides or valves which
control the connection with the lower portion of the screen or sifter.
D
011 J
1007
Improvements in Grain Screens or Sifters.
I, GEORG WAGNER, formerly of 6, Hofstallstrasse, Darmstadt, in the German
Empire, Works Director, now of 54, Kronprinzenstrasse, Frankfort on the 4
Main, in the German Empire, 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 machines for sifting grain and has for its object to
effect by a machine, which occupies practically no more space than machines now 4
generally employed, a quicker sifting of the grain than with such machines as
hitherto manufactured.
This result is obtained:

page_text: grain from the lighter impurities by means of centrifugal force.
By conveying the impurities more quickly to the screen passages than the grain
itself by the employment of so called "draw wings" arranged on the underside
of the distributing discs, and
By effecting the passage of the grain through the meshes of a silk sifter and
conveying the cleaned grain to the outlet from the machine by means of brushes
arranged under the silk sifter and which move simultaneously in a circular and
in a zig-zag path.
To enable my invention to be fully understood I will describe it by reference
to the accompanying drawings, in which:-
-
Figure 1 is a longitudinal section through a screen or sifter constructed
according to the invention.
Figure 2 is a section on the line - Figure 1.
:
Figure is an underside view of one of the distributing discs.
Figure 4 is a perspective view of one of the draw wings" arranged upon
tht underside of the distributing discs.
Figure 5 is a vertical section, and,
Figure 6 a plan view illustrating a different construction of the distributing
device.
The screen or sifter which is suspended so as to oscillate upon movable rods A
is caused to oscillate or swing by means of a vertical shaft B which passes through
the screen or sifter and which is cranked at its upper and lower ends and movably
connected with the screen or sifter at these two points.
At the part of the shaft which is not cranked there are arranged at suitable
distance one above the other a series of discs C between which there is provided
a second series of discs 1) which carry concentric rings E and extend from the
periphery of the screen or sifter to near the centre of the same. The discs D
are covered with silk which is carried by the rings so that spaces F are provided
which are divided into annular divisions by the rings E.
The grain to be treated passes from the inlet hopper or chute on to a flat tray b
and slides from this upon the upper of the distributing discs C rotated by the
shaft B. The said upper disc C then conveys the grain by centrifugal force
towards the periphery of the screen or sifter in such a manner that the cleaner,
specifically heavier, parts are carried further outwards than the impure, specifi-
cally lighter, parts which upon leaving the said distributing disc C fall directly
upon the silk dise D¹ stretched underneath the same so that a partial sifting or
separation is already effected.
In
The grain is then conveyed from the periphery of the screen or sifter towards
the centre of the same by means of the wings G, which are arranged upon the
underside of the rotating distributing discs C (as shewn in Figures 3 and 4) and
consist of two crossed parts, in such a manner that the upper lighter and impure
portion of the layer of grain upon the silk D¹ is more quickly conveyed towards
the centre of the screen or sifter by means of the upper part of the wing than
the lower heavier and purer portion. During the movement of the grain over the
silk D a portion of it falls through upon a plate D placed thereunder.
order to prevent the perforations in the silk from becoming clogged up by the
grain there are arranged in each division of the spaces F which remain between
the silk D¹ and the plate D brushes I upon frames H, which brushes as a result
of the concentric shape of their bearing surfaces and of the oscillating or swinging
motion of the screen or sifter are moved forwards simultaneously in a circular
and in a zig-zag path from the outer surface of the inner ring to the inner surface
of the next ring E and back again so as to clear the meshes of the silk from
the grain adhering thereto and to convey forwards the grain which has fallen
through the silk on to the plate D.
A sector shaped portion of the said plate D is perforated. As soon, therefore,

page_text: as the grain is conveyed to this portion by the brushes I it drops through the
perforations into a tray shaped passage K arranged underneath the same, by
means of which passage this portion of the grain is then conveyed to a sack out-
side the apparatus.
The portion of the grain which remains behind upon the upper face of the
silk D is conveyed by means of the lower part of the wing G towards the centre
of the screen or sifter and reaches the distributing disc underneath the same
and so on until all of the grain that can be utilized is conveyed away and the
impurities finally removed from the apparatus through outlets a¹ in the bottom
of the same.
In order to avoid the shocks arising from the swinging or oscillating motion
of the screen or sifter I provide in the middle of the same on the shaft Ba
balanced fly wheel L which can at the same time serve as a distributing disc
by causing the grain to drop from the silk disc D¹ above it on to its surface from
which it is caused to pass to a silk disc D¹ arranged underneath it, by centri-
fugal force.
By a suitable arrangement of slides or valves M (Figure 1) the above described
apparatus can be separated into two or more parts which can then be independently
employed for treating different kinds of grain at the same time. In this case
it is only necessary to provide separate air passages N and trays O for the different
divisions of the screen or sifter and also for the upper divisions of the apparatus
separate outlets P for the impurities besides the above named slides or valves
which control the connection with the lower portion of the screen or sifter.
The distribution of the grain instead of being effected by means of the discs C
can be effected by the arrangement illustrated in section in Figure 5 and in
plan in Figure 6. In this arrangement spiral or curved troughs R carrying
draw wings G on their undersides are employed by means of which the grain
is driven by centrifugal force against the periphery of the swinging sieve which
in this case is formed of silk S so that a sifting is effected at this stage and the
air can escape. Furthermore the silk is kept open and the grain which is sifted
off is conveyed away by means of brushes in the above described manner.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a grain screen or sifter having superposed circular sifters and a driving
shaft passing therethrough the employment of distributing discs C arranged upon
the driving shaft and which by centrifugal force distribute the material, fed
thereto near the shaft, upon the sifters, substantially as described
66
29
1
2. A grain screen or sifter of the kind described in Claim 1 wherein the dis-
tributing discs are provided on their undersides with draw wings' G, which 4
consist of two superposed and inclined parts, for the purpose of more quickly
feeding the upper lighter impure layer inwards, substantially as described.
3. A grain screen or sifter of the kind described in Claim 1 having brushes I
for maintaining the silk D' open and for feeding the sifted grain towards the
outlet passages K, the said brushes consisting of frames H which, under the
swinging action of the sifter are moved in a zig-zag fashion in concentric rings
independently of one another, substantially as described.
4. In a grain screen or sifter of the kind described in Claim 1 the employment
for the purpose of avoiding the shock resulting from the movements of the sifter,
of a balanced fly wheel L which is arranged in the centre of the screen and acts
as a distributing disc substantially as described.
5. A grain screen or sifter of the kind described in Claim 1 divided by valves M
into several parts having air passages N, trays O and outlets F whereby several kinds
of grain can be simultaneously sifted, substantially as described and illustrated.
6. A grain screen or sifter of the kind described in Claim 1 wherein the dis-

page_text: tribution is effected by the spiral troughs R carrying on the underside the draw
wings G, substantially as described and illustrated.
Dated the 21st day of October 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.