Improvements in Sifting or Screening Apparatus.
Year: 1894

page_text: Date of Application, 17th May, 1894
Complete Specification Left, 22nd June, 1894-Accepted, 28th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in Sifting or Screening Apparatus.
I, OTTO FUCHS, of Buttstaedt, Germany, Millowner, do hereby declare the
nature of this invention to be as follows :-
In sifting or screening apparatus (hereinafter referred to as sifting-apparatus)
according to my invention, the material under treatment is sifted by the rapid
oscillation of the sieve, which causes the particles of the said material situate inside
the sieve to be, by the operation of the momentum thus produced in them, arranged
therein according to their specific gravities, the particles of less specific gravity
being caused to locate themselves nearer to the geometrical axis of the sieve than
the particles of greater specific gravity which are driven towards the inner surface
of the gauze or other sifting-wall of the sieve.
In my improved sifting-apparatus the cleaning of the sifting-walls is effected
simultaneously with the sifting, by means of sudden puffs of air. These puffs of
air are caused as follows:-The sieve is arranged inside a fixed and hermetical
casing which is almost touched by the sieve during its oscillatory, motion. The
air contained between the said casing and the for the time being forward sifting-
wall of the sieve is suddenly compressed through the oscillation of the sieve, in such
a manner as to act as a puff, or by impact, upon the corresponding sifting-wall of
the sieve. This action has the effect of dividing-up or scattering asunder the mass
of particles of greater specific gravity, which is of great advantage in the case of
very adhesive flour, and powerful currents of air are caused to pass through the
sieve.
Sifting-apparatus according to the present invention is intended to serve, inter
alia, for the sifting of glutinous material.
In the accompanying drawings,
Figs. 1 and 2 show a longitudinal and a cross section respectively of one
construction of sifting-apparatus in accordance with my invention, the sieve being.
mounted on an inclined axle and caused to oscillate rapidly by means of cranks o
the said axle ;
on
Fig. 3 shows a longitudinal section of a modification of the construction shown
purpose
in Fig. 1, in which the sieve is provided internally with stop-fillets e for the
of rendering the sifting action more effectual;
Fig. 4 illustrates the action of the sieve;
Figs. 5 and 6 are a longitudinal and a cross section respectively of a sifting
apparatus provided with a number of superposed floors in contact with the lateral
sifting-walls of the sieve; and
Figs. 7 and 8 are respectively a cross section and a longitudinal section of a
sifting-apparatus which is similar to that shown in Figs. 5 and 6 but in which the
floors are not in contact with the lateral sifting-walls.
The sieve A is preferably made in the shape of a rectangular box which is caused
to oscillate rapidly both vertically and horizontally, or approximately so, by means
of a crank-shaft connected to the driving-shaft E which is carried in bearings in
the casing B. The sieve A is enclosed on all sides by the air-tight casing B of the
sifting-apparatus. When the shaft E is rotated rapidly, the sieve A describes a
path and assumes positions such as indicated in Fig. 4. The sieve has no rotation
about its own geometrical axis. Whilst oscillating, the sieve is successively
brought suddenly near to the four walls of the casing B and the air contained
between the casing B and the for the time being forward sifting-walls of the
sieve A is, in consequence of the great velocity of the oscillation of the sieve,

page_text: unable to move out of the way, and is therefore compressed by the sieve A and
thereby caused to exert a sudden powerful impulse or puff upon the said forward
Bifting-wall & so that the particles of greater specific gravity of the material under
treatment, which have been caused by their momentum to press against the said
sifting-walls in the manner hereinbefore referred to, are forced away from the said
sifting-wall and the sifting-walls is thus cleaned. The puff of air also acts
through the sifting-walls thus purified and exerts a pressure upon the portion of
the material under treatment which is adhering to the sifting-wall s that is situated
opposite and is not exposed to the direct action of the said puff. This material is
driven through the meshes of the latter sitting-wall and is thereby divided and thus
very uniformly sifted. The force of the puff of air is regulated by varying the
velocity of the oscillatory motion of the sieve.
In order to cause the material to be sifted to describe a path of the greatest
possible length, there may be arranged in the sieve A a floor or floors T (Figs. 5
and 6) which may be provided with stop-fillets e. These also prevent the material
from moving back. The floors T need not extend up to the lateral sifting-walls s
of the sieve A, as shown in Figs. 5 and 6, but may stop short of and out of contact
with the said sifting-walls as shown in Figs. 7 and 8.
Any number of the sieves may be coupled together one above another in order
that the consumption of power may be approximately constant.
Dated this 17th day
1004
:
COMPLETE SPECIFICATION.
Improvements in Sifting or Screening Apparatus.
I, OTTO FUCHS, of Buttstaedt, Germany, Millowner, 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:-
.
In sifting or screening apparatus (hereinafter referred to as sifting-apparatus)
according to my invention, the material under treatment is sifted by the rapid
oscillation of the sieve, which causes the particles of the said material situate
inside the sieve to be, by the action of the momentum thus produced in them,
arranged therein according to their specific gravities, the particles of less specific
gravity being caused to locate themselves nearer to the geometrical axis of the
sieve than the particles of greater specific gravity which are driven towards the
inner surface of the gauze or other sifting-wall of the sieve.
In my improved sifting-apparatus, the cleaning of the sifting-walls is effected
simultaneously with the sifting, by means of sudden puffs of air which are caused
as follows:-The sieve is arranged inside a fixed and hermetical casing which is
almost touched by the sieve during its oscillatory motion. The air contained
between the said casing and the, for the time being, forward sifting-wall of the
sieve is suddenly compressed owing to the oscillation of the sieve, in such a manner
as to act as a puff, or by impact, upon the corresponding sifting-wall of the sieve.
This action has the effect of dividing-up or scattering the mass of particles of
greater specific gravity,-which is of great advantage in the case of very adhesive
flour and powerful currents of air are caused to pass through the sieve.
Sifting-apparatus according to the present invention is intended to serve, inter
alia, for the sifting of glutinous material.
Referring to the drawings filed with my Provisional Specification,
Figs. 1 and 2 show respectively in longitudinal section and cross section, one
construction of sifting-apparatus in accordance with my invention, the sieve being

page_text: mounted on an inclined axle and caused to oscillate rapidly by means of crank arms-
on the said axle ;
:
Fig. 3 is a longitudinal section showing a modified construction in which the
sieve is provided internally with stop-fillets e for the purpose of rendering the
sifting action more effective ;
Fig. 4 illustrates the action of the sieve ;
Figs. 5 and 6 show respectively in longitudinal section and cross section, a sifting-
apparatus provided with a number of superimposed floors in contact with the lateral
sifting-walls of the sieve; and
Figs. 7 and 8 show respectively in cross section and longitudinal section, a
sifting-apparatus which is similar to that shown in Figs. 5 and 6, but in which the
floors are not in contact with the lateral sifting-walls.
The sieve A is preferably made in the shape of a rectangular box, which is
caused to oscillate rapidly both vertically and horizontally, or approximately so,
by means of a crank-shaft connected to the driving-shaft E which is carried in
bearings in the casing B. The sieve A is enclosed on all sides by the air-tight-
casing B of the sifting-apparatus. When the shaft E is rotated rapidly, the sieve A
describes a path and assumes positions such as indicated in Fig. 4. The sieve has.
no rotation about its own geometrical axis, but is successively and rapidly brought
near to each of the four walls of the casing B and the air contained between the
casing B and the, for the time being, forward sifting-walls of the sieve A is, in
consequence of the great velocity of the oscillation of the sieve, unable to move out
of the way, and is therefore compressed by the sieve A and thereby caused to.
exert a sudden powerful impulse or puff upon the said forward sifting-wall s so that
the particles of greater specific gravity of the material under treatment, which
have been caused by their momentum to press against the said sifting-walls in the
manner hereinbefore referred to, will be forced away from the said sifting-wall
which will thus be effectually cleaned. Furthermore the puff of air on passing
through the sifting-walls thus purified, exerts a pressure upon the portion of the
material under treatinent which is adhering to the sifting-walls that is situated
directly opposite, and is not, for the time being, exposed to the direct action of the
said puff, whereby this material is driven through the meshes of the latter sifting-
wall and is thereby divided and thus very uniformly sifted. The force of the puff
of air is regulated by varying the velocity of the oscillatory motion of the sieve.
In order to cause the material to be sifted to describe a path of the greatest.
possible length, there may be arranged in the sieve A a floor or floors T (Figs. 5.
and 6) which may be provided with stop-fillets e. These also prevent the material
from moving back. The floors T need not extend up to the lateral sifting-walls s
of the sieve A, as shown in Figs. 5 and 6, but may stop short of and out of contact.
with the said sifting-walls as shown in Figs. 7 and 8.
Any number of sieves arranged and operated as described may be coupled
together one above another in order that the consumption of power may be
approximately constant.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A sifting or screening apparatus in which a closed gauze-covered sieve is
caused to oscillate both vertical and horizontal, without rotation about its axis,.
within a hermetically closed casing in such a manner that the sifting or separation
of the material under treatment is effected by centrifugal action according to the
specific gravity of the constituent parts of the said material, and the sieve is at the
same time subjected to powerful one-sided puffs or impulses of air which are
produced by the oscillation of the said sieve within the said casing and which cause
the heavier particles of material to be forced through the gauze walls of the said:
sieve substantially as herein described.

page_text: or
screening apparatus constructed and operating substantially as
2. Sifting
described and shown.
2. Sifting or screening apparatus constructed and operating substantially as
described and shown.
Dated this 21st day of June 1994.
For the Applicant.
2. Sifting or screening apparatus constructed and operating substantially a
described and shown.
Dated this 21st day of June 1094.
For the Applicant.
W. LLOYD WISE,
'46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.