Improved Sifting Apparatus.
Year: 1892

page_text: Date of Application, 3rd Nov., 1892
Complete Specification Left, 21st June, 1893-Accepted, 22nd July, 1893
PROVISIONAL SPECIFICATION.
Improved Sifting Apparatus.
I, HERMANN RASCH, of 75/76 Priuzen-Allee, Berlin, Manager, do hereby
declare the nature of this invention to be as follows:-
This invention relates to an improved construction of sifting apparatus in which
two or more superposed sifting chambers provided with inclined sieves of a long
narrow form are enclosed in a casing which is made to travel in a horizontal
circular or other shaped path by means of cranks or other appliances. Upon all
the said sieve surfaces is delivered simultaneously the same description of material
to be sifted, such delivery being effected by special apparatus in a very uniform
manner, in order, by maintaining a comparatively thin layer of material to produce
a greater or more rapid sifting action with a comparatively short travel, than is
possible with a thicker layer of material combined with a longer travel. By the
circular path through which the inclined sieves are made to move, the material is
caused to travel downwards thereon in a path formed by a continuous series of more
or less circular loops.
Two or more such superposed sieve chambers are arranged side by side in
the casing.
For these purposes the apparatus may for example be constructed as follows.
At the end of the casing where the higher ends of the sieve surfaces are situated
is a transverse chamber into one end of which the material to be sifted is delivered
and in which it travels along an inclined surface towards the other end, descending
on its way through a series of openings or channels in such surface on to the
several sieve surfaces below. The said openings or channels may be provided with
any known means whereby their area can be reduced or increased so as to regulate
the quantity of material passing on to each sieve chamber, or to entirely cut off the
supply to some of the chambers if necessary..
The sifted material passing through the sieves falls on to the inclined bottom of
the sieve chamber, along which it travels to the lower end, where it descends
through tubular channels to a collecting chamber common to all the sieves, and
whence it is discharged in any desired manner.
It is preferred to arrange between the underside of the sieves and the bottoms of
the sieve chambers, perforated plates, through which the sifted material falls on to
the bottom, but which prevents the material from rebounding upwards against the
sieves again, as is the case without such an arrangement, and whereby the proper
sifting action is impeded.
If necessary, small balls may be placed upon such perforated plates, which in
rebounding against the underside of the sieve will tend to keep this clear."
The material passing along the upper surfaces of the sieves is led at the lower
end on to a sieve or sieves inclined in the contrary direction to the inclination of
the others, so that the material in travelling back along such sieve is subjected to a
final sifting whereby it is sorted into different grades of fineness, each of which is
collected in a separated receptacle, whence it is discharged in any convenient
manner.
Dated this 3rd day of November 1892.
ABEL & IMRAI,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Sifting Apparatus.
I, HERMANN RASCH, of 75/76 Prinzen-Allée, Berlin, Manager, 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 improved construction of sifting apparatus in which
two or more superposed sifting chambers provided with inclines sieves of a long
narrow form are enclosed in a casing which is made to travel in a horizontal
circular or other shaped path by means of cranks or other appliances. Upon all
the said sieve surfaces is delivered simultaneously the same description of material
to be sifted, such delivery being effected by special apparatus in a very uniform
manner, in order, by maintaining a comparatively thin layer of material, to produce
a greater or more rapid sifting action with a comparatively short travel than is
possible with a thicker layer of material combined with a longer travel.
By the
circular path through which the inclined sieves are made to move, the material is
caused to travel downwards thereon in a path formed by a continuous series of
more or less circular loops.
Two or more such sets of superposed sieve chambers are generally arranged
side by side in one and the same casing; on the accompanying drawing is shewn by
way of example an arrangement with eight such sets.
Fig. 1 shews a longitudinal section, Fig. 2 an underside plan, Figure 3 a sectional
plan, and Figures 4 and 5 cross sections taken respectively through the parts B
and A.
To the casing A containing the sieves is fixed the casing B for distributing the
ground material to the sifting surfaces g of the several chambers, the complete
apparatus being actuated by cranks as shewn.
The arrangement consists of a chamber B extending transversely across the
sieve chambers a d, be, e f &c. and having a bottom surface o inclined in the
direction of the feed, and provided with a series of feed openings h, corresponding
in number to that of the sieves in the several sieve chambers, there being two feed
openings to each chamber the one supplying the upper sieve g, while the other,
which is provided with a tube i, supplies the lower one. These feed openings can
be provided in the known manner with devices for increasing or decreasing their
sectional area, for regulating the quantity of ground material supplied to the
separate sieves, or for cutting off the supply to certain of the sieve chambers
or sieves.
The ground material which has passed over the sieve g and is freed from flour
passes from the same into the end chamber C, from which it can be conveyed on to
another sieve on which it can be sorted into different qualities such as semolina,
grits and fine meal, which may be collected in the receptacles C¹ C³ C³ and
discharged through openings k.
Between the sieves g and the bottoms æ along which the sifted material passes
may be provided perforated plates y which have the object of more or less
preventing the throwing upward of the sifted meal from the bottom z against the
under surface of the sieve, which is caused by the jigging motion of the apparatus,
and which is so detrimental to the action of the sieve. On the plates y may be
placed small loose elastic balls which are thrown against the sieves g by the jigging
motion and thus assist in keeping the same clear.
The flour separated in the upper and lower compartments of each sieve chamber
is led separate from the other materials, through tubes v to a discharge box C
common to both. If however the sieve is also to serve for separating flour, it
may be led over the bottom r to the discharge C³ or elsewhere.
The collecting boxes C C C C have inclined bottoms n m by means of which

page_text: the sifted or sorted materials are collected either from all or from any number of
contiguous sieve chambers, and conveyed in spirally directed paths to the common
discharge opening k.
The entire apparatus A B C receives a rotary motion from the cranks as shewn,
being suitably supported at the corners for this purpose.
Figs. 6 and 7 shew a part vertical section and part plan of a modification in
which, instead of having only two sieve compartments in each chamber as at
Figs. 1 to 5, there are three such compartments one above the other, the supply
being directed into any number of the chambers a b c &c. according to require-
ments; or there may be separate supplies provided to separate chambers or sets of
chambers.
The required motion may be imparted to the apparatus by other means than by
a crank motion as described.
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. A horizontal sieve apparatus having a combined rotary and reciprocating
motion imparted to it, in which two or more sieve compartments with inclined
sieves 9 9 are arranged one below the other, on to which sieves the same description
of ground material is simultaneously supplied, in order to operate upon a com-
paratively large quantity of material in apparatus occupying a comparatively small
space, the combined rotary and reciprocating motion causing the material to travel
in spiral paths down the inclined sieves, while two or more chambers containing
such sets of sieves may be arranged side by side in the same apparatus, substantially
as described.
2. In sieve apparatus such as is referred to in the preceding claim, the combination
with the sieve chambers of supply chambers the inclined bottoms o of which have
openings or shoots through which the ground material is fed on to the several
superposed sieves, substantially as described.
Dated this 21st day of June 1893.
DET
0 IMDA
ABEL & IMRAY,
Agents for the Applicant.