IMPROVE- MENTS IN SIFTING APPARATUSES
Year: 1881

page_text: LETTERS PATENT to Carl Pieper, Civil Engineer and Patent Agent, of
109/110, Gneissenaustrasse, Berlin, Prussia, for an Invention of "IMPROVE-
MENTS IN SIFTING APPARATUSES." A communication from August Nagel
and Reinhold Keemn Engineers of Hambura Germany
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office of
the Commissioners of Patents on the 14th January 1881.
CARL PIEPER, Civil Engineer and Patent Agent, of 109/110, Gneisenaustrasse,
Berlin, Prussia. "IMPROVEMENTS IN SIFTING APPARATUSES." (A communication
from August Nagel and Reinhold Kaemp, Engineers, of Hamburg, Germany).
This Invention relates to sifting apparatuses consisting of an inclined sieve which
is caused to oscillate on pivots by means of a cam or tappet wheel, and the object
of the Invention is to arrange the apparatus in such a manner as to allow products
of various degrees of fineness to be obtained with one sieve.
The apparatus is in the first place provided with adjustable stops, on which the
frame of the sieve strikes every time it drops. These stops and the points of the
sieve-frame opposite to them may be provided with elastic buffers. According as
the said buffers are adjusted higher the amount by which the sieve can drop after
having been lifted becomes smaller, and the fineness of the product passing through
the sieve is increased.
In the second place the angle of inclination of the sieve may be altered by
adjusting higher or lower the pivots on which the sieve oscillates, the parts being
so arranged that the sieve will always maintain its proper relative position to the
tappet-wheel. When the angle of inclination of the sieve is considerable the
material passing through the holes or meshes will also be finer than when this
angle is small.
The fineness of the sifted product may be increased, thirdly, by reducing the
size of acting surface of the sieve. For this purpose the aforesaid stops are so
arranged that either of them can be adjusted higher than the other one, while the
pivots are also provided with means for raising one of them more than the other.
The sieve may thereby be inclined at an angle laterally, or it may be made to
form a skew surface. In the first case the material to be sifted will slide downward
on one side of the sieve only, whereas in the second case it will travel over the
sieve in an oblique course, so that in either case the operative sifting-surface will
be smaller than otherwise.
The various adjustments may be carried out during the working of the
apparatus.

page_text: +
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Seal Patent Office on the 12th July 1881.
CARL PIEPER, Civil Engineer and Patent Agent, of 109/110, Gneisenaustrasse,
Berlin, S. W. Prussia. "IMPROVEMENTS IN SIFTING APPARATUSES."
nication from August Nagel and Reinhold Kaemp, Engineers, of Hamburg,
Germany.
A commu-
This Invention relates to sifting-apparatuses consisting of an inclined sieve or
riddle which is caused to oscillate on pivots by means of a cam or tappet-wheel,
and the object of the Invention is to arrange the apparatus in such a manner as to
allow products of various degrees of fineness to be obtained with one sieve and
without altering the size of its holes or meshes.
The Invention is based on the fact that the sifted product is finer in proportion
as the sieve is shaken less forcibly as its angle of inclination is increased, and as
the operative surface for a given quantity of material is reduced.
Fig. 1 of the annexed Sheet of Drawings represents a sectional side view of the
apparatus; Fig. 2 is a plan of the same; Fig. 3, a section on line x, y, of Fig. 2;
and Fig. 4 a side-view of a modified arrangement.
The frames of the sieve is supported by means of the journals p, and it rests
with the ends of its longitudinal bars on the tappet wheels n keyed on the shaft o.
These wheels when rotating alternately lift the frame and allow it to drop, whereby
it is shaken. The energy of this motion depends in the first instance upon the
height of the tappets of the said wheels, but the same may be varied, by means of
a cross-bar b placed below the sieve near its lower end, and which can be raised or
lowered by the regulating-screws h passing through the ends of the bar and fitted
with hand-wheels for turning them. At the points where the longitudinal bars of
the sieve-frame cross the bar b, the former are or may be provided with the buffers a
and the latter with the buffers a¹ made of an elastic material. The cross-barb having
been suitably adjusted by the screws h, the frame when dropping will not strike
any more on the deeper or recessed portions of the wheels n, as the buffers a and a¹
coming sooner in contact with each other diminish the height of its fall. By
altering the position of the bar b the intensity of shaking-motion of the sieve can
be regulated to any degree between zero and the degree depending upon the height
of the tappets of the wheels n. The more this intensity is reduced the less will be
the size of the grains passing through the sieve, and consequently the finer the
sifted product.
:
For the purpose of allowing the angle of inclination of the sieve to be altered
and the fineness of the sifted product to be varied thereby, the pivots on which the
sieve oscillates are provided with means for adjusting them higher or lower, while
they slide in guides r forming an arc of a circle, the centre of which is at or near
the centre of the wheel n, so that the sieve will always maintain its proper relative
position to this wheel. The adjusting-arrangement may consist in chains to which
the pivots are attached, see Fig. 1, these chains allowing of their being lengthened
or shortened; or the pivots are each provided with a pawl q, Fig. 4, maintained by
a counter-balance-weight in engagement with the teeth on the outside of the
curved guide r. Also a pinion gearing into a toothed bow and provided with
means for stopping its motion, or clamping-jaws which can be pressed together on
the guider by screws, or any other suitable and known device may be used for the
purpose. Whenever the inclination of the sieve is altered the cross-bar b must
be suitably readjusted, and when it is desired that this inclination be made variable
to a considerable extent the said bar should be guided in an arc of a circle, as
L

page_text: shown in Fig. 4, while its ends are pivoted to slide-blocks 6' through which the
adjusting screws h pass, and which move in the oscillating guides c.
For the purpose of reducing the size of the operative surface of the sieve, and of
thereby increasing the fineness of the sifted product, the sieve is made to assume a
slight lateral inclination by raising one end of the bar b and the corresponding
pivot p somewhat more than the other end of the bar and the other pivot. When
the bar b and the geometrical axis of the pivots p are both in a horizontal position
the material to be sifted spreads out uniformly over the whole surface of the sieve,
but if the bar and the axis of the pivots are inclined in the same sense the material
slides towards one side of the sieve, i.e., the operative surface of the sieve is reduced.
The bar b and the axis of the pivots may, however, also be inclined in a different
sense; the sieve in this case forms a skew surface, in consequence whereof the
material travels over the sieve in an oblique course, and also occupies only a part
of the same.
The various adjustments may be carried out during the working of
the apparatus.
The material to be sifted arrives on the sieve at z. The portion of the same
which has passed through the holes or meshes of the sieve is conducted by the
oblique partition-wall arranged below the sieve to the spout g', Figs. 1, 2, and 3,
whereas the wall 12 fixed to the upper surface of the sieve conveys the coarse
residue to the spout g². The sieve may be covered upon its whole extent for
preventing any scattering and dusting away of material.
Having thus described the nature and object of this Invention, and the manner
in which it is to be carried out in practice, as communicated to me by my
correspondents, I hereby claim as new and important features of the same,-
1. The combination with an inclined sieve s oscillating on pivots p and operated
by tappet wheels n of an adjusting-mechanism, by means of which the pivots p
may be raised or lowered either uniformly or by a different amount independently
of each other, substantially as hereinbefore described and for the purpose specified.
2. In combination with the inclined sieve oscillating on pivots p and operated
by tappet-wheels n of the cross-bar b provided with regulating-screws h, by which
the same may be adjusted higher or lower, either in a horizontal position or at an
angle thereto, substantially as and for the purpose described.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand and
seal, this Third day of July, in the year of our Lord One thousand eight
hundred and eighty one.
CARL PIEPER. (LS.)