IMPROVEMENTS IN THE METHOD OF AND IN THE APPARATUS FOR CLEANING AND SEPARATING GRITS AND SIMILAR PRODUCTS
Year: 1875

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and
Company, Patent Agency, of Frankfort-on-the-Main, in the Empire
of Germany, for the Invention of "IMPROVEMENTS IN THE METHOD OF
AND IN THE APPARATUS FOR CLEANING AND SEPARATING GRITS AND SIMILAR
PRODUCTS." A communication from Theodor Büllmann, residing
at Cham-Zug, in the Republic of Switzerland.
-
Scaled the 1st February 1876, and dated the 10th August 1875.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the
Office of the Commissioners of Patents, with his Petition, on the
10th August 1875.
I, FRANK WIRTH, of the Firm of Wirth and Company, Patent
Agency, of Frankfort-on-the-Main, in the Empire of Germany, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE METHOD OF AND IN THE APPARATUS FOR CLEANING AND SEPARATING GRITS
AND SIMILAR PRODUCTS," to be as follows:-
This Invention has for its objects improvements in the methods of
and apparatus for assorting and cleaning the different kinds of grits

page_text: or groats and bran which are produced in the manufacture of flour,
and it consists essentially of methods of combining the operation of
centrifugal force with currents of air produced by a revolving fan. The
groats and bran or other substances to be operated upon are fed into a
nearly horizontal sifting screen consisting of an outer frame carried by
suitable supports, and having placed within it an inner frame, across the
bottom of which wire or other gauze is stretched. Three such frames
are generally used, each provided with gauze of different fineness, in
order that fine, less fine, and coarse grits may be assorted and cleaned.
In order that the gauze of the-sieves or screens may keep the necessary
tension the inner frames are provided with two or more stretchers con-
sisting of bars running across them, which bars turn at one end in
ordinary bearings, whilst their other ends are provided with screwed
threads which work in nuts fixed to the opposite side of the frame.
According as the bars are turned in one or the other direction the
distance between the sides of the frame is increased or diminished, thus
stretching the gauze more or less. From the sifting arrangement
described the groats pass into one or more hoppers or shoots, the lower
end of each of which is provided with a circular mouth through which
the groats fall upon a horizontal dise fixed at or near the top of a
vertical shaft revolving at a suitable speed, preferably about 320
revolutions per minute. The circular mouth of the shoot is tubular,
and is screwed outside, so that a corresponding shoot screwed tube can
be raised or lowered to a greater or less distance from the revolving
disc. From the horizontal revolving discs the groats are thrown off by
centrifugal force and fall into receptacles circular in plan, one of which
is arranged beneath each disc. Each of these receptacles is divided.
into two or more (but preferably three) concentric compartments. The
exterior compartments are provided with bottoms, of which each has an
opening at one place only, and from these openings lead pipes or tubes
through which the purified and assorted groats are conducted to sacks
or other receptacles. The inner compartment has no bottom, but is in
direct communication below, with a closed dust box or chamber, which
is itself in communication with an exhausting fan (or other apparatus
for exhausting air). Beyond the outer periphery of each of the revolving
discs a horizontal bar projects which carries scrapers, one of which fits
in each of the concentric compartments, to the bottom of which it nearly

page_text: reaches. In their revolution (with the disc) these scrapers remove the
groats and discharge them through the pipes already described.
The fan is driven by any suitable motive power, and is provided with
suitable toothed wheels or straps, by which it causes the vertical shafts
and horizontal discs to revolve at the speed desired, which it is preferred
should be at the rate of two revolutions whilst the fan makes one
revolution.
The action of the apparatus is as follows:-The groats passing through
the sieve fall upon the revolving discs, whence they are thrown by
centrifugal force, the coarser grains being thrown further from the disc
owing to their greater specific weight, and falling in consequence thercof
into the exterior concentric compartment, the specifically lighter.
(because finer) grains which are not thrown so far falling into the
middle concentric compartment, and the dust and dirt being drawn by.
the action of the fan into the centre compartment, and thence into the
dust chamber, from which it can be removed as required through
suitable openings.
SPECIFICATION in
pursuance of the conditions of the Letters Patent,
filed by the said Frank Wirth in the Great Seal Patent Office on
the 4th February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANK
WIRTH, of the Firm of Wirth and Company, Patent Agency, of
Frankfort-on-the-Main, in the Empire of Germany, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of August, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors,*
give and grant unto me, the said Frank Wirth, Her special licence
that I, the said Frank Wirth, my executors, administrators, and
assigns, or such others as I, the said Frank Wirth, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE METHOD OF AND IN THE APPARATUS FOR CLEANING AND SEPARATING GRITS AND
SIMILAR PRODUCTS," a communication to me from Theodor Bühlmann, a
person resident at Cham-Zug, in the Republic. of Switzerland, the
upon
condition (amongst others) that I, the said Frank Wirth, my executors
or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause, the same to be filed in the
Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frank Wirth, do hereby declare the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawing
forming a part of this Specification :—
My machine is made to clean and assort all kinds of groats which are
produced in flour grinding. The operation is based on the combination
of centrifugal force with aspiration.
Figure 1 represents an elevation of my machine arranged double;
Figure 2 is a vertical section of the same.
Figure 3 is a view of sieving apparatus.
Figure 4 is a view of the circular compartments into which the various
kinds of groats fall.
The sifting apparatus, as seen in Figures 1 and 2, is attached to the
wooden standards A by the wood or iron shaking rods c, c; the groats
to be cleaned are now poured upon the sieve at its upper end. This
apparatus consists of an outer frame B supported by the rods C, C ;
within it is placed the sieve E, Figure 3.
5
In order that the sieve bottoms be kept at the necessary tension the
sieve is provided with spanners a, a, Figure 3; the same consists of
shafts running across the sieve frame; their ends are provided with

page_text: screw threads, the one being a left and the other a right hand screw,
each fitting respectively into its nut, the latter being fixed to the sides
of the sieve; thus the bottom will be stretched or slackened by turning
the shafts to the right or left. As the groats fall through the sieve
they drop into the funnel-shaped kennels F, F', thence on to the iron
plates G, G. The openings at the bottoms of the former are provided
with metallic regulating pipes d, d, which can be screwed up or down so
as to allow more or fewer groats to pass upon the plates G, G, at the
same time. Each of the plates is supported on its respective vertical
shaft H, H', making 160 turns a minute. By this rotatory movements
streams of groats are concentrically shot off the plates and caught in the
different boxes i, i, the heavier and better grains naturally going the
farthest, while the small particles of husks and dust are sucked by the
aspiration in the dust chamber K. This chamber is provided with slides
at each end, so as to empty the same when choked with dust and the
like. The aspiration is produced by the ventilator L making 350 turns
a minute, and by its shaft m the power is conveyed to the vertical
shafts H, H, either as shewn in the Drawing by a screw and cog wheel,
or by any of the well-known methods. Beyond the periphery of each
of the horizontal discs G, G, a horizontal bar g, 9, projects, on which
there are two shovels g¹, g". These shovels, can be raised or lowered at
will, and turning with their respective plates sweep the cleaned groats
round their compartments till they reach and fall down the pipes 7, 7,
and ', '.
Having thus fully described the said Invention as communicated to
me, and the manner of performing the same, I wish it understood that
I claim,-
First. The spanners a, a, attached to the sifting apparatus, by means
of which the sieves are constantly kept at the necessary tension.
Second. The discs G, G, in combination with centrifugal force, by
which the groats are cleaned and assorted into different compartments.
Third. The dust chamber K, in combination with the circular com-
partments i, i, and ",-, the funnel-shaped passage ", 2", and the
aspiration of the ventilator.
$.
Fourth. The application of the shovels g¹, g¹¹, 9, 9", attached to the.
horizontal discs for conveying the cleaned and assorted groats from

page_text: the circular compartments i, i, and i, , to the spouts or pipes h³, h³,
and h, h.
In witness whereof, I, the said Frank Wirth, have hereunto set my
hand and scal, this Twenty-ninth day of January, One thousand
eight hundred and seventy-six.