IMPROVEMENTS IN GRAIN SIEVES
Year: 1876

page_text: CION TCI Dy Jonn matyton Greemme vince of
the Commissioners of Patents on the 31st July 1876.
JOHN HAYTON GREENHILL, of 35, Mill Street, Belfast, in the County of Autriin.
"IMPROVEMENTS IN GRAIN SIEVES."
This Invention is for the purpose of separating nails, dust, husks, and other
foreign matter from grain, and consists of a series of metal plates extending across
the width of the sieve, such plates having holes in them just sufficiently large to
permit the grain to pass freely through, the holes being by preference wider at the
bottom than at the top. These metal plates may be flat, curved, or cylindrical.
Their size depends upon the quantity of grain required to be cleaned. It is
advisable they should be narrow (not exceeding four to five inches or thereabouts),
and a greater number of plates being employed in cach sieve. The thickness of
the plates should not be less than a quarter of an inch, the object being that if long
nails or similar material should fall end downwards through the holes, there would
not be sufficient room to permit them being so much angled as to pass away with
the grain. If flat plates are used they are placed in the same plane, but separated
from each other by slips of wood or inetal. Underneath the plates containing the
holes are shelves of wood or other material, such shelves being rather broader than
the perforated plates above then, and placed so near the plates that when the
grain falls through the holes there will be just sufficient room (and no more) for it
to pass freely between the shelves and perforated plates. These shelves are all on
the same plane, but separated from each other by open spaces, so that the grain
after sliding upon the shelves will fall through these open spaces on to a fine wire
web (or a board having at its extremity a wire web) placed underneath, by which
means the dust or fine material is separated from the grain. The spaces between
the shelves are under the slips of wood or metal which separate the perforated
plates. At the end of the wire web or board, and forming part of the sieve, is
placed a pit over which all the grain will pass. This pit is for the purpose of
allowing small pieces of metal or other heavy material of or about the same size of
the grain, and which may have passed through the perforated plates, falling by
reason of their gravity to the bottom, and being detained there while the grain
floats over such pit (after it has become filled with grain or other material), and is
discharged from the sieve.
The perforated plates, shelves, and other portions forming the sieve are enclosed
in a suitable framework, and the whole is agitated by a crank or other suitable
means. The sieve is suspended so that the discharging end is lower than the oppo-
[Price 2d1

page_text: site ond. If curved or cylindrical perforated plates are used instead of flat ones, as
above described, the shelves of wood or other material should be also curved
or cylindrical, so that the space between the perforated plates and the shelves is
parallel.
In case a cylindrical sieve is used a revolving motion may be imparted to it
instead of being merely agitated, but with the latter description of sieve it is advis-
able to have the wire web and pit separate from the perforated plates and shelves.