IMPROVEMENTS IN MACHINERY OR APPA- RATUS FOR CLEANING, SIFTING, AND DRESSING GRAIN, SEEDS, AND OTHER SUBSTANCES
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Joseph Mitton at the Office of
the Commissioners of Patents, with his Petition, on the 22nd January
1864.
I, JOSEPH MITTON, of Lincoln, in the County of Lincoln, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN MACHINERY OR APPA-
RATUS FOR CLEANING, SIFTING, AND DRESSING GRAIN, SEEDS, AND OTHER SUBSTANCES,"
to be as follows:-
This Invention relates to certain improvements in the construction of screens,
sifters, or riddles of cylindrical, hexagonal, or plane forms, suitable for cleaning,
sifting, and dressing grain and seeds, and also for sifting or screening coal,
gravel, ashes, and other like mineral or earthy substances, the object of the
improvements being so to construct the various forms of apparatus that they
may be adapted for the treatment of grains, seeds, or other matters of diffe-
rent sizes by rendering the interstices or spaces between the wires capable of
being reduced or enlarged at pleasure.
I propose to construct cylindrical apparatus by means of two discs forming
the ends of the screen, into one of which the grain or other matter is to be
conveyed by a hopper, these discs are provided at their periphery with a
series of horizontal bars or rods at such intervals apart that the bars of one
disc shall come between those of the opposite disc or end of the apparatus.
To the under side of these bars a series of rings or hoops of wire are fixed

page_text: by soldering or by fine thread wire, or both, in such manner that each ring or
hoop alternately shall be attached to alternate bars or rods. Between each
pair of hoops, and within their circumference, a smaller hoop surrounded by a
coil or spiral of wire is inserted, being held in position by bearing up against
or between each pair of hoops. Through the centre of the discs a screw
shaft passes, the thread of which works in a female thread cut in one disc,
and a collar or boss on the shaft is made to bear against the internal surface
of the opposite disc, beyond which the shaft is provided with a crank or
handle for rotating the apparatus and for turning the screw in the discs.
Now it will be obvious that as the screw is turned in its bearing in one
or other direction the discs will be separated or brought nearer together, each
actuating its series of longitudinal rods and rings, and forcing them together,
or drawing them further apart, whereby the interstices or spaces between
them will be changed.accordingly.
In some cases I propose to dispense with the use of the internal rings
covered with spiral wire.
To form a hexagonal or other polygonal form of screen the discs are to be
made of the requisite outline, and the proper number of bars fixed thereon,
these bars should consist of flat strips of metal bent to an obtuse angle down
their centres, and they should be also bent from end to end crosswise into
a series of serrated or angular indentations and ridges, the wires are then
to be wound or placed upon the bars, each notch or indent receiving a wire.
In this example one series of bars must be on a different level to the
other, and the distance between each may be controlled by a lever or rod.
The action is similar to that of the cylindrical apparatus.
Flat screens of a square or oblong square form may be made so that
their interstices can be enlarged or diminished by a similar principle.
A screw being made to act at each of two corners of the apparatus, the side
containing them forming the moveable part of the frame, and the screws
entering threads in the frame, it will follow that the wires may be relatively
approximated or separated.
I also propose to make these flat screens in such manner that they shall
have cross wires, each series of which shall be capable of approaching to or
receding from each other. To accomplish this I cause the upper series of
wires to be actuated by screws at one side of the frame, and the under
series by two other screws on one other side at right angles thereto, these
latter screws must take into a separate bar to which the under wires are
attached, inasmuch as that side of the frame containing the upper wires is
moveable.

page_text: So also the frame may be made a fixture, and the two pairs of screws may
work "therein and into two moveable bars (acting as supplementary shifting
sides), to which the double set of wires are to be attached.