IMPROVEMENTS IN APPARATUS FOR CLEANSING WHEAT
Year: 1855

page_text: LETTERS PATENT to William Polkinhorn, of Gwennap, near Redruth,
in the County of Cornwall, Miller, for the Invention of "IMPROVEMENTS
IN APPARATUS FOR CLEANSING WHEAT."
Sealed the 29th May 1855, and dated the 29th January 1855.
PROVISIONAL SPECIFICATION left by the said William Poikinhorn at
the Office of the Commissioners of Patents, with his Petition, on the
29th January. 1855.
I, WILLIAM POLKINHORN, of Gwennap, near Redruth, in the County of
Cornwall, Miller, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR CLEANSING WHEAT," to be as follows:-
In my improved apparatus the wheat is introduced in a dry state into a
receptacle or box. the interior of which is lined with sheet iron or other suitable
material; "the surface thereof being roughened by punching, or in any other
In this receptacle or box
manner, so as to produce a suitable rough surface.
a common grinding stone is placed in a vertical position, the stone being of
such a size that only a small space is left between its surface and the internal
lining. The axis of this stone, being connected with the machinery in ordinary
use for such purposes, is caused to revolve at a suitable rate of speed, the
receptacle or box remaining stationary. The wheat is thus subjected to a
frictional process between the stone and the rough lining of the receptacle or
017

page_text: box, of such a character that no portion can escape its influence, and the brush
end of the grain will be detached, together with all filth, whether smut, dirt, or
other impurities, while the wheat itself is not broken and receives no injury. The
revolution of the stone imparts a centrifugal force or motion to the contents of
the receptacle or box, so that after having been subjected to the frictional
process above mentioned, the wheat is raised or thrown to a level above the
axis of the stone, and escapes by means of a trunk or pipe, as represented in
the annexed Drawing.
The wheat is then conducted through the trunk or pipe above mentioned
into a revolving wire cylinder, placed at an oblique angle. and similar in many
respects to those in ordinary use for like purposes. except that the wire is of
such a peculiar fineness that the meshes offer the least possible obstruction to
the escape of the dirt. smut. and other impurities which have been previously
reduced to powder by the friction of the stone: and that it contains no con-
tinuous internal screw or worm, but has several arms which terminate in
blades placed somewhat obliquely, as represented in the annexed Drawing.
such arms and blades serving all the purposes of spiral ribs, in preventing the
escape of the wheat until perfectly free from extraneous substances.
The advantage of this construction is, that a much less surface of the wire
cylinder is blinded or covered than by a continuous spiral rib or worm. The
arms and blades are fixed at suitable distances on the shaft of the cylinder:
the latter is fixed to the external edges of the said blades. The meshes, of
about four-fifths or other suitable proportion of the wire cylinder. should be
of such a size as to permit the dirt, grit. smut, and other impurities to escape,
while the remaining and lower portion of the cylinder is constructed with
parallel rows of wire, arranged at suitable distances, so as to allow the wheat
only to pass through, but delivering all stones, nails, or other matters of a
larger size at the end of the cylinder. The wheat may then finally be sub-
jected to the action of an ordinary fan, which will blow off all substances
lighter than the wheat, which may still be adhering to or mixed with it. The
wheat will thus, by the frictional process in the receptacle or box above men-
tioned. and afterwards by its passage through the wire cylinder, be thoroughly
cleansed and freed from all its dirt and impurities, and, as I believe, much
more perfectly, and with a greater economy of time and power than by any of
the processes now in use.
The following are the references to the annexed Drawing:-B, receptacle
or box, with internal roughened, surface: b, the hopper or feeding aperture,
with moveable, slide; C, the stone, revolving upon its axis, and arranged with
gearings to carry the necessary driving bands; c, trunk or pipe for conveyance

page_text: of the grain to the cylinder; D, the wire cylinder on its axis; A, A, A, A, A,
transverse arms and blades; E, fan or blower; F. driving wheel; G & H,
front and edge views of arms and blades.
I do not claim the whole of the above apparatus as my Invention, inasmuch
as many portions thereof have been in previous use; but I claim the usc and
arrangement of the stone revolving vertically in a fixed receptacle or box for
the purpose of cleansing wheat, and the application of the centrifugal force
imparted thereby to the delivery of the wheat into the trunk or pipe, as above
described. And I also claim as my Invention, the arms and blades to be
placed in the wire cylinder, in the form and arrangement above mentioned,
and as delineated in the annexed Drawing
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Polkinhorn in the Great Seal Patent Office on the
7th July 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
POLKINHORN, of Gwennap, in the County of Cornwall, Miller, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of January, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself. Her heirs and successors, give and grant unto me, the said
William Polkinhorn, Her special licence that I. the said William Polkinhorn,
my executors, administrators, and assigns, or such others as I, the said
William Polkinhorn, 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 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
APPARATUS FOR CLEANSING WHEAT," upon the condition (amongst others) that
I, the said William Polkinhorn, by an instrument in writing under my hand
and seal, 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 immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Polkinhorn, do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
statement, that is to say:
is left between
The object of my Invention is to free wheat previous to grinding from all
dirt, grit, smut, and other impurities and extraneous substances more perfectly
and with greater economy of time and power, than has been effected in any of
the machines hitherto constructed. In my improved apparatus the wheat.is
introduced in a dry state into a receptacle or box, which I call the scouring
mill, the interior of which is lined with sheet iron or other suitable material,
the surface thereof being roughened by punching, or in any other manner, so
as to produce a suitable rough surface. In this receptacle or box a common
grinding stone is placed in a verticle position, the axis thereof being con-
nected with the machinery in ordinary use for such purposes. by which means
it can be made to revolve at any suitable rate of speed, while the receptacle
or box, which is fixed, remains stationary. The receptacle or box should be
so proportioned in size to the stone that only a small space
the internal lining of the former and the surface of the stone. Upon the stone
being caused to revolve. the wheat is subjected to a frictional process between
the stone and the rough lining of the receptacle or box, such process being of
such a character that no portion can escape its influence, and whereby the
brush end of the grain will be detached, together with all filth, whether smut,
dirt, grit, or other impurities, while the wheat itself is not broken, and receives
no injury. In cases also where, in consequence of the wetness of the harvest,
the grain has sprouted or vegetated, the sprouted end will by this process be
removed. The revolution of the stone imparts a centrifugal force or motion
to the contents of the receptacle or box, so that, after having been subjected to
the frictional process above mentioned, the wheat is raised or thrown to a level
above the axis of the stone. and escapes by means of a trunk or shoot, as
represented in the annexed Drawing. The elevation at which the grain is
allowed to enter the trunk or shoot can be varied by means of an iron slide.
which is raised or lowered by an adjusting screw, as represented in the Drawing.
The wheat is then conducted through the trunk or shoot above mentioned into
a revolving wire cylinder, placed at an oblique angle, and similar in some
respects to those in ordinary use for like purposes, except that about four-fifths
thereof are composed of fine wire, with the meshes about one-tenth of an inch
square, thus offering the least possible resistance to the escape of the dirt, grit,
smut, and other impurities which have been previously reduced to powder by
the frictional process above described; while the remaining and lower portion
of the cylinder is constructed with parallel rows of wire, arranged at suitable
distances, so as to allow the wheat only to pass through, but delivering all

page_text: stones and other matters or substances of a larger size at the lower end of
the cylinder. which is left open and uncovered. The cylinder differs also from
those in ordinary use, inasmuch as it contains no continuous internal rib or
worm, but is separated transversely into compartments by an arrangement of
arms, which terminate in blades placed somewhat obliquely, as represented
in the annexed Drawing. such arms and blades serving all the purposes of
spiral ribs. in preventing the escape of the wheat until perfectly free from
the dirt, grit. smut, filth. and other impurities with which it may have been
mixed. The arms and blades are fixed at suitable distances on the shaft of the
cylinder. the wirework composing which is fixed to the external edges of
the said blades. In a cylinder seven feet long I prefer having six sets of arms
and blades; but I do not confine myself to that number, nor to any particular
proportion of the cylinder. which may be composed with the fine meshed wire-
work. The advantage of the construction of the cylinder with the said arms
and blades which I have detailed is, that a much less proportion of the surface
of the wire cylinder is blinded or covered than by a continuous spiral rib or
The wheat may then be finally subjected to the action of an ordinary
fan. which will blow off all substances lighter than the wheat which may still be
adhering to or mixed with it. I may state, that the rate of speed at which I
prefer the stone should revolve is about three hundred and fifty revolutions in
a minute, but this may be varied according to circumstances. In cases where
there is only a small quantity of filth or other impurities to be removed, the
wheat might be subjected to the blast of a fan immediately after leaving
the scouring mill, instead of being passed through the wire cylinder.
worm.
The following are the references to the annexed Drawing, by which the
description I have given of my improved apparatus will be clearly understood.
Figure 1. A, driving wheel; B, scouring mill with revolving stone; C,
trunk or shoot; D, wire cylinder with fine meshes; E, coarse ditto; F, fan;
G, adjusting screw; H, moveable iron slide; I, transverse arms and blades.
Figure 2, front view of arms and blades; Figure 3, edge view of ditto.
Having now fully described the nature of my said Invention, and the manner
in which it is to be performed, I would have it clearly understood that I do by
no means confine myself to the precise details herein-before described, as the
same might be varied without departing from the general principle of my said
improvements; nor do I claim the whole of the above apparatus as my Inven-
tion, inasmuch as some portions thereof have been in previous use; but that
which I do claim as new and of my Invention is,-
Firstly, the use and arrangement of the stone revolving vertically in a fixed
receptacle or box for the purpose of cleansing wheat, and the application of

page_text: the centrifugal force imparted thereby to the delivery of the wheat into the
trunk or shoot, as above mentioned.
And, secondly, the construction and arrangement of the arms and blades to
be placed in the wire cylinder, in the form and arrangement above described
and set forth.
In witness whereof. I, the said William Polkinhorn, have hereunto set
my hand and seal, this Fourth day of July, in the year of our Lord
One thousand eight hundred and fifty-five.
WILLIAM POLKINHORN. (L.S.)