CERTAIN IMPROVEMENTS IN MACHINERY FOR GRINDING CORN AND OTHER MATERIALS
Year: 1834

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SHARP, of Manchester, in the County Palatine of Lancaster, Engineer, send
greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the First day of January, One thousand eight hundred and
thirty-four, and in the fourth year of His reign, did, for Himself, His heirs
and successors, give and grant unto me, the said Thomas Sharp, and to
RICHARD ROBERTS, of Manchester aforesaid, my copartner, His especial
licence, full power, sole privilege and authority, that we, the said Thomas
Sharp and Richard Roberts, our executors, administrators, and assigns,
others as we, the said Thomas Sharp and Richard Roberts, our executors,
administrators, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, an Invention of "CERTAIN
IMPROVEMENTS IN MACHINERY FOR GRINDING CORN AND OTHER MATERIALS," com-
municated to us from a Foreigner residing abroad; in which said Letters
Patent is contained a proviso obliging us, the said Thomas Sharp and Richard
Roberts, by au instrument in writing under our hands and seals, or under
the hand and seal of one of us, particularly to describe and ascertain the
nature of the said. Invention, and in what manner the same is to be performed,

page_text: and to cause the same to be inrolled in His said Majesty's High Court of
Chancery within six calendar months next and immediately after the date of
the said in part recited Letters Patent, as in and by the same, reference being
thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Sharp, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figures marked
thereon, that is to say:-
These improvements in machinery for grinding corn and other materials
consist in a peculiar mode of adapting the two stones or other cutting or
rubbing surfaces, between which corn or other material may be ground or
pulverised, the leading feature of which is, that the two stones or other
grinding surfaces are made to revolve together upon centres, which are eccen-
tric to each other. The modes of mounting these grinding surfaces, and of
driving them, as well as the materials of which such surfaces are made, adinit
of considerable variations; that is to say, the bearings by which such stones
or other grinding surfaces are supported, and the mechanism by which they
are driven, may be formed or constructed in several ways, and the grinding
surfaces themselves may be of natural stone or of artificial stone, or of metal,
or of any other fit material. In order to illustrate the principles upon which
these improvements are founded, we have, in the accompanying Drawings,
exhibited mills or machines for grinding, in one of which the grinding surfaces
are supposed to be of cast iron or steel, and in the other of stone, the grinding
surfaces in the former being made to turn horizontally, and in the latter
vertically.
Figure 1 is an elevation of a machine or mill, in which the grinders a and b
are discs of cast iron, mounted in a suitable iron frame; Figure 2 is a section,
of the same, taken vertically through the middle; and Figure 3 is a plan or
horizontal view of the same. The disc a, which corresponds to the bed stone
of a mill, is larger in its diameter than the runner b, and is securely fixed to a
vertical shaft c, which turns in an adjustible step d at bottom, and in a neck
and collar within the plummer box or loop o above. The upper disc or
runner is suspended by its tubular neck f. f, and collar in the upper part of
the framework, and is held there by a loop or plummer box 9, 9. The tubular
neck ff. forms the aperture, through which the grain or other material is to
be fed into the mill; and a finger h, affixed to the frame, extends over into
the feeding aperture, for the purpose of stopping or arresting the descending

page_text: grain or other material as it is fed in, which would otherwise revolve or be
carried round with the collar. A pinion is suspended by a neck and collar
from the frame, and is held in that position by the plummer box or loop c,
before mentioned. The vertical shaft c is passed through the pinion, and they
are locked together when revolving by a feather or rib k on the side of the
shaft c, which allows the grinding surfaces to be brought nearer together, or
set further apart, as the quality of the grain or other material may require, by
raising or lowering the step d, which is formed with a screw for the purpose of
adjustment. A horizontal axle 1, mounted in suitable bearings in the frame,
has a toothed wheel m aflixed to its inner extremity, which wheel takes into
the pinion i, consequently when rotatory motion is given to the axle 1, either
by hand labour through a winch n, or by steam or any other power through a
rigger or gear, the vertical shaft c, and with it the lower disc or bed stone, will
be made to revolve horizontally, and in revolving, by the friction of contact, to
give rotary motion also to the runner or upper disc b, between which surfaces
the grain or other material gradually introduced through the neck will
become ground or pulverized, and will be discharged from the grinding sur-
faces of their peripheries, whence it can be conducted by any suitable casing
to a receptacle placed below (as shewn by the red lines in the Drawings). It
will now be perceived that by the axis of the two grinding surfaces being
eccentric to each other, and yet the surfaces revolving together, that the upper
grinder or runner will as it revolves travel round upon the face of the lower
grinder or bed surface, and that consequently the points of contact between
the two grinding surfaces and the speed with which those points pass each
other will be perpetually changing. The peculiar rotary movements of these
grinding surfaces will produce greater friction upon the grain or other mate-
rials under operation, and cause the mill to perform its work more perfectly
and expeditiously than any other mills in which the grinding surfaces are of
corresponding magnitude; and also these mills may be driven by a consider-
ably smaller power than would be requisite to produce a corresponding
quantity of work in mills of ordinary constructions.
The Figures in the Drawings above described exhibit a convenient mode of
adapting two metallic dises as grinders, intended to revolve horizontally. It
must, however, be obvious that French burrs, or other stones suitable for
grinding, might be mounted so as to work in a similar way.
Figure 4 is a horizontal representation of the framework, axles, and grinders
of a machine or mill, in which a pair of stones are made to work vertically;
Figure 5, an end elevation of the same; and Figure 6 is a longitudinal section.
The larger stone, corresponding to the bed stone, is represented at a; the

page_text: lesser stone, corresponding to the runner, at b. The larger of these stones is
mounted upon a horizontal shaft c, turning in suitable bearings, supported by
the framework, and which it is proposed to drive by a band from a steam
engine passed over a rigger d, or it may receive its motion from any other first
mover. The lesser stone 6 is securely affixed to or mounted upon a cylindrical
tube c, to be inserted into a hollow cylindrical chamber or box f, within which
it is intended to revolve. This box is fixed to one of the standards of the
machine, and is held fast by a staple or strap g, passed over the upper part of
the box, and by a shaft h at the back. The shafts c and h, it will be per-
ceived, have adjusting screws i, i, by which the proximity of the faces of the
stones may be regulated. The grain or other materials intended to be
ground are to be fed by a hopper & into the box f; and when the material or
dry grain requires to be conducted forward through the tube e toward the
grinding faces, two spiral or twisted blades are attached to the end of the
tube e, which blades, by revolving with the tube and the runner stone, lead
the grain or other material forward into the tube by a sort of screw movement;
and when the grain or other material has thus been brought into the tube, a
straight blade m, made stationery within the tube, guides the grain or other
material forward to the surfaces of the stones. It is obvious that instead of
employing stones as grinders, steel or other metal plates or discs may be
adapted in a similar manner. In adapting stones for the grinding of grain wo
make the working surfaces of both without grooves or furrows, and as nearly
true or level as possibly, excepting that it may be found desirable to rough ono
of the stones slightly by fine pecks, and to form some few nicks or indentations
near the centre, as represented in the view of the face of a bed stone at
Figure 7; and also the upper or runner stone may be very slightly dished round
the centre, and nicked in the form of a star, as shewn in the view of the face
of a runner stone at Figure 8. When steel or cast-iron grinders are adapted,
we have found it desirable to cut upon the faces of each series of concentric
grooves or circles, by which means, as the two surfaces revolve together in the
way described, the edges of these circles in passing each other will act as
shears or cutting angles; but a similar effect may be produced by other kinds
of grooves or indentations.
Having described convenient modes of constructing and working our
improved machinery or mills for grinding grain and other materials, we desire
it to be understood that we do not intend to confine ourselves to the details of
such constructions, but claim, as embraced within our Patent right, any and
every variation of construction of machinery in which the two grinding sur-
faces of a mill, whether of stone or of other suitable material, may be made to

page_text: revolve together in the same direction upon pivots, axles, or axes, which are
eccentric to each other.
In witness whereof, I, the said Thomas Sharp, have hereunto set my
hand and seal, this Twenty-eighth day of June, One thousand eight
hundred and thirty-four.
Signed, sealed, and delivered (being
first duly stamped), by the within-
named Thomas Sharp, on behalf of
himself and his partner, Richard
Roberts, in the presence of
THOS (L.s.) SHARP.