IMPROVEMENTS IN MILLS FOR GRINDING WHEAT AND OTHER GRAIN
Year: 1865

page_text: LETTERS PATENT to William Pickford Wilkins, Engineer, of Ipswich,
in the County of Suffolk, for the Invention of "IMPROVEMENTS IN MILLS
FOR GRINDING WHEAT AND OTHER GRAIN."
Sealed the 19th May 1865, and dated the 6th February 1865.
PROVISIONAL SPECIFICATION left by the said William Pickford Wilkins
at the Office of the Commissioners of Patents, with his Petition, on the
6th February 1865.
I, WILLIAM PICKFORD WILKINS, Engineer, of Ipswich, in the County of
Suffolk, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN MILLS FOR GRINDING WHEAT AND OTHER GRAIN," to be as follows:-
My Invention relates to that class of mills for grinding corn in which the
grinding operation is performed by a roller or cylinder having teeth on the
periphery, and rotating within what is termed a concave, that is to say, the
segment of a hollow cylinder having teeth on the interior or concave surface
opposite the teeth of the cylinder.
In these mills, as heretofore constructed, there being nothing to prevent the
teeth of the cylinder effecting contact with the teeth of the concave except
the matters being ground, they are subject to rapid wear from actual contact
with each. other. To prevent this I form lugs on the grinding or toothed
concave and apply screws through the top plates, with the points of which the
lugs effect contact when it is raised up, and whereby the approach of the

page_text: concave to the teeth of the cylinder may be regulated to the greatest nicety
and actual contact prevented, although, at same time, permitting the requisite
proximity of the two sets of teeth necessary for the finest grinding. The
approach of the one part may be also regulated by other mechanical equivalents
which are obvious and need not here be described; or plain parts may exist
at the ends of the roller or cylinder, and the concave, which would come in
contact before the two sets of teeth actually touch.
My second improvement consists in arranging the teeth on the roller or
cylinder spirally, or in a winding direction around it, which may be of advan-
tage in detaining the material for a longer or shorter time in the mill and
under the grinding operation as may be desired. These mills or grinding parts
are usually mounted on timber frames, which, from the strain and from other
causes yield and derange the mill.
Now according to the third part of my Invention, I cast the frames and
some of the parts all in one piece, which ensures the permanent and proper
relation of the parts so combined. Instead of casting the parts in one and
the same piece I make the frame and parts of iron, and so bolt and check
them together as to be equally rigid as if cast-in one piece.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Pickford Wilkins in the Great Seal Patent Office on
the 5th August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PICKFORD WILKINS, of Ipswich, Engineer, in the County of Suffolk, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing, date the Sixth day of February, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Pickford Wilkins, Her special licence that I, the said
William Pickford Wilkins, my executors, administrators, and assigns, or such
others as I, the said William Pickford Wilkins, 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 MILLS FOR GRINDING WHEAT AND OTHER GRAIN,"

page_text: upon the condition (amongst others) that I, the said William Pickford
Wilkins, 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 immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said William Pickford Wilkins, do hereby
declare the nature of my 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 Sheet of Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say) :-
My Invention relates to that class of mills for grinding corn in which the
grinding operation is performed by a roller or cylinder having teeth on the
periphery, and rotating within what is termed a concave, that is to say, the
segment of a hollow cylinder having teeth on the interior or concave surface
opposed to the teeth of the aforesaid cylinder.
In these mills, as heretofore constructed, there has been nothing to prevent
the teeth of the cylinder effecting contact with the teeth of the concave except
the matters being ground, they were consequently subject to the very prejudicial
effects of actual contact with each other. To prevent this, I form lugs on the
grinding or toothed concave, and apply screws through the top plates, with
the points of which the lugs effect contact when it is raised up, and whereby
the approach of the concave to the teeth of the cylinder may be regulated to
the greatest nicety and actual contact prevented, at same time permitting the
requisite proximity of the two sets of teeth necessary for the finest grinding.
The approach of the one part to the other may be also regulated by other
mechanical equivalents, which are obvious, and need not be here described ;-or
plain parts may exist, at the ends of the roller or cylinder and the concave,
which plain parts should come in contact before the two sets of teeth actually
touch.
My second improvement consists in arranging the teeth on the roller or
cylinder spirally or in a winding direction around it, which is of advantage in
detaining the material a longer or shorter time in the mill, and therefore,
under the grinding operation, and as may be required. The mills or grinding
parts are usually mounted on timber frames, which, from strain and from other
causes yield and derange the mill.
Now according to the third part of my Invention, I cast the frames and some
of the parts all in one piece, which ensures the permanent and proper relation

page_text: DESCRIPTION OF DRAWINGS.
Fig. 1 represents a side elevation, and Fig. 2 an end view, of a mill
for grinding wheat and other grain, comprising my several improvements;
Fig. 3 represents a transverse vertical section of the same on an enlarged
scale, illustrating and showing more clearly my improvements; while Fig. 4 is
a side view, and Fig. 5 an end view, of the grinding cylinder detached, the
scale of which is still further enlarged.
The general arrangement of this is very similar to ordinary grinding mills
with metal surfaces, but in detail has some important differences. Thus with
reference to the contact of the cylinder with the concave, I mount and
support the concave A by levers B mounted on fulcra C, the levers being
suspended and regulated by screw rods D;D, in the usual manner; but in order
that the grinding surfaces shall not approach too close I provide faces E, E,
at both ends of the concave A, which faces come against the points of four set
screws F, which may be adjusted to regulate the approach of the teeth of the
concave A to the teeth of the cylinder to the greatest nicety, and so permit of
their closest proximity without actual contact, whereby a great and uniform
reduction of the materials under operation is ensured without chance of
damage to the grinding surfaces, as is frequently the case from actual contact
in mills of the ordinary construction. By the same set screws, F, F, and D, D,
the concave can be set so that the mill will grind coarser or finer as may be
desired..
The second improvement is illustrated in Fig. 4, being an enlarged view of
the grinding cylinder (or drum of a truncated conical form), and which
consists in arranging and forming the teeth thereof in a spiral or winding
direction on that cylinder, as represented; this spiral arrangement of the
teeth may also be adopted on the concave, if it is desirable to retain the matters
under operation a long time between the grinding surfaces, but for most
purposes I think it is sufficient if the teeth on the roller are so formed.
The third part of my Invention refers to the framing and uniting the parts
of the machine together so that there shall be no appreciable or prejudicial
spring or elasticity between the one grinding surface and the other. To
ensure this, I cast or otherwise form the top metal framing H of the machine
in one piece with, or so bolted to the side frames L, as to support rigidly the
bearings in which the shaft of the cylinder I is mounted, as also the set

page_text: screws F, F, and D, D. By this means the whole of these points of support
are placed in rigid connection, and if all the parts transmitting the strain
between such points are abundantly strong, no appreciable or prejudicial
elasticity will be exhibited. The fulcra of levers B are formed by a tie rod
stretched between the side frames L, which are of iron, rigidly bolted to H, as
represented in the Drawings. I construct the whole of the framework of iron,
which, with all the other parts of the machine represented in the Drawing,
are of the ordinary arrangement, and will therefore be readily understood
without any special description.
Having described the nature of my Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
First, the application of set screws F, F, and faces E, E, or other
equivalent adjustable bearing points for the concave, as and for the purposes
herein-before described.
Secondly, forming and arranging the teeth of the grinding cylinder in a
spiral or inclined direction, as described and represented in the Drawings
annexed.
Thirdly, I claim combining the different points of support holding the
grinding surfaces together in rigid connection, as and for the purposes herein-
before described, either by casting them in one piece, or otherwise forming
them of metal, and uniting them rigidly as herein-before mentioned.
In witness whereof, I, the said William Pickford Wilkins, have here-
unto set my hand and seal, this Third day of August, in the year of our
Lord One thousand eight hundred and sixty-five.
Witness,
W. CLARK,
Patent Agent,
53, Chancery Lane,
London.
W. P. WILKINS. (L.S.)