IMPROVEMENTS IN GRINDING MILLS
Year: 1877

page_text: LETTERS PATENT to William Newzam Nicholson and William Mather, both
of Newark-upon-Trent, in the County of Nottingham, Agricultural Engineers,
for the Invention of "IMPROVEMENTS IN GRINDING MILLS."
Sealed the 16th April 1878, and dated the 23rd October 1877.
PROVISIONAL SPECIFICATION left by the said William Newzam Nicholson
and William Mather at the Office of the Commissioners of Patents on the
23rd October 1877.
WILLIAM NEWZAM NICHOLSON and WILLIAM MATHER, both of Newark-upon-
Trent, in the County of Nottingham, Agricultural Engineers. "IMPROVEMENTS IN
GRINDING MILLS."
This Invention has for its object improvements in grinding mills, and applies
more especially to such as are constructed under the Patent No. 1828, granted to
us on May the Tenth, One thousand eight hundred and seventy-seven, and
consist,――
First. In an improved method of suspending the rotating cone.
And, Second. In an improved plan of adjusting and assisting the feed.
When the rotating grinding parts of mills are arranged vertically we find it adds
both to their efficiency and durability if the grinding cone is suspended on the
То
spindle, so as to have free movement from the centre in every direction.
accomplish this it is necessary that the cone should be centred with great accuracy,
and as the grinding parts of such mills must be made of metal of exceeding hardness,
so that it is difficult to penetrate them; for the purpose of centreing we cast or
otherwise fix in the crown of the cone a piece of wrought iron or other softer
material, on which the centre is carefully cut in a lathe or other machine. We
turn the end of the vertical spindle so that it fits freely in the centre thus made in
the crown of the cone, and we cast two vertical webs inside the cone. The spindle is
drilled a short distance from the top, and a round bar is inserted horizontally in the
hole. A cylindrical casting having having slots at both ends, one set of slots being at

page_text: right angles with the other is dropped loosely on the spindle, the round bar across
the spindle taking into the lower slots. The grinding cone is then dropped on the
spindle, the webs inside the cone taking into the upper slots, this arrangement
forming a sort of universal point, and allowing free play in every direction to the
lower part of rotating cone.
Our improvements in the feed adjustment are adapted to what is commonly
known as the silent or centrifugal feed, are as follows:-On the concave of the
Inill we fix a dome-shaped top with a screwed thread cast or chased in the same,
having also openings for the admission of air, and having on its outer edge a flange
projecting upwards in which are notches for the purpose of holding the adjusting
lever. A cylindrical spout into which the hopper delivers, having a screwed thread
cast or chased outside the same, is screwed into the above-described dome. This
spout has a hinged lever fixed to its top edge, which lever is made to drop into
the notches on the flange of the dome so as to hold the spout in any required
position.
By turning the spout by the lever to the right or left it is brought nearer to or
further from the grinding cone, and by this means a greater or less amount of feed
is given to the mill.
To prevent the interruption of the feed by the lodging of pieces of husk or other
foreign substance at the bottom of the spout, we cast, or fix slightly projecting
pieces on the top of the rotating cone, and we make the spout with one or more
projecting webs inside.
The pieces on the cone have the effect of crushing the
husks against the webs in the spout small enough to pass through the mill.
41 T

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Newzam Nicholson and William Mather in the Great Seal
Patent Office on the 23rd April 1878.
WILLIAM NEWZAM NICHOLSON and WILLIAM MATHER, both of Newark-upon-
Trent, in the County of Nottingham, Agricultural Engineers.. "IMPROVEMENTS IN
GRINDING MILLS."
This Invention has for its object improvements in grinding mills, and applies
more especially to such as are constructed under the Patent granted to us on
May 10th, 1877, and consists,-
. FY
First. In an improved method of suspending the rotating cone..
And, Second. In an improved plan of adjusting and assisting the feed.
When the rotating grinding parts of mills are arranged vertically we find it adds
both to their efficiency and durability if the grinding cone is suspended on the
spindle, so as to have free movement from the centre in every direction. To
accomplish this it is necessary that the cone should be centred with great accuracy,
and as the grinding parts of such mills must be made of metal of exceeding
hardness, so that it is difficult to penetrate them; for the purpose of centreing we
cast or otherwise fix in the crown of the cone a piece of wrought iron or other
softer material, on which the centre is carefully cut in a lathe or other machine.
We turn the end of the vertical spindle, so that it fits freely in the centre thus
made in the crown of the cone, and we cast two vertical webs inside the cone.
The spindle is drilled a short distance from the top, and a round bar is inserted
horizontally in the hole. A cylindrical or annular casting having slots at both
ends, one set of slots being at right angles with the other is dropped loosely on the
spindle, the round bar across the spindle taking into the lower slots. The grinding
cone is then dropped on the spindle, the webs inside the cone taking into the upper
slots, this arrangement forming a sort of universal joint, and allowing free play in
every direction to the lower part of rotating cone.
Our improvements to the feed adjustment are adapted to what is commonly
known as the silent or centrifugal feed, and are as follows:-On the concave of the
mill we fix a dome-shaped top with a screwed thread, cast or chased in the same,
having also openings for the admission of air, and having on its outer edge a flange
projecting upwards, in which are notches for the purpose of holding the adjusting
lever. A cylindrical spout into which the hopper delivers, having a screwed thread
cast or chased outside the same, is screwed into the above-described dome. This
spout has a hinged lever fixed to its top edge, which lever is made to drop into
the notches on the flange of the dome so as to hold the spout in any required
position.
By turning the spout by the lever to the right or left it is brought nearer to or
further from the grinding cone, and by this means a greater or less amount of feed
is given to the mill.
To prevent the interruption of the feed by the lodging of pieces of husk or other
foreign substance at the bottom of the spout, we cast or fix slightly projecting
pieces on the top of the rotating cone, and we make the spout with one or more
projecting webs inside. The pieces on the cone have the effect of crushing the
husks against the webs in the spout small enough to pass through the mill.
And that our Invention may be the more clearly described and understood we
have annexed hereto one Sheet of Drawings, the same being marked with figures
and letters of reference corresponding to the following explanation, that is to say :-
Figure 1 represents a vertical section through our improved grinding mill.
A is the mill frame or stand; B is the grinding cone, having a centre D of
wrought iron or other softer material, cast or otherwise fixed within it, and which
rests upon the driving spindle S; two vertical webs E, E¹, are cast inside the
grinding cone, which take into slots made in the upper edge of the annular

page_text: casting F; this casting is shown detached in Figure 2. Slots are also made in the
lower edges of this casting to receive the driving bar G, which is inserted horizon-
tally through the spindle S, thus forming a universal joint, and allowing free play
from the centre of suspension in every direction to the lower part of the rotating
cone B.
In the second part of our Invention for an improved feed adjustment a dome-
shaped top H, also shown detached in plan by Figure 3, is fastened to the grinding
concave C, and has a female screw thread chased or cast within it to receive the
spout J, which is made with a corresponding male screw. Portions of the female
screw are cut away from the interior of the dome top H and form openings K, for
the admission of air to the grinding cone.
The spout J has a lever L hinged to it for the purpose of turning it in its screw,
and so raising or lowering it from the grinding cone B. Notches are made in the
upper part of the dome top H, into which the lever L drops, thereby securely
holding it in any required position.
The spout J is formed with one or more projecting webs M on its interior
periphery, and projections N are also made upon the top of the grinding cone B;
these have the effect of crushing any husks or foreign substances against the web M,
so breaking them small enough to pass into the mill.
In witness whereof, I, the said William Newzam Nicholson, have hereunto
set my hand and seal, this Eighteenth day of April, One thousand eight
hundred and seventy-eight.
WILLIAM NEWZAM NICHOLSON. (L.S.)