IMPROVE- MENTS IN MILLS FOR CRUSHING AND GRINDING
Year: 1870

page_text: LETTERS PATENT to Henry Jackson, of Park Square, Leeds, in the
County of York, Consulting Engineer, for the Invention of "IMPROVE-
MENTS IN MILLS FOR CRUSHING AND GRINDING."-Partly a communication
from abroad by Charles Ross and John Ross, both of New York, in
the United States of America.
PROVISIONAL SPECIFICATION left by the said Henry Jackson at the
Office of the Commissioners of Patents, with his Petition, on the
2nd April 1870.
I, ILENRY JACKSON, of Park Square, Leeds, in the County of York,
Consulting Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN MILLS FOR CRUSHING AND GRINDING," to be as
follows:-
The Invention relates in the first place to mills wherein metallic
crushing and grinding surfaces are employed, the said crushing and
grinding surfaces being made of iron, steel, or other suitable metal.

page_text: The said crushing surfaces consist of a conical hopper, the interior of
which is corrugated, and of a tapering boss, which is attached to the
running plate and revolves in the centre of the said hopper. The
exterior surface of the boss is also corrugated, and the corrugations of
both the boss and the hopper lead into or between the grinding plates.
The said grinding surfaces are made of a flat or nearly flat circular form,
with teeth formed thereon, the said teeth being so arranged as that
about one-half of the total number of the said teeth will have their
cutting faces directed away from the cutting faces of the other portion
of the teeth, so that when the mill is at work one portion of the teeth
will be employed in grinding, and at the same time the action of the
mill will have a tendency to sharpen the cutting faces of the other
portion, the direction of rotation of the running plate being changed at
suitable intervals. Between both the said fixed and running grinding
plates air chambers are formed to keep the plates cool when working.
Under the running plate, or to or on the lower surface thereof, are fixed
or formed fan blades, which create a current of air between the grinding
surfaces, the said blades also acting as scrapers to clear the mill.
A further portion of the said Invention relates to those mills having
conical grinding surfaces formed of burr stones. The running stone of
cach of the said mills has previously to the present Invention becn
arranged to revolve vertically.
According to the present Invention the said stone is arranged to
revolve horizontally, the spindle being vertical. The said running stone
is formed in one piece, as in the case of the mills formerly made, but in
place of the stone being attached to the spindle by melted lead or
other suitable metal alone. the said attachment is effected in manner as
follows: A metal plate is fitted to the spindle, upon which the base of
the runner is caused to rest, and the space between the cyc of the said
runner and the spindle having been filled with melted metal a second a
plate is placed on the upper end of the runner, and the whole are
tightened together with a nut. The bottom plate carrics or is formed
with a fan blade or with fan blades, which create a current of air through
the grinding surfaces, and also act as scrapers to clear the mill.
For substances that are irregular in size the crushing arrangement 3
herein-before described, that is to say, the corrugated tapering boss and
hopper, may be attached to the mill last described.

page_text: When either of the said mills is to be employed in the grinding of
liquid or semi-fluid or pasty substances, as, for example, in the manu-
facture of paints, colors, or printers' inks, a worm or screw is fixed on
the top of the said spindle or in the centre of the aforesaid running plate,
and revolves in a conical hopper, and at the side of the hopper and close
to the said worm is fixed a vertical stop. For some kinds of substances
the thread of the worm may be broken instead of being continuous.
The action of the said worm or screw as it revolves against the stop
tends to feed the said substances towards the grinding surfaces, and at
the same time to keep the said substances in a state of agitation.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Jackson in the Great Seal Patent Office on
the 28th September 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, HENRY
JACKSON, of Park Square, Leeds, in the County of York, Consulting
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of April, in the year of our
Lord One thousand eight hundred and seventy, in the thirty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Henry Jackson, Her special license that I, the said
Henry Jackson, my executors, administrators, and assigns, or such others
as I, the said Henry Jackson, 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 law-
fully 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 CRUSHING AND GRINDING,"
upon the condition (amongst others) that I, the said Henry Jackson, 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.

page_text: NOW KNOW YE, that I, the said Henry Jackson, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawings, that is to say:-
The Invention relates in the first place to mills wherein metallic
crushing and grinding surfaces are employed, the said crushing and
grinding surfaces being made of iron, steel, or other suitable metal.
The said crushing surfaces consist of a conical hopper, the interior of
which is corrugated, and of a tapering boss, which is attached to the
running plate, and revolves in the centre of the said hopper. The
exterior surface of the boss is also corrugated, and the corrugations of
both the boss and the hopper lead into or between the grinding plates.
The said grinding surfaces are made of a flat or nearly flat circular form,
with teeth formed thereon, the said teeth being so arranged that about
onc-half of the total number of the said teeth will have their cutting 1
faces directed away from the cutting faces of the other portion of the
teeth, so that when the mill is at work one portion of the teeth will be
employed in grinding, and at the same time the action of the mill will
have a tendency to sharpen the cutting faces of the other portion, the
direction of motion of the running plate being changed at suitable 2
intervals. Between both the said fixed and running grinding plates air
chambers are formed to keep the plates cool when working. Under the
running plate, or to or on the lower surface thereof, are fixed or formed
fan blades, which create a current of air between the grinding surfaces,
the said blades also acting as scrapers to clear the mill.
A further portion of the said Invention relates to those mills having
conical grinding surfaces formed of burr stones. The running stone of
each of the said mills has previously to the present Invention been
arranged to revolve vertically.
2
According to the present Invention the said stone is arranged to 3
revolve horizontally, the spindle being vertical. The said running stone
is formed in one piece, as in the case of the mills formerly made, but in
place of the stone being attached to the spindle by melted lead or other
suitable metal only, the said attachment is effected in manner as
follows: A metal plate is fitted to the spindle upon which the base of 3
the runner is caused to rest, and the space between the cyc of the said
runner and the spindle having been filled with melted metal a second

page_text: plate is placed on the upper end of the runner, and the whole are
tightened together with a nut. The bottom plate carries or is formed
with a fan blade or with fan blades, which create a current of air
through the grinding surfaces, and also act as scrapers to clear
the mill.
For substances that are irregular in size the crushing arrangement
herein-before described may be attached to the mill last described.
When either of the said mills is to be employed in the grinding of
liquid or semi-fluid or pasty substances, as, for example, in the manu-
facture of paints, colors, or printers' inks, a worm or screw is fixed on
the top of the said spindle or in the centre of the aforesaid running plate,
and revolves in a conical hopper, and at the side of the hopper and close
to the said worm is fixed a vertical stop. For some kind of substances
the thread of the worm may be broken instead of being continuous.
The action of the said worm or screw as it revolves against the stop
tends to feed the said substances towards the grinding surfaces, and at
the same time to keep the said substances in a state of agitation.
In order that my Invention may be better understood, I have supplied
a Sheet of Drawings marked with letters of reference, to which Drawings
I will now refer.
Fig. 1 is a plan view of a portion of a crushing and grinding mill, one
half of the said plan shewing half of the tapering corrugated boss A
and running grinding plate B attached thereto, the other half of the
plan marked C shewing the back of the said running plate.
Fig. 2 is a sectional elevation of the said mill, in which A is the said
tapering boss B is the running plate; and D is the stationary grinding
plate. The said running plate is fixed to a projecting portion of the
tapering boss B, and the plate D is fixed to the cover E, the faces of
both of the said plates being furnished with cutting and grinding teeth,
as shewn at B in Fig. 1. The said plates and the tapering boss
may be
made of cast iron, steel, or other suitable metal. Air spaces G, G, are
left or formed between both of the grinding plates and the cover E and
the boss A to which the said plates are respectively attached, the said
spaces serving to keep the said plates comparatively cool when the mill
is at work. Tan blades II, II, are cast on or fixed to the under side of
the boss B, the said blades serving to clear the mill casing of the
materials which have been ground. The grinding plates are enclosed

page_text: in a casing I, which is supported on suitable standards bolted to the
foundation plate Y, one of which standards is shewn at X, an outlet for
the delivery of the ground materials being formed in a suitable position
in the said casing. The boss B is mounted on the vertical shaft L,
which is fitted to revolve in bearings fitted or formed on the boss K
projecting from the under side of the casing I and in the boss O
formed in the cross rail N fixed to the foundation plate, the said
shaft receiving motion through the strap pulley M. The lower
end of the said shaft is supported in the footstep P, which rests
on the lever R, which lever is supported at one end by the rod S,
and at the other end by the rod T, which connects it with another
lever U, on which is hung a weight V. The weighted end of the
lever U rests on the regulating screw W, so that by turning the hand
wheel on the said screw in one direction or the other, the grinding
plates can be set closer together or further apart, and thus the quality
of the grinding may readily be regulated. Should the mill become.
choked the running plate may be separated from the fixed plate by
simply lifting the weighted end of the lever U, and on releasing the
said lever the said running plate will be again restored to its working
position without requiring to be adjusted.
It will be seen on reference to Fig. 1 that the form of the teeth
or dress of the grinding plates is such that when at work only one half
of the teeth will be employed in grinding at one time, and that the
action of grinding will sharpen the other half of the teeth, so that
when the plates get dull the sharp cutting edges may be brought into
use by reversing the direction of the running plate.
For ordinary purposes I find that triangular-shaped teeth, as shown,
answer very well, but for grinding some substances I use circular teeth
formed of segments of circles, so arranged as to have double cutting
edges as in the case of the triangular-shaped teeth.
-
Fig. 3 is a vertical section of the principal parts of a vertical conical
burr stone mill arranged for grinding liquid or semi-liquid materials.
In the said Figure A is the hopper in which the materials are placed,
and B is a worm screwed on to the end of the vertical shaft L. On the
side of the hopper is cast or fastened a metal plate C, which forms a
stop and prevents the worm B from carrying round with it the materials
in the hopper. The said worm with the assistance of the said stop

page_text: agitates the materials in the hopper, and forces them between the
grinding surfaces.
For some kinds of substances I use a worm with a broken or discon-
nected thread. A circular plate E is securely fixed to the shaft L, and
the lower end of the runner I is fitted to rest on the said plate, and is
retained in position between the said plate and the washer D placed on
the upper end of the said runner by means of a nut or of the worm B,
which may be made to act as a nut. The vacant space or spaces in the
cyc of the runner may be filled with melted metal. Underneath the
plate E is cast or fixed a projecting piece F, to which is attached the
adjustable scraper G, which revolves in the box or casing K, into
which the ground materials fall and from which they are discharged
through a suitable outlet. The vertical shaft L may be driven by
bevil wheels or by a strap, as preferred, and the arrangement for
adjusting the runner, as shown in Fig. 2, may be applied to the mill
now being described. The runner H and the bed stones I fixed into
the cast-iron concave sheet J are usually made of French burr stones;
but in some cases marble or other stones are or may be used for this
purpose.
In manufacturing these mills both the fixed and running stones
are worked as near as may be to the required form, and are then
ground together until the grinding surfaces are smooth and are fitted to
one another. They are then dressed in a manner suitable for revolving
one or both ways and for the materials to be ground.
Having now described the nature of my Invention, I wish it to be
understood that I claim,-
First. The crushing and grinding mill illustrated by Figures 1 and 2,
or any mere modification thereof.
Secondly. The method of fixing the conical runner to the vertical
shaft, substantially as shewn and described.
Thirdly. The employment of the feed worm and fixed stop in mills for
grinding liquid or semi-liquid substances, substantially as herein
described and as illustrated in the Drawings.
And, lastly. The addition to the aforesaid conical runner of a
fan blade or of fan blades, and of a corrugated tapering crushing

page_text: boss acting in connection with a corrugated hopper, substantially as
herein described.
-
In witness whereof, I, the said Henry Jackson, have hereunto sct
my hand and seal, this Nineteenth day of September, in the year
of our Lord One thousand eight hundred and seventy.
HENRY JACKSON. (L.S.)