AN IMPROVED MODE OR AND MACHINERY FOR MANTRACTURING FLOUR
Year: 1869

page_text: LETTERS PATENT to David Johnson, of Wrexham, in the County
of Denbigh, Corn Miller, for the Invention of "AN IMPROVED MODE
OR AND MACHINERY FOR MANTRACTURING FLOUR "
Sealed the 2nd October 1869, and dated the 10th April 1869.
PROVISIONAL SPECIFICATION left. by the said David Johnson at
the Office of the Commissioners of Patents, with his Petition, on
the 10th April 1869.
I, DAVID JOHNSON, of Wrexham, in the County of Denbigh, Corn
Miller, do hereby declare the nature of the said Invention for "AN
IMPROVED MODE OF AND MACHINERY FOR MANUFACTURING FLOUR," to be as
follows:-
My Invention relates to a novel method of manufacturing the flour of
wheat, rice, and other grains, and the objects of the said Invention are
the production of improved qualitics of flour, a diminished cost of
manufacture, and the employment of machinery which shall be more
efficient, cheaper, and more simple of construction and which will occupy

page_text: less space and require less power to operate it than the machinery
heretofore employed in flour mills.
The said Invention consists,-
First. In cutting the grain into thin slices or small pieces before
reducing it to flour.
Second. In the peculiar arrangement of a series of rotating knives or
blades within a drum or case, which knives divide the grain into thin
slices as they fall through a hopper.
5
Third. In the peculiar arrangement of a series of reciprocating knives
working above a horizontal disc whereon the wheat or other grain is fed 1
by a suitable hopper, the said disc carrying the grain under the knives
which chop it into small pieces.
Fourth. In the arrangement of millstones to work with their
peripheries running together to reduce the wheat or portions of wheat
or other grain to flour, one of the said stones being made to run 1
quicker than the other, as herein-after more fully explained.
Fifth. In the employment of glass, agate, or other naturally hard
substances not hitherto used for the purpose, instead of the ordinary
millstones, arranged as above described.
Sixth. In the peculiar arrangement of a diamond tool in combination 2
or in connection with the said stones for the purpose of dressing or
surfacing their peripheries.
Seventh. In constructing the hoppers through which the grain is
fed to the knives and to the stones or rollers with a steam-tight
casing which is filled with hot water or steam at a suitable temperature. 2
The said Invention also consists in the combination of the novel means
described for reducing the grain to flour, and in the employment of a
portion of the same in combination with the ordinary stones employed
for that purpose.
The rotating knives or blades are fixed on the
periphery of a wheel which is enclosed within a suitable drum or case. 3
The wheat is introduced to the blades through a hopper at whose back is
placed an adjustable plate which is set so that the blades in rotating will
just clear its edge. The blades or knives are arranged with the edge of
each blade lying just above the back of the next blade, and the space
left between the edge of the one blade and the back of the other 3
determines the thickness of the slices of wheat, which as they are cut
pass through this space. The blades or knives are made adjustable by

page_text: means of screws or otherwise upon the wheel, so that the edge of the
blades can be elevated or depressed, thereby increasing or diminishing
the thickness of the slices. The grains as they pass through the hopper
fall upon the flat surface of the blades and the plate on the hopper which
may be adjusted to correspond with the elevation or depression of the
blades, will keep the grains from being carried round and thus escaping
from the action of the knives. If desired an adjustable plate may be also
placed at the front of the hopper. The out grain passes through the
space between the blades, and I prefer that the wheel which carries the
knives should have spirally arranged arms or a spiral plate to connect it
with the shaft or axis so that its rapid rotation causes a draught which
assists the delivery of the grain and keeps the apparatus cool, the bran
and light inferior portion of the grain being separated therefrom as it
passes from the case by a fan or other suitable means. The hopper is
provided with a plate, which by means of a spring or weight is pressed
down so as to force the grain into the position to be acted on by the
blades. The knives or blades for dividing the grain may also be
arranged to work up and down over the horizontal flat surface of a
rotating circular plate or disc of wood or metal. The grain is fed through
a hopper and carried upon the disc under the edges of the knives, and
they reduce it to small fragments, which by means of a fixed inclined
scraper are delivered at the periphery of the disc. The reciprocating
motion is given to the knives by a crank or excentric, and the said
knives are preferably arranged to work through or between stationery
plates which clean them and keep them free from adhering particles of
matter. The reciprocating blades may also be arranged over the
periphery of a drum of wood or metal rotating in a vertical plane, the
said drum being enclosed within a case or cylinder and provided with a
suitable hopper and delivery aperture. I prefer that the grain should be
delivered to tho knives in a single layer, so that there is no tendency to
crush the grain, and for this purpose I provide the hopper with a
reciprocating plate which is operated by a crank or excentric, and is
provided with a spring which causes it to rise and fall just sufficiently
to allow a single layer of the grain to pass freely from the hopper to the
blades. If the grain is not sufficiently reduced by one series of the
knives or blades it may be subjected to the action of two or more series
thereof arranged in either or both of the ways above described, and
though it may not be always desirable to do so; I may, in some cases,
complete the reduction of the grain to flour by means of these rotating

page_text: or reciprocating knives. The grain when reduced to small particles may
also be advantageously ground by the ordinary horizontal millstones.
I prefer, however, to employ for this purpose the improved means which
I have herein-before partly described as a portion of my Invention. For
this
purpose I mount on parallel horizontal shafts or axes two stones or
rollers whose peripheries run nearly in contact with each other, one of
the said rollers running more rapidly than the other, and means being
provided to vary the difference in the speed of the two rollers to suit
different qualities of grain. I am aware that in semolina mills rollers
moving together at different velocities have been employed, but these
rollers have invariably been provided with teeth formed of steel and
tempered or hardened. The difficulty of making and keeping these
steel cutters true and in good working condition is well known to all
familiar with their use. The teeth are expensive to cut with the required
accuracy in the first place, and even when properly cut they are
invariably thrown out of truth by tempering, and this difficulty occurs
whenever the teeth require sharpening which is very frequent, as they
soon become blunted by the continued attrition of the grain. The
restoring and tempering of these teeth is an operation requiring great
skill and experience and especial appliances for the purpose, and cannot
be done on the premises or by others than skilled mechanies. It is
obviously very desirable that the working surface of the stones should be
easily and cheaply dressed, and I therefore use millstones or rollers
formed of naturally hard mineral substances instead of rollers with steel
teeth, the surface of which substances may be easily dressed or faced by
means of a diamond cutter such as is now commonly employed for
dressing millstones, the said diamond cutter being however arranged
in a peculiar manner to adapt it to the purpose of my Invention. In
dressing ordinary horizontal millstones the stone remains stationary
while the diamond is moved across its surface in straight diagonal or
spiral lines according to the character of the "dress" required. In the
arrangement which I adopt the diamond is caused to travel across the
periphery of the stone while the same rotates. I prefer to employ
mechanism similar to the slide rest of a turning lathe for carrying and
moving the diamond, and by giving the stone either a continuous or
intermittent motion the surface of its periphery may be out quite plain
or may have a straight or inclined dress. I prefer to use the Belgian or
French burr stones which have a close hard grain, but open burrs may
be used. I also propose to use instead of the ordinary millstones, rollers

page_text: formed of glass, agate, or other similarly hard mineral substance or
composition which will not require artificial hardening or tempering.
The hopper through which the cut or chopped grain is fed to the stones
or rollers is provided with a device for regulating the feed and causing
the grain to pass in a thin layer between the stones or rollers. Brushes
are placed at the peripheries of the rollers to keep them clean, and also
to guide the flour to the delivery aperture. If the grain is not all
reduced to flour by the first operation the produce may be passed through
a bolter of wire, silk, or cloth. The coarser particles thus separated from
the flour may be re-elevated into the hopper of the same machine or
passed through a separate machine or series of machines and bolters as
may be required for different classes of wheat or other grain and different
qualities of flour. As before mentioned I provide the hopper with a
steam-tight casing for drying or partially drying the grain passing
through the hopper. This steam-tight casing may be filled with hot
water or steam and should be provided with means for permitting the
escape of the steam and for keeping it at the desired temperature. By
this means I diminish the cohesive force of the atoms of farina, which
are therefore more easily disintegrated, so that a quicker action of the
stones can be applied and a stronger and more lively flour produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Johnson in the Great Seal Patent
Office on the 8th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
JOHNSON, of Wrexham, in the County of Denbigh, Corn Miller, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said David Johnson, Her special
licence that I, the said David Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said David Johnson, niy
exccutors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the

page_text: 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 "AN IMPROVED MODE
OF AND MACHINERY FOR MANUFACTURING FLOUR," upon the condition (amongst
others) that I, the said David Johnson, 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 David Johnson, 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 accom-
panying Drawing forming a part of this Specification.
My Invention relates to a novel method of manufacturing the flour of
wheat, rice, and other grain, and the objects of the said Invention are
the production of improved quantities of flour at a diminished cost of
manufacture, and the employment of machinery which shall be more
efficient, cheaper, and more simple of construction, and which will
occupy less space and require less power to operate it than the machinery
heretofore employed in flour mills.
The said Invention consists,-
First. In cutting the grain into thin slices or small pieces before
reducing it to flour.
Second. In the peculiar arrangement of a series of rotating knives or
blades within a drum or case, which knives divide the grain into thin
slices as they fall through a hopper.
Third. In the peculiar arrangement of a series of reciprocating knives
working above a horizontal disc, whereon the wheat or other grain is
fed by a suitable hopper, the said disc carrying the grain under the
knives which chop it into small pieces.
Fourth. In the arrangement of rollers to work with their peripheries
moving together to reduce the wheat or other grain or portions of wheat
or other grain to flour, one of the said rollers being made to run quicker
than the other, as herein-after more fully explained.

page_text: Fifth. In the employment of glass, agate, or other equally naturally
hard substances not hitherto used, instead of ordinary millstones,
arranged as above described.
Sixth. In the peculiar arrangement of a diamond tool in combination
or in connection with the rollers or stones for the purpose of dressing
or surfacing their peripheries.
Seventh. In constructing the hoppers through which the grain is
fed to the knives and to the stones or rollers with a steam-tight casing,
which is filled with hot water or steam at a suitable temperature.
The said Invention also consists in the combination together of the
novel means described for reducing the grain to flour, and in the em-
ployment of a portion of the same in combination with the ordinary
stones hitherto employed for that purpose.
DESCRIPTION OF THE DRAWING.
Figure 1 is a vertical section of my improved machine, showing the
parts for slicing the grain; Figure 2 is a plan of a modified arrangement
of the cutting mechanism; Figure 3 is a plan of the grinding rollers;
Figure 4 is a section on the line x, x, Figure 3; Figure 5 illustrates the
means employed for dressing or surfacing the said rollers; Figure 6
shows a detached portion of the same.
Like letters indicate the same
parts throughout the Drawing.
The rotating knives or blades a are fixed on the periphery of a
wheel b, which is enclosed within a suitable drum or case c. The wheat
is introduced to the blades a through a hopper d, at whose back is
placed an adjustable plate d', which is set so that the blades a in rotating
will just clear its edge. The blades or knives a are arranged with the
edge of each blade lying just above the back of the next blade, as shown
in Figure 1, and the space e left between the edge of the one blade and
the back of the other determines the thickness of the slices of wheat or
other grain, which as they are cut pass through this space. The blades
or knives a are made adjustable by means of screws or otherwise upon
the wheel b, so that the edge of the blades can be elevated or depressed,
thereby increasing or diminishing the thickness of the slices. The
grains as they pass through the hopper d fall upon the flat surface of
the blades a and the plate d' on the hopper, which may be adjusted to
correspond with the elevation or depression of the blades, will keep the

page_text: grains from being carried around in the case and so escaping from the
action of the knives a. If desired an adjustable plate may be also
placed at the front of the hopper. The cut grain passes through the
plates between the blades, and I prefer that the wheel which carries the
knives should have spirally arranged arms or a spiral plate to connect it
with the shaft or axis, so that its rapid rotation causes a draught, which
facilitates the delivery of the grain and keeps the apparatus cool, the
bran and light inferior portions of the grain being separated from the
farinaceous portions thereof as it passes from the case c by a fan or
other suitable means. The hopper may also be provided with a plate,
which by means of a spring or weight is pressed down so as to force the
grain into a position to be acted upon by the blades. The knives or
blades for dividing the grain may also be arranged to work up and down
over the horizontal flat surface of a rotating circular plate or disc of
wood or metal, as shown in Figure 2. The grain is in this case fed
through a hopper d and carried upon the disc 6* under the edges
of the knives a*, and they reduce it to small fragments, which by
means of a fixed inclined scraper or other device are delivered at the
periphery of the disc. The reciprocating motion is given to the knives
by a crank or eccentric, and the said knives are preferably arranged to
work through or behind stationary plates d*, which clean them and keep
them free from adhering particles of matter. The reciprocating blades
may also be arranged over the periphery of a drum of wood or metal
rotated in a vertical plane, the said drum being enclosed within a case
or cylinder, and provided with a suitable hopper and delivery aperture.
I prefer that the grain should be delivered to the knives in a single
layer, so that there is no tendency to crush the grain, and for this
purpose I provide the hopper with a reciprocating plate, which is
operated by a crank or eccentric and is provided with a spring which
causes it to rise and fall just sufficiently to allow a single layer of the
grain to pass freely from the hopper to the blades. If the grain is not
sufficiently reduced by one series of the knives or blades it may be
subjected to the action of two or more series thereof arranged in either
or both of the ways above described, and though it may not be always
desirable to do so I may in some cases complete the reduction of the
grain to flour by means of these rotating or reciprocating knives. The
grain when reduced to small particles may also be advantageously
ground by the ordinary horizontal millstones. I prefer, however, to
employ for this purpose the improved means which I have herein-before

page_text: partly described as a portion of my machine, and which for the sake of
clearness I have illustrated separately in Figures 3 and 4. In carrying
into practice this portion of my Invention I mount on parallel horizontal
shafts or axes f two stones or rollers 9 whose peripheries run nearly in
contact with each other, one of the said rollers running more rapidly
than the other, and means being provided to vary the difference in the
speed of the two rollers to suit different qualities of grain. I am aware
that in semolina mills rollers running together at different velocities
have been employed, but these rollers have invariably been provided
with teeth formed of steel and tempered or hardened. The difficulty of
making and keeping these steel cutters true and in good working con-
dition is well known to all familiar with their use. The teeth are
expensive to cut with the required accuracy in the first place, and
even when properly cut they are invariably thrown out of truth by the
tempering, and this difficulty occurs whenever the teeth require sharp-
ening, which is very frequently as they soon become blunted by the
continued attrition of the grain. The restoring and tempering of these
teeth is an operation requiring great skill and experience and special
appliances for the purpose, and cannot be performed elsewhere than
in factories or workshops provided with such special appliances, or by
others than skilled mechanics. Moreover these steel rollers can only
be made of small diameter. It is obviously very desirable that the
working surface of the rollers should be easily and cheaply dressed, and
that they should be of much larger diameter than such steel rollers, so
as to increase their cutting angle and surface, and thereby diminish the
number of operations required to finish the flour, and I therefore use,
instead of rollers with steel teeth stones or rollers formed of a naturally hard
mineral substance, the surface of which substance may be easily dressed
or faced by means of a diamond cutter such as is now commonly employed
for dressing millstones, the said diamond cutter being however arranged in
a peculiar manner, as shown in Figure 5 and 6, to adapt it to the purpose
of my Invention. In dressing ordinary horizontal millstones the stone
remains stationary while the diamond, which is sometimes caused to
rotate on its axis, is moved across the surface of the stone in straight
lines. In the arrangement which I adopt, and which is illustrated in
Figure 5, the diamond his caused to travel across the periphery of the
roller g while the same rotates upon its shaft or spindle f. I prefer to
employ the carriage i which slides on the bed j, like the slide rest of a
turning lathe, for carrying and moving the diamond h, and by giving

page_text: the stone g either a continuous or intermittent rotary motion the surface
of its periphery may be cut quite plain or may have a straight or inclined
"dress." I prefer to use the Belgian or French burr stones, which have
a close hard grain, but open burrs may be used. I also propose to use in
the same manner as ordinary millstone rollers formed of glass, agate,
or other similarly hard mineral substance or composition which will
not require artificial hardening or tempering. The hopper / through
which the grain, or slices, or pieces thereof, are fed to the stones or
rollers g may be provided with a device for regulating the feed and
causing the grain to pass in a thin layer between the stones or rollers.
Brushes are placed at the peripheries of the rollers g to keep them
clean and also to guide the flour to the delivery aperture m. If the
grain is not all reduced to flour by the first operation the produce may
be passed through a bolter of wire, silk, or cloth. The coarser particles
thus separated from the flour may be re-elevated into the hopper of
the same machine or passed through a separate machine or series of
machines and bolters, as may be required for different classes of wheat
or other grain and different qualities of flour. As before mentioned I
provide the hopper with a steam-tight casing for drying or partially
drying the grain passing through the said hopper. This steam-tight
casing ¹, of which I have shown a transverse section in Figure 4,
may be filled with hot water or steam, and should be provided with
a inlet pipe and tap k², an outlet pipe and tap for the escape
of water, and an outlet valve * for the steam, or with other means
for permitting the escape of the steam and for keeping the hopper
at the desired temperature. By this means I diminish the cohesive
force of the atoms of flour, which are therefore more easily disintegrated,
so that a quicker action of the stones can be applied and a stronger
and more lively flour produced. I find that by having the peripheries
of the rollers 9 further apart from each other than when in use for
producing flour, that semolina of fine quality may be produced from
wheat, and that by having the peripheries of the rollers in the closest
approximation, without touching each other, such seeds as mustard
may be reduced to a fine state of division with one operation. The
importance of reducing the frictional area to a minimum is well known
to all practically acquainted with the grinding of wheat and other grain
and seed. By my improvements the operation is so conducted that each
particle of flour, as soon as made, is delivered and is not ground over
and over again, as in the old method.

page_text: Having thus fully described my said Invention, and shown how the
same may be conveniently and advantageously oarried into practice, I
claim,―
First. The mode of manufacturing flour by first cutting or dividing the
wheat or other grain or seed into slices or pieces.
Second. The rotating knives or cutters arranged and operating within
a drum or case, substantially as and for the purposes set forth.
Third. The reciprocating knives or cutters arranged in combination
with a horizontal rotating disc, substantially as and for the purposes
set forth.
Fourth. The rollers of stone or of glass, agate, or other naturally hard
material, arranged to work together for completing the manufacture of
the flour, substantially as set forth.
Fifth. The peculiar arrangement of the diamond cutter in combination
with the said rollers for dressing or surfacing the same, substantially as
set forth.
Sixth. Constructing the hopper through which the grain or seed, or
portions of grain or seed, are fed to the stones with a steam-tight casing,
substantially as and for the purposes set forth.
Seventh. The combination together of the rotating or reciprocating
cutters with the rollers g or with ordinary millstones, substantially as
and for the purposes set forth.
In witness whereof, I, the said David Johnson, have hereunto set
my hand and scal, this Sixth day of October, in the year of
our Lord One thousand eight hundred and sixty-nine.