IMPROVEMENTS IN MACHINERY FOR GRINDING WHEAT AND OTHER GRAIN
Year: 1879

page_text: LETTERS PATENT to John Auguste Arnold Buchholz, of Vauxhall, in the
County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN
MACHINERY FOR GRINDING WHEAT AND OTHER GRAIN."
ALL N1070 and dated the 2nd June 1970
PROVISIONAL SPECIFICATION left by the said John Auguste Arnold Buchholz
at the Office of the Commissioners of Patents on the 3rd June 1879.
JOHN AUGUSTE ARNOLD BUCHHOLZ, of Vauxhall, in the County of Surrey,
Engineor. "IMPROVEMENTS IN MACHINERY FOR GRINDING WHEAT AND OTHER
GRAIN."
This Invention relates to a novel arrangement of roller mill, in which three
crushing or grinding rollers are used in combination, the first and second rollers to
operate on the grain as it is fed to the machine, and the second and third rollers on
the meal produced by the first crushing operation after the fine flour has been
separated therefrom.
The rollers I prefer to make of chilled cast iron, the first and second rollers being
grooved, the grooves of the second roller being finer than those of the first. The
third roller will be by preference a plain roller, or it may in some cases be furnished
with fine grooves.
At the opposite side of the rollers to that at which the feed is supplied a sieve is
situated in line with the direction of the feed, and below this sieve and fixed thereto
is a tray for receiving the fine flour which falls through the sieve. A spout is
provided at the side of this tray for delivering the flour out of the machine.
Below this tray and in line with the bite of the second and third rollers is a
table for receiving the meal which is discharged from the end of the sieve, and con-
veying it to the lower rollers. A shogging end way motion is imparted to the sieve
so as to cause the meal to travel away from the rollers, and fall over the end of the
sieve, and a similar motion is imparted to the table below for traversing the meal
forward and delivering it into the bite of the lower rollers.
Fitted to the frame of the sieve is a brush, which works in contact with the
middle roller, and serves to clear it of any adhering meal or flour. To this roller a
speed of rotation is imparted somewhat superior to that of the upper roller, and to

page_text: the third or lowest roller still greater speed is given. The tendency of the ground
and crushed material as it leaves the second rollers is to move forward to the sieve,
which then by its shogging motion (produced by a suitable tappet action) separates
the fine flour, as before mentioned, from the coarser particles, and delivers the latter
to the feed table below.
As the tray which receives the fine flour reciprocates with the sieve the flour
will be collected and discharged down the shoot into an adjacent receptacle, while
the coarser particles of the crushed grain will be subjected to a second grinding or
crushing action between the second and third rollers, whereby the meal will be
reduced to fine flour.
An obvious modification of this Invention will be to employ two pairs of rollers,
the one pair being formed with coarse and finer grooves, as above explained, and
the other pair having the one roller fine grooves and the other a smooth surface.
The rates of speeds of the rollers of each pair will vary according to the character
of the material under operation, but their rates of speeds will conform to the
indications above given.
When two pairs of rollers are employed the first pair will act upon the uncrushed
grain, and the second pair upon the meal of coarse particles discharged from the
first pair of rollers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Auguste Arnold Buchholz in the Great Seal Patent Office on
the 3rd December 1879.
JOHN AUGUSTE ARNOLD BUCHHOLZ, of Vauxhall, in the County of Surrey,
Engineer. "IMPROVEMENTS IN MACHINERY FOR GRINDING WHEAT AND OTHER
GRAIN."
The obiect of this Invention is to reduce corn to flour, and to disengage the floury
particles from the bran by a more simple arrangement of mechanism than has
hitherto been employed for that purpose.
According to this Invention I submit wheat or other grain to the action of two
pairs of crushing or grinding rollers acting in succession, or preferably to their
equivalent., viz., three rollers so combined as to form two pairs of crushing
surfaces.
Sheet I. of the accompanying Drawings shews a novel arrangement of roller mill,
in which three crushing or grinding rollers are used in combination, the first and
second rollers to operate on the grain as it is fed to the machine, and the second
and third rollers to operate on the meal produced by the first crushing operation,
such meal in its progress to the bite of the second and third rollers being subjected
to the action of a sifting apparatus, which takes out the flour and then delivers the
meal to the crushing or grinding action of these rollers.
The rollers I prefer to make of chilled cast iron, the first and second rollers being
grooved, and the third smooth or fluted more finely than the others. I have
obtained a good result by the use of rollers, the first of which has twelve grooves to
the inch, and the second twenty grooves to the inch, the third being a plain roller.
A satisfactory result has also been obtained by grooving the first roller ten to
the inch, the second roller fifteen to the inch, and the third roller thirty to the
inch.
Fig. 1 is a side elevation, Fig. 2 a front elevation, and Fig. 3 a cross section of
my improved flour mill; and Fig. 4 is a plan of the same, shewing the frame in.
section on a level with the middle roller.
It should be remarked that I use Mechwart's arrangement of three-roller-mill
with the direct application of pressure by means of adjustable rings, the English
Patent of which is dated February Eleventh, One thousand eight hundred and
seventy eight, No. 563.
A, A, are cast iron standards forming the main framing of the mill, and B is a
wooden casing enclosing the grinding or crushing rollers, which are shown at
C, D, E, Fig. 3. These rollers are arranged one above the other, so as to act like
two pairs, and are otherwise fitted like Mechwart's Patent ring-roller-mill.
The middle roller D runs in bearings fixed in the standards A, which are bolted
to the bed plate, and are braced together at top by a stay bolt. The axles of the
top and bottom rollers C and E rotate in bearings set a little out of line with the
axis of the middle roller, and forming the extremities of pairs of rocking arms C¹, E¹,
which are strung on transverse rods C², E³, that have a horizontal adjustment in
the standards. The object of thus mounting these rollers is to allow of their being
swung away from the middle roller, and of being readily brought into contact there-
with, and held to their work by the adjustable pressure rings. The rods C³, E³, are
adjusted by means of screws turning in bearings on the framing, and tapped into
the ends of the rods, as shewn at Fig. 3, for the purpose of ensuring the parallelism
of the rollers C and E with the roller D.
The middle roller axle carries the driving pulley G, and also a spur wheel H,
which gears into spur pinions I and K on the axles of the rollers Cand E. The
spur wheel H has by preference three times the number of teeth of the pinions I and
K, and makes, say, two hundred revolutions per minute; the rollers I prefer to make

page_text: at least eight and a half inches in diameter. The axles of the rollers C and E are
furnished outside the standards with friction wheels, over which a ring L is sprung
for transmitting direct to the rollers the pressure required for reducing the grain,
the pressure being adjusted by tension wheels projecting from carriers M, which
slide on dovetailed projections from bracket arms A' attached to the standards.
This arrangement for imparting adjustable pressure to the rollers I consider
essential to the production of flour in the most efficient way, according to my
Invention.
The roller E is balanced by counter weights placed under the bearings. N is the
feed hopper fitted with a feed roller in the usual manner.
Attached to this machine is an arrangement of sifting apparatus for receiving the
meal or crushed corn from between the rollers C and E, sifting out the flour from
the same, and then delivering the tailings of the meal to the action of the rollers D
and E. This apparatus is best shewn in the vertical section, Fig. 3, where O and P
are two rectangular inclined sieves mounted in pairs of cast iron cheeks O', P¹,
having lugs to receive transverse supporting rods, which are carried by two pairs
of cranked rock levers Q, Q. These rock levers are pivotted to stay rods R, R',
which are made fast to the bracket arins A'.
Below the inclined sieves O and P the cheeks are fitted with horizontal trays or
bottom plates O, P, for receiving the flour (both fine and middlings") as it is
sifted out from the meal. These trays are so arranged with respect to each other
that the upper tray O will discharge its flour from the rear on to the tray P*
below, which tray will in turn discharge its contents from its front edge into a
receiver S.
A reciprocating motion is imparted to the sieves and trays by means of a crank
motion in the following manner:-T is a crank shaft having its bearings in the
bracket arms A, and receiving a rapid rotary motion through a band and pullies
from the axle of the lower roller E. This shaft T is formed with a pair of cranks
which are connected by rods T' to pendant extensions of the back pair of cranked
levers Q.
The result of this action is to cause the meal received onto the upper sieve O to
travel towards its rear, and to fall over onto the sieve P below, to which it is guided
by means of a spout U inclining slightly in wards, and contracting laterally towards
the lower sieve in order to provide a space on either side thereof for passages V,
which serve to conduct the flour from the upper to the lower tray.
The sieve O it will be seen is inclined upwards towards the rear, and the sieve P
is inclined upwards towards the bite of the rollers D and E.
This inclination upwards in the direction the meal has to travel serves to intensify
the action of the sieves, and thereby to economize sifting surface.
The action of the machine is as follows:-The grain as it leaves the hopper N is
guided by inclined boards into the bite of the first pair of crushing surfaces, in
passing through which it is reduced to meal, which contains a large proportion of
fine flour. The meal thus formed falls onto the upper sieve O, where by reason
of the fineness of the gauge of the woven wire cloth most of the flour is sifted out,
such product being a mixture of marketable flour and coarse flour known usually as
middlings, while the remainder, mostly in the form of rough bran, is jogged
upwards, and dropping over the upper edge of this sieve falls down the spout U on
to the lower sieve P, which sifts out the flour particles that have escaped the action
of the upper sieve O. The amount of flour thus sifted out will be found to equal,
say, from fifty to sixty per cent., according to the degree of hardness or mellowness 5
of the wheat, of which about two thirds will be fine flour and the remainder
middlings. The removal of the flour at this stage will greatly facilitate the treat-
ment of the tailings. This residue of the meal, chiefly coarse bran, is led between
the rollers D, E, by which it is finally crushed, and thus cleared of flour particles.
The fluting of the rollers most suitable for the above purpose will depend on the
nature of the grain to be operated upon, but the examples given above sufficiently
illustrate the variations of gauge which I have found it desirable to make in the

page_text: crushing rollers. The result is not however essentially modified, whether the fluting
be made a little coarser or a little finer.
In cross section the fluting must be so as not to form sharp edges, and I use by
preference fluting such as that shewn in the diagram, Fig. 1a.
Or ratchet toothed shaped fluting may be used; this will answer when worked
back to back, as shown in the diagram, Fig. 1b, the size of the arrows indicating
the difference of speeds.
The object of the fluting is not to cut but to increase the grip of the roller surfaces
on the bran, and to form vents for the flour severed from the bran under pressure
imprisoned between the crushing surfaces.
În Fig. 5 I have shown a modification of the mechanism for imparting a recipro-
cating motion to the sieves. In this arrangement the motion is taken directly from
the axle of the top roller, that is, without the intervention of a crank shaft, as above
described. Fitted to the axle of the roller C is a pair of excentrics c, which through
excentric rods c¹ connected with the upper ends of the cranked levers Q' impart a
reciprocating motion to the sieves.
Sheet II. shews a modification of the machine first described, being in fact a
double mill provided with sifting apparatus common to the two groups of crushing
rollers. Fig. 1 is a side elevation, and Fig. 2 a cross section of this arrangement of
roller mill.
Two complete machines, the first with three rollers C, D, E, the second also with
three rollers F, G, H, are bolted to a common bed plate, and connected by two cast
iron bridge pieces, to which the double sifting arrangement O, P, is attached. This
apparatus is operated in a precisely similar manner to that described with reference
to Sheet I., but the course of the meal through this sifting apparatus differs, inas-
much as it is intended to receive the meal formed from two feeds of corn, and to
sift the same and transfer the tailings in opposite directions simultaneously. The
upper sieve removes the flour from the wheat crushed between the first pair of
rollers C, D, in the first machine, which flour, falling through the sieve, is received
onto the tray 02 (shewn detached at Fig. 3), and it is discharged thence by spouts
O at opposite sides of the machine.
The sieve O conveys the tailings or residue to the second pair of rollers F, G, in
the second machine, to be there finally ground, while the lower sieve P receives the
crushed wheat from the first pair of rollers G, H, in the second machine (here the
lower pair), and removing the flour therefrom delivers it onto the tray P2, which
discharges it at one side of the machine into the receiver S. The sieve P, while
sifting out the flour, conveys the tailings to the rollers D, E, of the first machine to
be there also cleared of flour-particles. In order to prevent the meal crushed by
the rollers F, G, from mixing with the wheat which is being conveyed to the rollers
G, H, a feed divider W is employed. As the construction of this feed divider is well
known it need not be here explained.
By its use the second feed of grain is conducted through the meal as it leaves
the second pair of top crushing rollers to the rollers G, H.
Sheet III. shows a modification of my improved mill, in which two pairs of
crushing rollers are used in place of three rollers set one above the other. C, D,
and E, F, are two pairs of rollers placed side by side. The rollers D, E, are mounted
in bearings rigidly fixed to the cast iron framing A, while the rollers C and F turn
in bearings carried by the swinging levers C¹, F¹.
For ensuring the proper grip of the rollers they are fitted at their opposite ends
with adjustable pressure rings L, arranged on the principle of Mechwart's Patent
above referred to.
In order however to adapt this principle to pairs of rollers, I have found it
requisite to adopt the following contrivance :-L, L, are pairs of antifriction rollers
carried by radius arms L² on the axles of the fixed rollers D, E. These radius
arins are connected together adjustably by links and coupling screws, the turning
of which screws will draw the rollers L¹ together, or thrust them apart, as required.
These rollers are interposed between the rings L and the antifriction wheels D', E¹

page_text: respectively, so that by drawing the rollers L' together the rolling pressure put
upon the crushing rollers may be increased to any desired extent, and thereby afford
to this arrangement of mill the like grinding facilities presented by the first described
arrangement.
The wheat crushed between the rollers C, D, drops onto the upper sieve O, which
conveys the tailings to the second pair of rollers E, F, to be there acted upon to
dotach the flour particles from the bran. The action of the sieve O is also to sift
out the flour particles, which, falling onto the tray 04, are discharged by side shoots
into suitable receptacles. The crushed tailings delivered from the rollers E, F, fall
onto the lower sieve P, which sifts out the flour particles and discharges the residue
into the receiver S. The flour is received onto a tray P, which delivers it by side-
shoots, as above explained, into suitable receptacles.
I would here remark that a second sifting arrangement may if desirable be
attached to the mills illustrated on Sheets I. and II. in order to receive and sift the
meal crushed by the second pair of crushing surfaces; thus, in Sheet I. the sieve
will be applied to receive the meal delivered by the rollers D and E, and in Sheet II.
to receive that delivered by the rollers F and G and D and E respectively.
In some cases I may keep apart as a special grade of flour that which is yielded
by the wheat after the first crushing operation, instead of, as before mentioned, dis-
charging the whole yield into one common receptacle.
Having now set forth the nature of my Invention of "Improvements in Machinery
for Grinding Wheat and other Grain," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim,―
The arrangements of machinery above described, whereby I am enabled to reduce
the wheat and other grain to flour by the operation of two pairs of grinding rollers,
or three rollers acting as two pairs of grinding surfaces.
In witness whereof, I, the said John Auguste Arnold Buchholz, have hereunto
set my hand and seal, the First day of December, in the year of our Lord
One thousand eight hundred and seventy nine.
J. A. ARNOLD BUCHHOLZ, (LS)