AN IMPROVED AND RATIONAL METHOD FOR GRINDING to be as follows:- CORN
Year: 1885

page_text: 'I, JOSEPH SCHWEITZER, of Eniville, in the Republic of France, Miller, do hereby
declare the nature of my invention for "AN IMPROVED AND RATIONAL METHOD FOR
GRINDING
to be as follows:-
CORN
"
-
According to my invention, I cause corn to pass between two crown's which
have surfaces not flat like ordinary millstones, but each of the form of a frustum
of a cone, the upper being a hollow cone fitting over the lower. These surfaces
are preferably formed of steel segments held adjustably in metal bosses or crowns
by screws arranged to draw them back and push them forwards, and they are
channelled with grooves which in the upper surface are radial and in the lower
are inclined forwards from the radial direction and diminish in width towards
the outer periphery, being crossed by other grooves. The lower crown is fixed on
a vertical shaft having bearings by which it can be adjusted vertically, and the
upper crown is fixed on a vertical tubular shaft surmounted by a hopper. The
crowns are caused to revolve with different speeds or one of them may be stationary,
the other revolving. Corn fed into the hopper descends the tubular shaft to an
annular hollow formed in the upper part of the lower crown and thence it passes
From this casing
outwards becoming broken, into a casing enclosing the crowns.
the broken corn is led by a spout to a compartment from which air is exhausted
by a fan. Here it is subjected to the action of a revolving brush and passed over
a shaking sieve, whereby the dust and germs are separated from the farinaceous
fragments. When these are to be gradually reduced to flour, this may be effected
by ordinary grinding or by means of successive milling apparatus like that
described, the material and channelling of the acting surfaces being varied to suit
the different conditions of the material on which they have to act. Also suitable
bolting, sifting and purifying apparatus of known kinds are to be used at the
different stages of the gradual reduction process.
T
TOOK
ABEL & IMRAY,
Agents for the Applicant.

page_text: An improved and Rational Method for Grinding Corn.
I, JOSEPH SCHWEITZER, of Eniville in the Republic of France, Miller, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
According to my invention, I cause corn to pass between two crowns which have
surfaces not flat like ordinary millstones, but each of the form of a frustum of a
cone, the upper being a hollow cone fitting over the lower. These surfaces are
preferably formed of steel segments held adjustably in metal bosses or crowns by
screws arranged to draw them back and push them forwards, and they are
channelled with grooves which in the upper surface are radial or inclined, and in
the lower are inclined forwards from the radial direction and diminish in width
towards the outer periphery, being combined with counter grooves. The lower
crown is fixed on a vertical shaft having bearings by which it can be adjusted
vertically, and the upper crown is fixed on a vertical tubular shaft surmounted by
a hopper.
:
The crowns are caused to revolve with different speeds or one of them may be
stationary, the other revolving. Corn fed into the hopper descends the tubular
shaft to an annular hollow formed in the upper part of the lower crown and thence
it passes outwards, becoming broken, into a casing enclosing the crowns." From
this casing the broken corn is led by a spout to a compartment from which air is
exhausted by a fan. Here it is subjected to the action of a revolving brush and
passed over a shaking sieve, whereby the dust and germs are separated from the
farinaceous fragments. When these are to be gradually reduced to flour, this may
be effected by ordinary grinding or by means of successive milling apparatus like
that described, the material and channelling of the acting surfaces being varied to
suit the different conditions of the material on which they have to act. Also
suitable bolting, sifting and purifying apparatus of known kinds are to be used at
the different stages of the gradual reduction process.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shews an elevation of the grinding mill, Fig. 2 is a cross section, Fig. 33
shews sections of the upper and lower grinding crowns B and C, Fig. 4 shews a top
view of the lower crown C, Fig. 5 shews a plan of a crown with radial grooves,
Fig. 6 shews the brushing and screening apparatus, Fig. 7 shews a plan of the
lower crown for a mill for splitting grain, Figs. 8 and 9 shew sections of the
grooves thereof taken respectively on the lines A B and C D, Fig. 10 shews a plan 3
of the lower crown for a grinding mill, Figs. 11 and 12 shew sections thereof on
lines A. B and C D, Fig. 13 shews a plan of the lower crown for a converting mill,
Figs. 14 and 15 shew sections thereof on lines A B and CD, Figs. 16 and 17 shew
an underside view of the upper crown and a section thereof.
A is the framing, B is the upper crown, C is the lower crown, D tubular shaft 4
for the upper crown, E shaft for the lower crown, F bearing for the same,
G bearing for the upper shaft, H regulating screws for the grinding crowns,

page_text: I fixing screws for the same, J receiving hollow on the lower crown, K hopper,
L discharge spout, M shoot, N casing for the brushing and screening apparatus,
O brushing drum, P screening surface, Q fan, R compartment into which the germs
fall, S compartment for the split and purified grain.
The improved grinding mill may be employed either for longitudinally splitting
grain or for reducing or converting it into semolina and flour, or for grinding or
pulverising all other products, the grooves of the grinding crowns being modified
for these several purposes as will be hereinafter described. For this purpose the
apparatus employed are follows: Firstly, a splitting mill Fig. 1 consisting of two
crowns B and C shewn in section on Fig. 3 and formed of cast iron or other
suitable material; the upper crown B is fixed on a tubular shaft D, the lower
crown is fixed on a shaft E which revolves in a step bearing F. The crowns are
provided with grinding surfaces of truncated conical shape and grooved formed
either of steel, hardened cast iron, or other. suitable metal and which are fixed and
regulated by the following means as indicated at Fig. 3. There are three or more
screws I passing through the crowns B and C and into the grinding surfaces B¹
and C¹ so as to fix them in the crowns. There are three or more other screws H
which screw into the crowns B and C but not into the grinding surfaces which
screws serve to adjust the grinding surfaces in position in their crowns, the fixing
screws being tightened after such adjustment has taken place. The lower crown C
is provided with grooves a and counter grooves b which are inclined at an angle to
the radius as shewn at Figs. 7, 8 and 9. The grooves a serve for the introduction
of the grain between the grinding surfaces, and the counter grooves 6 serve for the
issue of the ground or split material. The grooves a are of considerable width and
depth at their upper or inner end where the grain enters them and they are made
to taper or diminish towards the outer periphery. The grooves are made with a
vertical short side and a more or less inclined long side, the latter representing the
hypothenuse of a rectangle triangle of which the vertical side forms the short side,
while the horizontal line passing along the tops of the grooves forms the long side.
By means of this form of groove the grain in entering will roll down to the deepest
part of the groove and assume a longitudinal position therein. Between each
groove a is a counter groove b which is formed in a contrary manner to a, that is
to say, these grooves are narrow and shallow at their inner ends and become larger
towards the outer end, the sectional form of the grooves being the same as that of
the grooves a.
The grinding surface of the upper crown is also provided with
grooves, but these are uniform in size and have a cross section similar to those of
the lower grinding surface. They are inclined at an angle to the radial line in the
same manner to the lower grooves, and they start at a short distance from the
inner circumference as shewn at Fig. 16. The crowns containing respectively
the upper and lower surfaces are made to revolve in contrary directions or they
may revolve in the same direction at different speeds, or the one may be stationary
and the other made to revolve. In operating with this grinding mill, the grain
introduced into the hopper K passes down through the hollow shaft of the upper
grinding crown and falls on to the rounded surface of the lower crown, from which
it rolls down into the annular hollow J where, owing to the action of rotation, the
grains place themselves in such a position that their longitudinal axes form
tangents to the circle of rotation.. From the hollow J, the grain passes radially
into the grooves a-which are for this purpose made of considerable width at their
inner end and are inclined at an angle to the radius in the direction of rotation.
Owing to the tangential position assumed by the grain in the hollow J and the
inclined bottom surface of the grooves, the grain will enter in a longitudinal
direction into the latter in which they will roll down to the bottom and are thus
made to preserve, during their passage between the grinding surfaces, a longi-
tudinal position in a more or less radial dirèction, which is an essential feature of
this invention. As the grain descends by degrees in the grooves a which diminish
in size and depth, they will arrive at a point where the grooves will no longer
contain the grain. At this point the upper grinding surface will drag them over

page_text: the sharp upper edges which separate the grooves a from the counter grooves b and
during such motion the sharp edges will split the grain without crushing it. As
soon as they are split they will fall into the counter grooves from which they
readily escape outwards as these increase in dimension towards the circumference.
Thus it will be seen that as soon as the splitting of the grain has been effected it
will be delivered from the mill and a useless retention of the grain between
the grinding crowns will be avoided, which retention would; on the one hand, be
detrimental to an effectual splitting process, and would, on the other hand, cause a
considerable loss of motive power and produce a waste of ground material.
As before stated, the grooves of the upper grinding surface only start at a short
distance from the inner circumference. This arrangement has for its object to
prevent the upper crown from acting upon the grain at the moment when this
enters the grooves of the lower crown, as any such action at that time might
prevent the grain from assuming the proper longitudinal position. The split grain
passes direct from the mill. into a brushing and purifying machine which then
readily removes therefrom the germ and the dust without otherwise acting on them,
or there may be interposed between the grinding mill and the brushing and
purifying machine a bolting cylinder for first acting on the split grain. The
brushing and purifying machine, which is an indispensable appendage to the mill
for splitting grain, consists of a casing enclosing a horizontal brushing drum O,
a screening surface P, receiving vibrating motion from an 'eccentric, and an exhaust
or blowing fan Q. The grain entering through the shoot M is carried round by
the brush O between it and the curved drum partly surrounding it, thereby
submitting the split grain to the requisite brushing action, and delivers the grain
onto the screen P through which the germ falls into the compartment R, while the
dust and bran or husks pass into a separate chamber, the brushed and cleansed
grain being delivered into the compartment S from which it is then removed for
being ground either in ordinary grinding mills or in progressive grinding mills, as
I will presently describe.
In the case where the split grain is required to be transformed into semolina and
flour for gradual reduction, there are employed one or more reducing mills, consisting
of the same elements as the splitting mill above described, with the exception of
the form of the grooves which, in this case, may be made radial, as shewn at Fig. 5,
or curved or inclined at any desired angle; their width and depth would be
proportioned to the degree of reduction to be obtained. Each reducing mill may
deliver the product into a purifying machine which purifies and classifies the
semolina and removes the particles of flour and bran therefrom, these being
extracted by an exhaust fan and conducted to special sorting apparatus. The
semolina remaining would be conducted into a second reducing mill where it is
subjected to a repeated grinding and sorting action and so on until the grain is
entirely reduced and deprived of the bran and husks. The meal thus produced
would then be passed through a converting mill which will reduce it to flour of the
requisite degree of fineness.
Figs. 10, 11 and 12 shew the lower grinding crown having grooves such as are
employed for reducing mills, and Figs. 13, 14 and 15 shew the form of grooves for
the converting mills. In the case of the reducing mills, the grooves are formed on
the same principle as described for the splitting. mills. The grooves a have the
same configuration but they are, of course, proportioned in size to the degree of
reduction to be obtained by the passage of the grain through the mill, but the
counter-grooves, instead of consisting only of one conduit, are divided into a series
of small parallel grooves c c opening, at one end, into the grooves a and terminating
at the circumference at the other end. The section of these grooves is similar to
that of the others, that is to say, with a vertical side and an inclined side, as
shewn at Fig. 11.
In the converting mill, which terminates the grinding operation for producing
flour, the form of the grooves is also the same as shewn at Figs. 10, 11 and 12,
but in order to prevent heating, the small grooves c, which are longest, are not

page_text: extended to the circumference and open into a counter groove d, as shewn at
Figs. 13, 14 and 15, so that the products which have once been thoroughly acted
upon are not retained uselessly between the grinding surfaces. The upper grinding
crowns are provided with grooves that may either be uniform in size or they may
be similar to those of the lower crowns. They may be either radial or oblique or
parallel to or inclined in an inverse direction to those of the lower crown.
last described arrangement is the most advantageous because it facilitates a more
rapid discharge of the grain.
The
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The use for grinding or splitting grain or other material, of grinding surfaces
of a truncated conical form held in an adjustable manner in revolving crowns by
means of regulating and fixing screws, the upper grinding surface being provided
with grooves inclined at an angle to the radius and having a cross section formed
by a short vertical side and a long inclined side, while the lower grinding surface
has firstly grooves, also inclined at an angle to the radius, which grooves are wide
and deep at their inner end to receive the grain from a central circular hollow and
are reduced in size towards the outer end and secondly counter grooves situated
between the first named grooves, and which are narrow at their inner ends and
increase in width towards their outer ends, the said grooves of the lower grinding
surface having a cross section similar in configuration to those of the upper grinding
surface, substantially as herein described.
2. In grinding apparatus such as is referred to in the preceding claim, constructing
the counter grooves of the lower grinding surface as a number of small parallel
grooves of uniform size, when the mill is to be used as a redueing mill, substantially.
as herein described.
3. In grinding apparatus such as is referred to in the first claim, providing the
lower grinding surface firstly with grooves decreasing in width and depth from the
inner to the outer end, secondly with small parallel counter grooves and thirdly
with other counter grooves that are made to increase in size towards the outer end,
substantially as herein described.
4. The use in combination with apparatus for splitting grain such as is referred
to in the first claim, of brushing and purifying apparatus, for separating the germs
and dust from the split grain, having a cylindrical brush operating only on a
portion of its circumference, a screening surface, and an exhaust or blowing fan,
substantially as herein described.