for the Manufacture of Semolina and Flour.
Year: 1885

page_text: for the Manufacture of Semolina and Flour.
I, GEORGE MACAULAY-CRUIKSHANK of 135 Buchanan Street Glasgow in the
County of Lanark, Fellow of the Institute of Patent Agents do hereby declare
the nature of this invention, a communication to me from abroad by Gustav
Adolph Buchholz of Frankfort on the Main, in the Empire of Germany, to be as
follows:
Under the processes of grinding hitherto commonly practised in the manufacture
of semolina and flour a large amount of superfluous labor is entailed in preparing
the grain for consumption consequences of which are,
(1) A great part of the grain is reduced to powder of almost no value.
(2) The separating of the flour from the bran is, considering the difficulty of
obtaining an absolutely pure semolina, next to impossible and in consequence a
large quantity of the mill products lose their value because of their impurities.
(3) The products are heated and much deteriorated in nourishing value and in
flavor.
(4) As a consequence of the use of a motive force much greater than sufficient
for the requirements the cost of manufacture is increased by so much as the motive
power is in excess of the requirements of a rational mode of grinding.
The object of this invention is to overcome these defects and to avoid in the
treatment of the grain in the process of its reduction into flour and bran all that
is superfluous and detrimental. These objects are effected by the use of improved
machinery in which the form and movement of the cylinders have the effect of
causing every product to leave the mill immediately it is reduced to its most
profitable quality and whereby its further and detrimental treatment is obviated.
The improved machinery consists of a reciprocating mill composed of a strong
iron frame carrying two three or more horizontal cylinders, plates, prisms or
grinding surfaces of other convenient form the bearings of which preferably
revolve between friction rollers carried in columns firmly secured to the frame by
bolts or otherwise.

page_text: The grinding surfaces of the cylinders or plates are grooved at right angles to
their longitudinal axis in such a manner that the profile of the grooves is less than
each particle of the material to be ground and between every two grooves a rib is
formed the width of which is in the proportion of as 2 to 5 to the groove or
nearly so.
The grinding motion of the cylinders so constructed is not a rotary but an
end wise or reciprocating movement and both cylinders of each pair may have a
grinding motion in directions opposite to each other or one only of each pair may
Bо move.
To protect the parts of the surfaces of the cylinders not in grinding action from
corrosion I cover them with a casing of wood or equivalent material and place
between the casing and the cylinder a woolen, leather, or other such like lining
saturated with an anti-corrosive agent.
By the reciprocating movement of the cylinders the process is divided into two
operations viz.
1. The introduction of the grain to be ground between the cylinders:-Contrary
to all known grinding methods the grain, under the invention, enters and passes
between the cylinders when they are stationary which moment happens at the
extreme of each reciprocation. The grain during these moments of rest falls into
the openings or channels formed by the grooves of the two cylinders or grinding
surfaces and it is then ready for the 2nd operation the effect of which is it
reduction consequent on the longitudinal movement of the grinding surfaces
breaking the grains. During the interregnums of motion the grain reduced to
small particles falls lower down in the grooves and is further reduced by the next
reciprocation of the cylinders or grinding surfaces.
All products the size of which after each grind as diminished in a greater measure
than the cross section of the grooves, fall naturally through these grooves and
consequently out of this part of the machine.
The grinding cylinders or surfaces are operated by a lever carried on a shaft and
moved backwards and forwards by an eccentric and connecting rod or equivalent
apparatus. On the same shaft as the lever a spur pinion or pinions is or are keyed
and geared with a rack or racks formed on or connected to the cylinder or cylinders
at one end or instead of such arrangement a cross head, lever and connecting rods
or other well known means of communicating reciprocating motion may be
adopted.
The end frames are connected together by a head or cross piece formed or
furnished with a feeding hopper in the bottom of which is a slide to regulate the
feed. The position of the cylinders or plates in each pair relatively with each
other is regulated by an endless double screw the operation of which draws the
grinding surfaces nearer or throws them further apart.
To shorten and simplify the grinding process several grinding machines con-
structed as described may be placed in tier one above another. Each upper
division of a machine so arranged prepares the grain for the one immediately
underneath the widths of the grooving diminishing towards the lowest set of
grinding cylinders or plates.
For small mills the cylinders or other grinding surfaces may have the grooves in
series in the direction of the length of the surface each succeeding series being
smaller.
Under a modified arrangement of the apparatus before described the grinding
surfaces in lieu of reciprocating may be caused to partially rotate in which case
I use two grinding conic frustra concentric to each other the outer being truncated
to receive the inner one of the pair. The truncated cone has on its inside a
grinding surface whilst the other has its like surface on the outside both being
ribbed and grooved parallel to their longitudinal axis in the manner hereinbefore
set forth. The angle of inclination of the outer cone is preferably greater than
that of the inner to facilitate the feeding of the grain or grist to the grinding
surfaces.. The inner cone which is mounted on a spindle capable of vertical adjust

page_text: ment to regulate the width between the grinding surfaces is reciprocated in a
rotary path with the said spindle by a lever connected to a bar operated by an
eccentric.
The grain is fed to the mill through hoppers placed one above another at the
upper part of the mill the said hoppers being concentric with the spindle.
The upper hopper rotates with the spindle and delivers the grain through a
series of vertical tubes into the lower hopper from whence it passes through like
tubes or an annular space into a distributing cylinder which has a ring screwed
upon it to regulate the opening therefrom to the grinding cones. The ground
material after passing between the cones falls into hoppers and is thence conducted
to sorting cylinders to separate the semolina from the grist and to conduct the
coarser portions of the meal to another similar grinding machine with smaller
groovings.
The taper of the cones is to a certain extent optional but in cases when the ribs
between the grooves would be considerably greater at the wider than at the
narrower part of each cone it is preferable to divide the surface into as many
horizontal zones as may be necessary for the correct division of the grooving. By
providing a series of such apparatus in tier and by diminishing the width of the
grooves to the undermost cones the grinding of semolina may be effected by a
single passage of the material through the mill and in some cases an exhauster
may be used with advantage in conjunction with the apparatus.
The grooves in the arrangement first described instead of being at right angles
to the longitudinal axes of the cylinders may be arranged in the form of a screw
thread around the said cylinders said thread being nearly at right angles to the
said axis in which case the grain is drawn in by the rotating action of the screw
and is broken up by the pushing action of the threads and these being nearly
vertical they form eduction passages for the material sufficiently reduced to pass
out. The screw cylinders may have the same or different pitch or when one of the
cylinders is stationary it may be without grooves.
The rotation of the rollers is effected by shafts and spur or other gearing and to
regulate the working distances apart a screwed spindle is used as hereinbefore
described.
To enable the cylinders to move out of their working position in case of accident
the adjusting screw rests on springs.
101
AY

page_text: for the Manufacture of Semolina and Flour.
1, GEORGE MACAULAY-CRUIKSHANK of 62, Saint Vincent Street, Glasgow, in the
County of Lanark, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention (a communication to me from abroad by Gustav
Adolph Buchholz of Frankfort on the Main in the Empire of Germany) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
Under the process of grinding hitherto commonly practised in the manufacture
of semolina and flour a large amount of superfluous labour is entailed in preparing
the grain for consumption consequences of which are
. (1) A great part of the grain is reduced to powder of almost no value.
(2) The separating of the flour from the bran is, considering the difficulty of
obtaining an absolutely pure semolina, next to impossible, and in consequence a
large quantity of the mill products lose their value because of their impurities.
(3) The products are heated and much deteriorated in nourishing value and
in flavor.
(4) As a consequence of the use of a motive forco much greater than sufficient
for the requirements the cost of manufacture is increased by so much as the
motive power is in excess of the requirements of a correct or rational mode of
grinding.
The object of this invention is to overcome these defects and to avoid in the
treatment of the grain in the process of its reduction into flour and bran all that
is superfluous and detrimental. These objects are effected by the use of improved
machinery in which the form and movement of the cylinders have the effect of
causing every product to leave the mill immediately it is reduced to its most
profitable quality and whereby its further and detrimental treatment is avoided.
The improved machinery consists of three kinds of mills all based on the same
principle and illustrated on sheets 1 to 6 of the drawings hereunto appended.
As shown under one arrangement on sheets 1 and 4 the machinery consists of a
reciprocating mill composed of a strong iron frame A, carrying two, three or more
horizontal cylinders, plates, prisms or grinding surfaces of other convenient form,
the bearings of which preferably move between friction rollers n, carried in
columns o, figures 6, 7, and 8 sheet 3, firmly secured to the frame by bolts or
otherwise.
The grinding surfaces of the cylinders or plates are, as seen by figures 7, 8, 9
and 10 sheet 1, grooved at right angles to their longitudinal axis in such a manner
that the profile of the groove is less than each particle of the material to be ground
and between every two grooves a rib is formed the width of which relatively with
the grooves is in the proportion of as, 2 to 5 or nearly so.
Figures 9 to 14, sheet 2 figures 1, 3, and 4 sheet 3 and the several figures on
sheet 4, represent further forms of grinding surfaces which may be employed.
The grinding motion of the cylinders so constructed is not a rotary but an
end-wise or reciprocating movement in the direction of their longitudinal axes and

page_text: both cylinders of each pair may have a grinding motion in directions opposite to
each other or one only of each pair may so move.
To protect the parts of the surfaces of the cylinders not in grinding action from
corrosion I cover them with a casing of wood or equivalent material as seen at
figure 6, sheet 1, and at figure 3, sheet 2, and place between the casing and the
cylinder a woollen, leather, or other such like lining saturated with an anti-corrosive
agent.
By the reciprocating movement of the cylinders the process is divided into two
operations viz—–
(1) The introduction of the grain to be ground between the cylinders:-Contrary
to all known grinding methods the grain, under the invention, enters and passes
between the cylinders when they are stationary which moment happens at the
extreme of each reciprocation. The grain during these moments of rest falls by
gravity into the openings or channels formed by the grooves of the two cylinders
or grinding surfaces and it is then ready for the 2nd operation the effect of which
is its reduction consequent on the longitudinal movement of the grinding surfaces
breaking the grains. During the interregnums of motion the grain reduced to
small particles falls lower down in the grooves and is further reduced by the next
reciprocation of the cylinders or grinding surfaces.
All products the size of which after each grind has diminished in a greater
measure than the cross section of the grooves, fall naturally through these grooves
and consequently out of this part of the machine.
The grinding cylinders or surfaces are operated by a lever L, carried on a shaft e
figs. 1, 2, 3, 4 and 6 sheet 1 and moved backwards and forwards by an eccentric
and connecting rod or equivalent apparatus. On the same shaft as the lever a spur
pinion or pinions f¹ is or are keyed and geared with a rack or racks f, formed on
or connected to the cylinder or cylinders at one end or instead of such arrangement
a crosshead, lever, and connecting rods as indicated at figures 11, 12, and 13,
sheet 1, may be used or other well known means of communicating reciprocating
motion may be adopted.
The end frames A, are connected together by a head or cross piece formed or
furnished with a feeding hopper d, in the bottom of which is a slide c, figures 1, 5, 6
and 14, sheet 1, to regulate the feed. The position of the cylinders or plates in
each pair relatively with each other is regulated by a hand wheel secured as seen.
more particularly by figures 1 and 2, sheet 2, on a shaft or spindle S, extending
between the bearings at each end of the cylinders or plates. The extremities of
the shaft or spindle have screw threads formed on them these being geared with
worm wheels formed or fixed on screws lying at right angles to the shaft S, the
inner ends of the said screws being connected to the bearings of the cylinders or
plates and thus when the shaft S, is turned the grinding surfaces are forced nearer
or drawn further apart.
To shorten and simplify the grinding process several grinding machines con-
structed as described may be placed in tier one above another, as indicated at
figure 5, sheet 3, and figure 5 sheet 6. Each upper division of a machine so
arranged prepares the grain for the one immediately underneath, the widths
of the grooving diminishing towards the lowest set of grinding cylinders or
plates.
For small mills the cylinders or other grinding surfaces may have the grooves in
series in the direction of the length of the surface each succeeding series being
sinaller.
Under a modified arrangement of the apparatus before described, illustrated by
figs. 1, 2, 3, 4, 5, 6, 7, and on sheet 5, the grinding surfaces in lieu of recipro-
cating may be caused to partially rotate in which case I use two grinding conic
frusta, concentric to each other the outer one c, being truncated to receive the
inner one of the pair. The truncated cone has on its inside a grinding surface
whilst the other has its like surface on the outside both being ribbed and grooved
parallel to their longitudinal axis in the manner hereinbefore set forth. The angle

page_text: of inclination of the outer cone is preferably greater than that of the inner to
facilitate the feeding of the grain or grist to the grinding surfaces. The inner
cone which is mounted on a spindle a, capable of vertical adjustment to regulate
the width between the grinding surfaces is reciprocated in a rotary path with the
said spindle by a lever L, L, L², connected to a bar T, operated by an eccentric.
The parts of the lever are hinged together vertically in order that they may follow
without resistence the vertical movements of the shaft a on which the lever is
keyed, these vertical movements being effected by the screw S.
The grain is fed to the mill through hoppers R¹, R³, figure 3, sheet 5, placed one
above another at the upper part of the mill the said hoppers being concentric with
the spindle. The hoppers are seen in detail at figures 17 and 18, sheet 5, and the
upper hopper R¹, rotates with the spindle and delivers the grain through a series
of vertical tubes into the lower hopper R2, from whence it passes through like
tubes or an annular space into a distributing cylinder d¹ which has a hand wheel m
upon it. The cylinder has a series of holes or openings made around its lower
part, and its upper part and also the hub or boss of the hand wheel is threaded so
that by turning the hand wheel on the cylinder a greater or less area of the holes
is uncovered and the feed of material to the grinding cones is thereby regulated.
The ground material after passing between the cones falls into hoppers h, and is
thence conducted to sorting cylinders to separate the semolina from the grist and
to conduct the coarser portions of the meal to another similar grinding machine
with smaller groovings.
The bar T, by which the lever L, is operated has a screwed part x formed upon
it on which two nuts y, and y¹ are placed, and when these nuts are in the positions
shown the bar T, is geared with the lever L, to actuate the machine the bar being
rendered loose when desired by screwing the nuts back. The exterior cones c may
be pressed down by screws v passed through the cover plate K, and acting on
rings n, as indicated at figure 1, sheet 5.
The taper of the cones is to a certain extent optional but in cases when the ribs
between the grooves would be considerably greater at the wider than at the
narrower part of each cone it is preferable, as indicated at figures 9, 10 11, 12 13,
14, 15 and 16, to divide the surface into as many horizontal zones us may be
necessary for the correct division of the grooving. By providing a series of such
apparatus in tier and by diminishing the width of the grooves to the undermost
cones the grinding of semolina may be effected by a single passage of the material
through the mill and in some cases an exhauster may be used with advantage in
conjunction with the apparatus.
The grooves in the arrangement first described instead of being at right angles
to the longitudinal axes of the cylinders may be arranged in the form of a screw
thread around the said cylinders and the cylinders may be made to rotate the said
thread being nearly at right angles to the said axis as at figure 3 sheet 5, in which
case the grain is drawn in by the rotating action of the screw and is broken up by
the pushing action of the threads and these being nearly vertical they form
eduction passages for the material sufficiently reduced to pass out. The screw
cylinders may have the same or different pitch or when one of the cylinders is
stationary it may be without grooves.
The rotation of the cylinders is effected by shafts and spur or other gearing and
to regulate the working distances apart an adjusting device is used as hereinbefore
described.
The effect of the rotating screw cylinders with thread of low pitch is in many
respects similar to the effect produced by the reciprocating grinding mill and they
are quite suitable for grinding certain materials, the difference in action being,
when rotating cylinders are used, the grain is entered between the cylinders not
only by its own weight but is also drawn in by the motion of the rollers.
As to the shape of the threads it is preferably that shown at figure 3 sheet 3,
and figure 3, sheet 6, which is a part of one of the rollers full size. The inclination
of the threads may be from 0° on to 45°, the most practical being found between

page_text: 5° and 10°. The screw thread cylinders that work together may have similar or
different inclination of their threads or one of them may have no inclination at all
as shown by figure 4 sheet 6.
Figures 1, 4 and 5, sheet 6 show a screw thread cylinder machine, the three
screw thread cylinders a, b, a¹, being arranged in such a way that a, rotates in a
direction opposite to a¹; the rotation of both being towards the middle cylinder b,
which has no motion. By this arrangement the material is partly drawn in
between the rollers by the action of the rollers themselves and it is moved in the
longitudinal direction by following the axes of the rotating rollers. The latter
break the grain on the crushing edges of the grinding cylinder b, the crushed parts
passing through the grooves downwards without further detrimental rubbing.
The diameter of the middle screw thread cylinder b, is twice as large as that of
the lateral rollers a and a¹ in consequence of its being acted upon on both sides
and it is occasionally turned partially round as the surfaces acted upon are blunted.
The working of the rotating rollers a a¹ is effected by the shaft R and suitable
gearing and the distance of the rollers a and a¹ from the roller b, can be regulated
by a device S, similar to that used for reciprocating rollers which device is
cushioned against a spring f to allow the rollers to yield to over pressure.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me, I declare that what I claim is :—
1. The new or improved process of grinding grain in the manufacture of
semolina and flour effected by the use of grinding cylinders, prisms, plates or
bodies of other forms, the said bodies having their grinding surfaces ribbed and
grooved and so arranged relatively with each other that the said surfaces have
between them a channel or passage one or both bodies being reciprocated in the
direction of the longitudinal axis without touching the other substantially as
described with reference to the accompanying drawings.
2. The arrangement and combination of parts constituting the grinding mill
substantially as hereinbefore described with reference to sheets 1 to 4 inclusive of
the drawings annexed.
3. The arrangement and combination of parts constituting the grinding mill
substantially as herein before described with reference to sheet 5, of the appended
drawings.
4. The arrangement and combination of parts constituting the improved grinding
mill substantially as hereinbefore described with reference to sheet 6 of the
drawings appended hereto.
GEO. M. CRUIKSHANK,
62, St. Vincent Street,
Agent.