IMPROVEMENTS IN MACHINERY FOR CONVERTING GRAINS INTO FLOUR, AND FOR TREATING THE FLOUR OR MEAL
Year: 1880

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Solicitors, at Frankfort on the Main, in the Empire of Germany, for an
Invention of "IMPROVEMENTS IN MACHINERY FOR CONVERTING GRAINS
INTO FLOUR, AND FOR TREATING THE FLOUR OR MEAL." A communication
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 13th October 1880.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frankfort
on the Main, in the Empire of Germany.
"IMPROVEMENTS IN MACHINERY FOR
CONVERTING GRAINS INTO FLOUR, AND FOR TREATING THE FLOUR OR MEAL."
[A communication from Heinrich Seck, of Frankfort / in the Empire of
Germany.]
One part of the present Invention has reference to improved machinery whereby
the process of converting grain into flour or meal is carried out in successive stages,
while between each such stage the product is subjected to a process of screening or
dressing, the novel features of such machinery, as compared with machinery
of present construction, being more particularly that several sets of crushing or
grinding cylinders or rollers are so arranged in combination that the grain or
meal to be treated passes directly from the one set to the other through the
intervening screening or dressing apparatus, instead of each grinding and screening
operation being carried on in a separate machine as heretofore, and that the supply
of grain is only regulated to the first set of the said grinding cylinders by a feed
roller.
By this means great saving of space, motive power, and labour, is effected, and
several apparatus serving for the transport of the grain from the one machine to the
other are dispensed with, thereby effecting considerable saving in expense. Also
the feed of the several apparatus is rendered very regular.
For the above purpose a series of dressing or screening drums or cylinders are
arranged one above the other in a framing, and at each end thereof are series of
grinding cylinders arranged and operating as follows:-The grain is first fed from

page_text: a hopper provided with a regulating feed roller into a pair of crushing cylinders
at the bottom of the framing, and the crushed grain passing from these is raised by
an elevator of known construction to a screening drum at the top of the framing,
in passing through which the finer particles, or flour, are separated from the
coarser particles, or middlings. The latter are then made to pass into a second pair
of grinding cylinders, from which the produce is led down an inclined shoot into a
channel in which is a revolving helical blade or worm that feeds the produce into
the second screening drum, the said worm being, by preference, fixed on the shaft
of the beaters of the said drum. The coarse particles pass from the interior of this
drun into a chamber where they are subjected to the action of revolving beaters
that throw the produce into a hopper leading to a third set of grinding cylinders.
From these the produce passes into another worm which carries it into a third
screening drum, and the coarse particles passing from this are again subjected to
the action of revolving beaters, which deliver them into a fourth set of grinding
cylinders situated at the bottom of the framing. The produce from these is again
raised to the top of the machine by an elevator, and is there again subjected to the
action of a fourth screening drum, from which the coarse particles are again fed by
revolving beaters into a fifth and last set of grinding cylinders. The produce from
these may either be subjected to the action of a fifth screening drum, or it may be
conveyed to another part of the mill to be further dealt with.
In order to prevent the particles of bran or husks that have been entirely freed
from meal from being again subjected to the action of the grinding cylinders after
each screening operation, the chambers containing the before described beaters are
connected to an adjustable suction by which they are carried off to a separate
receptacle. The finer particles separated at each screening operation are collected
by a transporting worm at the bottom of the casing of the drum, and are led away
for further treatment.
The grinding rollers are either smooth or serrated, or roughened, according as
may be required, and the requisite pressure is effected by means of springs acting
on levers on which the bearings of the cylinders are mounted. The accurate
adjustment of both bearings of the cylinder is effected simultaneously by two
worm wheels with screw nuts on screw spindles connected to the said levers, and
in gear with worms fixed on one and the same spindle rotated by hand. If the
bearing at the one end of the cylinder requires separate adjustment, this is effected
by putting the worm out of gear with the worm wheel on one side by means of
an eccentric, whereupon the worm wheel on the other side can be independently
adjusted.
The feed roller to the hopper through which the grain is fed into the first set of
grinding cylinders is rendered magnetic, so that any iron particles contained in the
grain adhere to the roller and are removed therefrom at the back.
The screening or dressing cylinders or drums may be of the usual construction,
that is to say, with a cylindrical or polygonal screening surface, which is carried on
revolving rollers so as to be made to rotate, while within the cylinder are radial
blades or beaters mounted on a revolving shaft which throw the meal against the
screening surface.
According to another part of the present Invention, applicable not only to the
screening drums of the before described machinery, but also to all other screening
or dressing cylinders or drums of similar construction, instead of constructing the
screening surfaces as the regular sides of a polygon, as heretofore, they are placed
at greater or less inclinations to such position, that is to say, the distance of the
one longitudiual edge of each polygonal side from the centre of the drum is greater
than the distance of the other edge, the inclinations of the several sides being all in
one and the same direction, so that a series of steps are formed at their junctions.
By this arrangement the meal or grain which is thrown in a more or less tangential
direction from the revolving beaters towards the inner surface of the drum instead
of meeting such surface at a very acute angle, as is the case with the ordinary
polygonal drum surface, will impinge almost perpendicularly thereon, in consequence

page_text: of which the screening action will be much more effective, and the wear of the
screening surface will be considerably decreased.
When constructing the surfaces of such polygonal screening drums of wire gauze
or open fabric the drum is, by preference, constructed as follows:-The framework
of the drum consists of four strong longitudinal tubular rods fixed to the end discs,
between each two of which rods are other rods of less strength, partly surrounded
by a concave bar at a slight distance from the rod. The strong rods have pins
projecting from their outer sides, on which is secured the one edge of a length of
the wire gauze or open fabric. The length of fabric is then passed under the inner
edge of the next concave bar, and outwards through the narrow space between the
said bar and its rod, from the outer side of which the fabric is then led round the
inner edge of the next strong tubular rod, to the pins of which its other edge is
then secured. By this means the surface of the wire gauze or fabric assumes the
before described angular position to the polygon. In place of tubular rods, rods of
angle iron or other shape may be employed.
Another part of the Invention relates to the casings of apparatus of the kind
above described. Such casings have, according to a previous Invention of my
correspondent, been made of cylindrical form, with helical channels on its inner
surface, so that by imparting a slow rotary motion to the casing, the meal, grain,
or other substance that has passed through the screening drum into the casing was
caused by the helical channels to travel towards one end, and was there delivered
into a shoot.
According to the present improvement the casing is made stationary, and only
the lower part thereof is of cylindrical form, and at the lowest point thereof is
a longitudinal channel or trough, in which a longitudinal shaft having a screw
blade or worm is made to revolve. On the outer surface of the screening drum are
one or more longitudinal brushes or strips of leather, or other suitable material,
that are made, by the rotation of the drum, to brush against the surface of the
casing so as to convey any meal or grain lodging thereon into the trough, in which
it is conveyed to a delivery shoot at one end of the casing by the revolving screw
blade or worm. The sides of the casing are provided with sliding doors, through
which access can be gained to the interior.
The arrangement of the first above described combined grinding and dressing or
screening machinery may be varied; thus, instead of arranging the several sets of
grinding cylinders and screening drums one above the other, they may be arranged
side by side also. Although the combination of five sets of such grinding cylinders
and screening drums has been described a greater or less number may be employed
without departing from the nature of this Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 12th April
1881.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frankfort
on the Main, in the Empire of Germany. "IMPROVEMENTS IN MACHINERY FOR
CONVERTING GRAINS INTO FLOUR, AND FOR TREATING THE FLOUR OR MEAL."
A communication from Heinrich Seck, of Frankfort /m., in the Empire of
Germany.
This Invention has reference to improved machinery whereby the process of
converting grain into flour or meal is carried out in successive stages, while between
each or several such stages the product is subjected to a process of screening
or dressing, the novel features of such machinery, as compared with machinery
of present construction, being more particularly that several sets of crushing or
grinding cylinders or rollers with the corresponding screening apparatus are so
arranged in a self contained system or in combination that the grain or meal to be
treated passes continuously without intermediate hoppers or feed rollers as now
used from the one set to the other through intervening screening or dressing
apparatus and peculiar and automatic centrifugal feed apparatus, as hereinafter
described, instead of each grinding and screening operation being carried on in
separate machines as heretofore, and that the supply of material need only be
regulated to the first set of the said grinding cylinders by a feed roller instead of
to each set as hitherto.
By this means great saving of space, motive power, and labour is effected, and
several apparatus serving for the transport of the material from the one machine
to the other, such as elevators, and worms, and intermediate hoppers, and feed
rollers are dispensed with, thereby effecting considerable saving in expense. Also
the feed of the several apparatus is rendered very regular.
The nature of the Invention will be readily understood on reference to the
accompanying Drawings, which show one of the various arrangements by which it
may be carried into practice.
Fig. 1 shews a longitudinal section through the dressing machines, feeding
worms, and centrifugal feed apparatus; Fig. 2 shews a cross section through the
dressing machines and an end view of the grinding rollers at R; Fig. 3 shews an
end view of the grinding rollers, and dressing machines at X, Fig. 1; Fig. 4 shews
a cross section through the grinding rollers and centrifugal feed apparatus at L,
Fig. 1 Fig. 5 shews a cross section through the grinding rollers and centrifugal
feed apparatus at R, Fig. 1; Fig. 6 shews a sectional plan of a dressing machine;
Figs. 7, 8, and 9, diagrams of the grinding and dressing process.
A, A, is the framing which carries the bearing levers of the grinding rollers B,
which have pullies Con their axes by which they receive rotary motion; D are
dressing machines which screen and sort the rolled material, meal or middlings,
delivered from the grinding rollers; E are new feed apparatus consisting of
revolving beaters, which receive the tailings or coarser unfinished material from
the dressing machine and feed it to the next grinding rollers; F are uprights which
carry the bearings for the shafts of the dressing machines, and which are connected
to the principal standards A; G are channels that receive the light finished bran,
which is separated from the meal by air draught before it enters the grinding
rollers, but this air draught is not a necessity to the system and may be dispensed
with.
The Drawings shew a system for roller mills in which wheat is subjected to a
five fold reduction or granulating process with intermediate dressing. The grain

page_text: is fed from the hopper a over the feed roller b to the grinding rollers B' where it is
first crushed. For the separation of the flour and middlings produced (which are
always separately screened at the first grinding operation) the crushed may be
led by an elevator H (Fig. 6) into another floor of the mill where it is delivered
into a dressing machine not shewn. After this dressing the unfinished material or
tailings is delivered into the second grinding rollers B2 for the second grinding
process, and falls from these over an inclined plane into the worm C¹ which is fixed
on the beater shaft of the dressing machine D' and which delivers the material
into the latter. After this second dressing the coarse material that has not passed
through the screening surface is delivered at the end of the machine into the
centrifugal feed apparatus E', which is fixed on the shaft of the dressing machine
and constitutes a principal feature of the present Invention. This apparatus
delivers the meal by centrifugal force through a longitudinal aperture in the casing
into the feed channel d. The beaters of this apparatus are shown similar in
construction to those of the centrifugal dressing machines described in H. Simon's
Patent, No. 1542, dated 19th April 1879, but instead of this arrangement they
may be constructed as shewn in longitudinal section and cross section rsepectively at
Figs. 10 and 11, where they consist of a number of more or less radial blades I
extending some distance from the axis, the surfaces of which blades may be slit
radially into sections, and each section so set or twisted with a gradually decreasing
inclination as by their resulting action to take up and propel the material coming
in at one end K, Fig. 3, both horizontally and radially in a manner and direction
best suited for obtaining a uniform feed or delivery over the whole breadth of the
rollers B. After the unfinished material has been rolled or ground for the third
time by the rollers B³ it falls over another inclined surface into the worm C²
which conducts it, as before described, to the dressing machine D², from the end of
which the coarse meal is again subjected to the action of the centrifugal feed
apparatus E, which delivers it in the before described manner to the grinding
rollers B. After this fourth grinding the meal is delivered into an elevator and
is raised by this into the dressing machine D³; here the flour and groats are again
separated and the coarse or branny particles are delivered by the centrifugal feed
apparatus E³ to the grinding rollers B for the last grinding process. The dressing
of this last produce can then be effected by another dressing machine in any
convenient part of the mill.
In order to prevent the light bran freed from flour that is produced during the
intermediate processes of the above operations from being subjected to further
grinding, it may be drawn off by a regulated suction at the centrifugal feed
apparatus E, before the produce operated upon is delivered into the next grinding
rollers, as indicated.
The flour and groats separated by the dressing machines D are collected by the
transporting worms e underneath the bolting or dressing cylinders, and are led
away for further treatment in the usual way. The grinding rollers have their
surfaces either grooved or ribbed, or made smooth according to requirements, and
the pressure exerted thereby is produced by the helical springs acting upon the
extensions of the bearing levers. The accurate adjustment of the moveable rollers
may be effected by means of screws actuated by worm wheels and worms connected
by a spindle, as indicated at Fig. 6, so as simultaneously to adjust the levers at
both ends of the rollers. Should one or other of the levers require separate adjust-
ment, the one worm is moved by means of an eccentric out of gear with its wheel,
whereupon either of the worm wheels can be rotated independently. The feed
roller b at the bottom of the hopper a, serving to regulate the feed may be made
magnetic, so that any particles of iron (nails, &c.) contained in the grain adhere to
the roller, and are removed automatically at the back. The covering x of the
bolting and sorting cylinders D, which may, according to requirements, be either of
silk, wire gauze, or perforated metal, may be of ordinary construction, but by
preference it is so constructed that separate screening surfaces are formed situated
at an angle to the geometrical sides of the polygon, so as to produce the stepped

page_text: configuration shewn on the Drawing. By this means the said screening surfaces
are brought into a position more or less approaching a right angle to the direction
in which the meal is thrown against them by the beaters, whereby the meal is more
quickly and perfectly screened, and the wear and tear of the screening surface is
much less than when the meal impinges thereon at a more or less acute angle, as in
centrifugal dressing machines of usual construction. The outer cylinders of the
dressing machines D may be carried on rollers which impart rotary motion thereto.
To one or more of the longitudinal bars of the outer bolting cylinder a soft brush
or strip of leather, caoutchouc, or other suitable material d extending the entire or
part of the length is fixed, with the object of conveying the flour passing through
the screening surface of the cylinder on to the surface of the casing into the
worms e¹, e², e³. The bolting or sorting cylinders may also be constructed as shewn
in longitudinal and cross section at Figs. 12 and 13, in which case the longitudinal
bars or rails supporting the covering may be of channel iron or U shaped bars L of
iron or other suitable material, the channel of each bar being filled out with wood,
to which the silk or wire covering or bolting cloth is attached, so as to form
polygonal screening surfaces M, M. To one of the before mentioned bars is fixed
the brush or strip of leather d, as described above, for conveying the screened flour
or material which falls upon the surface of the casing into the worm e.
Access may
be gained to each bolting cylinder at the side through doors f. The dressing
machines D may be driven by bands, or in any other convenient manner.
before described arrangement can, when desirable, be placed in a horizontal or
inclined instead of a vertical position, and the number of grinding rollers and
dressing machines can be varied, according as it may be required to grind more or
less "high or "low," the number of rollers or "breaks" effected by them being
increased in the first instance, and reduced in the last instance.
"
The
It is also sometimes preferred to arrange the rollers in horizontal pairs, as at
Fig. 11, instead of vertically, as shewn at Figs. 1 to 6, in which case the transporting
worms C¹, C², may be placed directly under the rollers, which then deliver the
ground materials straight into them.
Having thus described the nature of this Invention as communicated to me by
my correspondent, and in what manner the same is to be performed I claim,-
First. The use in grinding and dressing machinery of feed apparatus consisting
of revolving blades or beaters inside a casing, into which the materials to be acted
upon are fed, and from which they are discharged by the centrifugal action of the
blades or beaters through a longitudinal orifice, substantially as herein described.
Second. The combination of grinding rollers with dressing machinery, and with
the feed apparatus referred to in the preceding claim, arranged and operating
substantially as herein described.
Third. Constructing the screening drums or cylinders of centrifugal dressing or
bolting machines with a stepped covering so arranged that the several surfaces or
steps are presented in a position more or less approaching a right angle to the
direction in which the material is thrown by the beaters, substantially as herein
described.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this Ninth day of April, in the year of our Lord One thousand