Improvements in Grain Milling Apparatus.
Year: 1888

page_text: Date of Application, 6th Sept., 1888
Complete Specification Left, 6th June, 1889-Accepted, 27th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Grain Milling Apparatus.
I, JOSEPH SCHWEITZER, of 95 Boulevard Beaumarchais, Paris, France, Engineer
do hereby declare the nature of this invention to be as follows:-
This invention relates to apparatus for graduated milling of grain, each mill being
of such moderate height that a number of them can be superposed for effecting
gradual reduction, each being fed from the one above it without requiring elevators.
The axis of each mill is also so supported and worked that the parallelism of. the
grinding surfaces is not affected by wear, and theso surfaces are provided with means
of cooling by circulation of cold air or water.
One of the mills is constructed as follows :-
In the centre of a strong framing there is a long bearing for a vertical shaft,
this bearing being capable of being raised or lowered by a screw or rack, and
being closed at the bottom so as to form a reservoir for oil in which the vertical
shaft revolves. On the top of the vertical shaft is fixed a disc having the lower
grinding ring fixed on its face at the periphery.
To the underside of the disc is attached the driving pulley which projects down
from the disc so far that the middle line of the driving strap is in a plane about mid-
way between the upper and lower ends of the hearing for the vertical shaft; thus the
strain of the strap does not tend to give obliquity to the shaft and therefore does not
alter the plane of the grinding surface on the disc.
Above the disc is fixed a casing which carries on its lower face the upper stationary
grinding ring bolted to the casing which is hollow for the circulation of air or water
to keep the grinding surfaces cool.
The disc and its grinding ring being caused to revolve, the material to be ground is
fed in at the centre of the upper casing and is ground as it passes out between the
two grinding rings, the ground material being received in an annular casing
surrounding the grinding rings and passing thence by a spout.
A number of these mills being superposed, the material more or less broken up or
ground in the uppermost can be sifted or otherwise dealt with and the products
or part thereof can be fed to the next lower mill, and so on throughout the range
of mills.
Dated thin cih dan of Contamhan 1000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Grain Milling Apparatus.
I, JOSEPH SCHWEITZER of 95 Boulevard Beaumarchais, Paris, France, Engineer
do hereby declare the nature of this invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to apparatus for graduated milling of grain, each mill being
of such moderate height that a number of them can be superposed for effecting
gradual reduction, each being fed from the one above it without requiring elevators.
The axis of each mill is also so supported and worked that the parallelisin of the
grinding surfaces is not affected by wear, and these surfaces are provided with
means of cooling by circulation of cold air or water.
One of the mills is constructed as follows:-
1-
In the centre of a strong framing there is a long bearing for a vertical shaft,

page_text: this hearing being capable of being raised or lowered by a screw or rack, and
being closed at the bottom so as to form a reservoir for oil in which the vertical
shaft revolves. On the top of the vertical shaft is. fixed a disc having the lower
grinding ring fixed on its face at the periphery.
To the underside of the disc is attached the driving pulley, which projects down
from the disc so far that the middle line of the driving strap is in a plane
about midway between the upper and lower ends of the bearing for the vertical
shaft thus the strain of the strap does not tend to give obliquity to the shaft
and therefore does not alter the plane of the grinding surface on the disc.
Above the disc is fixed a casing which carries on its lower face the upper stationary
grinding ring bolted to the casing, which is hollow for the circulation of air or water
to keep the grinding surfaces cool.
The disc and its grinding ring being caused to revolve, the material to be ground is
fed in at the centre of the upper casing and is ground as it passes out between the
two grinding rings, the ground material being received in an annular casing
surrounding the grinding rings and passing thence by a spout.
A number of these mills being superposed, the material more or less broken up or
ground in the uppermost can be sifted or otherwise dealt with and the products or
part thereof can be fed to the next lower mill, and so on throughout the range of
mills.
The accompanying drawings shew an arrangement of milling apparatus constructed
according to my invention.
Fig. 1 shews a vertical section of a mill taken on line CD Fig. 2. Fig. 1ª is a
modified form of the grinding surfaces. Fig. 2 shews a horizontal section on
line A B Fig. 1. Fig. 3 shews the combination of three mills placed one above the
other, with accessory apparatus, arranged for effecting grinding in stages. As shewn
at Figs. 1 and 2, the mill consists of a framing a with a double bracket forming a
central socket in which is a step bearing & carrying at bottom the shaft of the lower
grinding surface e, and extending up along the whole height of the shaft so as to form
an oil reservoir in which the shaft is entirely immersed.
The step bearing is threaded externally and screws through a nut p rotatable in the
socket so that by rotating the nut by means of the worm gearing with teeth on the
nut, rotated by the hand wheel i, the bearing b can be raised or lowered.
In place of the screw thread and nut may be used a rack with helical teeth gearing
with a worm.
By these means the distance between. the grinding surfaces can be accurately
regulated.
At the upper part of the framing is an annular head on the underside of which is
fixed the upper grinding surface. The head c is formed hollow and may have a
current of cold water or air passed through it for cooling the upper millstone, and
thus prevent the mill from heating.
The lower millstone e is fixed on a disc f rotated by a driving pulley 9 which is
formed in one therewith. The disc is fixed on the shaft carried by the bearing b,
which is provided with brasses in contact therewith either along its entire surface or
only at certain points, arranged as shown so as to afford the shaft great stability and
support it against the lateral strain exercised by the driving gear. The grain or
other material to be ground or crushed is introduced into the hopper ; whence it
descends between the millstones, from which the ground material descends into the
annular casing whence it is led away through a shoot m.
The hollow framing a is provided with lugs Fig. 2 through which, and through
corresponding holes formed in the widened head o of the framing pass tie bolts, by
which the series of three or more mills can be firmly bolted together. The parts are
so constructed as to reduce the height as much as possible, and this is facilitated, by
supporting the shaft in a single step bearing. It is essential that the shaft should be
maintained perfectly vertical, in order that the millstones may be perfectly horizontal;
to insure this it is necessary that the wear of the bearing brasses should be perfectly
uniform in all parts, and consequently also that the lateral strain of the driving gear
+.

page_text: should be spread over the bearing surfaces in a symetrical manner in the direction of
strain.
For effecting this, the arrangement shewn at Fig. 1 is adopted in order that the
central plane of the pulley 9 shall be in a horizontal plane which is equidistant from
the central planes of the brasses ED of the shaft if these brasses are of the samo
length, or that the respective distances shall be in correct proportion to the amount of
surface offered by the bearings respectively. Three or more mills of the above
described construction are combined in the following manner :-
1. A splitting or breaking mill F, the product of which is delivered into a screen G
for removing dark coloured flour, from which the split grain passes into a cylindrical
brushing apparatus H where the dust adherring to the interior of the particles of
broken grain as also the germs, are removed. 2. One or more reducing mills R
which reduce the broken grain to semolina or grits, these products being sifted by the
screen T of suitable known construction for separating the flour or finer particlos.
3. A finishing mill X which delivers the product into a brushing apparatus V for
separating the bran, and delivering the finer products into the flour screen Z. The
screens may be replaced by purifying cylinders delivering the insufficiently ground
particles into a worm conveyer which feeds them back into the mill.
The above described arrangement obviates the use of elevators, the grinding opera-
tion being confined to one and the same floor; it reduces the necessary mill space and
simplifies to the greatest possible extent the mechanical devices employed.
The arrangement of the accessories for operating on the split grain, for screening
the produce of the reducing mills and for simultaneously brushing and sifting the
product of the finishing mill, relatively to the grinding apparatus is also new and
facilitates the method described of grinding in stages.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In grain grinding or milling apparatus such as is herein referred to, the use of
the step bearing for the mill shaft, constructed so as to extend along the whole length
of the shaft and forming at the same time an oil reservoir in which the shaft of the
lower mill revolves, the said bearing being formed with a screw thread or rack and
worm gear for regulating the distance between the mill stones, substantially as he rein.
described.
2. The arrangement of the driving pulley fixed upon the mill shaft and arranged
in a horizontal plane either centrally between the extreme points of support of the
shaft in its bearings or in such other position relative to those supports as to ensure a
uniform distribution of the lateral strain of the driving gear upon the bearing brasses
and thus obtain a uniform wear thereof, thereby insuring the vertical position of the
shaft, and consequently the horizontal position of the lower mill stone substantially
as herein described.
3. The mode of cooling the fixed mill stone by carrying the same on a hollow
head c through which cold water or air is made to circulate, substantially as herein
described.
4. The combined arrangement of several superposed grinding mills performing
different operations for effecting the grinding in stages, whereby all elevators are
dispensed with, and there are combined with the grindstones a brushing and screening
apparatus for purifying and separating the germs from the broken grain delivered
from the splitting mill, as also further brushing and purifying apparatus for treating
the produce of the reducing and finishing mills, substantially as herein described.
Datel this Gib daw of Tune 1880
ABEL & IMRAY,
Agents for the Applicant.