IMPROVEMENTS IN MILLS FOR GRINDING CORN AND OTHER LIKE MATERIALS
Year: 1882

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake
& C° Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN MILLS FOR GRINDING CORN AND OTHER LIKE MATERIALS"
Communicated to him from abroad by Wilhelm Hartmann, a person
resident at Geisa, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 29th June 1882.
WILLIAM ROBERT LAKE, of the firm of Haseltine Lake & Co Patent Agents
Southampton Buildings London " IMPROVEMENTS IN MILLS FOR GRINDING CORN
AND OTHER LIKE MATERIALS [A communication to him from abroad by
Wilhelm Hartmann, a person resident at Geisa, in the Empire of Germany.]
"
This invention relates to improvements in mills or apparatus for grinding corn
and like materiala.
The grinding parts consist of two discs one of which rotates, and they are
provided with grinding surfaces as follows that is to say-I take a number of
small stamped strips of sheet steel which I secure together and after they have
been planed or smoothed the surface of this bundle of strips is cut in the same way
as an ordinary file is cut and I prefer the cutting to be effected in such a manner
that the upper edges of the separate teeth will be like the teeth of a saw.
position of the teeth should be modified according to whether the speed is to be
quick or slow.
The
After these steel strips have been bent they are hardened, and thus prepared, are
arranged within a smoothly turned groove in the discs and held down therein by
means of rings.
The rotating disc turns loosely around a fixed axle and a driving pulley is upon
the nave of this disc. The said axle serves at the same time to connect a wall
bracket with the stationary disc.

page_text: I also provide an adjusting arrangement for ensuring finer or coarser grinding.
The pressure exerted by the corn upon the revolving disc is sometimes very great,
and in order not to lose any power thereby, through the friction, the face of the
nave of the revolving disc is caused to run against a guiding roller which is
capable of turning upon a pivot. This pivot is screwed into clamping gear which
may be worked backward and forward upon a screw-threaded pivot. In order
to be able to fasten the clamping gear upon the screw it is split, and is drawn
together by means of a clamping screw. As the guiding roller is made large
proportionately to the face of the nave, it does not revolve too rapidly.
The above described manner of fastening the stationary disc or mill stone with
the small wall bracket, provides, without any alteration whatever, means for
fastening the stationary disc, and also the whole mill upon a pedestal or support
when it is not possible or desirable to fasten it to a wall.

page_text: Figure 3, is a plan of the same.”
which is stationary; the
these discs is as follows,
Figure 4 is a section on the line x, x, Figure 3.
Figures 5 to 16 are detail views hereinafter describe
The grinding parts consist of two discs a and
other one rotates. The mode of constructing the
that is to say, a number of strips, stamped or otherwise formed out of steel or
other suitable metal, are arranged alternately with somewhat narrower iron strips
in a groove turned out of a disc; the said strips are secured in the said groove by
means of rings u which overlap their extremities as shown in Figures 8 to 11. The
edges of the steel strips which stand above the edges of the iron strips differ with
regard to length and height whereby grooves are formed between the said steel
strips, the said grooves being wider and deeper at the centre of the disc than at
the circumference, that is to say two narrow grooves converge into one single
broader groove, and two of these broader grooves again converge into a groove still
broader, as shown in Figure 10. By reason of this arrangement coarse material
can come between the grinding faces of the discs without interruption. The
peculiarity of this construction is the application of stamped out strips, which are
made of the desired shape before insertion into the grooves of the discs, and the
manner of fixing the said strips and securing them by means of rings which
overlap their extremities.
When using thick steel-strips it is advantageous, after their faces are worn out,
to be able to use them again; for this purpose, the iron strips are provided with
notches, while the steel strips have not any. When the steel strips are worn, by
putting two rings v, v beneath the said steel strips, they can, after having been
sharpened, be raised according to the thickness of the said rings; the iron strips
are not raised, their notches being adapted to receive the rings v, v as shown in
Figure 11. In most cases it is preferable to use thin steel strips, instead of thick
ones, because of their greater cutting power; but the said thin steel strips are more
liable to be broken especially with deep grooves or furrows. To guard against
this the said thin strips are protected in the manner shown in Figures 12 and 13
where, instead of using single thick steel strips, several quite thin ones of the same
shape are put together with distance pieces between them, above which they
project only very slightly. Because of the very slight leverage thus afforded to the

page_text: projecting parts of the steel strips, they are prevented from breaking, and the depth
of the groove or furrow is not limited.
According as the quality of the material to be ground may require, strips may
be formed with more or less deep indents, or under certain circumstances without
any indents, but in all cases the thin steel strips must have their upper edges bent
or curved, where they project beyond the distance pieces, in order that they may
be able to exert a shearing action. The said indents are formed in the same manner
as the cuts of a file or otherwise suitably constructed.
It is advisable not to make the steel strips longer for larger grinding discs than
for those of smaller diameter; preferably, in the former case, the strips are arranged
in rows, as shown in Figure 15. This permits the inner row of strips which has to
break the grain or the like, to be made stronger or thicker, whereas the outer row,
which is meant to grind the grain quite out, can be composed of thin strips.
As a rule, the strips are only provided with indents on their upper edges, but in
order to obtain still better results than under those circumstances the said strips
are so arranged that a grinding action also takes place on the side of them. For
this purpose, on the cutting edges of the principal strips, one or more similar
strips are placed, the height of which decreases by steps (see Figures 12, 13). By
this means the cutting surface of the grinding groove gets also an effective
roughness on the side, as is the case with existing grindstones.
The same result is obtained when using thick strips, by providing their faces,
which form the cutting surface of the groove, with teeth like those of a file.
It is well known that the pressure, which the grain exerts against the runner,
under certain circumstances is very considerable; according to the present
invention this defect is removed, the pressure being taken by a roller, see Figures 1,
3, 4, which can be moved forwards and backwards by means of an arrangement of
levers h and a nut m whereby the grinding discs a, b, can be moved closer to, and
further from, one another, which movement has a direct influence on the quality of
the product.
The power required in grinding the different kinds of grain varies exceedingly.
Those materials which require a great expenditure of power run, as a rule, easily
through the grooves on the face of the discs and therefore require only a low
speed of rotation and inconsiderable centrifugal power of the said discs, while in
the case of light and dry substances which are easily ground the discs are required
to run much faster. The power at disposal for driving a mill is frequently very
variable, especially in the country; the same is the case in the transmission of
power by horse gears, or the like, for driving the mill.
As the power and effect are pretty nearly proportional to the speed of the
runner, it is necessary to be able to alter the number of revolutions of the latter
within rather wide limits. This is best effected as shown in Figures 1, 2, 3 and 4
by means of change-wheels
The grain supplied to the mill must be more or less sifted, and for this purpose
it is necessary to be able in an easy manner, and preferably while the mill is in
motion, to alter the number of strokes of the bolting apparatus. This is rendered
possible by the bolting apparatus shown in Figures 1, 2, 4, 5, 6 and 7 wherein a
ring r carries at different positions on its periphery a number of projections 2, s
arranged circularly. When the shaft w revolves these projections, push the bolting
screen backwards and then allow it to spring forwards. By means of a spiral
spring p, a counterweight or similar device, the screen is impelled against a fixed
buffer, and by this impulse the grain is carried forward on the screen.
The position of the ring r is regulated in the following manner, that is to say,
the pin i, which is pressed against the spindle w by a spiral spring, is raised, and
with it the loose collar 71; the cam-ring is then shifted as far under the catch of
the bolter as is required to produce a desired number of strokes (or blows). The
circular grooves n, n turned in the spindle w correspond with the number of rings
of teeth or tappets; on account of the pin i catching in these grooves n the tappet
or cam ring can be fixed in a suitable position

page_text: Having thus fully described the said invention as communicated to me by my
Foreign correspondent, and the manner of performing the same, I wish it understood
that I claim, in a grinding mill:-
First. The strips formed of steel as above described, and fixed, with narrower
iron strips, in turned grooves and held therein by overlapping rings, substantially
as, and for the purpose, set forth.
Second. The said steel strips constructed in such a manner that the top edges
of the same, which form the grinding surface, are cut or roughened like a file.
Third. The employment of rings for re-adjusting the grinding surface constructed
as above described, on which rings the said steel strips rest, while the said iron
strips have notches cut in their ends so that they will not rest on the said rings
but on the bottom of the turned grooves, substantially as described
Fourth. The guide-roller adapted to be moved backwards and forwards to shift
the two grinding discs nearer to, or farther from, one another, substantially as
described.
Fifth. The said steel strips arranged side by side, or supported by distance-pieces
of any desired material, in such a manner that the grooves or furrows may be as
deep as desired, while the cutting parts project very slightly beyond the supporting
material.
Sixth. The said steel strips bent or curved at their edges and formed with, or
without, teeth or indents, substantially as described.
Seventh. The employment of the change-wheels for the purpose above specified.
Eighth. The grinding discs provided with two or more rows of strips, substantially
as described.
Ninth. The additional strips arranged in steps on the cutting side of the main
strips, in order to give the cutting surface of the grinding groove an effective
roughness on the side thereof.
In Witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Twenty ninth day of December in the year of Our Lord
One thousand eight hundred and eighty two
117M DAPT TAVE