IMPROVEMENTS IN DISCS FOR GRINDING MILLS
Year: 1885

page_text: I, LOUIS GATHMANN, of the City of Chicago, County of Cook, State of Illinois,
United States of America, Manufacturer do hereby declare the nature of my
invention for "IMPROVEMENTS IN DISCS FOR GRINDING MILLS
" 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 the construction of the working faces of annular
grinding discs for grinding mills for reducing grain and similar material, and it is
more particularly intended to be applied to those mills known as Feed-mills in
which the grinding discs or rings are of chilled iron.
The objects and advantages, as well as the nature of my invention, will fully
appear from the following description.
In the accompanying drawing,
Figure 1 is a plan view of the working face of a disc (say the runner disc)
constructed in accordance with my invention.
Figure 2 is a similar view of the working face of the opposing disc when
both discs correspond.
Figure 3 shows opposing similar discs in central transverse section say on the
line x-x of Figure 2, but more widely separated from each other, obviously, than
when they are in working position.
Figures 4, 5, and 6 are sectional views of portions of opposing similar discs in
working position and drawn to an enlarged scale.
A is, say, the runner disc, and B is the opposing and commonly stationary disc.
CC are a series of concentric, annular V-shaped ribs on the inner portion of the
face of each disc, which ribs alternate with corresponding ribs on the opposing
disc, so that when the discs are brought into proximity, the said ribs of one disc
enter the opposite and similarly shaped grooves C' of the other. Exterior to these
interfitting ribs and grooves C C¹, and upon each disc is a series of other annular
V-shaped ribs c and intervening grooves c¹, which are both narrower and more
shallow than the inner ribs C and grooves C¹.
I prefer that the outer ribs c of one disc shall oppose the corresponding grooves
of the opposite disc, as shewn in Figures 5 and 6, but it will be within the scope of

page_text: my invention if the ribs oppose each other as shown in Figure 4, said outer ribs
and grooves being so small that it is not material.
A characteristic of my invention is that the apices of the outer series of ribs o-
or the prominences of any other form of dress there employed, will be lower than
that of the apices of the inner ribs C, at least upon one disc, and I prefer that the
difference in elevation shall be substantially the same, or nearly so, in both discs,
as shown in Figure 6.
In operation the opposite discs are set to proximate each other to such a degree
as may be required for a particular quality of work to be done, as in the case of
other forms of dress.
DD are inner, tapering, feed furrows formed on a suitable draft and preferably
in each disc, and having their advanced faces (reference being had to the direction
of motion) perpendicular to the disc face, or proximately so, and their rear faces
inclined. These feed furrows extend across and cut the inner ribs and grooves C
and C. They may be all of one size or of different sizes, as preferred.
Traversing the outer ribs and grooves c c¹ are other furrows d, also having
similar abrupt front, and inclined rear faces, but smaller than the furrows D, and
preferably of the same depth as the annular grooves which they intersect. These
feed furrows D, d cut the ribs C, c into short sections having V-shaped abrupt
ends.
By reason of the inter-current arrangement of the ribs and grooves C and C¹³,
it is evident that the grain passing outward from the central feed opening, or eye
of the disc or discs, through the feed furrows D, will be caught between the
abrupt ends of the ribs C of the opposing discs, and will be cut or broken into
fragments.
These fragments, or the larger of them, will be carried along in the grooves C¹
till they reach the next feed furrow, where they will be released and be forced
further outward to be again caught and again reduced in the same way as before.
Reaching the furrows d they are further cut and reduced between the opposing
abrupt ends of the ribs c, and are swept along in the grooves till they reach other
feed furrows and so pass finally out from between the discs.
To facilitate the prompt discharge of the ground product, recesses E E are,
desirably, provided at intervals about the margin of the runner disc A, at which
recesses the outermost grooves c¹ terminate and discharge.
By reason of the intersecting arrangement of the feed-furrows d and grooves c¹,
some part of the material will tend to pass out through the furrows while other
parts will pass along the grooves, and this separation of the parts prevents massing
and clogging of such material in either class of passages. The recesses E still
further favor this result by affording prompt discharge of the material at these
points.
It is to be understood that the construction of the interfitting ribs C and
grooves C¹ intersected by the inner feed-furrows D, may be employed with any
suitable form of exterior dress in place of the ribs and grooves c c and, generally
I desire it to be understood that such modifications of the devices described as
shall attain one or more but less than all the results obtainable from my improve-
ment as set forth, shall not be regarded as departures from my invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
First. Two opposing grinding discs provided upon the inner portions of their
working faces with series of interfitting concentric ribs and grooves intersected by
tapering feed furrows; and upon the outer portions of their faces with smaller and
less elevated annular ribs and grooves also intersected by feed-furrows, substan-
tially as described.

page_text: Second. In a pair of opposing grinding discs, a form of dress comprising a series
of inner ribs C and grooves C¹ intersected upon one or both of the discs by
suitable deep feedfurrows D, the apices of the said inner ribs on one of the discs
being more elevated than the outer dress of the disc, substantially as described.
Third. In a pair of opposing grinding discs, a form of dress comprising a series
of inner ribs C and grooves C₁ intersected upon one or both of the discs by
suitable deep feed-furrows D, the apices of the said inner ribs on both discs being
more elevated than the outer dress of the disc, substantially as described.
Dated this 2nd day of November 1885
HASELTINE, LAKE & Co.,
For the Applicant.