Year: 1888

page_text: I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, and 323 High Holborn, in the County of Middlesex,
Civil 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 :-
The following is the specification which has been forwarded to me with instructions
to file.
The invention is best described by aid of the accompanying drawings, in which,
Figure 1 is a plan of the bedstone or grinding disc of the mill.
Figures 2 and 3, sections through mill stones or grinding discs constructed in
accordance with the invention.
Figure 4 a vertical section of a mill with discs having their faces placed vertically.
Figure 5 an end elevation of a mill with discs having their faces placed vertically.
Figure 6 a vertical section partly in elevation of a mill having discs with their faces
placed horizontally.
The apparatus as seen on the drawings consists of two metallic grooved grinding
discs A and B placed one above the other. One of them is, as shown on Figure 1,
provided with an opening or eye C for the introduction of the material to be ground.
The size of this eye varies according to the hardness of the substance to be ground,
the quantity and also the diameter of the discs, the latter varying in proportion to the
power available for driving the mill. The eye has for this very reason its axis placed
more or less near the centre of the disc and shaft. There are in the disc furrowed
depressions D, the pitch or coarseness of said furrows is greatest at the centre and
decreases towards the outside. The other disc B is solid and of a more regular form,
J

page_text: it is provided with furrows, the pitch of which also decreases as they proceed towards
the outside. The furrows becoine more numerous towards the outside, but at the
same time their depth decreases. As a matter of course the depth and the obliquity
vary according to the substances to be ground, erushed or pulverized.
One feature of the invention consists in drawing the substance to be ground into
depressions or cavities in the furrowed face of the discs, each time said depression or
depressions pass the eye or aperture of the bed disc. These depressions are provided
with furrows, some of which are directed obliquely towards the centre, and grind the
material into large pieces, and then deliver it to branch furrows, which grind it still
more, throw it towards the periphery of the central portion of the disc enclosed within
the dotted lines shown on the drawings, which completes the grinding and triturates
the material to the degree of fineness required. The degree of fineness is obtained
by bringing the grinding stones nearer to, or further apart from each other, this is
effected rapidly (even whilst the apparatus is at work) by means of the screw
regulator E.
The furrows (Figure 1 and Figure 2 which is a section through F G) are deepest
at H, and reach their mean depth at I and at J, Figure 1, they are in the same plane
as the grooves of the annular part outside the dotted circle aforesaid. By omitting,
in Figure 2, the hole through which the material is introduced, a section is obtained
of the runner B with an odd number of hollows, that is to say, the diameter passing
through it, meets on one side of the centre the greatest depth H and on the other
side of this centre a mean depth I, this resulting from an uneven division. When
the number of hollows is even, such as 2, 4, 8. etcetera, the diameter passes through
the deepest places, and the perpendicular to this diameter passes on the contrary
through the places where the points of the periphery of the central depressed portion
of the disc are on the same plane as the points of the external annular surface
thereof.
The mill stones are placed in a circular box or casing K, Figures 4 and 6
provided with a spout L for delivering the ground material. One mill stone is placed
against the lid M of the case outside which a hopper N is applied. The other mill
stone is placed on a revolving plate O. This plate forming a rynd is poised upon the
driving shaft P so that the runner finds its adjustment on the other stone. These
mill stones can be placed with their faces vertical as shown on Figure 4 or with
their faces horizontal as shown on Figure 6, but then the runner must be provided
with scrapers U or rakes or brushes to collect and discharge the ground material.
One feature of the machine, when the stones are placed with their faces vertically,
is that the material can be introduced at or near the centre of the stones, because
the driving shaft P does not pass through the stones nor through the cover M. The
lid is fixed by means of wing nuts Q, the cover can be removed and stones taken
out for cleaning or changing very quickly. The most inexperienced workman can
attend to the mill. It can, owing to its form, be mounted on columns, timber
supports, a floor, a bolting mill or any other object. It can be provided at its upper
part with a simple hopper R, Figures 5 and 6, or with one having a rocking sieve S,
it can also be provided, if necessary, with an aspirator. It can be actuated by a
pulley, by tooth wheel gearing, by hand or by an engine, the difference of speed
having no appreciable influence upon the working and regularity of the grinding
process. Several sets of mill stones may be provided, if desired. The furrows shown
on Figure 1 are most suitable for wheat, rye, barley, winter barley etcetera. For
oats, the eye is larger and the furrows further apart. For oil cake the depressions
are deeper, the eye larger. For malt and analagous substances the eye is larger,
the hollows deeper, the furrows finer and so on. To grind or crush oily or other
liquid substances, a tight joint may be made at T.
Owing to a great part of the grinding action being at the centre, a greater quantity
of ground material is obtained by the machine than was obtainable heretofore with a
larger surface motive power.
Attrition is effected gradually, but owing to the small time the material remains in
the mill it does not get heated.

page_text: In the drawings both the mill stones, namely the lid stone and the runner,
Figures 1, 2 and 3 have double surfaces for guiding, that is to say, there are furrows
on both sides. The central portion of the runner corresponding to the space within
the dotted line, Figure 1, can be provided with fine or coarse furrows which may
be straight or curved. The furrows may be in the same plane as the annular section
or provided with hollows or depressions. The mill stones can be hollow, convex or
conical without altering the nature of the invention.
By this invention several kinds of material may be ground with one pair of
stones.
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 by my foreign correspondent, I declare that what I claim is :-
1. A mill for grinding, crushing, or pulverizing etcetera, in which one of the
furrowed mill stones has depressions or hollows on its grinding surface or surfaces,
to which the material to be ground is fed through a feeding bole or aperture in
one of the stones which is placed eccentrically to the centre of rotation, substantially
as described.
2. In a mill such as described, the use of furrowed mill stones having depressions
or cavities in their grinding surfaces into which the material is drawn and broken
up into large pieces, then delivered into branch furrows in which the material is
ground or pulverized to the degree of fineness required, substantially as set forth.
3. In a mill with vertical grinding surfaces, the means employed for feeding the
material to the grinding faces substantially as described with reference to Figure 4.
4. In a mill with vertical grinding surfaces, the means employed for securing the
driving spindle to the revolving mill stone without passing it through either of the
stones, cover or feed channels, which consists in the rynd plate o or its equivalent
supported on the end of the spindle P, and attached to the mill stone B, substantially
as described.
5. In grinding mills, the use of mill stones with furrowed surfaces on both sides,
and formed with or without hollows or depressions, substantially as described.
ليوم
1000
WM. P. THOMPSON & Co.,
Agents for the Applicant.