Improvements in Mills for Grinding, Crushing, Pulverising, and the like.
Year: 1898

page_text: Date of Application, 7th Nov., 1898
Complete Specification Left, 17th July, 1899-Accepted, 2nd Sept.,
1899
PROVISIONAL SPECIFICATION.
Improvements in Mills for Grinding, Crushing, Pulverising, and the
like.
I, HOLBROOK GASKELL, Junr., of Clayton Lodge, Aigburth, Liverpool, in the
County of Lancaster, Gentleman, do hereby declare the nature of this invention
(which has been communicated to me from abroad by Messrs. Propfe, of Bern-
wardstrasse, Hildesheim, in the German Empire) to be as follows:-
This invention relates to improvements in mills of the centrifugal type for
grinding, crushing, pulverising and the like in which sets of rollers are con-
structed to be set in a circling motion about vertical axes. by centrifugal force.
In such mills it is necessary that the rollers should be secured against vertical
displacement by their own weight and against horizontal working strains, both
these tendencies resulting in a two-fold friction viz.:-friction between the
bottom surface of the roller and the surface of its seat, and friction between the
perforation (or bore) of the roller and the pivot (or spindle) whereon it revolves.
The object of the present invention is to reduce to a minimum this two-fold
friction.
According to this invention between the bore of the roller which I will refer
to as the main roller and the spindle on which it revolves there is provided a
ring or set of cylinders or rollers, or a number of rows (or tiers) of balls, which
reduce the friction arising from horizontal forces; while between the bottom
surface of the main roller and the surface of its horizontal seat or bearing, a set
of anti-friction balls are anged circumferentially so as to take up the vertical
pressure resulting from the said main roller's own weight.
The friction which this arrangement still permits is so slight, that any increase
of friction-however small in itself-will make itself felt in an objectionable
manner.
Thus, for example, the effect of the friction exercised by the bottom surfaces
of the aforesaid anti-friction cylinders or rollers-which it will be understood
is not a rolling but a sliding friction-is clearly perceptible. To counteract
this defect the surface on which these cylinders or rollers are supported is largely
reduced (say by being removed or hollowed out in a lathe) so that only a narrow
annular strip of surface is left, sufficient to supply the necessary support for the
rollers or cylinders while leaving only a narrow path for friction. The same
result would be attained by forming this annular strip at the inner edge of the
original supporting surface, or in the centre thereof.
Or instead of narrowing down the aforesaid supporting surface the lower ends
of the cylinders or rollers may be tapered conical or rounded off in such a manner
as to reduce the friction at their bearing surfaces.
Again, the friction at the supporting surface may be reduced by supporting
the several cylinders or rollers on balls the diameter of which must be sufficiently
small that each roller or cylinder may rest upon the topmost point of one or
more balls, or cylindrical bearing surfaces may be arranged radially.

page_text: Or the rollers or cylinders instead of being supported within the body of the
main roller as aforesaid may extend below such body so as to rest upon the
supporting or bearing surface of the main roller itself.
Dated this 7th day of November 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
.
COMPLETE SPECIFICATION.
Improvements in Mills for Grinding, Crushing, Pulverising, and the
⚫ like.
I, HOLBROOK GASKELL, Junior, of Clayton Lodge, Aigburth, Liverpool, in
the County of Lancaster, Gentleman, (a communication from Messrs. Propfe,
of Bernwardstrasse, Hildesheim, in the German Empire) 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 improvements in mills of the centrifugal type for
grinding, crushing, pulverising, and the like, in which sets of rollers are arranged
so as to revolve about a vertical axis and act by centrifugal force. In such
mills it is necessary that the rollers should be secured against vertical displace-
ment by their own weight, and against horizontal working strains, both these
tendences resulting in a two-fold friction, viz. friction between the bottom
surface of the roller and the surface of its seat, and friction between the perfora-
tion, (or bore), of the roller and the pivot, (or spindle), whereon it rotates. The
object of the present invention is to reduce, to a minimum, this two-fold friction.
I will describe the invention with reference to the accompanying drawing.
According to the said invention, between the bore of the roller M, and the
spindle L, there is provided a circular series, or set, of cylinders, or rollers, A,
(or a number of rows; or tiers, of balls), which reduce the friction arising from
horizontal forces; and between the bottom surface of the roller M, and the
surface of its seat W, anti-friction balls K, are arranged circumferentially, so
as to receive the vertical pressure resulting from the weight of the roller M,
as shewn in Figure 1.
The friction which this arrangement still permits is so slight that any increase
of friction however small in itself will make itself felt in an objectionable
manner.
Thus, for example, the effect of the friction exercised by the bottom surfaces
of the cylinders, or rollers, A, which it will be understood is not a rolling, but
a sliding, friction, is clearly perceptible. To counteract this the surface on
which the ends of the said cylinders, or rollers, A, bear is largely reduced in
any suitable way, (say by being removed in a lathe), so that only a narrow
annular strip of surface is left, (as shewn at X in Figures 2 and 3), to afford the
necessary support for the said rollers, or cylinders. A, whilst leaving only a very
small frictional surface. The result can be attained by forming this annular
strip in any suitable position, for example, at the outer edge of the original
supporting surface, as shewn in Figure 1, or at the inner edge of the original
supporting surface, as shewn in Figure 2; or in the centre thereof as shewn in
Figure 3.
Or instead of narrowing down the supporting surface the lower ends of the
cylinders, or rollers, A, can be coned, or tapered, or rounded off, in such a
manner as to reduce the frictional surface, as shewn in Figure 4. Or the
friction at the supporting surface may be reduced in the manner illustrated

page_text: in Figure 5 and in Figure (which latter figure is a devolopment of the
cylindrical arrangement Figure 5).
In the arrangement shewn in these figures, the cylinders, or rollers, A, are
supported by balls u, the diameter of which must be such that each roller, or
cylinder, A, will rest upon the topmost point of one ball, or more than one ball.
Or the rollers, or cylinders, A, instead of being supported within the body of
the main roller, M, may extend below such body and rest upon the seat W, as
shewn in Figure 7.
The antifriction cylinders, or rollers, and balls, should of course be of iron, or
steel, or equivalent, or sufficiently hard material.
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: -
1. In mills for grinding, crushing, pulverizing, and the like; antifriction
cylinders, rollers, or balls, to receive the pressure exercised at right angles to
the axis of rotation of the grinding, crushing, or pulverizing, roller, and ball
bearings to receive the axial pressure due to the weight of the grinding crushing,
or pulverizing, roller; substantially as herein before described.
2. In an arrangement according to the preceding claim, a seat, or supporting
surface, for the ends of the antifriction cylinders, or rollers; the said surface
being limited by the removal of part of the actual seat, or by tapering, or reducing,
the ends of the said antifriction cylinders, or rollers, so as to reduce the contact
surface between the said ends and the said scat; substantially as hereinbefore
described.
3. In an arrangement according to the preceding first claim the interposition
of balls, such as u, between the ends of the antifriction cylinders, or rollers, and
the bearing surface; substantially as herein before described.
4. In mills for grinding, crushing, pulverizing, and the like, the several
arrangements for reducing friction, as herein before described and illustrated in
the accompanying drawings.
Dated the 17th day of Tule 1900
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.