Improvements in Apparatus for Grinding Substances.
Year: 1888

page_text: Date of Application, 6th Jan., 1888
Complete Specification Left, 4th Oct., 1888
Complete Specification Accepted, 5th Jan., 1889
Improvements in Apparatus for Grinding Substances.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern and Co., the General
Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex, Patent
Agents, do hereby declare the nature of this invention (a communication from abroad
by Marc Raty and Emile Lambert, both of Saulnes, in the Republic of France,
Engineers) to be as follows:-
This invention relates to that class of grinding apparatus in which loose balls or
the like are employed for grinding or crushing the substances, the object being to
cause the said substances to travel horizontally through the apparatus at a speed
varying with the hardness of the substances and the degree of fineness which it is
required to obtain.
In most existing apparatuses of this class the introduction and discharge of the
substances is effected intermittently and a stoppage of the apparatus is therefore
necessary if it is provided with doors operated by hand; or mechanism is employed
for opening these doors while in operation as well as an Archimedean screw for
feeding through the centre if the apparatus is continuous in its action, but the feed.
and discharge of the substances is intermittent. The only grinding apparatuses in
which there is a continuous feed of the substances are centrifugal machines, bolting
mills or grinders and grinding apparatus in which a blast of air is employed. These
apparatuses however are of complicated construction and are costly to keep in repair..
very small product results from them and for many purposes they are useless, such
for example as for rendering some substances homogeneous.
A
In carrying out this invention the apparatus comprises a cast iron cylinder the
inner surface of which is corrugated. The substances to be ground are introduced
continuously through a channel at one end of the cylinder and are continuously
discharged through openings made in the other end of the cylinder near the periphery
thereof, the said openings being smaller than the crushing-balls or the like; or hollow
arms provided with gratings can be employed for a like purpose the discharge then
taking place through the centre.

page_text: The cylinder is horizontal so that the balls are
its whole length.
always regularly distributed over
As the ground substance is discharged through the discharge openings its place is
filled by the following portion of the substance and the spaces between the balls is
always evenly filled up. It follows therefore that during the rotation of the cylinder
a removal takes place at the interior of the mass of the balls from one end to the
other of the apparatus. The larger the quantity of the substance fed to the cylinder
the more rapid will this movement be, so that for a given speed and length of
cylinder the fineness to which the substance is reduced will depend solely on the
quantity regularly introduced and on the number of the balls.
It has been found advantageous to employ a number of these apparatuses driven by
a shaft and two bevel wheels. An Archimedean screw conducts the substanco
(granulated slag or cement for example) to be ground from a receiver and distributes
it into the several apparatuses. A similar screw receives the ground product and
conducts it away.
In order to prevent the balls and substance in the cylinder from passing out
through and obstruoting the admission opening the feeding channel communicates
with the interior of the cylinder through curved passages formed by arms arranged
tangentially to the shaft of the cylinder. A small self-closing door allows of adding
to or withdrawing the balls as desired..
Dated the 6th day of January 1888.
G F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant,

page_text: Improvements in Apparatus for Grinding Substances.
I, GEORGE FREDERICK REDFERN, of the, firm of G. F. Redfern & Co., the General
Patent Office No. 4, South Street, Finsbury in the County of Middlesex, Patent
Agents, do hereby declare the nature of this invention (a communication from abroad
by Marc Raty and Emile Lambert, both of Saulnes, in the Republic of France,
Engineers,) 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 that class of grinding apparatus, in which loose balls or the
like are employed for grinding or crushing the substances, the object being to cause
the said substances to travel horizontally through the apparatus at a speed varying
with the hardness of the substances and the degree of fineness which it is required to
obtain.
In most existing apparatuses of this class, the introduction and discharge of the
substances is effected intermittently and a stoppage of the apparatus is therefore
necessary if it is provided with doors operated by hand; or mechanism is employed
for opening these doors while in operation as well as an Archimedean screw for feeding
through the centre if the apparatus is continuous in its action, but the feed and
discharge of the substances is intermittent. The only grinding apparatuses in which
there is a continuous feed of the substances are centrifugal machines, bolting mills or
grinders and grinding apparatus in which a blast of air is employed. These
apparatuses however are of complicated construction and are costly to keep in repair.
A very small product results from them and for many purposes they are useless, such
for example, as for rendering some substances homogeneous.
In order to enable the invention to be fully understood, I will describe how it can
be carried into effect by reference to the accompanying drawing, in which
Figure 1 is a longitudinal section of an apparatus for grinding various substances
and constructed according to my invention.
Figure 2 is a cross section on line A B of figure 1, and
Figures 3 and 4 are similar views on lines Ć D and E F respectively of
figure 1.
In carrying out this invention, the apparatus comprises a cast iron cylinder the
inner surface of which is corrugated. The substances to be ground are introduced
continuously through a channel L K at one end of the cylinder and are continuously
discharged through openings P, P, P made in the other end of the cylinder near the
periphery thereof, the said openings being smaller than the crushing-balls or the like. Or
hollow arms, provided with gratings, can be employed for a like purpose, the discharge
then taking place through the centre.
The balls have no movement of translation in the cylinder. If for example 800
kilogrammes of balls be employed, the rotating movement of the cylinder, which is
placed horizontally, will spread them out or distribute them uniformly throughout the
whole length thereof.

page_text: If the substance to be ground be introduced at one end of the cylinder, it will mix
with the balls and will also become evenly spread over the whole length.
The openings P, P, P are too small to allow the balls to pass out and sufficiently
large to allow the ground material to pass out, so that in the interior of the pile of balls
near the openings P, P, P, that is to say, towards the outlet of the cylinder the
substance is more completely ground than that near the admission end.
The rotation of the cylinder produces a continuous mixture of the balls with the
substance and this alway tends to fill with the said substance the spaces between
the balls throughout the whole length.
The
It follows therefore that during the rotation of the cylinder a movement of translation
of the mass therein, takes place through the balls from one end to the other of the
apparatus whilst the balls themselves have no such movement of translation.
larger the quantity of the substance fed through the channel L K to the cylinder the
more rapid will this movement be, so that for a given speed and length of cylinder,
the fineness to which the substance is reduced will depend solely on the quantity
regularly introduced and on the number of the balls.
The openings P, P, P are of any suitable shape provided as before described they
are smaller than the balls and placed opposite the admission end of the cylinder either
on the periphery, on the bottom, or on the herein before mentioned hollow arms.
It has been found advantageous to employ a number of these apparatuses driven by
a shaft and two bevel wheels R, S. An Archimedean screw M conducts the substance
(granulated slag or cement for example) to be ground, from a receiver and distributes
it into the several apparatuses. A similar screw N receives the ground product and
conducts it away.
In order to prevent the balls and substance in the cylinder from passing out through
and obstructing the admission opening K, the feeding channel communicates with
the interior of the cylinder through curved passages G, G, G, G, formed by arms
H, H, H, H, arranged tangentially to the shaft of the cylinder. A small self-closing
door O allows of adding to or withdrawing the balls as desired, introducing the key
which fastens the cross bar on the shaft, and of inspecting the interior.
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 :-
The improved grinding machine hereinbefore described and illustrated in the
accompanying drawing.