An Improved Ball-mill for Pulverizing or for Mixing and Pulverizing.
Year: 1893

page_text: Date of Application, 14th Nov., 1893
Complete Specification Left, 15th Jan., 1894-Accepted, 3rd Mar., 1894
PROVISIONAL SPECIFICATION.
An Improved Ball-mill for Pulverizing or for Mixing and
Pulverizing.
:1.
1 MEYER JOSEPH DAVIDSEN of 144 Boulevard de la Villette, Paris, Civil
Engineer do hereby declare the nature of this invention to be as follows:-
My invention relates to a mixing and grinding machine of continuous and
uninterrupted feed and discharge. It consists of a tube, horizontally placed on
bearings, in such a manner that it can be set in motion, revolving on its own axis
and half filled with balls which roll freely in the interior of the tube.
A feature in my construction is that there is no internal shaft, and that the inner
surface of the tube is smooth. The balls then act mainly by friction and not by
blows, by which a very uniform and quiet working is attained, and by the abscense
of the internal shaft, it is possible to keep the tube half full of balls, whereby the
best economy and the greatest output are gained.
The stuff to be treated is introduced in the centre of the tube at one end and
the finished powder is discharged at the other end at the periphery. An overcharge
of the apparatus, so that the stuff would rise above the level of the balls, is thus
impossible, and only a small quantity of stuff is in the tube at a time, which small
quantity of stuff is treated by a large quantity of balls, so that a quiet and thorough
pulverization and an exceedingly intimate mixing are attained. Every particle
must pass the whole length of the tube before being discharged and it can not
escape the pulverizing action of the balls. The use of sieves is consequently
unnecessary and soft materials not suited for sifting can therefore be ground in
this way. Besides, it is possible in this way to mix and grind together different
stuffs of unequal density.
Fig. 1 in the accompanying drawing shows the simplest form of this apparatus.
It consists of a drum a, resting on pivots at both ends. One of these pivots is
hollow, and through this the feed is effected. At the other end the cylinder has a
number of discharge holes, on the periphery, smaller than the balls used for
grinding. Through these holes & the finished powder leaves the mill.
:
The tube is always kept half full of balls, and the turning of it is effected by a
driving gear with cogwheels.
Figure 2. shows another way of placing the tube. Instead of pivots, roller
bearings are here used. In this case the driving can be effected direct through
one of the supporting rollers, and the discharge can take place through a circular
grate d as shewn..
In Figure 3 the tube is conical. The material is introduced at the narrow end,
and moves at a quicker speed towards the discharge openings at the periphery
of the wider end. In this case a combination of pivot and roller-bearing is
shewn.
In such cases where the material to be treated is of a very wearing nature or
where it is of importance that it should not come in contact with iron the interior
of the tube can be fitted with a protecting cover. This can be made of iron, steel,
stone, wood, china or baked clay. The balls can in a like manner be made of these
or other materials.
Dad thin 14th dow of Navambou 1992

page_text: An Improved Ball-mill for Pulverizing or for Mixing and
Pulverizing.
MEYER JOSEPH DAVIDSEN 144 Boulevard de la Villette, Paris 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 :-
My invention relates to a mixing and grinding machine of continuous and
uninterrupted feed and discharge. It consists of a tube, horizontally placed on
bearings, in such a manner that it can be set in motion, revolving on its own axis,
and half filled with balls which roll freely in the interior of the tube.
A feature in my construction, is that there is no internal shaft, and that the
inner surface of the tube is smooth. The balls then act mainly by friction, and
not by blows, by which a very uniform and quiet working is attained, and by the
absence of the internal shaft it is possible to keep the tube half full of balls,
whereby the best economy and the greatest output are gained.
The stuff to be treated, is introduced in the centre of the tube at one eud and the
finished powder is discharged at the other end at the periphery.
An overcharge of the apparatus, so that the stuff would rise above the level of
the balls, is thus impossible and only a small quantity of stuff is in the tube at a
time, which small quantity of stuff is treated by a large quantity of balls, so that
a quiet and thorough pulverization and an exceedingly intimate mixing are attained.
Every particle must pass the whole length of the tube before being discharged, and
it can not escape the pulverizing action of the balls. The use of sieves is
consequently unnecessary, and soft materials, not suited for sifting, can therefore
be ground in this way. Besides, it is possible in this way to mix and grind together
different stuffs of unequal density.
Fig. 1. in the drawing accompanying my Provisional Specification, shows the
simplest form of this apparatus. It consists of a tube or long drum a resting on
pivots at both ends. One of these pivots is hollow, and through this the feed is
effected. At the other, ênd the drum has a number of discharge-holes, on the
periphery, smaller than the balls used for grinding. Through these holes d, the
finished powder leaves the mill.
The tube is always kept half full of balls, and the turning of it is effected by a
driving gear with cogwheels.
Figure 2 shows another way of placing the tube. Instead of pivots, roller-
bearings are here used. In this case the driving can be effected direct through
one of the supporting rollers, and the discharge can take place through a, circular
grated as shewn.
$
In Figure 3 the tube is conical. The material is introduced at the narrow end,
and moves at a quicker speed towards the discharge openings at the periphery
of the wider end. In this case a combination of pivot and roller-bearing is
shewn.
In such cases where the material to be treated is of very wearing nature or
where it is of importance that it should not come in contact with iron, the interior
of the tube can be fitted with a protecting cover. This can be made of iron, steel,
stone, wood, china or baked clay. The balls can in a like manner be made of
these or other materials.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
A tubular mill for the continuous reduction or grinding of various materials,

page_text: consisting of an horizontally placed tube or long cylinder or cone revolving on its
own axis, suspended on pivots at both ends, or on roller-bearings, which can be
used as means of transmitting the driving power, or on pivot and rollerbearing
combined, but without any central shaft, and with smooth inside surface, by which
construction is attained, that the tube can be worked half full of loose balls, and
the stuff to be treated is pulverized by friction, and can be fed in continuously at
the centre of one end, and the finished powder be discharged continuously at the
periphery of the other end.
Dated this 15th day of January 1894.