Improvements in Grinding, Crushing, and similar Machines.
Year: 1898

page_text: Date of Application, 5th July, 1898-Accepted, 29th Apr., 1899
Improvements in Grinding, Crushing, and similar Machines.
I, CARL HOFMANN, of 66, Klosterstrasse, Breslau, in the German Empire, Merchant,
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 grinding, crushing, and similar machines of the ball and
ring type, and its object is to improve the efficiency of such machines.
In a machine constructed to embody these improvements, the balls are preferably
oval and have an oscillatory motion imparted to them in addition to their rotary
motion around the ring.
The accompanying drawings illustrate a machine constructed according to this
invention.
Figure 1 illustrates the machine in longitudinal section.
Figure 2 shews it in plan.
Figures 3, 3, 4 and 5 are representations of the devices for imparting oscillatory
motion to the balls.
Figures 6 and 7 are respectively a plan and a side elevation of the mechanism
whereby the speed of the machine may be varied. This mechanism is also shown in
front elevation in Figure 1.
Referring to Figures 1 and 2, a represents the ring in which the material to be
crushed is placed. b is a vertical rotary shaft carrying the four projecting arms c,
the outer extremity of each of which is furnished with a pivotted link or arm & capable
of moving towards or away from the central shaft b. The lower ends of the links d
are movably secured to the cups or shells f which loosely contain the balls e. As
shown, these balls are preferably oval. The cups f are so connected to the links & at
the points g that they may give way and enable the balls to surmount and pass any
unusual obstacles contained within the ring.
The device for causing the balls to oscillate across the ring during their rotation
therein, is illustrated most clearly in Figure 3. A grooved cam h surrounds the
shaft 6 and with the groove are engaged the bowls i, 1, 2, 3, which are carried by
the arms k. These arms are suitably jointed in their lengths and are connected to
the links d. Thus, upon the rotation of the shaft b, the arms c and the balls e are
carried round the ring a and cause, also, the rotation of the arms k. These latter, by
their engagement with the grooved cam are also reciprocated, and cause the oscillation
of the balls across the ring.
The cam h may be either fixed or caused to rotate slowly, the latter being preferred,
as with a stationary cam the balls would always move across the ring at the same
points and unequal wear would result. With a slowly rotating cam, however, all parts
of the ring will be equally worn.
The devices by means of which the desired rotation of the cam may be effected,
are shown in Figures 3ª, 4 and 5. Fixed to the shaft b is a sleeve the lower part of

page_text: which is formed into or is provided with a disc or plate m carrying the pinion o. This
pinion gears with internal teeth formed within a surrounding casing n, and also with a
wheel P which is free to rotate upon the sleeve l. This wheel is in one piece with a
bevel wheel q which in turn gears with a bevel wheel r to which the pinion & is
secured. This pinion engages with the wheel t which is provided with an additional
projecting tooth u. This tooth is adapted to come intermittently into contact with
the pinion which is mounted in a plate secured to the upper end of the sleeve l, and
engages with the wheel w secured to the groove cam h. The pinion v is thus carried
round by the plate in which it is supported and rotates idly by its engagement with
the wheel w until it comes into contact with the tooth u on the wheel t. The
pinion v is then held and forms a rigid connection between the wheels t and w, so
that the cam is carried round with the sleeve until the tooth u is disengaged from
the pinion v, when the cam again becomes stationary, and the pinion resumes its idle
rotation. The cam may be held in its stationary position by springs or equivalent
frictional or other suitable devices. In this manner a slight angular motion is
imparted to the cam during the working of the machine.
The improved machine may also be furnished with mechanism for automatically
increasing its speed as the crushing or grinding progresses. A form of apparatus
which may be employed is represented in Figures 1, 6, and 7. The main driving
shaft is provided with fast and loose pulleys of the usual construction and with
a coned pulley x¹. From this latter pulley a belt 3 passes to and around the
inversely coned pulley x2 mounted upon the shaft y the end of which carries the
bevel wheel y for driving the machine. The belt passes through the belt
fork the lower end of which is formed with an extension x5. The boss or
support of the belt fork is mounted upon and is capable of sliding along the
square shaft . Connected to the boss is the partial or half nut capable of
engaging with the rotary screw x, by the rotation of which the boss and the
strap fork may be moved along the shaft x. The belt is thus moved along the coned
pulleys as the grinding proceeds, the movement being in such a direction as to
increase the speed of the machine. 10 is a guide bowl attached to the belt fork.
The screwed shaft may be rotated by means of a chain or the like from the main
shaft x.
When the belt reaches the end of the coned pulleys the machine is auto-
matically stopped.
To return the belt to the other end of the pulleys a slight angular motion is given
to the square shaft by means of the rod 2 and the lever 2¹. By this motion the half
nut is moved away from the screwed shaft and the belt fork is free to move along
the square shaft. A rack 22 is arranged in gear with a pinion to which is attached a
reel or drum having wound around it the cord or chain z³. One end of this cord is
attached directly to the belt fork and the other end passes around a pulley on the
opposite side of the mechanism and is then in turn also attached to the fork. The
rotation of the drum in one direction will draw the fork towards it, and its rotation in
the other direction will cause the fork to move away. The rotation of the drum in
the required direction may be effected by raising or depressing the rack 2².
The dotted lines in Figure 7 show the positions of the various parts when the belt is
free to be inoved from one end of the pulleys to the other. The extension 5 of the
fork is now in engagement with the belt, and the bolt 10 which has before served to
maintain tension in the belt, has now left it so that the belt is slack.
The links & or the cups or casings f may advantageously be additionally connected
to the arms c by means of chains or the like.
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
1. A crushing, grinding, or similar machine, of the ball and ring type, in which the
balls have an oscillatory motion imparted to them by means of the mechanism set
forth, in addition to their rotary movement around the ring, all constructed arranged

page_text: and operated substantially as hereinbefore described and as illustrated by the
accompany drawings.
2. In a crushing, grinding, or similar machine of the type set forth, means or
devices for imparting an oscillatory movement to the balls during their rotation,
constructed arranged and operating substantially as hereinbefore described and as
illustrated by the accompanying drawings.
3. A grinding, crushing, or similar machine, constructed and arranged substantially
as herein before described and as illustrated by the accompanying drawings.
Dated Gais 4th day of July A.D. 1990.
W. E. HEYS & SON,
Agents for the Applicant.
W. E. HEYS & SON,
Agents for the Applicant.