Improvements in Machinery and Apparatus for Grinding or Crushing Mineral, Vegetable, and Animal Substances.
Year: 1890

page_text: Date of Application, 24th Nov., 1890
Complete Specification Left, 24th Sept., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Machinery and Apparatus for Grinding or Crushing
Mineral, Vegetable, and Animal Substances.
WILLIAM HENRY THOMPSON 155 Fenchurch Street London Engineer do
hereby declare the nature of this invention to be as follows :-
The object of my invention is the improvement of machinery and apparatus in
which the crushing or pulverizing is effected by means of the centrifugal force of
a ball driven or round a circular track by means of two oscilating discs or flexible
drivers or driver Whereby each of the said disc impelling the balls have a seperate
and independent motion imparted to it so as to give the ball a movement on two
axis or to work it so as to insure a better presentation of its surface to the work
and further arrangement for more readily fitting and adjusting dises having wearing
surface on both faces also means of more readily holding and adjusting the screens
or screen frames and gaining access to the wearing or working parts the better
arrangement and protection of the bearing and distribution of the substance under
operation.
In carrying my invention into practice I arrange each of the two driving discs
on a seperate shaft in such a manner that while the said discs are both kept in
frictional contact with the ball they each have a seperate or independent motion the
shafts carrying the discs are mounted on bearings in a line or in suitable relation to
each other and are free to have a lateral or sliding movement which is controlled by
means of a spring weight or equivalent acting on the shaft in such a manner as to
allow the discs to give to the ball and to follow it in its movements or to keep in
frictional contact with it while it is rolling over the substance under its action cach
shaft is provided with suitable driving pulley and is driven at such speed as may
be best suited to the conditions of working the bearings carrying the two shafts are
arranged on suitable standards or frames mounted on the bed plate in such a manner
as to admit of their being moved or adjusted to and from the mill casing for purpose
of withdrawing the discs gaining axcess to the screens the interior of the mill and
changing or renewing the wearing parts-each of the said standards or frames at
the end or bearing nearest to the disc or mill case is extended in the form of a boss
on which is mounted moveable screens or screen frame in such a manner as to be
carried too & fro with said framing which in working order is set up so as to hold
screen frame in position against the mill casing (that is the casing or case containing
the mill track). The screen frame or frames are provided with suitable packing to
insure a good joint with the said casing and when desirable the said extension or
boss is provided with a rubber ring or spring so arranged that the screen frame or
frames are held in working position against the mill case by compressing the
said rubber or spring by the action of setting up the frames carrying the shafts
and disc.
To facilitate the operation of moving or sliding the frames carrying the discs
and screen frames to & from the mill casing they may be arranged with a rack and
pinion or screw or other suitable device or the said frames may have a radial
movement if found desirable.
A provision is made for the exclusion of the powder or ground substance from"
bearing nearest the mill case discs & screens by means of a suitable packing
surrounding the shaft and bear ng against a shoulder formed at the end of the
bearing nearest to the discs against which shoulder the packing is set up round the
shaft by means of a long sleeve or brass in which the shaft revolves such sleeve
being adjusted by a suitable arrangement of screws when reducing or crushing by
the wet process as an additional protection the bearing is extended beyond the

page_text: shoulder against which the packing is held by the sleeve and formed with an
annular water space surrounding the shaft into which annular space the water
supply for the mill is conducted with necessary pressure and discharged around the
shaft into the mill in the form of a circular jet the force of which prevents the pulp
from entering into the bearing. The discs prefferably have a square hole and are
each fitted to or held on the said shaft by means of a square nut or sleeve formed
with a shoulder or head at one end and an internal screw which fits a screw cut on
the end of the shaft terminating with a shoulder the aforsaid square nut or sleeve
is passed through the hole in the disc and then advanced along the screw on the
shaft until the disc is held firmly between the head or shoulder on the nut and the
shoulder on the shaft at the termination of the screw. The outer or bearing farthest
from the mill case may be made adjustable so as to be set or kept in proper relation
to the inner bearing or bearings; the springs by which the shafts are controlled
keeping the discs in contact with the ball are provided with fixed or loose collars at
each end and are set on or adjusted to the proper tension by means of a mut or
other suitable device traversing a screw cut on each shaft and advancing along the
said shaft in such a manner as to compress the spring between the nut and the
bearing in the action of setting the discs up to the ball.
The lateral movement of the said shaft or shafts may be further controlled by
the addition of another spring arranged on the outer end of the shaft and set up
against the outer end of the bearing by means of a nut and screw on the end of the
shaft. The shaft may also be adjusted or controlled by arranging a forked lever to
work between two shoulders or a journal formed on each shaft such lever or levers
being arranged so that their radiation or movement governed by a spring or weight
imparts the necessary lateral movement keeping the discs in contact with ball.
The splash plates troughs hopper guides dust casings or retainers may be attached
to and move with the screen frames or be carried on the movable frames or
standards or parts of either may be so arranged as may be found desirable. The
screws by which the discs are held by the square nuts are arranged or cut right and
left handed that is one shaft and nut has a right-handed screw and the other a left-
handed also the screws for adjusting the springs controlling the lateral motion
are s.milarly arranged. In order to insure a more uniform or better distribution
on the mill track of the substance to be crushed a swinging scraper plough plate or
distributor of V. or other suitable section or form is arranged so as to swing loosely
in or on the ends of the mill shafts (or on the mill shaft when only one shaft is
employed for carrying the discs) between the said discs or in proper or such
relation to the mill track as will allow of its resting on front surface of the ball or
that part of the ball presented to the direction in which it is travelling and to
depend on the contact pressure or progress of the ball for its action or power to
clear overcome the resistance or level the substance on the said mill track.
In another part of my invention the mill case containing the track on which the
ball exerts its centrifugal force is arranged in a horizental position and mounted.
upon and connected to the top end of a vertical shaft provided with suitable
bearings and driving pulley, by which a revolving motion is imparted to the said
shaft and mill casing. The framing supporting the aforesaid shaft & bearings is
extended upwards and formed in such a manner as to admit of its carrying the discs
or flexible driver for impelling the ball which discs or flexible driver in this
arrangement do not revolve but are held fast and suspended over the mill case or
pan in such relation to the mill track as to press upon and keep in frictional contact
with the ball and causing it to revolve on its axis while it is being carried round
with the mill track on which it impinges with a crushing force according to the
velocity imparted to the said track.
The substance to be crushed is fed to the mill by means of a circular hopper
arranged over the discs in connection with conical or other suitable guides for
facilitating a uniform distribution of the substance to the surface of the mill track.
In the arrangement for wet grinding the mill case is formed with a return rim
or movable guide ring with such return or outward curves as may be found

page_text: necessary to conduct and discharge the overflowing pulp into a circular stationary
trough from which it may flow through suitable outlets. In order that the water
may efficiently flow through the mill a passage is formed through the discs or
flexible driver (or the stud shaft or other arrangements by which it is held) in such
a manner as to direct the water to the bottom at the centre of the mill case or pan
underneath the discs or driver from which it flows outward over the edge or rim of
the mill case as aforesd.
When
In the process of dry grinding a circular dust casing is suspended over the mill
case in connection with a fan or other suitable device for exhausting and delivering
the powdered substance part of the said dust case is made telescopic and balanced
by weight so that it may be raised from or lowered to the mill casing for the
purpose of regulating the admission of air or gaining access to the mill.
desirable to arrange the revolving mill case & track in the form of a duplex mill or
to work it in a vertical position a horizontal shaft provided with a driving pulley
is mounted on bearings supported by a suitable frame and arranged so that its ends
overhangs or project beyond such bearings so as to admit of each end carrying a
circular mill case to which it is fitted in such a manner as to revolve with the shaft
by means of the driving pulley. The discs or flexible driver are arranged vertically
and in proper relation to the mill track so as to impel the ball as hereinbefore
mentioned and fitted on a suitable stud or shaft carried by a moveable frame
arranged either to radiate or slide to & from the mill case for the purpose of
withdrawing or adjusting the discs or driver.
If the said shaft is arranged for a single mill carrying a revolving case at one
end only it may be found desirable to make the bearing at the opposite end is
adjustable so that it can be set to meet the conditions of wear that may arise
from additional strain and weight on the bearing nearest the mill case when
grinding wet the mill case is formed so as to retain the pulp and admit of its over-
flowing into a stationary trough or case arranged with necessary outlets the
substance to be treated is fed or entered through the mill casing at the outlet or
aperture to which it is conducted from a hopper by suitable guides.
The water is prefferably conducted through the centre of the discs or drivers to
the back of the inill case in the manner herein before mentioned. For dry grinding
the mill is encased with movable dust casing provided with hopper and guides as
aforesd. and outlet to admit of the powder being drawn off by fan or other exhaust.
The mill case may carry suitable gratings or screens to prevent the ground
substance leaving the mill until sufficiently pulverized.
The discs aforesd. each or both have a rotary motion imparted to them if
desired.
W. H. THOMPSON.
COMPLETE SPECIFICATION.
Improvements in Machinery and Apparatus for Grinding or Crushing
Mineral, Vegetable, and Animal Substances.
WILLIAM HENRY THOMPSON Engineer 155 Fenchurch Street London 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 object of my invention is the improvement of machinery and apparatus in
which the crushing or pulverizing is effected by means of the centrifugal force of a
ball driven or impelled round a circular track by means of two oscilating discs or
flexible drivers Whereby each of the said discs impelling the ball has a separate
and independent motion imparted to it so as to give the ball a movement on two
axis or to work it so as to insure a better presentation of its surface to the work
a further arrangement for more readily fitting and adjusting discs having wearing

page_text: urfaces on both faces also means of more readily holding and adjusting the screens
or screen frames and gaining access to the wearing or working parts also the better
arrangement and protection of the bearings and distribution of the substance under
operation.
In carrying my invention into practice I arrange each of the two driving discs
on a separate shaft in such a manner that while the said discs are.both kept in
frictional contact with the ball they each have a separate or independent motion
the shafts carrying the discs are mounted on bearings in a line or in suitable
relation to each other and are free to have a lateral or sliding movement which is
controlled by means of a spring weight or equivalent acting on the shaft in such a
manner as to allow the discs to give to the ball and to follow it in its movements
or to keep in frictional contact with it while it is rolling over the substance under
its action each shaft is provided with suitable driving pulley and is driven at such
speed as may be best suited to the conditions of working, the bearings carrying the
two shafts are arranged on suitable standards or frames mounted on the bed plate
in such a manner as to admit of their being moved or adjusted to and from the mill
casing for the purpose of withdrawing the discs gaining access to the screens, the
interior of the mill, and changing or renewing the wearing parts, each of the said
standards or frames at the end or bearing nearest to the disc or mill case is
extended in the form of a boss on which is mounted moveable screens or screen
frames in such a manner as to be carried to and fro with the said framing which in
working order is set up so as to hold screen frame in position against the mill
casing, that is the casing containing the mill track.
'
The screen frame or frames are provided with suitable packing to insure a good
joint with the said casing and when desirable the said extension or boss is provided
with a rubber ring or spring so arranged that the screen frame or frames are held
in working position against the mill case by compressing the said rubber or spring
by the action of setting up the frames carrying the shafts or discs. To facilitate
the operation of moving or sliding the frames carrying the discs and screen frame
to and from the mill casing they may be arranged with a rack and pinion or screw
or other suitable device or the said frames may have a radial movement if found
desirable, provision is made for the exclusion of the powder or ground substance
from the bearings nearest the mill case discs and screens by means of a suitable
packing surrounding the shaft and bearing against a shoulder nearest to the discs,
against which shoulder the packing is set up round the shaft by means of a long
sleeve or brass in which the shaft revolves such sleeve being adjusted by a
suitable arrangement of screws. When reducing or crushing by the wet process as
an additional protection the bearing is extended beyond the shoulder against which
the packing is held by the sleeve and formed with an annular water space
surrounding the shaft into which annular space the water supply for the mill is
conducted with necessary pressure and discharged around the shaft into the mill in
the form of a circular jet the force of which prevents the pulp from entering into
the bearing. The discs preferably have a square hole and are each fitted to or
held on the said shaft by means of a square nut or sleeve formed with a shoulder or
head at one end and an internal screw which fits a screw cut on the end of the shaft
terminating with a shoulder the aforesd. square nut or sleeve is passed through
the hole in the disc and then advanced along the screw on the shaft until the disc
is held firmly between the head or shoulder on the nut and the shoulder on the shaft
at the termination of the screw.
The outer or bearing farthest from the mill case may be made adjustable so as
to be set or kept in proper relation to the inner bearing or bearings. The springs
by which the shafts are controlled keeping the discs in contact with the ball are
provided with fixed or loose collars at each end and are set on or adjusted to the
proper tension by means of a nut (or other suitable device) traversing a screw cut
on each shaft and advancing along the said shaft in such a manner as to compress
the spring between the nut and the bearing in the action of setting the discs up to
the ball.

page_text: The lateral movement of the said shaft or shafts may be further controued by
the addition of another spring arranged on the outer end of the shaft and set up
against the outer end of the bearing by means of a nut and screw on the end of the
shaft. The shaft may also be adjusted or controlled by arranging a forked lever
to work between two shoulders or a journal formed on each shaft such lever or
levers being arranged so that their radiation or movement governed by a spring or
weight imparts the necessary lateral movement for keeping the discs in contact
with the ball. The splash plates trough hopper guides dust casing or retainer may
be attached to and move with the screen frames or be carried on the moveable
frame or standard or parts of either may be so arranged as may be found
desirable.
The screws by which the discs are held by the square nuts are arranged or cut
right and left handed that is one shaft and nut has a right handed screw and the
other a left handed also the screws for adjusting the springs controlling the lateral
motion are similarly arranged.
In order to insure a more uniform or better distribution on the mill track of
the substance to be crushed a swinging scraper plough plate or distributor of
V or other suitable section or form is arranged so as to swing loosely in or on the
ends of the mill shafts (or on the mill shaft when only one shaft is employed for
carrying the discs) between the said discs or in proper or such relation to the mill
track as will allow of its resting on front surface of the ball or that part of the ball
presented to the direction in which it is travelling and to depend on the contact
pressure or progress of the ball for its action or power to clear overcome the
resistance or level the substance on the said mill track.
In another part of my invention the mill case containing the track on which the
ball exerts its centrifugal force is arranged in a horizontal position and mounted
upon and connected to the top end of a vertical shaft provided with suitable
bearing and driving pulley by which a revolving motion is imparted to the said
shaft and mill casing. The framing supporting the aforesd. shaft and bearings is
extended upwards and formed in such a manner as to admit of its carrying the
dises or flexible driver for impelling the ball which discs or driver in this arrange-
ment do not revolve but are held fast and suspended over the mill case or pan in
such relation to the mill track as to press upon and keep in frictional contact with
the ball causing it to revolve on its axis while it is being carried round the mill
track on which it impinges with a crushing force according to the velocity imparted
to the said track.
The substance to be crushed is fed to the mill by means of a circular hopper
arranged over the discs in connection with conical or other suitable guides for
facilitating a uniform distribution of the substance to the surface of the mill track.
In the arrangement for wet grinding the mill case is formed with a return rim or
moveable guide ring with such return or outward curves as may be found necessary
to conduct and discharge the overflowing pulp into a circular stationary trough
from which it may flow through suitable outlets, in order that the water may
effeciently flow through the mill a passage is formed through the discs or flexible
driver (or the said shaft or other arrangement by which it is held) in such a manner
as to direct the water to the bottom at the centre of the mill case or pan under-
neath the discs or driver from which it flows outward over the edge or rim of the
mill case.
In the process of dry grinding a circular dust casing is suspended over the mill
case in connection with a fan or other suitable device for exhausting and delivering
the powdered substance part of the said dust case is made telescopic and balanced
by weights so that it may be raised from or lowered to the mill casing for the
purpose of regulating the admission of air or gaining access to the mill. When
desirable, to arrange the revolving mill case and track in the form of a duplex mill
or to work it in a vertical position a horizontal shaft provided with a driving
pulley is mounted on bearings supported by a suitable frame and arranged so that
its ends overhang or project beyond such bearings so as to admit of each end

page_text: shown partly in section.
Fig. 2. is a plan shown partly in section and without the plow plate or scraper.
A A¹ are the two driving discs mounted on shafts B B₁ to which they are held
by the nuts C & C each of which pass through the discs and work on the screws
formed on the shaft in such a manner that by setting up the nuts the discs are held
firmly between the shoulders or head formed on the nuts and the shoulders on the
shafts at the other end of the screws, the threads of the screws are cut in opposite
directions in order that the action of impelling the ball E may tend to keep the
nuts set up tight, the shaft B has a left handed thread and B' a right hand thread
the shafts revolve in the bearings a b & a' b' formed on the standards D & D¹ and
are free to have a lateral or sliding movement which is controlled by the action of
a spring (hereinafter mentioned) in such a manner as to follow any wear and keep
the said discs in frictional contact with the ball E following it in its movement
while it is rolling over and exerting its centrifugal force on the substance fed to the
mill ring or ball track F.
The standard bearings a & a¹ are extended beyond the standards so as to form
bosses or bearings on which are mounted the moveable screen frame G & G and
screens c c with which are combined the outlet troughs or passages d & and
casing or splash plates e & e¹ which combination encloses or forms the sides of the
mill case H to which they are set up with elastic pressure by the operation of
moving or adjusting the standards into working position which operation is effected
with sufficient force to compress the rubber rings or springs f& f1 between the
flanges or shoulders & gl and the boss of the screen frames, and thereby firmly
holding each of the screen frames against the surfaces on the mill casing which are
prepared to receive them as shown at hh & h the use of bolts being thus obviated
the screen frames and apparatus connected therewith can be instantly removed.
i is a long bush or sleeve made moveable for the purpose of setting up the packing
surrounding the shaft against a shoulder provided to retain it in the manner of a
9

page_text: stuffing box on the other or outer side of the said shoulder k is the annular water
space for surrounding the shaft with water under pressure discharging into the mill
in the form of a circular jet preventing the pulp getting to the bearings, this
arrangement is also shown in enlarged view at Fig. 3 Sheet 3.
For some processes of wet grinding it may be found desirable to remove the
packing so as to allow a leakage from the annular water space round the shaft into
the packing space the pressure of the water so leaking through carrying away with
it any oil (escaping from the sleeve forming the bearing of the shafts) through the
outlet pipe (N) Fig. 3 Sheet 3. Both standards or frames are worked or traversed
to and fro from the mill case by means of the rack and pinion, m, as shown in
sectional view of standard D Fig. 1 Sheet 1 the pinion, m, being operated by the
application of a lever to the end of the shaft n. I shows the scraper or plow
plates in its position with one plate in front of the ball and provided at its centre
with studs o & o' which take their bearing in the holes p & p' in the nuts c & c¹
the said holes contain springs 7 & 7 for the purpose of steadying or holding the
plow plate in position or allowing for the lateral movement of the shafts the arrange-
ment of the scraper is also shown by diagram Fig. 4 Sheet 4 the scraper may be
formed with any desired number of arms or plow plates and be balanced or varied
in form as may be necessitated by the work. is the hopper from which the
substance to be pulverized falls into the shoe in the hopper box s from which it is
distributed into and through the passages tt on to the mill track or ring F the
pulley u is arranged, with a crank connected to the shoe with a connecting rod for
operating the shoe in, the ordinary manner by a strap applied to the pulley from
the counter shaft, mill shaft or other convenient motion ev & v are the thrust
collars fixed on the shafts so as to work in conjunction with the ring w and w
which work in the fork of the levers and a to which they are connected by the
study & y in such a manner that the levers are radiated by the lateral or sliding
movement of the shafts B & B which movement is controlled by the spring J
through the medium of the rods & ¹ the thrust of the spring being taken by the
head of the rod and the internal shoulder K formed in the spring case the discs
being thrust upon the ball with an elastic pressure by the aforesd. connections
working in conjunction with the spring J the adjustment of which is effected by the
movement of the band wheel and right and left handed screw L working in the
nuts M & M from which the screw is released when it is necessary to run
the standards D & D back from the mill.
Sheet 3 & 4.
Fig. 1 & 2 show two mills partly in section according to a another part of
my invention in which the power is applied to the ball by the rotation of the
mill case and mill ring or ball track while the discs remain stationary and
forming an elastic driver are in such contact with the ball as to cause it to
revolve on its axis while it is being carried round by its contact with the ring
or ball track in the mill case on which track it exerts a centrifugal force
according to the weight of the ball and the speed at which the mill case
revolves with which force it acts upon the substance distributed on the mill ring
or ball track by the centrifugal motion it receives on falling into the revolving
mill case from the hopper. Fig. 1. is a mill arranged for dry grinding a is the
driving pulley the rotation of which carries round the shaft and mill case c
and mill ring or track d operating the ball e which rolls or turns on its axis
by its frictional contact with the discs ff which are free to have a certain
amount of radial or rocking movement on the shaft 9 which movement is
resisted with elastic pressure by the rubber buffer or springs h, h, h, which are
kept apart by the sleeve the whole combination being set up by the nut j
and held in a working position so as to form the elastic or flexible driver the
combination forming the lexible driver is adjusted or kept in proper relation
to the mill ring or ball track by the hand wheel and screw the movement
of which raises or lowers the shaft. g which takes its bearing in the slide box

page_text: formed with the frame m which also carries the hopper n. o is the guide for
conducting the substance falling from the hopper on to the ball track the whole
mill when in operation being encased by the telescopic casing which is balanced
by its connection with the weight and chain which arrangement is repeated
at the front of the case not shown. s is the fixed outlet
passage connected
with p. p. by the flexible connection p₁ p¹ the outlet passage is connected with
the apparatus that may be employed for exhausting and delivering the powder
from the mill.
Fig. 2. is a mill arranged for wet grinding in which the details are the same
as Fig. 1 except the shaft g is tubular or made hollow for the passage or
conduct of the water from the pipe to the underneath surface of the lower
disc or to the bottom of the mill case and the return rim over which the pulp
is carried or conducted (by the inflow of the water) into the circular stationary
trough pp which is provided with suitable outlets.
Having now particulary described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare what I
claim is
Firstly. I claim the arrangement of the mechanism for impelling the ball
whereby the said ball is driven round the mill track or ring by two discs
mounted or carried on separate shafts in order that each disc may act inde-
pendly or have an independent rotary motion imparted to it, the said shafts
having a sliding or lateral movement controlled by an arrangement of springs
or weights so as to keep the said discs in frictional contact with the ball while
it is rolling round the mill track and excerting its centrifugal force on the
substance to be reduced substantially in the manner and for the purposes herein
described and shown by drawings Fig. 1. Sheet 1. and Fig. 2. Sheet 2.
Secondly. I claim the arrangement of moveable or sliding standards or frames
carrying driving discs and shafts and moveable apparatus forming the screen
frames, screen, troughs or outlet passages, splash plates or casing for preventing the
ground materal leaving the mill except by the trough or other proper outlet
passages further I claim the arrangement by which the screen frames and
apparatus connected therewith are set up to the mill case and held in working
position by the movement of the standard and compression of the spring instead
of using a series of bolts and other fastenings, substantially in the manner and for
the purpose herein described and shown by drawings Fig. 1. Sheet 1 and Fig. 2.
Sheet 2.
Thirdly. I claim the arrangement for holding or connecting the dises to the
shafts by means of long nuts or sleeves working on screws on the said shafts in such
a manner as to grip the discs between a shoulder formed on each shaft and the
shoulder or head formed. on each nut the said screw being right and left handed
(i.e.) one shaft being provided with a right hand screw and the other with a left
hand screw in order that the action of the discs on the ball may tend to keep the
nut set up tight substantially in the manner and for the purpose herein described
and shown by drawings Fig. 1. Sheet 1. and Fig. 2. Sheet 2.
Fourthly, I claim the arrangement and combination of an annular water space
with a packing space or box formed by the adjustment of a moveable sleeve or
bush forming the bearing surface carrying the mill shaft and disc substantially in
the manner and for the purpose herein described and shown by drawings Fig. 1.
Sheet 1 Fig. 2 Sheet 2 and Fig. 3. Sheet 3.
Fifthly. I claim the arrangement of the plow plate or scraper arranged to
swing or turn freely upon its axis or bearing so as to fall into contact with and
depend upon the movement of the ball for its rotary and effective action substantial'y
in the manner and for the purpose herein described and shown by drawings
Fig. 1 & 4 Sheet 1 & 4.
Sixthly. I claim the arrangement and combination of mechanism or parts
whereby the power is applied to the ball by the rotation of the mill case and

page_text: ring or ball track while the discs remain stationary and forming a flexible or
elastic driver are in such relation and contact with the ball as to cause it to revolve
on its axis while it is being carried round by its contact with the mill ring or ball
track on which it exerts a centrifugal force according to the weight of the ball and
the speed at which the mill case and track revolves which force acts as the crushing
power upon the substance distributed on the mill ring or ball track and brought
into contact with the ball by the circular or centrifugal motion it receives on falling
from the hopper into the revolving mill case from which (in a wet mill) when
reduced it is carried away or caused to overflow as a pulp by the central influx of
water underneath the discs or flexible driver near the bottom of the mill case-I
further claim the combination with or the incasing of such mills with telescopic
casing, substantially in the manner and for the purpose herein described and shown
by drawings Fig. & 2 Sheet 3 & 4.
Lastly. I claim the improved general arrangement and combination of machinery
or apparatus for grinding and crushing substance in the manner herein described
and illustrated in the accompanying drawings.
W. H. THOMPSON.