Improvements in Mills for Crushing, Grinding, or Pulverizing and Amalgamating or Mixing Various Substances.
Year: 1884

page_text: Improvements in Mills for Crushing, Grinding, or Pulverizing
and Amalgamating or Mixing Various Substances.
I WILLIAM HENRY THOMPSON of 14 Devonshire Square, Bishopsgate Street
in the County of Middlesex, Engineer do hereby declare the nature of the said
Invention for IMPROVEMENTS IN MILLS FOR CRUSHING, GRINDING, OR PULVERIZING
AND AMALGAMATING OR MIXING VARIOUS SUBSTANCES to be as follows:-
The invention relates to improvements in that class of mill described in the
specification of Letters Patent granted to me dated November 8. 1876 No. 4325 in
order to render them more readily accessible, to reduce the cost, to obtain a larger
output for a given expenditure of power and to lengthen the duration of the
wearing parts.
In carrying my Invention into effect I employ two castings each forming a mill
case and I arrange these castings at a suitable distance apart and at opposite ends
of a bed plate or frame.
Each of the cases is formed on the inner side, that is to say, on the side facing
the other case with a bearing carrying the main mill shaft which is thus supported
by two bearings and it is of such length as to overhang or extend beyond each
bearing into and across each of the aforesaid cases.
Mounted on each overhanging or extending end of the said shaft is a pair of
driving discs of somewhat similar character to those described in my aforesaid
specification.
These discs are moved or adjusted on the said shaft by means of adjusting
screws, two of which pass through both dome bearings and are provided on their
inner ends with heads to bear against the inner disc whilst they are acted upon at
their outer ends by nuts which act to set the two discs at the requisite distance
apart from each other, a third adjusting screw, screws into the outer end of the
main shaft and by the head thereof working within a recess in a plate fixed to
the outer dome bearing, acts to adjust the two discs and consequently the ball, in
correct position with respect to the mill ring track or way with which each case is
fitted.
These adjusting screws are worked from the outer side of each of the cases
which are fitted with hinged outer sides or doors to facilitate access to the interior
of the case
:

page_text: Each mill ring, track or way is set up or held to the inner side of its case by
means of wedge headed bolts and the outer periphery of the mill ring, track or way
is coned to the same angle as the wedge headed. bolts so as to enable the said ring,
track or way to be turned round and held or set in any position.
The hinged doors at their upper parts are fitted with guide plates to direct the
material to the space between each pair of discs and the opposite side of each mill
case is also provided with somewhat similar guides for a like purpose. I also fit the
lower part of each mill case with inclined guides extending to some distance around
the same in order to cause the material thrown outwards by the balls to be again
directed towards the same.
The outer of these lower guides is carried by a casting forming the lower portion
of the outer side of the mill case and to which the door is hinged whilst the inner
guide is cast on or attached to the inner side of the case.
Each of the cases is fitted as heretofore with suitable inlet channels over which
are arranged suitable hoppers from which the material is fed into the mill.
On the periphery and near the outer side of each case is an outlet passage
through which the dust or powder as it is made in the mill is drawn by suitable
air exhaust.
The inner or bearing side of each case is formed with inlet air passages around
the bearings the object of which is to draw the air partly at that point for
supplying the exhaust and so prevent the dust from getting at the bearings.
Other inlet or air passages are also formed near the bottom of each case so as to
form a more perfect air current for lifting and carrying the dust through the
exhaust passage.
The main or mill shaft is driven by a pulley mounted upon the shaft between
the two bearings aforesaid and the fly wheel is mounted close to the driving
pulley.
For wet grinding I employ a similar construction of mill but it is fitted with
water bearings constructed according to Letters Patent granted to me dated
December 15, 1883, No 5751 through which bearings the feed water is supplied to
the mill, and instead of forming the aforesaid hinged doors solid I construct them
of a frame on which are fixed the sieve plates through which the pulp passes when
reduced sufficiently fine. In this latter arrangement as the pulp or ground material
passes through the sieve formed door, the exhaust and inlet air passages are not
therefore required.
According to another part of my invention I make the discs alike on both sides
and I also form the domes upon which they work double so as to enable such
parts to be turned when one side thereof is worn thereby making them do
double duty.
If desired, only one case may be employed fixed at one end of the main shaft in
a similar manner to that above described.
Another part of my Invention relates to improved means for drawing or
impelling an upward current through a vertical tubular formed framing and
regulating or conducting the said current in such a manner as to draw and deliver
from the mill the pulverized substance after it has been reduced to a suitable degree
of fineness.
In carrying this part of my invention into effect the substance is reduced or
pulverized by the centrifugal force exerted by a ball driven horizontally around
the inner periphery of a suitably formed ring or case by discs in the manner
described in the specification of Patent No 4325 of 1876 before referred to.
The ring or case in which the ball exerts its force is fixed on the tubular
framing in a horizontal position, the driving discs are mounted horizontally on a
vertical shaft (running through the aforesaid tubular framing) and are brought
into contact with the ball in such a manner as to impel and drive it around the
ring aforesaid. The disc working below the ball is fitted with vanes or propelling
blades arranged in such a manner, as (while revolving with the disc) to draw a
current of air and impel it through the mill in an upward direction, the substance

page_text: to be pulverized is fed in and falls on the disc working above the ball which is so
formed as to distribute the substance to the action of the said ball, above this last
named disc and also mounted horizontally on the same shaft is another plate or
disc which is fitted with vanes or propelling blades, so adjusted that in course of
the rotary motion imparted to them they draw regulate and continue the current
of air carrying away the powdered substance from the mill. This disc is moveable
on the vertical shaft and is connected to levers, to which are attached weights
working similar to a steam engine governor arrangement of mechanism, and
acting in such a manner as to regulate the lifting power of the current of air, by
adjusting the distance of the last mentioned propelling disc to and fro from the
mill, the powdered substance after leaving this propelling disc passes into a circular
case mounted at the top of the tubular framing.
This circular casing is covered with a fine woven wire mesh or guáze the object
of which is to retain the powdered substance while the air is passing away. The
powdered substance thus retained falls through suitable outlets into the receptacles
provided.
The steam engine governor arrangement of mechanism instead of regulating the
air current passing through the mill by moving the propelling disc aforesaid may be
connected to a suitable damper or door which is fitted to the mill and acted on by
the mechanism in such a manner as to regulate the air current passing through tho
mill by admitting a given quantity of air according to the speed at which the mill
is driven.
:

page_text: 4
S
S
and Amalgamating or Mixing Various Substances.
WILLIAM HENRY THOMPSON of 14 Devonshire Square Bishopsgate Street in
the County of Middlesex Engineer do hereby declare the nature of invention
for IMPROVEMENTS IN MILLS FOR CRUSHING GRINDING OR PULVERIZING AND.
AMALGAMATING OR MIXING VARIOUS SUBSTANCES and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:―
The Invention relates to Improvements in that class of mill described in the
Specification of Letters Patent granted to me dated November 8th 1876 N° 4325
in order to render them more readily accessible to reduce the cost, to obtain a
larger output for a given expenditure of power and to lengthen the duration of the
wearing parts.
In carrying my invention into effect I employ two castings each forming a mill
case and I arrange these castings at a suitable distance apart and at opposite ends
of a bed plate or frame.
Each of the cases is formed on the inner side that is to say on the side facing the
other case with a bearing carrying the main mill shalf which is thus supported by
two bearings and it is of such length as to overhang or extend beyond each bearing
into and across each of the aforesaid cases.
Mounted on each over hanging or extending end of the said shaft is a pair of
driving discs of somewhat similar character to those described in my aforesaid
Specification.
I
These discs are moved or adjusted on the said shaft by means of adjusting screws
two of which pass through both dome bearings and are provided on their inner
ends with heads to bear against the inner disc whilst they are acted upon at their
outer ends by nuts which act to set the two discs at the requisite distance apart
from each other, a third adjusting screw, screws into the outer end of the main
shaft and by the head thereof working within a recess in a plate fixed to the
outer domo bearing acts to adjust the two discs and consequently the ball in
correct position with respect to the mill ring track or way with which each case is
fitted.
These adjusting screws are worked from the outer side of each of the cases which
are fitted with hinged outer sides or doors to facilitate access to the interior of the
case
Each mill ring track or way is set up or held to the inner side of its case by
means of wedge headed bolts and the outer periphery of the mill ring track or way
is coned to the same angle as the wedge headed bolts so as to enable the said ring
track or way to be turned round and held or set in any position.
The hinged doors at their upper parts are fitted with guide plates to direct the
material to the space between each pair of discs and the opposite side of each mill
case is also provided with somewhat similar guides for a like purpose I also fit

page_text: the lower part of each mill case with inclined guides extending to some distance
around the same in order to cause the material thrown outwards by the balls to be
again directed towards the same.
The outer of these lower guides
carried by a casting forming the lower portion.
of the outer side of the mill case and to which the door is hinged whilst the inner
guide is cast on or attached to the inner side of the case.
Each of the cases is fitted as heretofore with suitable inlet channels over which
are arranged suitable hoppers from which the material is fed into the mill.
On the periphery and near the outer side of each case is an outlet passage.
through which the dust or powder as it is made in the mill is drawn by suitable
air exhaust.
The inner or bearing side of each case is formed with inlet air passages around
the bearings the object of which is to draw the air partly at that point for sup-
plying the exhaust and so prevent the dust from getting at the bearings. Other
inlet or air passages are also formed near the bottom of each case so as to form
a more perfect air current for lifting and carrying the dust through the exhaust
passage.
The main or mill shaft is driven by a pulley mounted upon the shaft between
the two bearings aforesaid and the fly wheel is mounted close to the driving
pulley.
For wet grinding I employ a similar construction of mill but it is fitted with
water bearings constructed according to Letters Patent granted to me dated
December 15th 1883 N° 5751 through which bearings 'the feed water is supplied to
the mill and instead of forming the aforesaid hinged doors solid I construct them
of a frame on which are fixed the sieve plates through which the pulp passes when
reduced sufficiently fine.
In this latter arrangement as. the pulp or ground material passes through the
sieve formed door the exhaust and inlet air passages are not therefore required.
According to another part of my invention I make the disc'alike on both sides
ánd I also form the domes upon which they work double so as to enable such
parts to be turned when one side thereof is worn thereby making them do double,
duty
stances in a dry state.
Fig. 1-Shows front elevation of two Mills arranged on one Main Shaft the
internal arrangement of each Mill is shown by the sectional view A and the external
view A¹.
.
Fig. 2. is a view of the inner end or side of the Mill Case showing Exhaust
Channel K.
Fig. 3. is a section of that part of the Mill opening into the Exhaust Channel.
Figure 4 is a plan section of Mill Case showing exhaust channel and arrange-
ment of bolts for holding the Mill Ring in position.
Main
Fig. 5 Shews end view of arrangements for carrying and adjusting driving discs.
The principal parts of the Mill are Cases A and A¹-Bearings B and B
Shaft C Driving Pulley D Fly Wheel E-Flexible discs F. F Ball G Ball
track or Mill Ring H access door I.
The pulverising is effected by the Ball G which is driven or rolled around the
track or Mill Ring H by the driving discs F and F¹ so that it may freely exert the
centrifugal force arising or resulting from its circular motion-The driving discs F
is shown in section so as to show the arrangement for rendering the discs adjust-
able and flexible that they may keep in frictional contact with the Ball giving to
and following it in its play over the substance under action) Both discs F and F¹
are fitted upon dome bearings, as shown in Section by (a) on which they are held
with an elastic pressure by means of the adjusting bolts (6 b) which pass through

page_text: .
the dome bearings with screwed end fitted with nuts by which the dome bearings
are drawn together carrying with them the two discs (F F¹) causing them to com-
press the rubber washers (c) which form a spring keeping the discs the necessary
distance apart and holding them to the dome bearings with an elastic pressure that
permits of their free oscillation-when the discs are thus set they may be moved
bodily adjusted and set for the better working of the Ball by means of the adjusting
screw (d) one end of which works in a thread cut into the end of the main shaft Č
and the other end is connected to cross plates (e and e¹) which are attached to the
outer dome Bearing (a) by means of the bolts (ff) the connection of the adjusting
screw to the crossplate is effected by recessing the inner plate (e) to receive the
shoulder (g) formed on the adjusting screw which when covered by the outer
plate (e) admits of the adjusting screw turning freely and traversing the discs to
and fro by their connection with it through the crossplates (e & e 1) the adjusting
bolt is set so as to retain the discs in any position they may have been set by means
of the lock nut (h) a projection or lugs on the dome bearings as shewn at (i) fits into
recess shewn by (k) formed or cast in the disks F and F¹ so as to form a clutch
carrying round the discs with the dome bearings which are held on the Main
Shaft C by being formed with a square hole fitting on the end of the said Shaft C
which is also squared to receive them The Mill Ring or track is bevelled on the
outer periphery and one of its side surfaces takes bearing against the inner side of
the Mill Case to which it is held firmly by the Wedge bolts marked l. which pass
through to the outside of the Mill Case where they are easy of access for settling
up or slackening out by the nuts at their screwed ends these wedge bolts are made
to the same angle as the Mill Ring periphery on which they bite (m) is an abut-
ment mounted with access door I enclosing the outer end of this Mill Case this
door is held closed by the fly bolts as shown by slackening out these bolts the door
may be let down to admit of access to the interior of the Mill for setting the discs
or examination of working parts and when it is desired to remove wearing parts
for renewal or otherwise the abutment being moveable may be withdrawn carrying
with it the access Door and so leaving the end of the Mill Case open that the track
can be readily withdrawn-When released by slackening the wedge bolts.
The operation of the Mill is as follows:-
The top part of the Mill is mounted with a suitable hopper from which the
material to be pulverized falls into the Mill through the inlet channel (nn) and on
to the Mill Ring or track (H) where it is reduced to powder by the centrifugal and
percussive force imparted to the Ball (G) by driving it around the circular track or
Mill Ring the abutment (m) is formed with an incline (o) which follows the radius
of the Mill Ring at the bottom a sufficient distance to conduct back to the track
for retreatment any of the substance which may fly away from the action of the
Ball, the inclined or angled pieces (p & p1) are also for conducting the substance
from the inlet channels to the Mill Ring.
When the substance under the Action of the Ball is reduced to a sufficiently
fine powder it is drawn off through the exhaust channel (K) by means of an air
current drawn through the Mill by a suitable exhaust fan drawings and delivering
the powder into any proper receptable.
The inlet channels (n. n) are encased so that the air current is drawn through
the airways (r) around the Main Bearing B from which it is drawn and conducted
in such a manner as to utilize its current for preventing the powdered substance
from getting to the bearing B the airways may be fitted with a Bell mouth or
other suitable known ways of best effecting the direction of the air current.
Sheet II Shews view for Mill arranged for the process of wet pulverization as
adopted for the reduction of gold quartz ores &c which is similar in arrangement
and construction to the Mill described and shewn in Sheet I with the exception of
the combination, of the water box with the Main Bearing B for supplying the
feed water and the manner of discharging the pulverized substance from the Mill.
Fig 1 is a front elevation A shown partly in Section showing Section of Main
bearing combined with water box gland and aperture from which the water

page_text: discharges into the Mill also Section of Screen fitted access door 1. A¹ shows
external view.
Figure 2 is a plan showing Main Bearing B in water box and Section of Screen
fitted access door.
Figure 3-end view showing external view of access door and manner of mounting
it on Mill Case.
Fig. 4 is a view of inner end or side of Mill Case showing section of Main
Shaft C and bearing combined with water box.
Figs 5 and 6 are enlarged views of the combination of water box and main
bearing.
(I) is the access door mounted on hinges (a) and fitted with bars marked (b) forming
screen frame to which the screen plates (c) are attached these screen plates are
protected from the destructive action of particles flying away from the action of
the Ball by the perforated guard plate (d) in which the perforations are larger than
those in the screen. and which is arranged so that any of the particles (too course
to pass through the screen plates c) that may work through any of its perforations
fall down between it and the screen plates onto the Mill Ring or track so as to
again come under the action of the Ball-The screen plates are so fastened to the
bars marked (b) as to form a screen regulating the degree of fineness of the pulp
passing from the Mill-The door is held to the case by fly bolts by unfastening
which may be opened so that the screens may be readily cleaned or changed and
the Mill examined.
Fig. 5 is a longitudinal section of water box bearing.
Figure 6 is an end view of same shown in half section.
C is the main or Mill Shaft.
The lower part of the bearing and part of the Water box are formed with a
casting forming the Mill Case, the water supply for the Mill flows from the supply
pipe (e) into the water space (f) surrounding the bearing (B) and exiting or
discharging into the Mill by way of the aperture (marked by arrows) This
aperture is circular round the taper end of the bearing in such a manner as to
discharge the water into the Mill in the form of a Circular jet around the end of
the bearing and so by the force with which it is discharged prevent the pulp
getting at and working its way to and injuring the bearing surfaces-the
moveable back plate (g) forms the back end of the Water box and is arranged
with a gland (h) for packing the shaft so as to prevent the escape of water at this
part the moveable top plate (i) forms the cover for the water box and carries the
Lubricators the oil tubes of which pass through the water space into the bearing
the circular exit aperture may be extended or varied in form as may be found
best for directing the water for effecting the desired purpose.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
First. I claim the arrangement and combination of a mill having an access door
mounted upon an abutment both removable and made with incline pieces for
directing the substance to the Mill Ring.
I claim the arrangement and combination of machinery forming a Duplex or
Double Mill with one main shaft in the manner and for the purpose as shewn.
Second. I claim as an Improved arrangement of water bearing described in my
Patent No 5751 1883 hereinbefore mentioned The bearing formed and combined
with water box gland exit or discharge aperture as shewn.
Third. I claim the arrangement and combination of machinery forming a
Duplex or Double Mill with one main shaft as shewn.
Fourth. I claim the arrangement of air ways around the bearing whereby the
air current is drawn and directed so as to prevent the pulverized powder gaining
access to the bearings as shewn,

page_text: .
Fifth. I claim the arrangement of a swing or hinged door fitted with screens
and screen guard and mounted on the end of the mill or mill case so as to admit
of easy access to the interior of the Mill for examination and changing of screens &
in the manner and for the purpose as shewn.
Sixth. I claim the arrangement of a Mill ring or track having a bevelled or
angled outer periphery in combination with a Mill case fitted with wedge shaped
.bolts whereby one of the side surfaces of the said track takes its bearing against
the inner side of said Case to which it is held firmly by wedge bolts as she wn.
Seventh. I claim the arrangement of the Driving Discs or impelling mechanism
one of both ends of the main or mill shaft such end or ends projecting beyond
¡the main bearing upon which it or they are mounted and combined with an
arrangement of mechanism for setting and adjusting the driving discs as shewn.
T