Improvements in Machinery or Apparatus for Grinding or Pulverizing.
Year: 1890

page_text: Date of Application, 16th July, 1890
Complete Specification Left, 16th Apr., 1891-Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in Machinery or Apparatus for Grinding or
Pulverizing.
We, CHARLES WILLIAM KITTO, of Blomfield House New Broad Street, in
the City of London, Patentee, CHARLES WALTER KITTO, of 60 the Mall,
Hammersmith, Middlesex, Manager of Works, and HUGH HAMILTON KITTO,
of 90 Lordship Road, Newington, also in Middlesex, Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention has reference to improvements in machinery or apparatus for wet
and dry grinding, of the kind known as the Globe Mill, wherein grinding or
pulverising is effected by a ball impelled around a circular path or track by driving
discs.
In mills of this kind as heretofore constructed, it has been necessary to adjust,
from time to time, the combined driving clutches and dome bearings, (hereinafter
referred to as dome bearings) and the driving discs carried thereby, for the purpose
of maintaining the discs in driving contact with the ball and thus to compensate for
wear, the adjustment being effected in an endwise direction by nuts operated by hand.
By this mode of hand adjustment there is danger, unless considerable care be exercised,
of setting the ball out of the centre of the ball track which results in undue wearing
of the track and a reduction in the output of the mill. To obviate these disadvan-
tages and to enable the discs to automatically adjust themselves, suitable springs
are provided, for example spiral or volute springs, arranged to act upon the outer
sides of the dome bearings so as to tend to force these bearings towards each other,
the outer ends of the springs bearing against adjustable nuts or collars on the
driving shaft. Another spring, but having a less extensile force than the others, is
arranged to bear against the inner sides of the central portions of the discs to keep
these discs upon their bearings.
In some arrangements of grinding mills of the kind herein referred to, the end wise
adjustment of the dome bearings is effected by sleeves that extend through the
sides of the mill and are acted upon by nuts on the driving shaft. To admit of the
ready removal of these sleeves when necessary, without disturbing the packing
leather or leathers of the water bearings used in wet mills, or the caps of the
bearings used in dry mills, the sleeves are, according to this invention, each split or
made in two halves. The ends of the split sleeve are made of taper or conical form
and between them and the dome bearing and adjusting nut, when the sleeve is in
position for use, are rings formed with correspondingly tapered or conical bearing
surfaces, the arrangement being such that when the adjusting nut or nuts is or are
tightened up, the two halves of the sleeves will be forced tightly upon the driving
shaft by the action thereon of the rings.
Each dome bearing is according to this invention provided with three, four or
more clutch drivers arranged to enter a corresponding number of recesses in the
driving disc it is intended to drive. By this means a more uniform driving of the
discs is effected and the ball is subject to a more uniform pressure than when two
clutch drivers only are used as is usual in the mills heretofore constructed and the
liability heretofore experienced of the ball to "shoot "and become broken by sudden
impact on the ball track and thereby damaging this track at the part where the
ball strikes is obviated, and the efficiency of the mill is increased.
In wet mills of the kind mentioned, it is usual to use a screening partition
composed of a grid like plate to which the sieves proper are secured by a number
of set screws.
This construction entails considerable cost, and much time is
occupied in fixing and removing the screws. It also sometimes happens that the
heads of some of the screws become broken off, and then much time is lost and

page_text: :
1
trouble experienced before the shanks of the screws can be drilled out or other-
wise removed, since these mills are often used in localities away from workshops.
To obviate these disadvantagest.buttons.or. catches are used so pivotted, to the
grid-like plate that by a partial turn, they can be caused to hold or release
the sieves as required. Suitable frames may be interposed between the buttons
or catches, or the sieves may each be fixed in at frame ortibetween twof frames.
The ends of each button or catch or of some of them, may be arranged to act
upon the frames of two adjacent, screens. In wet mills, the ground material
after passing through the screen usually passes into and through a box. or
receptacle provided with a dockedy perforated or reticulated cover arranged below
the driving shaft and cast in one with the bed plate. With this arrangement
it frequently happens that oil flowing on to the shaft from the adjacent bearing
drops and is also thrown off by centrifugal force, and finds its way into the
pulp thereby causing sickening or flouring of the mercury, used for amalga-
mating gold and silver present in the pulp, and seriously interfering with, the
amalgamating process. To obviate this, according to this invention, the pulp is
discharged into a box that may be of sheet copper or be lined with sheet copper
to form mercury plates for catching gold and silver. This box has an opening
in its top or in one side, or both, to receive pulp, but is otherwise closed at the
top; it has an outlet at one or both ends and its bottom may be inclined to
facilitate the flow of pulp. A bonnet or shield provided with an oil pocket or
pockets is arranged to surround or partly surround the driving shaft, and catch
any oil that may be thrown off by centrifugal force and thus prevent it reaching
mercury plates external to the mill.
In order that the end walls of the mill may be readily removed without
interfering with the water or other bearings employed, these bearings according
to this invention, are carried by standards that form part of the end walls, the
remainder of which is made in segments or parts that can be readily connected
together and to the standards and mill casing. By this construction, the mill can also
..be readily converted from a wet mill into a dry mill or vice versa according to require-
ment. For thus adapting a wet mill for use as a dry mill, end walls are provided,
each made, with an outlet branch for connection with an air exhauster, these
end walls being so formed that they can be readily secured to the mill case in
place of the covered grid-like plates used for carrying the screens when, the
mill is used as a wet mill.
Dated this 16th day of June 1900
COMPLETE SPECIFICATION.
Improvements) in Machinery or Apparatus for Grinding.or
Pulverizing.
'
We, CHARLES WILLIAM KITTO, of Blomfield House New Broad Street," in
the City of London, Patentee, CHARLES WALTER KITTO, of 60 the Mall,
'Hammersmith, Middlesex, Manager of Works, and HUGH HAMILTON KITTO,
of 90 Lordship Road, Newington, also in Middlesex, Engineer, do thereby
'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 has reference to improvements in machinery or apparatus: for
wet and dry grinding, of the kind known as the Globe Mill, wherein grinding
or pulverising is effected by a ball impelled around a circular path or track by
driving discs.

page_text: In mills of this kind as heretofore constructed, the necessary adjustment required
from time to time, by the combined driving clutches and dome bearings, (herein-
after referred to as dome bearings) and the driving discs carried thereby, for the
purpose of maintaining the discs in driving contact with the ball and to compensate
for wear, has been effected in an end wise direction by nuts operated by hand. By
this mode of hand adjustment there is danger, unless considerable care be exercised,
of setting the ball out of the centre of the ball-track which causes undue wearing of
the track and a reduction in the output of the mill. To obviate these disadvantages
and to enable the discs to automatically adjust themselves, the apparatus shown in
vertical central section in Fig. 1 is employed in which A A represent the driving
discs which are mounted each on a dome bearing B which rotates with, but is
capable of end wise movement on the shaft C. D is the ball driven by the said
discs. E E are suitable spiral or volute springs, one of these (E) by way of
example being shown as a spiral spring while the other (E) is a volute spring.
The said springs are arranged to act upon the outer sides of the dome bearings
so as to tend to force these bearings towards each other, the outer ends of the springs
bearing against adjustable nuts F working on screw threaded portions of the
driving shaft, or against adjustable collars on the same. G is another spring which
is arranged between the driving discs so as to bear against the central portions of
the inner sides of the discs to keep the same upon their bearings.
The springs E E¹ being properly adjusted by the nuts or collars F serve to cause
the discs A to grip the ball D with the necessary force and to continue so to grip
the same in spite of the wearing thereof for a much longer time than with the
arrangements heretofore in use.
In some arrangements of grinding mills of the kind herein referred to, the
endwise adjustment of the dome bearings is effected by sleeves that extend through
the sides of the mill and are acted upon by nuts on the driving shaft. To admit of
the ready removal of these sleeves when necessary, without disturbing the packing
leather or leathers of the water bearings used in wet mills, or the caps of the bearings
used in dry mills, the sleeves are, according to this invention, each split longi-
tudinally or made in halves as shown partly in section and partly in elevation in
Fig. 2 in which H H represent the respective halves of the sleeve. The ends of
the split sleeve are made of taper or conical form and between them and the dome
bearing and adjusting nut, when the sleeve is in position for use, rings I are arranged
which are each formed with an internal taper to correspond with and to receive the
end of the sleeve, the arrangement being such that when the adjusting nut or nuts
are tightened up, the halves of the sleeves will be forced tightly upon the driving
shaft by the action thereon of the rings. The said sleeves can thus be readily
removed by setting back the said adjusting nuts or collars and removing the rings I
from the ends of the sleeve.
Each dome bearing is according to this invention provided with three, four or
more clutch drivers arranged to enter a corresponding number of recesses in the
driving disc it is intended to drive. In the arrangement shewn in end view in
Fig. 3, four clutches B' are employed, each of which projects into a recess A' in
the corresponding disc A. By this means a more uniform driving of the discs is
effected and the ball is subject to a more uniform pressure than when two clutch
drivers only are used as is usual in the mills heretofore constructed and the liability
heretofore experienced of the ball to "shoot" and to be broken by sudden impact
on the ball track, thereby damaging said track at the part where the ball strikes is
obviated, and the efficiency of the mill is increased.
In wet mills of the kind mentioned, it is usual to use a screening partition
composed of a grid-like plate or frame to which the sieves proper are secured by a
number of set screws. This construction entails considerable cost, and much time
is occupied in fixing and removing the screws. It also sometimes happens that the
heads of some of the screws become broken off, and then much time is, lost and
trouble experienced before the shanks of the screws can be drilled out or otherwise
removed, since these mills are often used in localities away from workshops. To

page_text: obviate these disadvantages buttons, catches or hasps are used so pivotted to the
grid-like plate or frame that by a partial turn, they can be caused to hold or release
the sieves as required. This arrangement is shown in elevations in Fig. 4 in which J
represents the grid-like plate or frame. K K are the sieve frames and K' the
pivotted hasps or catches. Suitable frames may be interposed between the buttons
or catches, or the sieves may each be fixed in a frame or between two frames. The
ends of each button or catch or of some of them, may be arranged to act upon the
frames of two adjacent screens as shown at K³.
Furthermore in wet mills of this kind the ground material after passing through
the screen usually passes into and through a box or receptacle provided with a
locked perforated or reticulated cover arranged below the driving shaft and cast in
one with the bed plate, and it frequently happens that oil flowing on to the shaft
from the adjacent bearing drops or is thrown off by centrifugal force, and finds its
way into the pulp thereby causing sickening or flouring of the mercury, used for
amalgamating gold and silver present in the pulp, and seriously interfering with the
amalgamating process. To obviate this, according to this invention, the arrange-
ment shewn in Figs. 5 and 6 may be employed in which the pulp is discharged
through the sieves K at the end of the mill into a box L that may be of sheet
copper, or be lined with sheet copper, to form mercury plates for amalgamating the
gold and silver. This box has an opening L' in its top or in one side, or both, to
receive pulp, but is otherwise closed at the top; it has an outlet at one or both ends
and its bottom L² may be inclined to facilitate the flow of pulp. A bonnet or shield M
shewn in section in Fig. 6 provided with an oil pocket or pockets M' is arranged to
surround or partly surround the driving shaft C and catch any oil that may be thrown
off by centrifugal force and thus prevent it reaching mercury plates external to the
mill.
In order that the end walls of the mill may be readily removed without interfering
with the water bearings employed, these bearings according to this invention, are
carried by standards Neach of which forms part of the end wall as shown in Figs. 4
and 7, the remainder of the said walls being segments or parts J that can be readily
connected together and to the standards N and the mill casing as shown in Fig. 4.
By this construction, the mill can also be readily converted from a wet mill into a
dry mill or vice versa according to requirement. For thus adapting a wet mill for
use as a dry mill, end walls J are provided as shown on the right hand side of
Figure 7, each made with an outlet branch J for connection with an air exhauster,
these end walls being so formed that they can be readily secured to the mill case in
place of the covered grid-like plates J shown at the left hand side of Fig. 7 used
for carrying the screens when the mill is used as a wet mill.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In a grinding machine or apparatus of the kind herein referred to, the com-
bination with the dome bearings and discs carried thereby, of springs arranged to
act against the outer sides of the said dome bearings and against adjustable nuts or
collars on the driving shaft, and a spring arranged between and so as to act against
the central portions of the inner sides of the discs, substantially as herein before
described for the purposes specified.
2. In a grinding machine or apparatus of the.kind herein referred to, constructing
the sleeves used for adjusting the position of the dome bearing from the exterior of
the machine or apparatus, each in two parts having taper or conical ends and
arranging between the two parts and the dome bearing and the adjusting nut, rings
formed with correspondingly tapered or conical bearing surfaces, substantially as
herein before described with reference to and shown in Fig. 2 for the purpose
specified.
3. In a grinding mill of the kind herein referred to, driving each of the discs A
by means of a dome bearing provided with three four or more clutch drivers as

page_text: hereinbefore described with reference to and shown in Fig. 3 for the purpose
specified.
4. In a wet mill of the kind herein referred to, securing the sieves to the grid-like
plates or frames at each end of the mill by pivoted devices such as buttons catches
or hasps so that by a partial turn of such devices the sieves can be fastened in place
or released as desired, substantially as herein before described with reference to
Fig. 4 of the drawings for the purpose specified.
5. Providing a wet mill of the kind herein referred to, with a box L having an
opening in its top, or side or both, through which the pulp is discharged from the
mill but which is otherwise closed at the top, an inclined bottom, and an outlet at
one or both ends, the said box being made of or lined with copper substantially as
hereinbefore described with reference to Fig. 5 of the drawings for the purpose
specified.
6. In a wet mill of the kind herein referred to, surrounding or partly surrounding
the driving shaft with a bonnet or shield provided with an oil pocket or pockets
substantially as hereinbefore described with reference to and shown in Figs. 5 and 6
of the drawings for the purpose specified.
7. In a grinding mill or apparatus of the kind herein referred to, mounting the
water bearings of the driving shaft in standards that form part of the end walls the
remainder of which is made in segments or parts that can be readily connected
together and to the standards and mill casing substantially as herein before described
with reference to and shown in Figs. 4 and 7.
Dated this 16th day of April 1891.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants..