Improvements in or connected with Edge Runner Mills.
Year: 1894

page_text: Date of Application, 20th Mar., 1394
Complete Specification Left, 20.h Dec., 1894-Accepted, 4th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in or connected with Edge Runner Mills.
I, HARRY VAUGHAN RUDSTON READ, of Broad Street Avenue in the City of
London, Engineer, do hereby declare the nature of this invention, (a communication
to me from Henry Mantey, of Orizaba, Vera Cruz, in the Republic of Mexico,
Engineer,) to be as follows:-
In grinding with edge runner mills, there are two methods employed, the wet and
the dry. The greatest difficulty which has been experienced with the wet method
is in keeping the ores well under the grinding wheels, while with the dry method the
difficulty has been to properly remove the finely ground ore.
The present improvements relate particularly to dry grinding, and while they may
be applied most satisfactorily to the form of edge runner mill described in. United
States Patents Nos. 488,146 and 487,930; both of December 13th 1892, they will
be found to also apply to other forms of edge runner mills.
The main object of the improvements is to remedy the above noted defect in dry
grinding mills, and to render dry grinding more practicable than the wet method in
every respect, in order to take advantage of the known fact that a greater quantity
of ore can be crushed in a given time by the dry method than by the wet.
The
In the improved form of mill the grinding basin and runners are completely
enclosed with an airtight casing, which is provided with a suitable valved inlet for
the ore to be crushed, and valved outlets for the ground ore, and a blast is applied
to the grinding surface of the basin for removing the finely ground ore and an
exhaust at the outlet opening for assisting in the removal of the ground ore.
blast is also applied to the journals of the mills in such a manner as to prevent the
accumulation of dust therein. Suitable valves are provided for the blast and
exhaust in order that the removal of the ground ore and the fineness of grinding
can be gauged or regulated to a nicety. Suitable scrapers are also provided for
keeping the ore in the path of the runners.
The following is one method in which the invention is carried into effect :-
The grinding basin has the customary sloping circular wall and the grinding
bedstone. The basin is built upon suitable girders which are supported in brick-
work. Directly below the basin ample room is provided for the operating
mechanism.
The central step or bearing has supported therein the lower end of the vertical
drive shaft. A large bevelled gear wheel is keyed to the vertical shaft above its
bearing, and the power shaft is supported in suitable bearings and provided with a
power pulley at one end and a cog gear at the other end, which meshes with the afore-
said large cog gear and thereby drives the vertical shaft. The driving mechanism
is located below the main floor of the mill and under cover in order that it may be
kept free from dust.
The vertical shaft extends up through the grinding basin and is surrounded by
a central casting, which is provided at its upper end with a flanged bearing or
bushing. The flange of said bearing rests upon the top of the central.casting.
This flanged bearing, if. unprotected, would soon become clogged with dirt and
dust, which constantly rises from the basin, but in order to protect it a cap is
provided which. is secured around the vertical shaft by means of a collar and
extends down around the upper end of the central casting. The said cap fits

page_text: loosely around the central casting in order to allow a small air space between them
and revolves with the vertical drive shaft. Tapped into one side of the said cap is
a short pipe which is connected with one of the main blast pipes by a flexible tube
or hose in order that there will be a constant blast of air into the cap around the
bearing and out through the space between the cap and the casting, which will
effectually prevent the entrance of any particles of dust to the bearing.
The cross beam is keyed to the upper end of the vertical drive shaft above the
protected bearing. Adjacent to the opposite ends of the cross beam are openings,
in which are journalled rotable bushings which are formed with squared or
polygonal heads (by means of which they can be turned or adjusted) and with
eccentric longitudinal openings. The crank axles have the inner journal ends
journalled in the eccentric openings of rotable bushings, and the outer journal ends
upon which the runners are journalled. The journal ends are secured in place in
the rotable bushings by means of a nut or other suitable device.
The edge runners are journalled upon the end of the crank axles, a Hanged
bushing being interposed in each bearing and a raw hide ring being mounted in an
annular groove in the inner face of each runner and serving to form a close joint
with the Hange of the bushing. The runners are kept in place on the axles by
means of linch pins.
For the purpose of effectually preventing the entrance of particles of dust to the
bearings of the runners, a cap is provided which is rigidly supported from the crank
axies and surrounds the flanged bushing. Tapped into the upper wall of said cap is a
short tube through which a constant blast of air is supplied from the main blast pipe
which is connected thereto by a flexible tube. In this manner the blast is constantly
entering the cap and escaping round the bearing for preventing the entrance of
particles of dust. Oil cups are provided for supplying oil to the runner bearings.
Extending up from the basin and surrounding the runners and basin, is a suitable
air-tight casing. Into one side of the casing is tapped an ore supply chute, which
has an enlarged circular portion in which rotates a pocketted feed wheel, and at the
upper part of the said feed wheel is the hopper into which the ore to be ground is
placed. By rotating the feed wheel a supply of ore is fed to the basin without
allowing the entrance of the outside air. A suitable door is provided, which is
kept normally closed, by means of which entrance can be had into the basin for
cleaning and examining the machine.
Extending up the side of the casing opposite to the ore supply, is an air-tight
conduit, which has a series of openings opening into the mill enclosure, which are
normally closed by removable stoppers, which are preferably provided with
suitable handles. Corresponding to the openings in the opposite wall of the air-
tight conduit, are a series of normally closed openings, which provide access to the
aforesaid openings.
When it is desired to remove the stopper from either of the first named openings,
the covering is taken from the second named openings corresponding therewith and
the stopper taken out. The purpose of this series of openings will be explained
presently.
Extending down from the top of the casing is a blast pipe having a controlling
valve for regulating the flow of air therethrough. The blast pipe extends down in
line with the vertical drive shaft until directly over the cross beam, at which point
it is supported by an extension; it has an elbow from which extend branch pipes
and branch nipples. Each branch pipe projects out parallel to the cross beam and
then down past the ends of the cross beam, at which points they are braced by
metal straps. The branch pipes are formed at their lower ends with T terminals
having an outlet slot, through which the air blast passes. The terminals are supported
very close to the bedstone of the basin, so that the blast will keep the finely ground
particles of ore constantly agitated and floated. Another brace rod extends from
the underneath side of the cross beam to each of the branch pipes. The first
named flexible tubes connect with the branch pipes below the cross bean while the
second named flexible tubes connect with the nipples of the elbow coupling. In

page_text: this manner the air blast is supplied to all of the points which it is desired.to
reach.
Scraper blades are supported from the cross beam by rods and they extend
around in front of the mill-stones in such a manner as to effectually keep the ore
under the runners.
The lower end of the airtight conduit extends off at right angles and leads to
any suitable exhaust fan. There is a slide valve in the conduit, by means of
which the exhaust can be regulated by allowing the entrance of the outside air.
By the employment of a blast and exhaust as above described, the discharge of
the ground material can be regulated to such a nicety that the ore can be ground
to any desired fineness without any difficulty. The blast keeps the finely ground
ore constantly floating within the casing and the exhaust removes it as fast as it
reaches the desired fineness. The first named series of openings are for the
purpose of assisting in regulating the fineness of the material discharged. If the
ore is not to be ground very fine it is discharged through the lowest opening, but if
it is to be ground to au extreme fineness, the highest opening is utilized. It will
be seen that all particles not ground to the desired fineness will be too heavy to be
raised to the high opening, whereas if extreme fineness is desired the larger
ground particles can be discharged through the lower openings without trouble.
Dated this 19th day of March 1894.
H. V. K. KEAD,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.
Improvements in or connected with Edge Runner Mills.
I, HARRY VAUGHAN RUDSTON READ, of Broad Street Avenue, in the City of
London, Engineer, do hereby declare the nature of this invention, (a communication
to me from Henry Mantey, of Orizaba, Vera Cruz, in the Republic of Mexico,
Engineer,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
In grinding with edge-runner mills there are two methods employed, the wet and
the dry. The greatest difficulty which has been experienced with the wet method
is in keeping the ores well under the grinding wheels, while with the dry method
the difficulty has been to properly remove the finely ground ore.
The present improvements relate particularly to dry grinding, and while they
may be applied most satisfactorily to the form of edge-runner mill described in
Patent No. 16721 dated September 19 1892, they will be found to also apply to
other forms of edge-runner mills.
The main object of the improvements is to remedy the above noted defect in dry
grinding mills and to render dry grinding more practicable than the wet method in
every respect, in order to take advantage of the known fact that a greater
quantity of ore can be crushed in a given time by the dry method than by
the wet.
In the improved form of mill the grinding basin and runners are completely
enclosed with an air-tight casing, which is provided with a suitable valved inlet for
the ore to be crushed and valved outlets for the ground ore, and a blast is applied
to the grinding surface of the basin for removing the finely ground ore, and an
exhaust at the outlet opening for assisting in the removal of the ground ore.
The blast is also applied to the journals of the mills in such a manner as to
prevent the accumulation of dust therein. Suitable valves are provided for the
blast and exhaust in order that the removal of the ground ore and the fineness

page_text: OI grinding can be gauged or regulated to a nicety. Suitable scrapers are also
provided for keeping the ore in the path of the runners.
In order that the invention may be fully understood I will first describe the
same with reference to the accompanying drawings and then more particularly point
out the novel features in the annexed claims.
In said drawings
Fig. 1 is a sectional elevation of the improved mill.
Fig. 2 is a sectional elevation taken at right angles to Fig. 1.
Fig. 3 is a top plan view with the top of the casing broken away.
Fig. 4 is an enlarged sectional elevation of a portion of the vertical power shaft.
Figs. 5, 6 and 7 are detail views of the runner journals showing the manner of
protecting the journals from dust.
Figs. 8, 9 and 10 are detail views of one of the terminals of the main blast pipe.
Fig. 11 is a detail view of the exhaust pipe showing the regulating valve.
1 is the grinding basin, having the customary sloping circular wall and the
grinding bed 2. The basin is built upon suitable girders such as 3, which are
supported in brickwork 4. Directly below the basin, ample room is provided for
the operating mechanism.
5 is the central step or bearing, in which rotates the lower end of the vertical
drive shaft 6. 7 is the large bevelled gear wheel keyed to the shaft 6 above its
bearing 5, and 8 is the power shaft supported in suitable bearings 9 and provided
with a power pulley 10 at one end and a bevel pinion 11 at the other end which
meshes with the bevel gear wheel 7 and thereby drives the vertical shaft 6. It will
be seen that the driving mechanism is located below the main floor of the mill and
under cover, in order that it may be kept free from dust.
The central shaft 6 extends up through the grinding basin and is surrounded by
a central support or standard 12, which is provided at its upper end with the
flanged bearing or bushing 13. The flange of bearing 13 rests upon the top of the
support 12.
This bearing 13, if unprotected, would soon become clogged with dirt and dust
which constantly rises from the basin, but in order to protect it, a cap 14 is
provided, which is secured around the shaft 6 by means of the collar 15 and extends
down around the upper end of the support 12. The cap 14 fits loosely around the
support 12 in order to allow a small air space between them and revolves with
the shaft 6. Tapped into one side of the cap 14, is a short pipe 16, which is
connected with one of the main blast pipes by a flexible tube or hose 17, in order
that there will be a constant blast of air into the cap around the bearing 13 and
out through the space between the cap and the support, which will effectually
prevent the entrance of any particles of dust to the bearing.
18 is the cross beam keyed to the upper end of the shaft 6 above the protected
bearing 13. In the opposite ends of the cross beam 18, are the openings 19 in
which are journalled the rotable bushings 20, which are formed with the squared or
polygonal heads 21 (by means of which they can be turned or adjusted) and with
the eccentric longitudinal openings 22 for the axles. 23 are the crank axles
having the inner journal ends 24, which are journailed in the eccentric openings of
rotable bushings 20, and the outer journal ends 25, upon which the runners are
journalled. The journal ends 24 are secured in place in the bushings 20 by means
of a nut or other suitable device.
26 are the edge runners, which are journalled upon the ends 25 of the crank
axles 23, a flanged bushing 27 heing interposed in each bearing and a raw hide
ring 28 being mounted in an annular groove 29 in the inner face of each runner
and serving to form a close joint with the flange of the bushing 27. The runners
are kept in place on the axles by means of linch pins 30.
For the purpose of effectually preventing the entrance of particles of dust to the
bearings of the runners, a cap 31 is provided, which is rigidly supported from the
crank axles 23 and surrounds the flanged bushing 27. Tapped into the upper wall
of said cap, is a short tube 32, through which a constant blast of air is supplied

page_text: from the main blast pipe which is connected thereto by a flexible tube 33. In
this manner the blast is constantly entering the cap and escaping round the
bearing for preventing the entrance of particles of dust. 34 are the oil cups for
supplying oil to the runner bearings.
Extending up from the basin 1 and surrounding the runners and basin, is a
suitable air-tight casing 35. Into one side of the casing is tapped an ore supply
chute 36, which has an enlarged circular portion 37, in which rotates a pocketed
feed wheel 38. 39 is the hopper into which the ore to be ground is placed. By
rotating the feed wheel in the direction indicated by the arrows, a supply of ore
is fed to the basin without allowing the entrance of the outside air. 40 is a suitable
door, which is kept normally closed, by means of which entrance can be had into
the basin for cleaning and examining the machine.
Extending up the side of the casing 35 opp site to the ore supply, is an air-
tight conduit 41, which has a series of openings 42, opening into the mill
enclosure, which are normally closed by removable stoppers 43, which are preferably
provided with suitable handles. Corresponding to the openings 42, in the opposite
wall of the conduit 41, are a series of normally closed openings 44 which provide
access to the openings 42.
When it is desired to remove the stopper from either of the openings 42, the
covering is taken from the opening 44 corresponding therewith and the stopper 43
taken out. The purpose of this series of openings will be explained presently.
Extending down from the top of the casing 35 is a blast pipe 46 having a
controlling valve 47 for regulating the flow of air therethrough. The blast
pipe 46 extends down in line with the main shaft 6 until directly over the cross
beam 18, at which point it is supported by an extension 48. 49 is a coupling from
which extend the branch pipes 50 and the branch nipples 51. Each branch
pipe 50 projects out parallel to the cross beam 18 and then down past the ends of
the cross beam, at which points they are braced by the metal straps 52. The
branch pipes 50 are formed at their lower ends with T terminals 53 having
the outlet slot 54, through which the air blast passes see Figs. 9 and 10. The
terminals are supported very close to the bedstone 2 of the basin, so that the
blast will keep the finely ground particles of ore constantly agitated and floated.
55 is another brace rod extending from the underneath side of the cross beam 18
to each of the branch pipes 50. The flexible tubes 17 connect with the branch
pipes 50 below the cross beam 18, while the flexible tubes 33 connect with the
nipples 51 of the elbow coupling. In this manner the air blast is supplied to all of
the points which it is desired to reach.
56 are scraper blades supported by the curved rods 56" which are keyed to tho
ends of the cross beam 18 and extend around in front of the runners. Each of
the scrapers 56 extends parallel to the cross beam 18 on the outside of one of the
runners. 57 are angular scraper blades supported inside of the runners a little
forward of the axis of rotation. The scrapers 57 are supported by the curved
rods 57 which are bolted to the underside of the cross beam 18. The arrange-
ment of the scrapers 56 and 57 is such as to effectually keep the ore under the
runners.
The lower end of the conduit 41 extends off at right angles and leads to any
suitable exhaust fan. 58 is a slide valve in the conduit 41, by means of which the
exhaust can be regulated by allowing the entrance of the outside air.
By the employment of a blast and exhaust as above described, the discharge of
the ground material can be regulated to such a nicety that the cre
can be
ground to any desired fineness without any difficulty. The blast keeps the finely
ground ore constantly floating within the casing 35 and the exhaust removes it
as fast as it reaches the desired fineness. The series of openings 42 are for the
purpose of assisting in regulating the fineness of the material discharged. If the
ore is not to be ground very fine, it is discharged through the lowest opening,
but if it is to be ground to an extreme fineness, the highest opening is utilised. It
will be seen that all particles not ground to the desired fineness will be too heavy

page_text: το De raiseu
to the nign opening, whereas it extreme fineness is not desired, the
larger ground particles can be discharged through the lower openings without
trouble.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of the basin, the central driving shaft, the cross-beam secured
to the shaft, the adjustable bushings supported in the cross-beam and formed with
eccentric openings extending through them, the axles journailed in the openings, the
runners mounted on the axles, and means for adjusting the bushings, substantially
as described.
2. The combination of the basin, the central driving shaft, the cross-beam
secured to the shaft, the axles journailed in the cross-beam, the runners mounted
on the axles, the central support surrounding the shaft, the cap fitting loosely
around the support having a collar by which it is secured around the shaft, the
short pipe tapped into the cap, the central blast pipe extending down in line with
the shaft and supported on the cross beam, having a controlling valve and branch
pipe, and the tube connecting the branch pipe with the short pipe of the cap,
substantially as described.
3. The combination of the basin, the central driving shaft, the cross-beam
secured to the shaft, the axles journalled in the cross-beam, the runners mounted on
the axles, the cap secured to the axles and surrounding the bearings of the runners
having the short tubes, the central blast pipe extending down in line with the shaft,
and supported on the cross-beam, having a controlling valve, and the tubes
connecting the blast pipe with the short tubes of the caps, substantially as
described.
4. The combination of the basin, the central driving shaft, the cross-bea n
secured to the shaft, the axles journalled in the cross-beam, the runners mounted on
the axles, and the central blast pipe extending down in line with the shaft and
supported on the cross-beam, having a controlling valve and branch pipes extending
out parallel to the cross-beam downward past the ends and provided with T shaped
slotted terminals at points adjacent to the bed of the basin, substantially as
described.
5. In a grinding mill, the combination of the runners, means for driving said
runners, protecting caps. enclosing the bearings of the mill, and a blast communi-
cating with said caps for forcing a constant current of air through them and
thereby preventing the entrance of particles of dust to the bearings, substantially
as set forth.
6. The combination of the basin, the central driving shaft, the cross-beam
secured to the shaft, the axles journalled in the cross-beam, the runners mounted on
the axles, the central blast pipe extending down in line with the shaft and
supported on the cross-beam, having a controlling valve and branch pipes, the
casing having a vertical series of outlet openings, stoppers for said outlet openings,
a supply chute connected with the interior of the casing having a feed chamber, a
pocketted feed wheel located in the feed chamber, and an exhaust pipe connected
with the outlet openings having openings registering with the outlet openings
provided with stoppers, substantially as described.
Dated this 20th day of December 1894.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.