Mills for Pulverizing or Granulating.
Year: 1898

page_text: Mills for Pulverizing or Granulating.
I, HORACE LESLIE KENT, of Number 29, St. Felix Street, Brooklyn, in the
County of Kings, City and State of New York, United States of America,
Mechanical Engineer, do hereby declare the nature of the said invention
to be as follows:-
This invention relates to mills for crushing, granulating or pulverizing rock,
quartz, ores or other materials. It relates to that class of mills in which the
material is crushed between the interior of a revolving ring and the exterior of a
roll within said ring. This invention is characterized by the arrangement of the
crushing ring to encircle a plurality of rolls (preferably three) by which rolls
it is supported, these rolls being pressed outwardly by springs to impart the
requisite crushing pressure. The rolls and ring are enclosed in a suitable casing,
and means is provided for feeding the material into this casing and between
one of the rolls and the ring.
Fig. 1 of the accompanying drawings is a side elevation of this mill, being
partly broken away to show the interior construction, and partly in vertical mid-
section;
Fig. 2 is an end elevation, the right-hand half being in vertical mid-section,
and the lower part of the lett-hand half being also in section;
Fig. 3 is an elevation of the feeder which is only partly shown in Fig. 2;
Fig. 4 is a vertical mid-section of the feeder;
Figs. 5 and 6 are sections showing details of the bearing equipments;
Fig. 7 is a diagram of the working parts of the mill; Figs. 8, 9 and 10 are
similar diagrams showing modifications;
Fig. 11 is a fragmentary section answering to Fig. 5.
Referring to the drawings, A is the enclosing casing, B is the revolving crushing
ring, and CC are the crushing rolls within the ring, preferably three in number
as shown.
The ring B is supported wholly upon the three rolls CC, which latter are
pressed outwardly against the ring by means of suitable springs SS. The rolls
are fixed on shaits DD which extend horizontally out through openings in the
casing, and are held in bearings EE on opposite sides. These bearings are
mounted on movable guiding frames FF, which connect together the two bearings
of each shaft, hold them in alignment, and provide for transmitting the spring
pressure to them. Preferably the frames are constructed as slides, each having
two parallel bars a a, the inner ends of which carry the bearings, and the outer
ends of which are fixed in a cross-head b, which receives at its middle the outward
thrust of a spring S, which is seated against the casing, and held in a socket c

page_text: formed in the cross head. The tension of the spring is adjusted by means of
a screw d which screws through the cross head, and its inner end bears upon
a disk e against which the spring presses; a set-nut f locks the screw in place.
Preferably all three of the rolls are supported in like manner by bearings E
and frame Fall of the same construction. The bars a a slide in any suitable ways
or guides formed on the casing, being preferably tubular bearings 9 9 as
shown.
The ring B is revolved solely by frictional contact with the rolls. Power may
be applied to one, two or all of the rolls, one being sufficient. I prefer to apply
power to the shaft of the upper roll, (see Fig. 2) as thereby the weight of the
ring which is carried by this roll is utilized to impart the necessary driving
traction. The speed must be sufficiently high to cause the material fed against
the ring to be carried around with it centrifugally.
The casing A may be of any suitable shape or construction, being cast in two
parts divided horizontally at the middle, as shown, so that the upper half can
be disconnected and lifted off to enable the ring to be removed.
The revolving ring B is closely embraced on opposite sides between stationary
annular projections H H within the casing, so as to leave only narrow spaces h
(Fig. 2) on opposite sides of the ring, sufficiently wide to permit the escape of
granulated or pulverized material, while preventing passage of uncrushed material.
I prefer to construct these annular portions H H as separate rings, fastened in
the casing by screws ii at intervals, divided with the casing, and preferably cut
away at the bottom (wholly or partly) to form openings jj for the more ready
discharge of the pulverized material.
The material to be crushed is fed through the casing into the interior of the
ring B, and onto the descending side of one of the rolls C, so that it will fall in
between mutually approaching faces of the ring and roll. I prefer to feed in
simultaneously at both sides, but one side will suffice. The material is deposited
in a hopper G, which branches at its bottom into two chutes kk (Fig. 3) which
terminate over upright chutes II formed on the opposite sides of the casing A;
these chutes extend down outside the casing proper, and terminate each with a
bottom incline (Fig. 2) which directs the material through an opening
in the casing, and throwing it across the stationary ring H, discharges it within
the revolving ring.
772
To prevent the escape of dust through the feeding chutes and hopper, I prefer
to provide the hopper with doors nn the pivotal rods of which carry weighted
arms n¹, so that the doors tend to remain closed, as shown in Fig. 1, but when
a sufficient weight of material is fed into the hopper, they open downwardly as
shown in Fig. 4, dumping the material down the chutes.
To provide for a uniform feed readily adjustable to the requirements of different
materials and to different rates of feed, I provide by preference the construction
of feeder shown in Figs. 1, 3 and 4. This consists of a receiving hopper J
supported on brackets J¹, with a vibrating chute or shaker K freely hung beneath
it, by means of adjustable bolts ss at the sides and at the back. These bolts
are so adjusted that the shaker is struck and slightly lifted at each revolution by
à camp on a shaft L so as to impart to it a frequent jarring or vibratory movement.
The rapidity of feed may be governed in three ways; first, by varying the speed
of the shaft L by running its driving belt q (Fig. 2) on one or other of the pairs
of pulleys qr; second, by adjusting the inclination of the shaker, which is
effected by an adjustment of the bolt t; and third, by varying the extent of lift
by the camp by adjusting the bolts ss. The feed may also be adjusted by means
of a slide movable in the hopper J to more or less cover the front outlet
thereof.
I provide means for protecting the journal bearings EE against admission
of dust or loss of oil. The outer ends of the shafts D (except the driving shaft)
are enclosed by means of caps uu formed in halves and fastened by screws to

page_text: the opposite halves of the bearings. To prevent end thrust of the shafts, each
is provided with a thrust collar v; the cap u is made large enough to freely
enclose this collar, as shown in Fig. 5. It thus prevents dust or grit working
into the bearing, and prevents the escape of oil. At the opposite end of each
bearing next to the casing A, I provide a dust excluding packing box P, shown in
Figs. 5 and 6. This consists of a casing made in halves and fastened by screws
to the respective halves of the bearing E, open at top, so that any fibrous material
may be packed into it, in order to closely embrace the shaft and prevent any dust
or grit working along the shaft into the bearing.
The casing A is constructed with slots or openings suitably arranged to facili-
tate assembling or dismounting the machine. The top half of the casing has an
upright slot w extending from the shaft D to the joint between the sections, so
that the upper half may be lifted off from the lower, and the upper shaft D then
removed from it. The lower half of the casing is provided with inclined slots w¹
through which, the upper half being removed, either of the lower shafts D may
be lifted out. These slots may be normally closed by thin plates or sheets of
metal, leather, etc., to prevent escape of dust from the interior.
It is characteristic of my invention that the ring B is a loose or free ring
supported solely by the crushing rolls which it encircles, and cushioned upon the
springs SS which press against these rolls, so that when any hard material enters
between the ring and either roll, both the ring and roll may yield, the roll yielding
by compressing its spring, and the ring being displaced against the other rolls
and compressing their springs. The ring is made concave on its inner face, and
the rolls are made with convex faces conforming thereto, so that the ring tends
to run centrally upon the rolls, but in case any thick material enters upon one
side, it may be thrust sidewise until it strikes one of the fixed rings H. The ring
being cushioned by the spring-mounted rolls, the machine runs quietly and with
the minimum of jar and vibration.
I prefer to employ three rolls as already described, and as shown in the
diagram Fig. 7. My invention is not however limited to three rolls, being applic-
able with a greater or less number. In Fig. 8 I have shown four rolls, all being.
pressed outward in the direction of the radiating arrows. In Fig. 9 I have
shown two rolls at diametrically opposite points. In all these constructions the
crushing pressure is wholly independent of the weight of the ring, and is deter-
mined by the tension of the cushioning springs. By means of the screws d d
(Figs. 1 and 2) the pressure of each roll against the ring may be varied from
zero up to any desired limit. In Fig. 10, I have shown a modification in which
the weight of the ring is alone relied upon to give the crushing pressure, the ring
being supported on only one crushing roll C cushioned on a spring S, and guided
if necessary by exterior guide rolls yy, shown in dotted lines, or by mounting
similar rolls within the ring in the positions approximately of the two lower rolls
in Figs. 1 and 2; or by mounting a single combined guiding and crushing roll
in the position shown at C in Fig. 10. The material entering at the opening m
falls upon the inner surface of the ring, is carried around centrifugally, and is
crushed between the ring and the roll C with a pressure depending upon the
weight of the ring. This construction is not recommended, but has nevertheless
the advantage peculiar to my invention that the ring is a free ring, supported and
driven by a crushing roll which is spring-mounted so as to cushion the revolving
ring.
Fig. 11 shows an improvement in the packing box P, over that shown in Fig. 5.
It is removed somewhat further from the bearing, and between is a water
chamber enclosing the shaft and having water inlet and outlet pipes r and at
by which a small stream of water is caused to flow around the shaft to cool it in
case the mill is used for grinding hot material, and to wash off any grit that
may have worked its way through the packing box P. The pipes are connected
by sections of flexible hose with a source of water, and the pipes a¹ lead to any

page_text: suitable waste. The water chamber Q may or may not communicate with the
packing box P.
I have shown in Fig. 2, in dotted lines, one means of supporting the mill
on beams of wood, and also a screw conveyer z beneath the open bottom of the
casing to carry away the powdered material.
Datel this 14th day of February 1898
J. C. MEWBURN & ELLIS,
55 & 56, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Mills for Pulverizing or Granulating.
I, HORACE LESLIE KENT, of Number 29, St. Felix Street, Brooklyn, in the
County of Kings, City and State of New York, United States of America,
Mechanical Engineer, do hereby declare the nature of the said invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to mills for crushing, granulating or pulverizing rock,
quartz, ores or other materials. It relates to that class of mills in which the
material is crushed between the interior of a revolving ring, and the exterior of a
roll within said ring. This invention is characterized by the arrangement of the
crushing ring to encircle a plurality of rolls (preferably three) by which rolls
it is supported, these rolls being pressed outwardly by springs to impart the
requisite crushing pressure. The rolls and ring are enclosed in a suitable casing.
and means is provided for feeding the material into this casing and between
one of the rolls and the ring.
Fig. 1 of the accompanying drawings is a side elevation of this mill, being
partly broken away to show the interior construction, and partly in vertical mid-
section;
Fig. 2 is an end elevation, the right-hand half being in vertical mid-section.
and the lower part of the left-hand half being also in section;
Fig. 3 is an elevation of the feeder which is only partly shown in Fig. 2;
Fig. 4 is a vertical mid-section of the feeder;
Figs. 5 and 6 are sections showing details of the bearing equipments;
Fig. 7 is a diagram of the working parts of the mill; Figs. 8, 9 and 10 are
similar diagrams showing modifications;
Fig. 11 is a fragmentary section answering to Fig. 5.
Referring to the drawings, A is the enclosing casing, B is the revolving crushing
ring, and CC are the crushing rolls within the ring, preferably three in number
as shown.
The ring B is supported wholly upon the three rolls CC, which latter are
pressed outwardly against the ring by means of suitable springs SS. The rolls
are fixed on shafts D which extend horizontally out through openings in the
casing, and are held in bearings EE on opposite sides. These bearings are
mounted on movable guiding frames FF, which connect together the two bearings
of each shaft, hold them in alignment, and provide for transmitting the spring
pressure to them. Preferably the frames are constructed as slides, each having
two parallel bars a a, the inner ends of which carry the bearings, and the outer

page_text: ends of which are fixed in a cross-head b, which receives at its middle the outward
thrust of a spring S, which is seated against the casing, and held in a socket
formed in the cross head. The tension of the spring is adjusted by means of
a screw d which screws through the cross head, and its inner end bears upon
a disk e against which the spring presses; a set-nut flocks the screw in place.
Preferably all three of the rolls C are supported in like manner by bearings E
and frame Fall of the same construction. The bars a a slide in any suitable ways
or guides formed on the casing, being preferably tubular bearings gas
shown.
The ring B is revolved solely by frictional contact with the rolls. Power may
be applied to one, two or all of the rolls, one being sufficient. I prefer to apply
power to the shaft of the upper roll, (see Fig. 2) as thereby the weight of the
ring which is carried by this roll is utilized to impart the necessary driving
traction. The speed must be sufficiently high to cause the material fed against
the ring to be carried around with it centrifugally.
The casing A may be of any suitable shape or construction, being cast in two
parts divided horizontally at the middle, as shown, so that the upper half can
be disconnected and lifted off to enable the ring to be removed.
The revolving ring B is closely embraced on opposite sides between stationary
annular projections H H within the casing, so as to leave only narrow spaces h
(Fig. 2) on opposite sides of the ring, sufficiently wide to permit the escape of
granulated or pulverized material, while preventing passage of uncrushed material.
I prefer to construct these annular portions H H as separate rings, fastened in
the casing by screws ii at intervals, divided with the casing, and preferably cut
away at the bottom (wholly or partly) to form openings jj for the more ready
discharge of the pulverized material.
The material to be crushed is fed through the casing into the interior of the
ring B, and onto the descending side of one of the rolls C, so that it will fall in
between mutually approaching faces of the ring and roll. I prefer to feed in
simultaneously at both sides, but one side will suffice. The material is deposited
in a hopper Ġ, which branches at its bottom into two chutes kk (Fig. 3) which
terminate over upright chutes II formed on the opposite sides of the casing A;
these chutes extend down outside the casing proper, and terminate each with a
bottom incline (Fig. 2) which directs the material through an opening m
in the casing, and throwing it across the stationary ring H, discharges it within
the revolving ring.
To prevent the escape of dust through the feeding chutes and hopper, I prefer
to provide the hopper with doors nn the pivotal rods of which carry weighted
arms n', so that the doors tend to remain closed, as shown in Fig. 1, but when
a sufficient weight of material is fed into the hopper, they open downwardly as
shown in Fig. 4, dumping the material down the chutes.
To provide for a uniform feed readily adjustable to the requirements of different
materials and to different rates of feed, I provide by preference the construction
of feeder shown in Figs. 1, 3 and 4. This consists of a receiving hopper J
supported on brackets J, with a vibrating chute or shaker K freely hung beneath
it, by means of adjustable bolts ss at the sides and t at the back. These bolts
are so adjusted that the shaker is struck and slightly lifted at each revolution by
a camp on a shaft L so as to impart to it a frequent jarring or vibratory movement.
The rapidity of feed may be governed in three ways: first, by varying the speed
of the shaft L by running its driving belt q (Fig. 2) on one or other of the pairs
of pulleys ; second, by adjusting the inclination of the shaker, which is
effected by an adjustment of the bolt t; and third, by varying the extent of lift
by the camp by adjusting the bolts ss. The feed may also be adjusted by means
of a slide M movable in the hopper J to more or less cover the front outlet
thereof.
I provide means for protecting the journal bearings EE against admission

page_text: of dust or loss, of oil. The outer ends of the shafts D (except the driving shaft)
are enclosed by means of caps uu formed in halves and fastened by screws to
the opposite halves of the bearings. To prevent end thrust of the shafts, each
is provided with a thrust collar; the cap u is made large enough to freely
enclose this collar, as shown in Fig. 5. It thus prevents dust or grit working
into the bearing, and prevents the escape of oil. At the opposite end of each
bearing next to the casing A, I provide a dust excluding packing box P, shown in
Figs. 5 and 6. This consists of a casing made in halves and fastened by screws
to the respective halves of the bearing E, open at top, so that any fibrous material
may be packed into it, in order to closely embrace the shaft and prevent any dust
or grit working along the shaft into the bearing.
The casing A is constructed with slots or openings suitably arranged to facili-
tate assembling or dismounting the machine. The top half of the casing has an
upright slot w extending from the shaft D to the joint between the sections, so
that when the upper half is to be lifted off from the lower, the upper shaft 1) may be
lowered through said slot. The lower half of the casing is provided with inclined
slots w¹ through which, the upper half being removed, either of the lower shafts D) may
be lifted out. These slots may be normally closed by thin plates or sheets of
metal, leather, etc., to prevent escape of dust from the interior.
It is characteristic of my invention that the ring B is a loose or free ring
supported solely by the crushing rolls which it encircles, and cushioned upon the
springs SS which press against these rolls, so that when any hard material enters
between the ring and either roll, both the ring and roll may yield, the roll yielding
by compressing its spring, and the ring being displaced against the other rolls
and compressing their springs. The ring is made concave on its inner face, and
the rolls are made with convex faces conforming thereto, so that the ring tends
to run centrally upon the rolls, but in case any thick material enters upon one
side, it may be thrust sidewise until it strikes one of the fixed rings H. The ring
being cushioned by the spring-mounted rolls, the machine runs quietly and with
the minimum of jar and vibration.
I prefer to employ three rolls as already described, and as shown in the
diagram Fig. 7. My invention is not however limited to three rolls, being applic-
able with a greater or less number. In Fig. 8 I have shown four rolls, all being
pressed outward in the direction of the radiating arrows. In Fig. 9 I have
shown two rolls at diametrically opposite points. In all these constructions the
crushing pressure is wholly independent of the weight of the ring, and is deter-
mined by the tension of the cushioning springs. By means of the screws dd
(Figs. 1 and 2) the pressure of each spring against its roll may be varied from
zero up to any desired limit. In Fig. 10, I have shown a modification in which
the weight of the ring is alone relied upon to give the crushing pressure, the ring
being supported on only one crushing foll C cushioned on a spring S, and guided
if necessary by exterior guide rolls yy, shown in dotted lines, or by mounting
similar rolls within the ring in the positions approximately of the two lower rolls
in Figs. 1 and 2; or by mounting a single combined guiding and crushing roll
in the position shown at C¹ in Fig. 10. The material entering at the opening m
falls upon the inner surface of the ring, is carried around centrifugally, and is
crushed between the ring and the roll C with a pressure depending upon the
weight of the ring. This construction is not recommended, but has nevertheless
the advantage peculiar to my invention that the ring is a free ring, supported and
driven by a crushing roll which is spring-mounted so as to cushion the revolving
ring.
Fig. 11 shows an improvement in the packing box P, over that shown in Fig. 5.
It is removed somewhat further from the bearing, and between is a water
chamber Q enclosing the shaft and having water inlet and outlet pipes and .l
by which a small stream of water is caused to flow around the shaft to cool it in
case the mill is used for grinding hot material, and to wash off any grit that

page_text: may have worked its way through the packing box P. The pipes * are connected
by sections of flexible hose with a source of water, and the pipes z¹ lead to any
suitable waste. The water chamber Q may or may not comniunicate with the
packing box P.
I have shown in Fig. 2, in dotted lines, one means of supporting the mill
on beams of wood, and also a screw conveyer z beneath the open bottom of the
casing to carry away the powdered material.
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:-
1. In a pulverizing mill, the combination of a revolving ring and a spring-
mounted crushing roll within and supporting said ring, the ring being free to
yield and both ring and roll being cushioned in substantially the manner specified.
2. In a pulverizing mill, the combination of a revolving ring and a plurality of
spring-mounted crushing rolls within and supporting said ring, so that the ring
is yieldingly mounted on said rolls to substantially the effect specified.
3. In a pulverizing mill, the combination of a revolving ring and a plurality of
rolls turning on substantially stationary axes, within and supporting said ring,
and a spring arranged to press one (or more) of said rolls outwardly against the
ring to cushion the ring on such roll, substantially as specified.
4. In a pulverizing mill the combination of a plurality of crushing rolls and
their shafts turning on substantially stationary axes, a revolving ring encircling
and supported by said rolls, movable bearings for said shafts, springs for forcing
said bearings outwardly to press the rolls against the ring, and means for adjust-
ing the tension of said springs, substantially as specified.
5. In a pulverizing mill the combination of a revolving ring, combined with
three crushing rolls within and supporting said ring, and means for pressing them
outwardly against the ring, whereby the ring is yieldingly supported at three
points, substantially as specified.
6. In a pulverizing mill the combination of a plurality of crushing rolls, a free
revolving ring encircling and supported solely by said rolls, the inner face of
said ring being concave and the outer faces of said rolls being convex and con-
forming thereto, and yielding means for forcing the rolls outwardly against the
ring, whereby the ring is centered and held against lateral displacement, sub-
stantially as specified.
7. In a pulverizing mill, the combination of a crushing roll, a free revolving
ring encircling said roll, a casing enclosing said roll and ring, and fixed rings
within said casing on opposite sides of said ring and normally slightly out of
contact therewith, whereby narrow spaces are left between the revolving ring and
fixed rings through which the pulverized materials may escape, but preventing
the escape of the uncrushed material, substantially as specified.
8. In a mill of the described kind, the construction of the bearings for the
roll shafts on opposite sides of the casing, with a frame uniting the two bearings
of one shaft to keep them in alignment, and a spring applied to such frame for
pressing the bearings outwardly, substantially as specified.
9. In a mill of the described kind, the frame for uniting the two bearings of
one roll shaft constructed as a slide movable in ways formed on the casing, sub-
stantially as specified.
10. In a mill of the described kind, the construction of the casing in two parts
divided horizontally, with slots through which the roll shafts project, said slots
extended to the subdivision of said casing to facilitate the removal of the shafts,
substantially as specified.
11. In a mill of the described kind, having one of the crushing-rolls at the top
and beneath the upper side of the ring, the application of driving power to the
shaft of such upper roll, so that the weight of the ring, in addition to the pressure

page_text: against it of the lower rolls, is utilized to impart the traction for driving the ring,
substantially as specified.
12. The combination with a mill of the described kind, of a feeder having
substantially the construction specified, so that the fineness of grinding may be
controlled by regulating the rate of feed to the mill by said feeder.
Dated this 11th day of November 1898.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.