Improvements in Machinery for Pulverizing Ores or other Hard Substances.
Year: 1889

page_text: Date of Application, 8th Mar., 1889
Complete Specification Left, 9th Dec., 1889-Accepted, 11th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in Machinery for Pulverizing Ores or other Hard
Substances.
I, EDWIN PACKARD, of Remson Street, Brooklyn, New York, in the United States
of America, Engineer, do hereby declare the nature of my invention to be as
follows:
This invention relates to pulverizing mills in which crushing rolls or rollers revolve
and travel against an annular dic, and consists in the improved construction, arrange-
ment and combination of parts, the objects of which are first, to secure a positive
application of the power employed directly to the rotation of the rollers whereby they
travel against the annular die and crush the material between them, by the momentum
and centrifugal weight of the rolls.
Second, to provide yielding connection in the shafting whereby a single roller may
be positively rotated against the die.
Third, to provide suitable gearing attached to the driving shaft and the rollers,
whereby several rollers may be positively rotated within and against the same die.
Fourth, to place the journals and connections of all operative parts requiring
lubrication, outside the milling pan or chamber.
Fifth, to provide a suitable hopper and connections for delivering the material
immediately in front of the rolls.
Sixth, to secure the movement of material falling within the die by suitable wings
of lifting shoes attached underneath the rolls.
Seventh, to so place the screens, hoppers and connections for removing the ground
material that it may be discharged from the mill screened or unscreened, wet
or dry.
The improved mill consists of a pan and base combined, in which the operation of
pulverizing by the rollers is carried on and which is secured to a timber or other
foundation. This pan may be single or double.
An annular die within and against which the rollers rotate, is secured within the
pan. On the top of the pan and die is secured a screen frame, which may be
encircled with a trough to carry away the ground material, or with an encircling
cover, to direct the material passing through the screens into passages leading into a
discharging hopper.
If the mill is to be used with one roller only such roller is rotated on its own
central axis by a vertical suspended shaft upon the lower end of which it is fixed, and
upon touching or being pressed against the annular die either by a spring or other-
wise, it rolls round and upon the inner surface of the die, adhering to that surface
by the centrifugal force developed by its rotation round the central axis of the die,
thereby effectually pulverizing any material introduced between it and the die.
A cover and feed spout combined, turn loosely upon a vertical shaft or stud which
is rigidly fixed in a central hub or boss forming part of or an attachment to the
lower pan of the mill. To the upper end of the shaft is attached the receiving hopper
by means of the hub in the centre of it.
The shaft suspended from above carries the roller at its lower end, and is
connected to a vertical shaft above provided with a driving pulley by a universal
joint.
To the bottom of the roll are attached stirrers or flukes. These stirrers may be
made of steel, chilled iron, or other hard material, and are secured to the rolls by
being fitted into dovetailed grooves or flanges on the bottom of the rolls before the
lower end of the suspended shaft, which is taper, is driven into them. They are thus
securely held in position.

page_text: !
On the outer circumference of the revolving cover are attached small vanes or
wings and a slot in the cover through which the suspended shaft passes. is covered by
a plate. An opening in the lower pan leads to a spout through which the material
ground may be discharged below the annular die.
Instead of only one roller three or more may be used.
In this arrangement the rollers are attached to the lower ends of taper shafts which
rotate in bearings supported by trunnions above, either as an integral part or as an
attachment so that the rollers can move, radially.
1
11
The shafts and the rollers are rotated by pinions, securely fastened to the upper
extremity of the shafts, and which in turn are driven by a spur wheel attached to and
operated by a central shaft tumming on a footstep attached to or forming part of the
lower pan This shaft may be rotated by any suitable means. The trunnions which
carry the roller axles are journalled in and supported by a frame which rests upon
the central boss of the pan and rotates freely round the central shaft. To this frame
is attached the rotating cover and feed distributing spouts, and to these spouts. are
secured by bolts or other fastenings, feed pickers and elevating shoes. Small vanes
or wings are attached to the revolving cover at its periphery, and slots in this cover
provide for the radial movement of the roller shafts, these slots being partly covered
by plates. The rotation of the rolls against the annular die carries with them
the frame and all its attachments. The feed hopper in this case is placed at one
side and opens upon the die.
=
The operation with a single roll as first described is as follows:-Power being
applied to the driving pulley the shaft and the roll are rotated on their own axis, and
the roll touching and being pressed against the inner surface of the annular die
either by a spring or its equivalent, rolls upon that surface, and carries, with it the
cover and the feed spout causing them to rotate round the shaft. The roller presses
against the die by centrifugal force, caused by its rotation on the surface, and round
the central axis of the die and of the shaft.
Material being introduced into the stationary feed hopper, finds its way into the
feed spout and from this spout is thrown against the annular die, immediately in front
of the roller and by it is reduced to powder. This material falling to the bottom of
the pan is constantly kept stirred up and agitated by the stirrers or flukes, and if
water is introduced, the material which is sufficiently fine, is carried through screens
suitably arranged into a trough from which it is discharged through a spout. If it
is desired to grind dry the stirrers, throw, the pulverized material out through an
opening and if this product is not sufficiently fine it may be screened and the tailings
returned to the mill. A light current, of air is, caused to flow into the mill by means
of vanes, so as to effectually prevent the escape of dust, through the joint between
the stationary and the moveable or revolving cover.
The roller and the die may be of such shape as to cause the roller to roll truly
within the annular die without slipping, or their shape may be such as to cause some
sliding motion at the top and bottom of the roller which for some materials is more
effective than a true rolling motion.
It is evident that the shape of the roll and the die, may be altered, as may be
found the most effective for the nature of the, work required to be done."
The operation of the mill when three or more rollers, are used is as follows:-The
driving shaft and central spur wheel being rotated rotary motion is communicated
through the pinions to the rollers and these pressing against the inside of the die roll
upon that surface and consequently rotate round the central axis of the mill, pressing
against the die by centrifugal force. As the rollers thus roll round they carry with
them the frame to which are attached the journal bearings of the rollers by means
of the trunnions, and this frame carries with it the rotating cover with the feed
distributing spouts, the feed-picker, and the elevating and distributing shoes. It
may be convenient for starting, the mill to have one or more of the rollers held
against the die. by a spring pressing outwards against the journal boxes but as soon
as the rolls. begin to rotate, within the die they adhere to it by centrifugal force,
11
1

page_text: The material to be ground being introduced through the feeding hopper rests on
the upper ledge of the annular die and is taken therefrom by the feed pickers which
by the inclination at which they are set, throw it into the feed distributing spouts or
guides and they in turn deliver it on the surface of the die immediately in front of
the advancing rollers by which it is pulverized. The material then falling to the
bottom of the pan is taken up and thrown by the elevating shoes against the
screens.
The portion sufficiently fine, passes through the screens and down through passages
into the discharging hopper; the material that does not pass the screens falling back
and being operated upon again!
"
As the rolls swing radially on their trunnions to pass over obstructions a sliglit
motion is given to the pinions on the ends of the shafts but not sufficient to interfere
with the satisfactory working of the gearing.
To grind wet with the mill as thus constructed it is only necessary to introduce the
water required.
In either of the constructions as described, wet grinding can be satisfactorily done.
even if the revolving cover, feed distributing pipe, spouts and elevating shoes are
dispensed with, by using the stirrers or flukes on the bottoms of the rollers.
It will be observed in this mill as constructed for either one or more rolls, that the
rotary motion of the rolls within and against the annular die, and round the central
axis of the mill, is accomplished by giving a positive rotary motion to each individual
roll and not by drawing or shoving them round either on spindles or otherwise, and
this peculiarity in the way of driving rolls within a die, causes far less strain upon
the driving connections than any construction heretofore devised for a similar purpose
and consequently accomplishes the pulverization of refractory substances in the most
satisfactory manner. This method of driving rollers also makes it possible to have
all journals and places that require lubrication outside the chamber in which the
work of pulverization is carried on, thus making them far more durable than they
can be if within the chamber. This method or principle of causing the rolls to rotate
within and against the die, by rotating each individual roller positively, also brings
a great deal less strain on the journals in which the roll shafts rotate than that
method in which the power which causes the rotary motion within and against the
die is conveyed through the medium of these journals.
It will be oliserved that instead of the journal boxes forcing the rolls round, the
rolls by means of their rotation carry the journal boxes and everything attached
to them.
A hole may be put in the central hub or boss of the mill by which the air forced
out through the screens, may be returned to the grinding chamber instead of passing
out by the discharging spout or opening.
The lubrication of the bearings of the roller shafts may be satisfactorily accom-
plished by means of holes drilled in the centre of the shafts.
In the mills described the shafts of the rolls are in a perpendicular direction, and
the annular die lies horizontally, but it will readily be seen that this principle of
driving rolls within a die will work equally well if the shafts of the rolls are in a
horizontal direction and the die standing perpendicular and the driving mechanism
of either construction described will work satisfactorily in such position without
modification.

page_text: COMPLETE
SPECIFICATION.
Improvements in Machinery for Pulverizing Ores or other Hard
Substances.
1. EDWIN PACKARD, of Brooklyn, New York, United States of America, Engineer,
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 and accompanying drawings, (that is to say):--
This invention relates to pulverizing mills in which crushing rolls or rollers revolve
and travel against an annular die and consists in the improved construction, arrange-
ment, and combination of parts, the objects of which are:
First, to secure a positive application of the power employed, directly to the rotation
of the rollers whereby they travel against the annular die and crush the material
between them, by the momentum and centrifugal weight of the rolls.
Second, to provide yielding connection in the shafting whereby a single roller may
be positively rotated against the die.
Third, to provide suitable gearing attached to the driving shaft and the rollers
whereby several rollers may be positively rotated within and against the same die.
Fourth, to place the journals and connections of all operative parts requiring lubri
cation, outside the milling pan or chamber.
Fifth, to provide a suitable hopper and connections for delivering the material
immediately in front of the rolls.
Sixth, to secure the movement of material falling within the die by suitable wings
or lifting shoes attached underneath the rolls.
Seventh, to so place the screens, hopper and connections for removing the
ground material that it may be discharged from the mill, screened or unscreened,
wet or dry.
These objects are accomplished by the mechanism illustrated in the accompanying
drawing in which the same numerals indicate the same parts, and in which
Figure represents a vertical section of the improved mill.
Figure 2a plan view of the same, the roller shaft being in section, the driving
mechanism omitted, and part of the revolving top or cover broken away, and,
Figure 3 a view of a portion of an annular die and of a roller reversely shaped or
arranged from that shewn in figure 1.
In the drawing 1 indicates the base and pan or chamber of the mill, within which
the operation of pulverizing is carried on, and which is secured to a suitable support 2.
On the top of the said pan or chamber is secured the screen frame 3, which is
provided with an encircling trough 4 for receiving and discharging the pulverized
material passing through the screen 5.
This combined screen frame and trough is formed with a discharge spout 6, and
inner wall which is nearly vertical, and over the upper portions of the said wall is
secured an inwardly curved plate or cover 7.
The ring or anular die 8, against which the roller is revolved for pulverizing the
material, is inclined inwardly and secured between flanges projecting from the pan or
chamber and the screw-frame, as shewn in figure 1.
As thus arranged there is an annular space between the said ring or die and lower
end of the pulverizing roll, and the bottom of the pan or chamber, into which space
the partially and wholly pulverized material descends during the operation of the
mill.
An opening S₁, is formed near the bottom of the pan or chamber 1 and communi-
cates with a spout 8, through which the pulverized material may be discharged
beneath the ring or annular die.
Projecting upwardly from the bottom of the pan or chamber is a central boss 9, in
which is rigidly fixed a stud or shaft 10.
Surrounding this shaft and the upper end of the boss 9 is a loosely fitted sleeve 11,
which projects downwardly from an annular plate or disc 12 which is arranged within

page_text: the upper portion of the screen frame and constitutes a revolving top or cover for
the pulverizing pan or chamber.
On the under surface of this top or cover is secured or formed a feed spout 13
which delivers the material against the annular die, immediately in front of the roller
by which it is pulverized.
This feed spout is in communication with the receiving hopper 14, which is secured
by a centre 14, upon the upper end of the stationary stud or shaft 10 and provided
with a number of open bottomed compartments, 15, as shown in figure 2, which
successively correspond with the upper open end of the spout 13 during the revolution
of the top or cover 12.
This revolving cover is also provided upon its upper surface, at suitable intervals
round its periphery, with small wings or vanes 16, for causing a light current of air
to flow into the mill and effectually prevent the escape of dust through the space
between the stationary and revolving covers.
The crushing or pulverizing roller 17 is rigidly secured to the lower end of the
roll shaft 18 and positively rotated thereby against the annular die S. which is
arranged a suitable distance above the bottom of the pan or pulverizing chamber.
To the bottom of the roller are attached the stirrers 17', which may be made of steel,
chilled iron or other hard material. They are driven into and secured in suitable
dove-tailed grooves or flanges formed in or upon the bottom of said roller before the
tapered lower end of the roll shaft 18 is secured to the latter.
The roller shaft passes up through a slot 12¹ formed on the top or cover 12 and
is provided with a sleeve 19, which rests and revolves against suitable anti-friction
blocks 20, which are secured in flanges, projecting upwardly from the edges of a
plate, which covers a portion of the slot 12, in the top or cover 12 through which
the roller shaft passes.
This slot permits radial movement of the shaft and the roller at its lower end
when they are in operation and under the influence of centrifugal force.
The upper end of the shaft is connected to and suspended from a flexible or
universal joint 23, which is secured to a suitably supported driving shaft 24 having a
pulley 25, or other suitable gearing for imparting motion thereto.
A. spring of any suitable form may be secured upon the revolving top or cover 12
and arranged to press against the roller shaft 18 or the sleeve 19 thereon, so that the
roller 17, on being revolved, and also pressed radially against the ring or die 8 by
the said spring or centrifugal force, will be rotated upon its own axis against the
inner surface of the die, held thereto and made to turn round the central axis of the
ill or said die, and thus effectively pulverize the material introduced between it and
the die.
The roller 17 and the ring or die 8, as shewn in figures 1 and 2 are of such shape
and arrangement as to cause the roller to move truly within the die without slipping
or sliding vertically, but, under the shape and arrangement of the same parts, as
shewn in figure 3, there will be some vertical slipping or sliding motion of the roller
since the line of contact between the same and the die, if extended, would fall outside
of the universal joint or centre of motion, and, of necessity, permit some upward
movement of the roll over the inner surface of the die, which in grinding or pul-
verizing some materials, is found to be more effective than when the roller is confined
to a true or unvarying rolling motion against the die.
It is evident that the shape of the roller and die may be varied, as may he
found most effective in view of the nature of the material operated upon or the work
to be done.
Instead of only one roller three or more may be used. In this arrangement the
rollers are attached to the lower ends of taper shafts which rotate in bearings supported
by trunnions above, either as an integral part or as an attachment, so that the rollers
can move radially.
These shafts and the rollers are rotated by pinions securely fastened to the upper
extremity of the shafts, and which in turn are driven by a spur wheel attached to
and operated by a central shaft turning on a footstep attached to or forming part

page_text: of the lower pan. This shaft may be rotated by any suitable means. The trunnions
which carry the roller axles are journalled in and supported by a frame which rests
upon the central boss of the pan and rotates freely round the central shaft. To this
frame is attached the rotating cover and feed distributing spouts, and to these spouts
are secured by bolts or other fastenings, feed pickers and elevating shoes. Small
vanes or wings are attached to the revolving cover at its periphery, and slots in this
cover provide for the radial movement of the roller shafts, these slots being partly
covered by plates.
The rotation.of the rolls against the annular dies carries with them the frame and
all its attachments. The feed hopper in this case is placed at one side and opens
upon the die.
The operation of the improved mill with a single roller as shewn is as follows:-
Material being introduced into the stationary receiving hopper: 14 and power
applied to the pulley 25, the shaft 18 and the roller 17 will be rotated on their own
axis, made to turn round the centre of the mill and carry with them the top or
cover 12 and the feed spout 13, which rotate upon the stud or shaft 10.
The material fed into the stationary receiving hopper 14 is discharged from its
compartments, 15, into the feed spout 13, from which it is thrown against the die 8,
immediately in front of the roller 17 and is thereby crushed or pulverized; it then
falls upon the bottom of the pan or chamber, where it is kept constantly stirred or
agitated by the stirrers 17' on the bottom of the roller.
The stirrers also act in discharging the material both through the screens 5 and
into the trough 4 and through the opening 81 and the spout 8", according to
whether wet or dry grinding is being effected.
If water be introduced the material that is sufficiently fine will be passed out
through the screens 5 into the trough 4 from which it will be discharged through
the spout 6.
On the other hand, if it be desired to grind material in a dry state, the opening $1
will be unclosed, when the stirrers 17 will force the pulverized material out through
the said opening.
If this production be not sufficiently fine it may be screened and the tailings
returned to the mill.
The vanes or wings 16, as stated, cause a light current of air to be forced into the
mill, so as to effectually prevent the escape of dust through the space between the
stationary and revolving covers.
In this mill the positive rotary motion of the roller against the inner surface of
the die and its movement round the central axis of the mill are accomplished by giving
a positive rotary motion to the roller and, also radial movement, by centrifugal force,
and not by drawing or forcing it round on a spindle carried and driven by a revolving
centre or driver.
This peculiarity in the manner of driving the roller against the inner surface of
the die causes far less strain on the driving connections than any construction
heretofore devised for a similar purpose, as far as I am aware, and it also
accomplishes the pulverization of refractory substances in a most satisfactory manner.
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, with an annular die, of a radially moveable roller shaft
and roller and mechanism for positively revolving the same upon their own axis
and for turning them round the central axis of the mill, substantially as described.
2. The combination, with a pan or pulverizing chamber and an annular die
arranged above the bottom thereof, of a suspended, radially moveable roller shaft
and roller which are also arranged above the bottom of the said pan or chamber, and
mechanism for positively revolving the shaft and roller upon their own axis and for
turning them round the central axis of the mill, substantially as described.
3. The combination with the pau or chamber and the annular die or ring, of the

page_text: radially moveable shaft having a fixed roller at its lower end rotating against the
inner surface of the said die, mechanism for positively revolving the said shaft and
roller upon their own axis, and a universal joint for permitting of their turning and
connecting them to the revolving mechanism, substantially as described.
4. The combination, with the pan or chamber and the annular die or ring, of the
radially moveable shaft having a fixed roller at its lower end rotating against the
inner surface of the die, and mechanism for positively revolving and turning the shaft
and roller upon their own axis and round the central axis of the mill. the said
mechanism consisting of the driving shaft, the pulley and the universal joint sub-
stantially as described.
5. The combination, with a pan or chamber provided with an annular die and a
revolving top or cover, of a radially moveable roller shaft passing through the said
cover and having a roller at its lower end, and mechanism for positively revolving
the said shaft and roller upon their own axis and for turning them round the
central axis of the mill, and revolving the said top or cover, substantially as
described.
6. The combination, with the pan or chamber 1, provided with the annular die S,
and the top or cover 12 formed with the radial slot 121 and provided with the plate
having anti-friction-lined flanges, of the radially moveable shaft passing through the
slot in the said cover and provided with the sleeve 19 and the roller 17, and mechanism
for positively revolving the said shaft and roller upon their own axis and for turning
them round the central axis of the mill and revolving the said top or cover, sub-
stantially as described.
7. The combination, with the pan or chamber provided with an annular die and
a revolving top or cover having a feed spout, of a stationary receiving hopper com-
municating with the said feed spout, a radially moveable roller shaft passing through
the said cover and having a roller at its lower end, and mechanism for positively
revolving the said shaft and roller upon their own axis and for turning them round
the central axis of the mill and revolving the said top or cover substantially as
described.
8. The combination, with the pan or pulverizing chamber and an annular die
arranged above the bottom thereof, of a suspended, radially moveable roller shaft;
a roller secured to the lower end thereof and provided with stirrers on its lower end,
which are also arranged above the bottom of the said pan or chamber,and mechanism for
positively revolving said shaft and roller upon their own axis and for turning them
round the central axis of the mill, substantially as described.
9. The combination, with the pan or pulverizing chamber 1, formed with the
opening S and provided with the annular die 8, the screens 5, and the screen frame 3.
of the suspended radially moveable roller shaft 18, the roller 17 secured to the lower
end thereof and provided with the stirrers 17, and mechanism for positively revolving
said shaft and roll upon their own axis and for turning them round the central axis
of the mill, substantially as described.
10. In a pulverizing mill, the combination, with the pan or pulverizing chamber 1,
formed with the opening 8 and provided with the annular die S, the screen 5. and
the screen frame 3. formed with the trough 4 and spout 6 of the suspended radially
moveable roller shaft 18, the roller 17 secured to the lower end thereof and provided
with the stirrers 17 and mechanism for positively revolving the said shaft and roller
upon their own axis and for turning them round the central axis of the mill, the said
mechanism consisting of the driving shaft 24, the pulley 25 and the universal joint 23,
substantially as described.
Dated thie (1
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Patentos.