Certain Improvements in Crushing and Pulverizing Mills.
Year: 1890

page_text: Date of Application, 14th Jan., 1890-Accepted, 15th Feb., 1890
COMPLETE SPECIFICATION.
Certain Improvements in Crushing and Pulverizing Mills.
I, MILES BENJAMIN DODGE, residing at No. 8 Hill Street, in the city and county.
of San Francisco, and State of California, one of the United States of America,
Mining 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 :-
My invention relates to improvements in rotary pulverizers, in which the ore or
cement is crushed or pulverized in a rotating cylinder or chamber by means of
mutual attrition of particles, assisted by pieces of iron or other material which is
contained in the chamber with the material to be crushed.
My invention consists in an improved manner of securing the grate-bars which.
form the sides of the chamber so that they may be kept perfectly tight and prevented
from loosening, and in certain details of construction of the adjustable mechanism,
all of which will be more fully explained by reference to the accompanying drawings;
in which
Figure 1 is a longitudinal vertical section of my pulverizer.
Figure 2 is a vertical section, taken transversely through the axis and the grate
bars from the sides.
Figure 3 is an enlarged perspective view, showing the wedge, the devices for
locking the grate-bars in place, and the elastic buffer, the parts being separated from
each other.
Figure 4 is an enlarged section taken through one end, showing the wedge, cushion,
and locking device.
Figure 5 is an enlarged transverse section of one of the cylindrical projections, and
the sleeve fitting over it.
Figure 6 is an end view of the nut-lock.
Figure 7 is an enlarged interior perspective view, showing a portion of one of the
heads of the machine, the grate-bars, and the locking-bar at the angle.
A, A care the heads of the machine, between which extend the grate-bars B, the
ends of these grate-bars slipping into slots or channels, which are formed by projecting
strips C, cast on the head of the machine, and supplemental plates D, which are
bolted so that their edges are a sufficient distance from the strips C, to form the proper
channels to receive the ends of the bars B, as plainly shown in Figure 7: The shape
of the interior chamber when the bars are in place is hexagonal, there being narrow
spaces between the bars B, through which the material can escape when pulverized
finely enough, and that portion of the material which is sufficiently fine will pass.
through the screens E, which are exterior to these bars.
There are spaces left where each of the sides overlap the next adjacent sides, as
shown at F, Figure 2, and (the drum turning from right to left, as shown by the.
arrows, Figure 2; it will be seen that material within the drum will be prevented.
from passing through these spaces F, so as to fill the space between the outside of the
bars and screens; but any material which passes between the bars, and is not fine
enough to pass through the screens, will be returned into the drum through these
spaces F, and will be again subjected to the attrition and crushing action, until it is
ufficiently fine to pass through the screens.
I have found great difficulty in securing the bars B, so that they will not become
oose and wear themselves out rapidly by the constant jar and action of the machine; .
and for the purpose of overcoming this difficulty and securing these bars solidly in
place, I employ longitudinal bars G, which extend from end to end of the machine
nd in line with one side of each set of bars B,

page_text: The end of this bar G, is chambered and has an inclined surface, as shown plainly
at H, Figure 4, and a wedge I, fits into this chamber in such a manner that when
drawn outward, it presses against the inclined surface H, and thus forces the bar
against the edge of the outer grate-bar B, so as to crowd the grate-bars against
the opposite end of the channel in which they lie and prevent their moving.
In order to operate this wedge I, the outer end is continued in the form of a
long screw-bolt J, which extends out through the end A of the crushing cylinder
or drum.
A cylindrical chamber K, is formed upon the end of the drum, through which each
of the screw-shanks J, passes. and outside of these cylinders is fitted a sleeve L, which
slips over the cylinder K. Upon the outside of the cylinder K, are formed lugs M,
which extend lengthwise of the cylinder, and corresponding grooves or channels N,
are made in the inside of the sleeve L, so that these channels fit over the. lugs, and
thus prevent the sleeve L, from turning around upon the cylinder.
O is a spring of any description, but, preferably, a rubber buffer in the form of a
thick disk or cylinder, and it has a hole through its center, so that it may slip down
over the screw-shank J, and rest upon the head of the cylinder K, as shown plainly in
Figure 4.
Outside of this rubber disk is an iron disk-washer or plate P, which also slips over
the bolt J, and rests upon the outside of the elastic buffer O.
In order to prevent this plate P, from turning around upon the buffer, it is provided
with projecting arms Q, which enter corresponding slots R, in the outside of the
sleeve L.
It will be manifest that by making the cylinder K, and washer P, of larger
diameter, or the spring O, of smaller diameter, I can omit the sleeve L, and by
the arms engaging lugs or grooves on the outside of cylinder K, the parts are
prevented from loosening by the constant jar of the machine.
The outer face of the plate P, is chambered, as shown at S, so that the nut T,
which screws on to the end of the bolt J, fits into this chamber.
A small rectangular extension of the depressed chamber S, is made, as shown at U,
and into this chamber is laid a small rectangular piece of metal V, so that when
the nut T, is turned to present one of its rectangular sides to this chamber, and the
piece is laid into this chamber, it acts as a nut-lock, preventing the nut from
turning backward.
Outside of this chamber is fitted a guard-plate W, which is secured by a bolt and
screw upon the exterior of the plate P, and this retains the locking-piece V, in its
chamber, and prevents its falling out.
The operation will then be as follows:
The grate-bars B, having been laid in their channels so as to form the hexagonal
chamber, as shown more plainly in Figure 2, the bars G, are laid so as to rest against
the side of the grate-bar nearest the opening F; the opposite grate-bar resting
against a stop at the opposite end of the channel.
The wedge I is then laid into the channel in the bar G, so that its inclined face
rests upon the inclined bottom H, of the channel; the screw-shank J, passing out
through the cylindrical chamber K, the elastic buffer O, and the exterior plate or
washer P.
The nut T is then screwed upon the bolt J, and screwed down upon the exterior
plate or washer P, until the spring O is compressed as much as may be desired; this
action drawing the wedge Joutward, and forcing the bar G, strongly against the
sides of the adjacent grate-bar B; which action crowds all the grate-bars closely
together, and prevents any motion.
The nut T, being turned to the proper place, is secured by the locking-plate V,
and the guard-plate W, outside of it.
The elasticity of the buffer O, causes it to maintain a constant pull upon the bolt J,
and wedge I, so that any wear or tendency to loosening in any of the parts will be
immediately and automatically taken up by this action, and the bars will thus be

page_text: prevented from moving, and from the rapid and excessive wear which takes place
whenever they are allowed to become loose and move upon each other and the particles
of rock which are forced in between them.
far
as
Whenever there is so much wear that the wedge I has moved out as
possible, it may be moved back by unscrewing the nut and by introducing a
shim X, which lies upon the inclined bottom H, of the chamber in the end of the
bar G, the wedge will again act as at first described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim, is
1. A rotary pulverizer, comprising a polygonal drum having channeled heads,
parallel bars forming the sides of said drum, locking bars G, lying parallel with and
adjacent to each of the sides and having inclines at their ends, wedges acting upon
said inclines, screw-shanks and nuts by which the wedges are drawn out and locked,
and the elastic springs or buffers, upon which the pressure is exerted, and by which
the wedges are automatically adjusted, substantially as and for the purpose described.
2. The locking-bars G, having the inclined surfaces at their ends, the wedges I,
pressing upon said inclines, and having the screw-shank J, by which they are
operated, in combination with the cylindrical extension from the head of the rotary
drum, into which the wedges are drawn, the keys or lugs M, on the extensions, the
springs O, and the exterior plate or washer P, with the corresponding keyways or
channels by which the washer is prevented from turning upon the cylinder, the
nut-locking and guard-plates V, and W, substantially as described.
3. A rotary pulverizer, comprising the polygonal drum, the parallel bars forming
the sides thereof, wedge-shaped locking-bars having screw-shanks adjacent to said
side-bars, the cylindrical extension K, through which the screw-shank of the
wedge-shaped bars pass, the springs O, the exterior washers or plates P, the nuts
resting against said plates, and the arms Q, upon said washers or plates, and engaging
lugs on grooves, whereby the washers are prevented from turning, substantially as
described.
Dated this Fourteenth day of January 1890