Improvements in Apparatus for Grinding Middlings and the like.
Year: 1899

page_text: Date of Application, 10th Jan., 1899-Accepted, 25th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Apparatus for Grinding Middlings and the like.
I, JOHN ELVIN MICHELL, of corner of Liberty Street and Park Place, Jackson,
in the County of Jackson, State of Michigan, United States of America, Miller,
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 follow-
ing statement:
My invention relates to grinding mills that are more particularly designed for
the reduction of middlings and other products of wheat flouring mills that have
been previously sized or Hattened, as by the action of a roller mill.
It is a principal object of this invention to provide simple and thoroughly
effective mechanism for disintegrating and pulverizing the material to be treated
and at the same time avoid the cutting action that attends the employment of
mill stones, grinding-burrs or rotary disks or rings, and the flattening action of
the roller process of grinding. To this end it is the purpose of my invention
to effect the reduction of middlings and similar material by the abrasive action
of rotary spiral or convolute blades operating upon an accumulated body of such
material confined under an automatically regulated pressure in an annular cham-
ber of wedge-shaped cross section between the converging peripheral portions of
two reversely dished and stationary pressure plates. The material acted upon is
disintegrated between the abrasively acting surfaces of the extreme ends of said
rotary convolute blades, on one hand, and the converging walls of the confining
pressure plates, on the other hand, and the reduced material is continuously
forced outward through an annular adjustable opening formed by and between
the opposing circumferential edges of the stationary pressure plates. Other pur-
poses and objects of the invention will appear from the features of construction
and novel combinations of parts in a grinding mill, as hereinafter more particu-
larly set forth.
In the annexed drawings illustrating the invention―
Figure is a vertical section of my improved grinding mill.
Figure 2 is a horizontal section on the line 2-2 of Figure 1.
Figure 3 is an elevation of the grinding mill, at a right angle to Figure 1.
Referring to the drawings, the numeral 1 designates a substantial main frame
provided with suitable bearings for a vertical shaft and a lower horizontally
arranged shaft 3 to which a driving pulley 4 is secured, the said shafts 2 and 3
being connected by bevel gearing 5, as shown.
To the top of the main frame there is securely bolted the bottom 6 of a
stationary cylindrical casing 7 by which the upper portion of the vertical shaft 2
is surrounded.
The cylindrical casing 7 has an upper head or cover 8 in the centre of which
is a circular feed inlet 9 around which a cylindrical feed hopper 10 is mounted.
An annular and dished upper pressure plate 11 is bolted in an inverted posi-
tion to the under side of the cover 8, around the feed inlet and a dished lower

page_text: This lower pres-
sure plate 12 is supported underneath by a horizontally arranged plate or bar 13
that is suspended by means of rods 14 which are extended through the cover 8
and surrounded by spiral springs 15 resting on said cover. The upper ends of
these rods 14 are screw-threaded for attachment of thumb nuts 16 bearing on the
springs 15 which thereby provide a yielding and adjustable support for the lower
pressure plate. Obviously any other suitable means may be provided for adjust-
ing the lower pressure plate, if desired.
pressure plate 12 is adjustably supported beneath.
It will be obvious by reference to Figure 1, that the pressure plates or disks 11
and 12 are reversely dished and that their bevelled or dished peripheral portions
are spaced apart so as to afford an annular opening 17 leading out from an
annular chamber 18 of wedge shaped cross section the upper and lower walls of
which are formed by the converging portions of said pressure plates. Obviously,
the width of the annular opening 17 can be increased or diminished, as may be
desired, by simply adjusting the thumb nuts 16 on the screw rods 14 that suspend
the lower dished presure plate. Both pressure plates 11 and 12 are stationary
except for the vertical adjustment given to the lower plate.
The upper portion of the vertical shaft 2 carries spiral blades 19, Figures 1
and 2. that are arranged to rotate in a horizontal plane between the stationary
dished pressure plates 11 and 12, in the direction of the arrow shown in Figure 2,
so as to have a conveying action from the centre to the circumference. On the
top of the scroll formed by the spiral or convolute blades 19, at their outer ends,
there is secured an annular flange 20 the inner periphery of which coincides
with the central feed inlet 9 through the cover 8 and upper dished pressure plate.
This annular flange 20 turns with the spiral blades 19, in a circular guideway 21
formed in the inverted upper dished pressure plate 11, and a similar guideway 22
may be formed in the lower dished plate 12 for the lower edges of the spiral
blades.
The annular flange 20 provides a brace for the spiral blades 19 and also serves
as a guard so that as the material to be disintegrated and pulverised is fed into
the machine through the hopper 10 it will first drop to the central portion of the
scroll and then be at once conveved outward by the spiral blades and forced into
the annular wedge shaped chamber or space 18 and thence through the annular
opening 17 in its periphery. There is no such flange at the bottom of the scroll,
because in that situation it would afford an objectionable lodgement for the
material and would thereby interfere with the required action of the spiral blades.
The degree of presure necessary for forcing the bedy of the material out through
the annular opening 17 depends on the raising and lowering of the lower pres-
sure plate 12, by means of the adjusting thumb nuts 16 on the suspension rods.
It is obvious that the more narrow the annular opening 17, the greater will be
the pressure necessary for forcing a given quantity of material through said
opening and, consequently, the finer will the material be pulverised. The pul-
verizing or disintegrating of the material is effected by abrasive action of the
ends of the rotary convolute blades 19 against the accumulated laver of material
confined under messure between the converging walls of the dished plates 11,
12, the degree of this pressure being determined by the adjustment of the lower
pressure plate. The lower pressure plate or disk 12 is held in yielding suspen-
sion by the springs 15 the action of which allows said lower plate to vield some-
what so as to adjust itself automatically to any slight irregularities in the bulk
A regulated
or quantity of material being fed into and through the machine.
adjustment can be given by means of the thumb nuts 16, as before described.
To increase the disintegrating and pulverizing action of the convolute or spiral
blades 19, their outer end portions may be provided with corrugations, 23,
Figure 2, if desired, or the ends of the blades may be left smooth.
The reverselv dished pressure plates or disks 11 and 12 are stationary except
for the vertically yielding adjustment of the lower plate, it being the purpose
of these plates to confine the material under a regulated pressure while disinte-

page_text: gration or pulverising is effected through the friction induced by the bulk of
material acted on by the rotary spiral blades.
The pulverized material passing through the narrow annular opening 17 falls
onto the bottom 6 of the cylindrical casing 7 and is then carried by rotary arms or
sweeps 24 to a discharge spout 25, Figure 3, through which it makes its exit
from the machine. The rotary arms 24 are carried by the vertical shaft 2 and
operate within the lower part of the casing 7 from the bottom of which the dis-
charge spout 25 depends."
In Figure 3, the number 26 designates lubricating devices for the bearings
of the vertical shaft 2 by which the abrasive scroll blades 19 and sweep arms 24
are carried.
With this machine, the material acted on is disintegrated or reduced by
abrasive action of the convolute or spiral blades 19 against the layer of material
confined between the converging walls of the stationary and reversely dished
pressure plates 11, 12; and the annular circumferential opening 17, is simply to
afford automatic discharge of the reduced material, as controlled by the yielding
adjustment of the lower pressure plate. The more pressure necessary to open or
widen this annular passage 17, the more severe will be the abrasive or disinte-
grating action of the scroll blades 19 on the material passing between the ends
of said blades and the converging peripheral portion of the dished pressure
plates. The machine is thoroughly operative, practical and successful, for the
reduction of fine middlings, stock or material that has been sized down or flat-
tenel by previous reductions of a roller mill.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. In a grinding mill, the combination with stationary dished pressure plates,
one inverted over the other with an annular automatically adjustable opening
between the adjacent edges of said plates and a central feed inlet through the
upper plate, of rotary spiral blades mounted between said dished plates to exert
a disintegrating action on the layer of material confined between the converging
walls of said plates and the rotary spiral blades and force the disintegrated
material outward through said annular opening, substantially as described.
2. In a grinding mill, the combination of a stationary casing having in its
top a central feed inlet, stationary dished pressure plates, one inverted over the
other with an annular automatically adjustable opening between the adjacent
edges of said plates, the upper plate being provided with an annular opening
in communication with the central feed inlet, and rotary spiral blades mounted
between said dished plates to exert a disintegrating action on the layer of material
confined between the converging walls of said plates and the rotary spiral blades
and force the disintegrated material outward through the annular opening
between said plates, substantially as described.
3. In a
grinding mill, the combination of a stationary vertical cylindrical
casing provided at the top with a central feed inlet, a stationary annular upper
dished pressure plate secured in said casing in an inverted position around the
under side of the feed inlet, a stationary lower dished pressure plate supporte-]
in said casing blow the annular upper dished plate with an annular opening
between the adjacent edges of said plates, and rotary spiral blades mounted
b. tween said dished plates to exert a disintegrating action on the layer of
material confined between the converging walls of said plates and the rotary
spiral blades and force the disintegrated material outward through the annular
opening between said plates, substantially as described.
4. In a grinding mill, the combination of a stationary vertical cylindrical
casing having in its top a central feed inlet and provided with a discharge spout
at the bottom a stationary annular upper dished pressure plate secured in said
casing in an inverted position around the under side of the feed inlet, a stationary
lower dished pressure plate supported in said casing below the annular upper

page_text: dished plate, the said plates having an annular opening between their opposing
edges, means for adjusting the said lower plate vertically to vary the width of
said annular opening, a vertical rotary shaft extended centrally through said
stationary casing and inclosed stationary plates, rotary spiral blades mounted on
said shaft between the said pressure plates to exert a disintegrating action on the
material confined between the converging walls of said plates and the rotary
spiral blades and force the disintegratel material outward through the annular.
opening between said plates, and rotary arms carried on the vertical rotary shaft
immediately below the lower pressure plate to convey the reduced material to
the discharge spout, substantially as described.
5. In a grinding mill, the combination of a vertical rotary shaft, a cylindrical
casing supported around a portion of said shaft and having an upper head or
cover provided with a central feed inlet, a discharge spout in the bottom of said
casing, an annular upper dished pressure plate secured in an inverted position
in the upper part of said casing around its feed inlet, a lower dished pressure
plate movable to and from the said upper plate to vary the width of an annular
opening between the peripheral edges of said plates, rotary spiral blades mounted
to operate in a horizontal plane between said reversely dished pressure plates,
rods for suspending the lower pressure plate, springs and adjusting nuts on said
rods, and rotary arms mounted below the pressure plates to convey the disin-
tegrated material to the discharge spout, substantially as described.
Dated this 10th day of January 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.