Note: Descriptions are shown in the official language in which they were submitted.
Docket 6340 ~ Z S
Background of the Invention
Field of the Invention
The present invention relates to sorting devices
and more particularly, to sorting devices for wood chips
according to their thickness, to be used in the production
of paper pulp.
Prior Art
The great majority of devices used for sorting
varying sizes for material chips generally utilize screens
having an appropriate mesh that will permit chips smaller
than certain dimensions in thickness, length and width to
10 pass through the screen and be collected, while the rejected ;
materi.al passes over the screen for subsequent disposal.
Other prior apparatus for this purpose utilizes
a plurality of equal diameter disks disposed in a plurality
of rows, over which the material to be sorted i9 fed.
The disks rotate in the same direction, which causes the
material to progress along the sorting device. Such
devices are intended primarily for a gross separation of
chunky or elongated over sized chips from materials of a
generally smaller size. The acceptable smaller sized
chips pass between the disks relatively easily, while the
over sized chips are held back by the disks and carried to
the discharger. Long thin pieces which would be acceptable
except for their length, because they are longer than the
distance between disks, are transported crosswise to the
direction of flow of the other chips to the discharge end
of the apparatus.
-2-
Docket 6340 ~ ~161Z~
When using such a device for gross sorting of
wood chips, it is thus necessary that the material not
be upset too much or the longer thin pieces will pass
through the disks and contaminate the acceptable chips
S being collected. The disks are therefore of uniform
diameter so that the chips will be horizontally trans-
ported along the device.
A further disadvantage associated with this
latter type of prior art device is that when disks having
a smooth outer peripheral edge are used, the material chips
being sorted tend to slide over the disks and not be gripped
thereby, and are therefore not as eff~iciently sorted as is
desirable, which results in a substantial loss of otherwise
usable material chips that remain with the rejected chips
and are disposed of.
Another disadvantage associated with these
prior art devices is that when some form of member having
other than a circular disk shape'is utilized, for example,a
star-shaped or other convoluted periphery, these members in
adjacent rows are arranged to mesh with each other like
gears while rotating at the same peripheral speeds in order
to avoid upsetting the oversized chips and thereby interrup-
ting their orderly travel along the tops of successive rows
of disks, but this also results in carrying to the reject
outlet a good number of chips which would be accepted if
upset to present a different dimension to the spaces between
adjacent disks.
I~ -3-
Z~
Summary of the Invention
The present invention overcomes the above described
difficulties and disadvantages associated with prior art
devices by providing a material chip thickness sorting
apparatus which not only sorts chips of acceptable thickness
of small enough width and length to pass between adjacent
discs, but upends long chips of the desired thickness so that
they too will be separated into the accepted material.
In accordance with one aspect of the invention
apparatus is provided for sorting selectively a mixture of chips
of differing maximum thicknesses to segregate those chips hav-
ing a predetermined maximum thickness from those chips having
a thickness below the predetermined maximum thickness. The
apparatus includes a plurality of rows of discs rotatably
mounted about substantially parallel axes of rotation with
adjacent rows of discs intermeshing and drive means for rotat-
ing the discs. Means is also provided for feeding the mixture
of chips to the tops of the discs adjacent a first row of the
discs for transportation along the tops of the discs. The
intermeshing rows of discs define spaces between them having a
dimension parallel to the axes of rotation of the discs which
is about equal to the maximum thickness referred to above.
The rotating discs have different diameters and radially
contoured peripheries such that turbulence is generated in the
chips as they move from the feed means along the tops of the
discs to cause the chips to be continuously reoriented and their
minimum dimension presented to the spaces between the discs.
--4--
`' ~.~.G12~
The apparatus of the invention utilizes a plurality
of parallel rows of disc members with the discs in each row
disposed in spaced parallel vertical relation along a common
horizontal central axis of rotation. The discs of adjacent
rows intermesh radially with equal axial spaces between them
to permit chips of no greater thickness than such space to
pass downwardly between the overlapping disc surfaces, the
width of this space being controlled to correspond with
the maximum desired thickness of accepted chips.
The chips to be sorted are fed into the apparatus
above the first of the rows of the discs. The material
leaving the infeed will then be transported over the discs,
with chips whose thickness is less than the width of the space
between adjacent intermeshing discs dropping therebetween.
-4a-
Docket 6340 ~ ~61Z5
The remaining thicker chips are transported to the last
of the rows of disks and dropped onto an output device
for removal from the apparatus.
It is important to the practice of the inven-
tion that adequate provision be made to develop forcestending to align the traveling chips lengthwise with
the disks and also to upset them so that they present
their thicknesses to the spaces between adjacent inter-
meshing disks. A particularly effective way of accomplishing
this result is to cause adjacent disks to rotate at dif-
ferent peripheral speeds. One preferred form of the
invention for this purpose has the disks in each ~ow of
alternating diameters, e.g. a two-inch variation, so
that even if all rows are driven at ~he same angular
rate, both aligned and intermeshing disks will rotate
at different peripheral speeds.
In another form of the invention, the desired
difference in peripheral speeds of adjacent disks is
accomplished by having the disks in each row of a different
common diameter from those in the adjacent row or rows,
and to drive all rows at the same angular rate. The
resulted repeated changes in the rate of forward movement
of the chips along the tops of the disks, and in their
vertical inclinations as they pass from disks of one
diameter to those of another diameter, are effective in
upsetting the chips to present them in the appropriate
alignment for passage between intermeshing disks if they
are within the acceptable thickness range.
Docket 6340 l~ Z5
As an alternative form disks of uniform
diameter can be used, in which case adjacent rows
- should be driven at different angular rates to produce
different peripheral speeds of disks in adjacent rows.
Other arrangements of disks and spacers in accordance
with the invention,are described in detail hereinafter.
In every case, each disk has a radially contoured outer
peripheral edge portion, with the depth of the contour
sufficiently shallow to prevent chips of thickness greater
than the predetermined thickness from passing between the
outer peripheral edge of a member and an opposing spacer,
the purpose of the contoured disk periphery being to
avoid smooth cylindrical edges which will have minimum
frictional or gripping engagement with the chips.
The contoured peripheries of tne disks provide
a gripping action facilitating transport of the chips
across the tops of the rows of disk members, and a
plurality of forms of disk peripheries are provided by
the present invention. One preferred form has a contour
formed of a plurality of blending alternately reversed
radii in the plane of the disk, with the radii being
sufficiently small that chips of greater than the desired
thickness will not pass between the outer peripheral con-
toured edge portion of a disk and an opposed spacer.
An alternative form of disk periphery has a
contour defining a plurality of spaced, substantially
semi-circular recesses in the plane of the disk wlth
Docket 6340 ~ lZ~
the depth of the semi-circular recesses being limited
as with the radii mentioned above. A further alternative
construction is a peripheral contour formed of a plurality
of generally triangular tooth-like protrusions in the
plane of the disk with the depth between protrusions being
limited as with the radii mentioned above.
A still further alternative disk construction
has a peripheral contour formed of a plurality of wave-like
projections having a radiused leading edge portion in the
direction of rotation of the disk and a generally flat
portion extending radially inward toward the bottom of
the radiused portion of the rearwardly adjacent projection
and formed in the plane of the disk with the depth of
the contour being limited as aforementioned.
Many other forms of the peripheral contour of
the disks are possible, so long as the depth of the
contour is such that it will prevent chips of greater
than the desired thickness from passing between the
edge of a disk and an opposed spacer. In addition, the
pattern of different peripheral speeds of adjacent disks
is preferably such that the longer chips of acceptable
thickness will be oriented parallel to the flow of
material over the disks rather than crosswise as with
prior art devices. This assists in the up-ending of
such long chips so that they can more easily pass between
the disks.
A further advantage of the present invention
over such mentioned prior art devices is in the possibility
of an alternate construction in which rows of the disks
Docket 6340 ~6~25
are provided in an inclined plane rather than in a
horizontal plane as is contemplated as one alternative
embodiment of the present invention. The inclined plane
may be either upwardly or downwardly inclined relative
S to the infeed and outfeed mechanisms, so that the rate
of material feed may be increased or decreased as desired.
In addition to the use of an inclined plane, it
is contemplated, as a further alternative, to use a
cascading arrangement of the rows of disks wherein a
plurality of rows would be in a horizontal plane adjacent
the infeed mechanism, a further plurality of rows would
be downwardly inclined and subsequently disposed adjacent
the first set of horizontally disposed rows, and a third
plurality of rows would be horizontally disposed subsequent
to the inclined rows and leading to the output mechanism.
This would produce a variable rate of material flow which
would assist in up-ending or otherwise reorienting the
chips so that those of the desired thickness would pass
between the disks of the device.
Before proceeding to description of preferred
embodiments of the invention, it should be noted that
while the apparatus of the invention was developed essen-
tially for the sorting of wood chips for use in the
manufacture of paper pulp, it is applicable to the sorting
of chips of other materials in accordance with thickness,
and is particularly applicable to such chips which are of a
substantial range of length and width dimensions. Accor-
dingly, references herein to "chips" are to be understood
as correspondingly comprehensive and not limited to wood
chips.
lZ5
Docket 6340
Brief Description of the Drawings
Fig. 1 is a side elevational view of a preferred
embodiment of the present invention;
Fig. 2 is a rear elevational view of the emhodi-
ment of Fig. l;
Fig. 3 is a partially cut away top plan view
of the embodiment of Fig. l;
Fig. 4 is a top plan view of an alternative
construction of the disk members and opposed spacers of
the invention;
Fig. 5 is a front elevational view of the disk
member arrangement shown in Fig. 4;
Fig. 6 is a top plan view of a second alternative
arrangement of the disk members of the invention;
Fig. 7 is a front elevational view of the disk
member arrangment shown in Fig. 6;
Fig. 8 is a top plan view of a third alternative
arrangement of the disk members of the invention;
Fig. 9 is an illustration of a fragment of a
preferred contoured edge portion of the disk members of
the invention;
Fig. 10 is an illustration of a fragment of a
second preferred form of contoured edge portion of the
disk members of the invention;
Fig. 11 is an illustration of a third contoured
edge portion of disk members of the invention;
Fig. 12 is an illustration of a fourth alternative
construction of the edge portion of a disk member of
the invention;
.
12~i .
Docket 6340
Fig. 13 is a partial cross sectional view of
the contoured edge portion of a disk member of the
invention showing a doubled edge portion;
Fig. 14 is a schematic view showing the hori-
zontal positioning of a plurality of rows of disk membersof the invention;
Fig. 15 is a schematic view showing a cascading
plurality of rows of disk members of the invention;
Fig. 16 is a schematic view illustrating an
upwardly inclined row of disk members relative to the
direction of flow of the material; and
~ ig. 17 is a schematic illustration of a plurality
of rows of disk members inclined downwardly relative to
the direction of flow of material.
Detailed ~escription of the Preferred Embodiments
Referring to Figs. 1-3, the basic construction
of the apparatus of the present invention includes a
frame structure 10 and a plurality of disk members 12
with spacers 14 mounted between the disks, all of which
; 20 are secured for rotation to a plurality of drive shafts 16
rotatably supported in the frame structure 10. The drive
shafts 16 are driven by a chain 20 through a sprocket 18
which in turn is driven by motor 22 via sprocket 24,
chain 25 and a sprocket 26 on the same shaft 27 as sprocket 18.
Above the first row of disks 12 is an infeed
chute 30 through which the chips to be sorted are intro-
duced into the apparatus. Arrows A show the direction of
Z5
Docket 6340
flow of *he material chips to be sorted, arrows B show
the direction of flow of chips of the desired size which
have fallen between the disks 12, and arrow C shows the
direction of flow of the discarded chips which are thicker
than desired.
The frame structure 10 is basically of tubular
steel construction made sufficiently strong to carry the
weight of the apparatus as well as the load of the material
chips being sorted. Safety screens 32 are preferably
removably secured to the sides and ends of the apparatus,
over that portion which houses the drive mechanism, so as
to prevent possible injury to individuals working around
' the apparatus. The screens 32 are removable so that the
drive mechanism of the apparatus may be serviced.
'rhe infeed chute 30 is preferably made of sheet
metal constructed to produce a chute having a rectangular
cross section, but which is radiused at the bottom portion
33 so that the chips are introduced at a tangent to the
first row of disks 12. The infeed chute 30 is pr,eferably
secured to the top of the frame structure 10 such as by
means of brackets 36 bolted to the frame structure and to
the infeed chute. Sheet metal can also be used to provide
sides 37 and 39 on each side of the disks 12, to provide a
guide for the material chips from the infeed to the
discharge.
All of the drive shafts 16 which support the
disks 12 are rotatably supported in the frame structure 10,
by bearings 40 which are in turn supported on suitable '
` Docket 6340 1~161Z5
parts of the frame structure 10. At one end of each
drive shaft 16 is a sprocket 44 which is in driven
engagement with chain 20. At the opposite end of each
drive shaft 16, a plurality of alternating disks 12
and spacersl4 are clamped between a shoulder 45 on the
shaft and a nut 46 threaded on the end of the shaft
inboard of the adjacent bearing 40.
As stated above, all of the sprockets 44 are
in driven engagement with chain 20, which extends between
drive sprocket 18 and ollower sprocket 50. In addition,
two idler sprockets 51 and 52 are provided to maintain
appropriate driving engagement of the chain 20 with the
sprocket 44 on each drive shaft 16.
The drive motor 22 can be of any desired charac-
teristics sufficient to provide the necessary power rangefor driving the disks 12 at the necessary rotational
speeds for proper sorting of the material chips. By way
of example only, in an apparatus constructed as shown in
which six rows of generally disk members 12 of a diameter
in the range of 15 to 17 inches, and with each row of
disks approximately 12 inches long, a one-horsepower
variable speed drive motor, which will vary the mo~or
output drive shaft speed hetween 114 rpm and 1117 rpm,
is satisfactory.
It is also desirahle to be able to change the
diameter of drive sprocket 24, and thus the drive shaft
of the motor should be provided with some means for
chan~ing this sprocket as h~ell. In general, a speed
ran~e of 20 to 40 rpm for the disk shaft 16 has been
found satisfactory.
t~-'J ~
-12-
~ Docket 6340 l~l~lZ5
Referring now to Fig. 8, a variety of disk
members 12 and spacers 14 are contemplated for use with
the present invention, the preferred ones of which are
shown in these figures. Fig. 4 illustrates one such
pattern in which a series of first disk members 78 of
relatively large diameter are disposed on drive shafts 16
with alternatively positioned relatively smaller diameter
disk members 80, all of which are separated by relatively
larger and smaller diameter spacers 82 and 84, respectively.
This construction provides each row of disks
with a pattern of alternately relatively larger and
smaller disks which intermesh with an adjacent row of
disks so that in the apparatus, there will be alternate
pairs of adjacent equal diameter intermeshing disks of
larger and smaller diameter, while on each row there will
be a repeating pattern of larger and smaller diameter
disks.
The spacers 82 and 84 have outer diameters such
that the distance from the edge of either size disk to
the edge of the opposing spacer will be not greater than
the distance between adjacent intermeshing disks. Tha*
is, in the case of a relatively larger disk 78, the corres-
ponding opposed spacer 84 will be of a relatively smaller
diameter than spacer 82, so that the distance between the
outer peripheral edge of disk 78 and spacer 84 is not
greater than the distance between two adjacent inter-
meshing disks.
-13-
6i12~;
Docket 6340
The preferred relative diameters of this disk
pattern is best seen in Fig. S. For example, where the
larger disks 78 are approximately 17 inches in diameter,
it is advantageous to utilize relatively smaller disks 80
of a diameter of 15 inches. These dimensions, however,
should not be considered as limiting, and substantial
variations in the relative dimensions can be made without
detracting from the advantages of the invention.
Referring to another pattern which may be utilized
in the present invention, Fig. 6 again illustrates the
use of two different diameter disk members 78 and 80,
but in this variation all of the disks on any given drive
shaft 16 are of the same diameter, while the adjacent
shaft or shafts will contain either the larger or smaller
diameter disks. This pattern provides adjacent intermeshing
disks which are alternately larger or smaller, while on
any given row the disks are of the same diameter.
A third variation of disk pattern is illustrated
in Fig. 8, wherein the pattern of disk members in each
row is such that a single, relatively larger diameter
disk 78 is followed by two relatively smaller diameter
disks 80, with this pattern being repeated for the width
of the disposition of the disks on the drive shaft.
Adjacent drive shafts have the same pattern, but are
staggered so that a larger diameter disk 78 is disposed
between smaller diameter disks 80 on an adjacent drive
shaft. The spacers 82 and 84 are so arranged that they
-14-
Docket 6340 1~161ZS
correspond with the s~aller disk~ 80 and lar~er
disks 78, respectively. The spacing between the per-
ipheral edge portion of each disk and the opposing
spacer should not be greater than the distance between
adjacent intermeshing disks.
It will be noted in Figs. 4, 6 and 8 that
above each of the spacers 14 there is a sort of pocket,
which is about approximately twice as wide in axial
extent as the space between intermeshing disks 12 and as
long in the direction parallel with the disks as the
diameter of the particular spacer. These pockets,
however, cause no problem in operation, nor do they
interfere with the desired results of the apparatus, as
now described.
Chips do drop into these pockets, but they
cannot move further downwardly unless they are within
the desired thickness range for acceptance between inter-
meshing disks. Chips of greater thickness which drop
into a pocket will remain there only temporarily. SoDner
or later, additional chips will drop into the same pocket
until several will become wedged together and thrown
clear, apparently by being picked up by the upwardly
moving trailing edge portion of the disk in the next
forward row which adjoins the pocket.
Several examples of the novel radially contoured
peripheral edge portions of the disk members are basically
illustrated in Figs. 9-12. One design for a contoured edge portion
I
-15-
I
Docket 6340
is illustrated in Fig. 9 in which a quadrant of the
contoured edge portion of the disk member 12 is illus-
trated as formed of a plurality of blending alternately
reversed radii 85 and 86 in the plane of the disk.
A second variation of the outer peripheral
contour of each disk member 12 is illustrated in Fig. 10
in which the edge is formed of a plurality of spaced
substantially semi-circular recesses 87, producing spaced
lands 88 between them, also in the plane of the disk.
A third alternative form of the outer peripheral
contour of a disk member is shown in Fig. 11 in which
the outer edge is formed of a plurality of triangularly
shaped tooth-like protrusions 90 in the plane of the disk 12.
A fourth variation of the contour of the outer
peripheral edge of each disk member is shown in Fig. 12,
in which it is formed of a plurality of wave-like pro-
jections each having a radiused leading edge portion 92
in the direction of rotation of the disk-shaped member
; and a generally flat portion 94 extending radially inward
toward the bottom of the radiused portion 92 of the
rearwardly adjacent projection, and being formed in the
plane of the disk.
The depth of the contour on the edge of any of
the above disk members should not be any greater than
that which will permit chips of the desired maximum thickness
to pass between the edge of the member and an opposing
spacer. The exact depth for any given contour configuration
l~lSlZ~
Docket 6340
and thickness of chip to be sorted can best be determined
experimentally so that the combined effect of depth,
pitch and peripheral speed is such that overthick chips
cannot go through in this area. For example, an arrange-
ment which has proven satisfactory i9 a disk with a 17 inchdiameter having a contoured edge portion of adjacent
reversed radii with a distance between centers of 7.5 degrees
with a depth variation of .24 inch.
In addition, all of the configurations of con-
toured edge portions of disk members illustrated inFigs. 9-12 may have beveled edge portions in cross section,
as illustrated at 95 in Fig. 13, or may be flat sided,
whichever is desired.
In addition to varying the design of the con-
lS toured outer edge portion of the disk members in orderto assist in the gripping of the chips being sorted, it
is contemplated that variations in the positioning of
the rows of the disks can be utilized to effect the
material flow across the top of the disks. One such
position is illustrated in Fig. 14, which corresponds to
the position of the disks 12,as illustrated in Fig. 1.
This positioning produces an essentially horizontal
plane in which the chips to be sorted will flow in the
direction indicated by the arrows A in Fig. 1.
P~ second contemplated positioning~of the rows
of disks 12 is illustrated in Fig. 15, in which a cascading
e~fect is utilized wherein a plurality of rows 96 of
disk members adjacent the infeed chute are in essentially
a horizo~tal plane, a second adjacent set of rows 98 of
-17-
Docket 6340 1~61~
disk members is inclined downwardly relative to the
first set of rows, and a third set of rows 100 of
disk members is again disposed in a horizontal plane,
leading toward the reject output of the apparatus
where the material is discharged. This will produce a
variation in the material flow as it passes over the
cascading portion of the material flow path which will
assist in mixing the chips to be sorted, thus causing
additional interaction that will up-end chips and expose
them to the openi~gs between adjacent disks so that
those of the desired thickness range will pass vertically
downward between the members and be collected.
A third variation of positioning of rows of
disks 12 is illustrated in Fig. 16, in which a material
lS flow path is created in an upwardly inclined angle from
the infeed chute, with the material flow as indicated by
the arrow.
A fourth variation of the positioning of rows
of disk members is illustrated in Fig. 17, where an
inclined plane of material flow is created extending down-
wardly from the infeed chute, with the material flow in
the direction of the arrow. These last two variations
will, respectively, effect a decrease and an increase in -
the rate of material flow across the top of the disks.
It is to be noted that although in the description
above in connection with the variations in patterns for
rows of disks, such as those illustrated in Figs. 4-8,
only uniform patterns were given. E~owever, when using
-18-
Docket 6340
some of these patterns, some variations in the pattern
will be necessary adjacent the side waIls of the device
in order to keep the proper spacing between adjacent
disk-shaped members. For example, the pattern illus-
S trated in Fig. 6 is varied along the side rail 37 sothat a larger disk 78 is secured to the drive shaft 16
on which the remaining disks are the relatively smaller
diameter disks 80.
A similar variation may exist on other pattern
designs, where it is necessary to maintain the proper
spacing between an outer peripheral edge portion of a
disk and an opposed spacing member such that it will not
be greater than the distance between adjacent intermeshing
disks of the regular pattern, for the remainder of the rows.
Although the spacing of the disks can be of any
desired distance between them so that a chip of any desired
maximum size will be permitted to pass through, in the case
of sorting of wood chips for use in producing paper pulp,
for which this invention has particularly advantageous
use, it is contemplated that the spacing between adjacent
intermeshing disks will be nominally 7 millimeters. However,
even in the use contemplated for the paper pulp industry,
this may vary in the range of 3-12 millimeters or greater in
order to accumulate a broader range of chips with a desirable
thickness.
--19--
Docket 6340 ~ 5
Although the foregoing illustrates the preferred
embodiments of the present invention, other variations are
possible. All such variations as would be obvious to one
skilled in this art are intended to be included within the
scope of the invention as defined hy the following claims.
--~0-- '
