U.S. patent number 3,845,907 [Application Number 05/402,590] was granted by the patent office on 1974-11-05 for apparatus for comminuting trash.
Invention is credited to Werner Schwarz.
United States Patent |
3,845,907 |
Schwarz |
November 5, 1974 |
APPARATUS FOR COMMINUTING TRASH
Abstract
In apparatus for comminuting trash in which two parallel
disposed shafts, one having a degree of axial play and the other
substantially no axial play, a motor, reduction gearing disposed
between the motor and shafts through which the motor drives the
shafts, a reversing device for driving the motor in different
directions and a plurality of groups of disc-shaped blades disposed
at regular intervals on each shaft and arranged such that the
groups on one shaft engage in the interstices between the groups on
the other shaft are provided. The inner distance between two
adjacent groups on the shaft having substantially no axial play is
equal to the degree of play plus the width of the group on the
shaft having a degree of play. Each blade has at least one step
region including a tongue with the surfaces which define the tongue
forming an opening angle of the order of magnitude of 30.degree..
The step regions of the blades on each shaft are angularly offset
with respect to one another.
Inventors: |
Schwarz; Werner (Seeheim
A.D.B., DT) |
Family
ID: |
27431140 |
Appl.
No.: |
05/402,590 |
Filed: |
October 1, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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180687 |
Sep 15, 1971 |
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Foreign Application Priority Data
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Oct 22, 1970 [DT] |
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2051756 |
Apr 10, 1971 [DT] |
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2117519 |
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Current U.S.
Class: |
241/36; 241/191;
241/224; 241/230; 241/236; 241/290; 241/292.1 |
Current CPC
Class: |
B02C
18/142 (20130101) |
Current International
Class: |
B02C
18/14 (20060101); B02C 18/06 (20060101); B02 () |
Field of
Search: |
;241/36,191,195,222,224,227,230,231,235,236,242,243,290,293
;83/501,664 ;74/665G |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Custer, Jr.; Granville Y.
Assistant Examiner: Feinberg; Craig R.
Parent Case Text
This is a continuation-in-part of application Ser. No. 180,687,
filed Sept. 15, 1971 now abandoned.
Claims
What is claimed is:
1. Apparatus for comminuting trash comprising:
a. a motor;
b. at least two parallel shafts driven at least indirectly by said
motor;
c. a plurality of disc-shaped blades disposed on each of said
shafts and secured thereto for rotation therewith, each of said
blades having at least one tongue extending into the direction of
rotation and at least some of the blades on each of said shafts
being spaced from adjacent blades on the same shaft, with the
blades on one shaft extending into the spaces between blades on the
opposite shaft;
d. means for rotatably supporting one of said shafts so as to have
at least a predetermined degree of axial play parallel to said
shaft associated therewith;
e. means for rotatably supporting the other of said shafts so as to
have substantially no axial play associated therewith relative to
the one shaft, and
f. the blades on one shaft extending into said spaces on the other
shaft with a clearance equal to said predetermined degree of axial
play.
2. Apparatus for comminuting trash according to claim 1 in which
said blades are disposed at regular intervals on each of said
shafts in groups of at least two blades and arranged so that the
blade groups on one shaft extend into the spaces between the blade
groups of the other of said shafts and the tongues of the blades on
each of said shafts being angularly offset with respect to each
other.
3. Apparatus for comminuting trash according to claim 2
comprising
a. means for reversing the rotation of both of said shafts;
b. an inlet above said blades; and
c. an outlet below said blades.
4. Apparatus for comminuting trash according to claim 2 in which
the inner distance between two adjacent blade groups on the shaft
having relatively no axial play associated therewith is equal to
the degree of axial play plus the width of the blade group on the
shaft having a degree of axial play associated therewith.
5. Apparatus for comminuting trash according to claim 2, in which
the tongues of said blades on each of said shafts are helically
offset with respect to each other along that shaft.
6. Apparatus according to claim 2 wherein the degree of axial play
is approximately 0.2 mm and wherein a spacer sleeve is provided
which is wider than any group of blades by the amount of said
degree of play.
7. Apparatus for comminuting trash according to claim 1 in which
the inner distance between adjacent spaced blades on the same shaft
is equal to the degree of play plus the width of the blades on the
other shaft extending into the space between said blades.
8. Apparatus according to claim 1 comprising means on the blades on
the shaft having relatively no axial play associated therewith for
guiding the blades on the other shaft parallel to the axis of said
other shaft.
9. Apparatus according to claim 8 in which said blade means
comprises flank portions on the blades on each shaft for engaging
and defining an overlap portion with the adjacent blades on the
other shaft.
10. Apparatus according to claim 1 comprising means on said blades
for enabling the blades on one shaft to remain in cutting
engagement with the blades on the other shaft beyond said
tongue.
11. Apparatus according to claim 1 comprising means for limiting
the force of engagement between the blades on the shaft having
axial play associated therewith and adjacent blades on the shaft
having relatively no axial play associated therewith, said
engagement force limiting means comprising means for limiting the
axial play on the shaft having axial play associated therewith.
12. Apparatus according to claim 11 comprising bearing means for
supporting said shaft having axial play associated therewith and
said limiting means comprises means for adjusting the position of
said bearing means.
13. Apparatus according to claim 12 in which said means for
adjusting said bearing means position comprises means axially
disposed with respect to said shaft having axial play associated
therewith for limiting the movement of said bearing means in one
direction.
14. Apparatus as defined in claim 1, wherein said shafts have a
center spacing of approximately 130 mm.
15. Apparatus as defined in claim 1, wherein said shafts have a
hexagonal circumferential configuration, and have a width between
parallel sides of 41 mm and consist of non-hardened chromium steel,
preferably 12 percent chromium steel.
16. Apparatus as defined in claim 1 wherein each blade group
comprises two blades which are arranged next to one another without
spacings therebetween and whose step regions are offset with
respect to one another, preferably by 180.degree..
17. Apparatus as defined in claim 1 wherein even groups of blades
which are each substantially 15 mm wide are provided on each
shaft.
18. Apparatus according to claim 1 wherein the degree of axial play
is in the order of magnitude of 0.2 mm.
19. Apparatus according to claim 1 wherein the degree of axial play
is up to 0.2 mm.
20. Apparatus as defined in claim 1, wherein the numbers of shaft
revolutions have a ratio of approximately 40:70.
21. Apparatus as defined in claim 3, wherein the actuation of said
reversing means is torque dependent.
22. Apparatus as defined in claim 1, wherein said shafts have
comminuting lengths of approximately 40 cm and the gearing includes
a worm meshing with a worm gear, the worm gear mounted on a shaft
which has mounted thereon and secured against rotation relative
thereto a smaller toothed wheel which meshes with a larger toothed
wheel of the other shaft, and a second smaller toothed wheel being
disposed on the other shaft and secured against rotation relative
thereto which meshes with a second larger toothed wheel of said
shaft, said worm being driven by a motor which is an approximately
7.5 HP motor.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for comminuting trash
such as bottles, borings, crates or the like. More particularly,
the present invention relates to an apparatus for comminuting trash
including a motor, reduction gearing connected with the motor, at
least one shaft driven by the reduction gearing, blades fastened to
the shaft, an inlet opening disposed above the blades and an outlet
opening disposed below the blades for ingress of the trash and
egress of the comminutant respectively.
A larger number of devices for comminuting trash are known. These,
however, are specialized and do not possess the desired versatility
since they do not process everything that accumulates in industrial
operations such as the boring and grinding industry, in warehouses
and retail businesses, etc. There are also a variety of automobile
batteries, plastic containers, oil barrels, wooden crates,
catalogs, television tubes, bottles, steel shavings resulting from
boring and grinding, etc. which they cannot process and comminute.
Moreover, known devices of this type require more operating
experience from the operating personnel and more care than might be
expected. Fruit crates, for example, must first be broken up before
being inserted for comminution.
Such a device must be able to handle the problems of glass dust
resulting from smashing bottles and the comminution of metal
objects which wrap themselves around the shaft and jam the device
instead of being comminuted by the blades.
SUMMARY OF THE INVENTION
It is, therefore, a general object of the present invention to
provide an apparatus for comminuting trash such as bottles,
borings, crates or the like.
It is a more particular object of the present invention to provide
a comminuting apparatus which can be operated with practically no
operational knowledge.
It is another particular object of the present invention to provide
a comminuting apparatus which is compact in size and yet is
sufficiently versatile to accomplish the comminution of a variety
of items such as automobile batteries, plastic containers, oil
barrels, trash accumulations in industrial operations such as the
boring and grinding industry, etc.
It is yet another particular object of the present invention to
provide a comminuting apparatus including a plurality of groups of
disc-shaped blades mounted on a pair of driven shafts disposed
parallel to each other with one shaft having a degree of axial play
and the other shaft having substantially no axial play and with the
inner distance between two adjacent groups on the shaft having
substantially no axial play being equal to the degree of play plus
the width of the group on the shaft having a degree of play.
It is still another particular object of the present invention to
provide a comminuting apparatus including a reversing device which
can be either time or torque dependent.
It is yet another particular object of the present invention to
provide a comminuting apparatus including an improved blade
design.
These and other objects are accomplished according to the present
invention by the provision of an apparatus for comminuting trash
including two parallel shafts with one of the shafts having a
degree of axial play associated therewith and the other shaft
having substantially no axial play associated therewith; a
plurality of groups of discshaped blades disposed at regular
intervals on each shaft, so that the blade groups of the one shaft
mesh in the interstices between the blade groups of the other
shaft, and so that the inner space between two adjacent groups on
the shaft having substantially no axial play associated therewith
is equal to the degree of play plus the width of the intermeshing
blade group on the shaft having a degree of play associated
therewith, and further so that the shafts move during operation in
opposite rotational directions and at a slightly different speed; a
motor; reduction gearing disposed between the motor and shafts
through which the motor drives the shafts; a reversing device for
driving the motor in different directions; and inlet opening
disposed above the blade groups through which trash is supplied to
the blade groups; and an outlet opening disposed below the blade
groups through which the comminutant is removed.
As used herein, the terms "play" and "axial play" are used in their
ordinary dictionary senses, namely, the degree of freedom and
uncontrolled motion of a shaft journaled in its housing, i.e., in
the case of axial play, to move or function freely within
prescribed limits in either direction parallel to the axis of the
shaft. This is to be distinguished from the controlled movement of
one shaft relative to another.
The forward direction of rotation of the shafts is such that when
viewing the blade groups through the inlet opening, the blades move
toward one another. That is, if one were to view a point on a blade
on each of the shafts, these points would appear to approach each
other as the two shafts are caused to rotate in the opposite
directions.
The blades have one or a plurality of step regions where they
deviate from a larger diameter to a smaller diameter. The step
regions include surfaces which define a tongue and generally
sickle-shaped recesses. The tongues extend in one direction of
rotation of the blade. The surfaces defining the tongue form an
opening angle of the order of magnitude of 30.degree.. A retreating
area of the step region disposed below the tongue and toward the
smaller diameter can accommodate items of the dimensions of
ordinary wine, beer, liquor bottles or bottle necks thereof. The
blades are mounted on each shaft so that the step regions thereof
are angularly offset against one another.
Because of the axial play, room is provided between the sides of
the blades for the glass dust mentioned above. However, the axial
play is still small enough so that no metal pieces can get stuck in
the resulting gap which then, instead of being comminuted, would
only be pulled through the apparatus whole. Because of the
different number of revolutions (speeds) of the two shafts, the
items to be comminuted are caused to rotate if required and as a
result are chewed by the blades from different sides. The different
speeds prevent sudden stresses and jamming of the apparatus. The
reversing device also serves to prevent the apparatus from becoming
jammed.
In one embodiment of the present invention the blades are provided
with a hexagonal bore. These blades are then mounted on a shaft
which has a hexagonal circumferential configuration. In this
embodiment, a substantially improved torsion connection between the
blades and shaft results. However, this blade configuration is
expensive to fabricate because the bore can only be produced by
means of removal of material and must be carefully and slowly
machined. Hexagonal shafts are more easily fabricated and
commercially available in a relatively large number of different
dimensions. However, they are substantially more expensive than
circular shafts which can be turned much more easily, for
example.
In order to obtain a substantially improved torsion connection
between shaft and blade which is much less expensive, which
requires no removal operations, which permits precision work where
necessary to be done at relatively low cost, and which finally
permits the arrangement of the blades in such a manner that their
cutting tongues are offset by any desirable angular relationship,
such as, for example, angles of 180.degree., 120.degree.,
90.degree. etc., other embodiments of the blades and shafts are
possible. For example, the blades are provided with a cylindrical
bore, with recesses provided parallel to the bore at regular
angular spacings. The inner surfaces of the recesses follow a
circular arc. The shaft has a cylindrical circumference and fits
into the blade bore. The shaft has at least one longitudinal groove
parallel to its longitudinal axis whose inner surface complements
the inner surface of one of the recesses in the blade, so that
together they define a cylindrical bore. A cylindrical rod is
fitted into the cylindrical bore defined by the shaft groove and
blade recess.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the apparatus of the present
invention to scale.
FIG. 2 is a sectional view taken along 2--2 of FIG. 1, to scale,
but without motor, reversing device, fill funnel and feet.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2, showing
the blade groups on one of the shafts as well as part of the
gearing.
FIG. 3a is a vertical sectional view of the gear box showing the
two shafts and the meshing gearing to drive each shaft.
FIG. 4 is a sectional view, to scale taken along the line 4--4 of
FIG. 2, showing the other shaft as well as part of the gearing
associated therewith.
FIG. 5 is a full scale side view of a blade according to one
embodiment of the invention showing the stepped region thereof.
FIG. 6 is a view of FIG. 5 as seen in the direction indicated by
arrow A.
FIG. 7 is a side view of a mounted blade according to another
embodiment of the invention showing the stepped region thereof.
FIG. 8 is a view of FIG. 7 as seen in the direction indicated by
the arrow C.
FIG. 9 is a side view of a blade according to a further embodiment
of the invention showing three stepped regions.
FIG. 10 is a view of FIG. 9 as seen in the direction indicated by
arrow D.
FIG. 11 is a schematic representation of the angular offset of the
stepped regions of two successively mounted blade groups.
FIG. 12 is a schematic partial view as seen in the direction
indicated by the arrow B of FIG. 3.
FIG. 13 is a schematic circuit diagram of one embodiment showing
the reversing capability for the drive motor.
FIG. 14 is a sectional view comparable to the sectional view
according to FIG. 3, showing the blade groups on one of the shafts
and part of the gearing according to another embodiment of the
invention.
FIG. 15 is a sectional view for the embodiment of FIG. 14 which is
the same as the sectional view according to FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus according to the present invention is supported on
four legs 11, as shown in FIG. 1. The legs 11 support a hopper or
basket 12 or the like, into which the trash to be comminuted is
placed through an inlet opening 12'; a 7.5 HP electric motor 13,
whose shaft is perpendicularly disposed with respect to inlet
opening 12'; a box 14, in which fuses, on and off switches as well
as the known reversing device are provided; a gear box 16; a blade
box 17; and an outlet duct 18 including an outlet opening 18'.
The gear box 16 (FIG. 2) has an upper wall 19 and a lower wall 21
which serve as the bearing supports for a perpendicularly disposed
worm gear shaft 22. The worm gear shaft 22 has at its upper end an
internal multi-edge opening or socket 23 into which the shaft of
electric motor 13 fits. In the center region of the gear shaft 22 a
worm 24 is provided which is seated secured against rotation in any
conventional manner. A bearing 26 in the upper wall 19 and a
bearing 27 in the lower wall 21 mount the worm shaft 22 to the
bearing supports. Bearing 27 includes a double tapered roller
bearing and can support an axial thrust load whose direction
depends on the rotational direction of motor 13.
A worm tooth gear 28 meshes with worm 24. The worm gear 28 is
mounted on a shaft 31 and secured against rotation thereon in any
conventional manner. As can be seen from FIGS. 3 and 3a, shaft 31
also supports a smaller toothed wheel 32 to the right of gear 28.
The right-hand end of shaft 31 is mounted to be freely suspended
and rotatable in a bearing 33. The bearing 33 is screwed to the
left-hand end of the cylindrical portion 34 of a hexagonal shaft
36. Bearing 33 and shaft 31 can thus rotate independently of one
another, but are coaxial.
A larger toothed wheel 37 meshes with gear 32. The toothed wheel
37, (FIG. 4), is securely fastened as, for example by welding, to a
hub 46. The hub 46 is wedged on the left-hand cylindrical portion
38 of a second hexagonal shaft 39. The cylindrical portion 38
includes a plurality of spline-type keys 38" each of which engages
a key way 46' formed in the hub 46. The keys 38" are preferably
press-fitted into the key ways 46' resulting in the wedging action.
For purposes of clarity, FIG. 4 does not show the worm 24 or the
worm shaft 22. The cylindrical portion 38 is stepped toward the
left and terminates in a reduced diameter extension 38' which is
supported in a bearing 41 of sidewall 42 of the gear box 16. At its
other end, the cylindrical portion 38 passes through the right
sidewall 44 of the gear box 16 and is there supported in a bearing
43. The hub 46 includes a smaller gear 47 which is integrally
formed thereon. The gear 47 thus rotates at the same speed as gear
37. The gear 47 meshes with a larger gear 48 which, however, has a
somewhat smaller diameter than gear 37. The gear 48 is wedged on
the cylindrical portion 34, (FIG. 3), in a manner similar to that
of hub 46 on cylindrical portion 38. It is thus possible to
substantially reduce the number of revolutions of motor 13 and to
drive the two hexagonal shafts 36 and 39 in opposite directions and
at a different speed. Also, it is possible to have a ratio of shaft
revolutions of approximately 40:70, for example. Of course, it
should be understood that other ratios may be achieved as
desired.
The gear box 16 can, for example, have a width of 19 cm, an inner
height of 22.5 cm and an inner length of 59.5 cm. The gear box 16
is designed to be oil tight so that the gearing can be splash
lubricated from the sump level 49. This gear box construction has
been found to successfully withstand the high axial and radial
forces which develop during the comminuting operation.
The blade box 17 has a stable frame structure which is open at the
top to receive the trash from the hopper 12, and opened at the
bottom to discharge the comminuted trash to the outlet duct 18. The
frame structure includes the sidewall 44 which forms a party wall
with the gear box 16. The three remaining walls 51a, 51b and a
third, not shown, are generally U-shaped or channel beams which are
preferably welded together. FIG. 3 shows in cross-section the
channel 51b which is exemplary. The channel 51b includes,
typically, a web portion 52 and flanges 52a and 52b. The upper
flanges of all three walls are joined in a conventional manner such
as through the use of bolt joints with a corresponding three-sided
flange portion (not shown) of the hopper 12. The U-shaped beam 51b
is provided in its web portion 52 with two bearing supports 52c and
52d (the latter shown in FIG. 15) for the end pins 53 of the two
hexagonal shafts 36 and 39 and their associated bearings 53a and 53
b (the latter shown in FIG. 15). Each hexagonal shaft 36 and 39
bears fourteen blades 54 which are preferably similarly configured
and which are each combined into groups of two 56, 57, 58, 59, 61,
62, 63. For reasons for simplicity, FIG. 3 shows only the blade
groups of the hexagonal shaft 36. These blade groups are spaced
apart by spacer sleeves 64, which are all of the same dimension,
but which are wider than the width of a blade group which are
preferably 15 mm in width, by the degree of axial play of one of
the shafts 36.
It should be noted at this time that the degree of axial play is
not shown in FIG. 12 because it is of such a small magnitude in
comparison to the size of the elements shown. Pressure rings 66 and
67 axially pretension the entire arrangement of the blade groups
and the spacer sleeves 64 when assembled as shown in FIG. 3, so
that any axial displacement on the hexagonal shaft 36 is
substantially eliminated.
Referring to FIG. 12 it can be seen that an qual number of blade
groups 68 on the hexagonal shaft 39 are provided. These blade
groups fit into each interstice between adjacent blade groups on
shaft 36 so that a gap opening 69 remains through which the
comminuted material can fall downwardly and through outlet opening
18'.
In one embodiment of the present invention, the blades 54 have the
shape illustrated in FIGS. 5 and 6. In this embodiment the blades
54 have a hexagonal opening or bore 54' which is adapted to fit in
a conforming manner on the hexagonal shafts 36 or 39. The hexagonal
shafts are intentionally hardened so that their toughness index
will be enhanced. The shafts 36 and 39 are made from an unhardened
chromium steel, preferably 12 percent chromium steel. In
contradistinction, however, the blades 54 are hardened to a
Rockwell hardness of 60-62. The blades 54 are made from a material
identified by the number 2090 according to DIN (Deutsche Industrie
Normen, German Industrial Standards), which is a 12 percent
chromium steel.
From point 72 to point 73, i.e., over an angle of 200.degree., the
peripheral surface 74 defines a circular region 74' of the blade
with a radius of 140 mm. The peripheral surface 76 which follows
point 73 in a clockwise direction also follows a circular path
whose center 77 is offset downwardly by 29 mm and to the right by
34.5 mm with respect to center 78.
A region 76' defined by the peripheral surface 76, when viewed from
the center 78, has a continuously increasing radius. A step region
79' follows the region 76' and includes a tongue 79. The tongue 79
has a planar upper surface 81 which is perpendicular to the plane
of the drawing and a lower surface 82 which is also planar but is
inclined downwardly at an angle of 10.degree. perpendicularly to
the plane of the drawing. The surface 82 is preferably ground. From
the tip 83 of the tongue 79 to the beginning of region 74' at point
72, a recess 84 is formed in the approximate shape of a sicle. This
recess 84 forms the receding portion of the step region 79'. More
precisely, the ground surface 82 transitions into a curved surface
having a radius of 15 mm and extending through an arc of
approximately 120.degree., and this curved surface blends into the
surface 86, which is perpendicular to the plane of the drawing and
which in turn extends to point 72 of region 74'.
The vertically measured distance between surface 86 and the tip 83
of tongue 79 is 40 mm, while the surface 81 forms an angle of
75.degree. with respect to the vertical (FIG. 5). Except for the
surface 82 and a portion of the adjacent curved surface having the
radius of 15 mm nothing is ground along the circumference of blade
54.
Edges 88 and 89 are rounded so that they are not very sharp. The
side surfaces 91 and 92, however, are ground to be plane and
parallel, the thickness of the blades being preferably 15 + 0.01
mm. The opening angle of the tongue 79 defined by the surfaces 81
and 82 is preferably 30.degree. as shown in FIG. 5. It has been
found that variations of this angle up to .+-. 20 percent are
acceptable.
The approximately 30.degree. angle is important particularly when
comminuting metal. On the one hand, it prevents the forces produced
by the entrance of the metal from increasing too rapidly, which
would be the case with larger angles, such as e.g., 50.degree.;
while on the other hand, the angle is sufficiently large to
effectively produce a large hole in the metal sheet and also large
enough so that it can be pulled out of the metal sheet during each
reversing process. A tongue with too small an angle would more
easily penetrate into the metal, but would have difficulty in being
withdrawn from the hole during reversal.
In the other embodiment of the present invention which is
illustrated in FIGS. 7 and 8, blade 110 has the shape of blade 54
shown in FIGS. 5 and 6, but blade 110 has a cylindrical bore 112
which is concentric with center 111. Blade 110 also has parallel
surfaces 127 and 123', which like blade 54 and 40 mm apart.
Recesses 113, 114, and 116 are provided at an angular offset with
respect to each other according to the relationship 360.degree./n,
where n = 2, 3, 4 etc., and is preferably 3. The inner surfaces 117
of the recesses follow a circular arc of approximately 200.degree..
The distance of the center 118 of all recesses 113, 114, 116, from
center 111 is the same. In the embodiment illustrated, the center
118 is disposed on the extension of the inner surface of the bore
112.
A cylindrical shaft 119 is provided which corresponds to the
hexagonal shafts 36 and 39 and which has a diameter such that it
can be inserted through the bore 112, so that all blades 110 can be
disposed thereon. The shaft 119 has a longitudinal groove 121 which
extends over the entire length of the shaft over which the blades
110 are to be mounted. As is shown in FIG. 7, the groove 121
supplements with its inner surface the inner surface 117 of recess
113 to form a circular bore 121'. Thus, when recesses 113 and
longitudinal groove 121 are congruent to form the bore 121', a
cylindrical rod 122 can be placed therethrough so that shaft 119
will carry the blade in both directions of rotation of the shaft.
For the next blade 110, the recess 116 supplements longitudinal
groove 121; for the blade 110 after that, recess 114 supplements
longitudinal groove 121, etc., so that tongues 123 of blades 110,
which are designed in the same manner as tongues 79 of blades 54
and which here have an opening angle of 30.degree. .+-. the
variation stated above, are offset with respect to one another by a
preferred angle of 120.degree.. Preferably, the bore 121' is formed
such that more than one-half of the bore is within the blade
body.
Alternatively, additional longitudinal grooves 121a and 121b could
also be provided at the periphery of shaft 119 parallel to the
longitudinal groove 121 and offset by 120.degree. so that
additional bores may be formed with recess 114 and recess 116. It
must be noted here, however, that any practical number of
additional grooves and resulting bores are possible, but that too
many longitudinal grooves would not be desirable since they would
tend to weaken the shaft 119. This would also have the drawback
that the longitudinal grooves would have to be manufactured on a
machine with graduated circle devices since the angular offset of
120.degree. or the like must be precise. If, however, only a single
longitudinal groove 121 is provided these angular relationships
need not be of concern.
During the manufacturing process, holes are first drilled to
correspond to the recesses 113, 114 and 116. Then bore 112 is
drilled and worked with a reamer, if required. The only tool
required is thus a drill.
With respect to the rod 122, the shaft 119 and the blades 110 or
125, it has been found that a rod diameter of 15 mm .+-. 4.5 mm, a
shaft diameter of 40 mm .+-. 12 mm and a blade width of 280 mm .+-.
42 mm is preferable.
The blade 125 which was fabricated according to a further
embodiment of the present invention as illustrated in FIGS. 9 and
10 is carried along in a form-fitting manner by shaft 119. However,
it has three tongues 123, each offset by 120.degree.. The blade 125
has, therefore, the general outline of a triangle with regions each
having a surface 124 which lies on a circular arc and having the
same length partly defining the sides of the triangle. From the
three tips 126 which later from the tip of the nose and which are
designed to be cutting edges, areas 127 recede.
The surfaces 127 and 128 define a recess 127' which is generally
sickle-shaped and which is large enough so that it can hold bottle
necks and the like. The back of the tongue 123 is a smooth
continuation of the surface 124. Tongue 123 of blade 125 like
blades 54 and 110 opens at an angle of 30.degree. .+-. the
variation stated above. Tongue 123 may be undercut in the same
manner as tongue 79 of blade 54 to an angle of 10.degree. to form
the surface 128.
Each one of the blade groups has the individual blades 54, 110 or
125, respectively, arranged next to one another without spacings
therebetween so that the tips 83 or 126 of the step regions 84 or
127' of the tongues 79 or 123 are offset by 180.degree.. This
explains why in FIG. 3 the right-hand blades extend higher than the
left-hand blades, while the left-hand blades protrude lower than
the right-hand blades. Each blade group is offset by 60.degree.
with respect to the next blade group.
Let us now consider the tips 83 or 126 of the tongues of the
right-hand blades 54 or 110 of each blade group 56-63. For example,
the tip of the tongue of one blade for the blade group 56 is on a
radius 93, (FIG. 11), and the tip of the tongue of a corresponding
blade for the blade group 57 is on a radius 94 etc. The angular
deviation is preferably 60.degree.. The preferably 60.degree.
deviation continues with succeeding blade groups until the tip of
the tongue of a corresponding blade for the blade group 63 lies on
radius 93. This then results in the schematic arrangement shown in
FIG. 11.
The spacing between the hexagonal shafts 36 and 39 or of the
cylindrical shafts 119 is such that with a given blade
configuration, the blades always overlap and define an overlap
portion 95, as shown in FIG. 12.
This has the result that the blades on one shaft can be guided
laterally, i.e., parallel to the shaft axis, by the blades on the
other shaft and that no common gap opening along the hexagonal
shafts 36 and 39 or along the cylindrical shafts 119 appears,
except the limited gap openings 69, as shown in FIG. 12.
The shafts 36, 39 or 119 preferably have a center spacing of
approximately 130 mm. The distance between the parallel sides of
the hexagonally configured shafts 36 and 39 is preferably 41
mm.
The peripheral surface 76 makes it possible for a blade to remain
in engagement as long as possible with an adjacent blade on the
other shaft. Metal cans or the like are then not only crushed but
also cut apart. It is insignificant which shaft receives the axial
play.
However, both shafts must not have the axial play.
Blades 125 are also arranged in blade groups and are arranged to be
offset with respect to one another by 60.degree. within the blade
groups in a corresponding manner to blades 54 and 110.
A motor of 7.5 HP was selected for the embodiments. The motor
permits the use of sufficiently long hexagonal shafts 36 and 39 or
cylindrical shafts 119 for the gears employed so that fruit crates
can be thrown whole into the hopper 12 and need not be broken up
first. The motor 13 is also able to produce a torque which
produces, with respect to the moment arms between the recesses 84
or 127' and the geometrical longitudinal axis of the shaft, moments
sufficient to effect the desired comminution, Standard motors with
4 or 10 HP cannot be used because the 4 HP motor would not be
powerful enough and the 10 HP motor would be too powerful. An
apparatus which would be provided with a 10 HP motor would be too
cumbersome for the intended purposes. A 7.5 HP motor is fed with 15
amperes. This is a value which can be handled by normal electrical
lines.
The point at which motor reversal takes place can be made time or
torque dependent. With respect to time dependent reversals, one
would only require a clock, which would switch the motor, for
example, every five minutes into a reversal of rotation. Also, a
revolution counter could also be used so that the motor could be
reversed, for example, every 10 revolutions.
With respect to torque dependent reversals, one could measure by
how many angular degrees the ends of shaft 31, for example, are
twisted with respect to one another and the reversal could be
effected when a certain torsion has been reached. Also, it has been
found that with a strong load, the 7.5 HP motor requires 12 amperes
of current and that from this point on the motor rotation should be
reversed. Since the current through the motor is proportional to
the torque, the current can also be used as a criterion under the
torque dependent category. In this regard consider, for example,
the circuit diagram of FIG. 13. A current coil whose armature is
attracted whenever the current through the motor winding has
reached a certain level, for example 12 amperes, is connected in
the lead to the motor winding. The armature controls a bistable
member which produces the pulses shown at its output. With these
pulses the polarity reversing switch is controlled from the solid
line position to the dashed line position.
Another embodiment of the invention is shown in FIGS. 14, 15, in
which portions which are the same as corresponding portions in
FIGS. 3 and 4, are designated by the same reference numerals. It
has been found that for certain comminuting applications, such as
comminuting tires, axial play in one shaft of up to approximately
0.2 mm produces advantageous results. Additional axial play is
achieved over the embodiment described with reference to FIG. 3 by
supporting the shaft 36' by bearing 53a' which is larger than
bearing 53a in the embodiment of FIG. 3. The bearing 53a' supports
end pin 53' and is in turn supported within bearing support 52c',
each of which is correspondingly larger to accommodate the larger
bearing 53a'. As is well known, the larger the radial ball bearing,
the greater the degree of axial play of the bearing and the axial
play of the shaft supported by the bearing. The bearing 53a
supporting the shaft 36 in the embodiment of FIG. 3 is large enough
to permit the shaft 36 to move through the distance allowed by the
spacing between the blades on the other shaft 39, and the larger
bearing 53a' will permit the shaft 36' to move through the greater
distance of 0.2 mm allowed by the spacing between the blades on the
shaft 39 in this embodiment.
In this embodiment the additional axial play is accommodated in a
machine of similar size to the machine described with reference to
FIG. 3 by providing a single blade 54 at the end blade position
63'. The blade groups are spaced apart by spacer sleeves 64' which
are of the same axial dimension, but which are 0.2 mm wider than
the width of the blade group. The difference, in the order of
approximately 0.2 mm, corresponds to the limits of axial play
allowed on one of the shafts 36' relative to the other shaft 39.
The blade groups on one shaft 36' fit into each interstice between
adjacent blade groups on shaft 39. The spacing between the
hexagonal shafts 36' and 39 is such that with the given blade
configuration the blades 54 always overlap and define an overlap
portion. Thus, as described in connection with the embodiment of
FIG. 3, the blades on the one shaft 36', having axial play, can be
guided laterally, i.e., parallel to the shaft axis, by the blades
on the other shaft 39 with relatively no axial play.
The degree of axial play of shaft 36' is limited, as in the
embodiment of FIG. 3, by the blades on the fixed shaft 39 and the
axial play on the shaft 39 is limited to substantially no axial
play in relation to shaft 36' as in the embodiment of FIG. 4, by
the size and arrangement of the bearings supporting the shaft 39
because the embodiment shown in FIG. 15 is exactly the same as in
FIG. 4.
Shaft 39 is a solid shaft end to end. It is supported at three
places by bearings 140, 141 and 53b, each of which is a different
size, the end bearing 140 is bearing support 41 being substantially
smaller than the other bearings 141 and 53b as well as the bearings
supporting shaft 36. The inherently small axial play of the small
end bearing 140 is further limited by the bearing support 41 and
substantially all of the axial play is eliminated from the shaft 39
by the spaced arrangement of the bearings 140, 141 and 53b along
the shaft 39, which produces forces and bending moments on the
bearings 140, 141 and 53b in response to the comminuting forces on
the blades 54. In particular, substantially all of the axial play
on the shaft 39 is eliminated by the small bearing 140, which is
remote from the blades 54 and in which the inner ring of the
bearing is moved radially by the comminuting forces on the blades
54 acting about the bearing 141.
It should be understood that the axial play can be substantially
eliminated by other means in addition to the means described
above.
It is advantageous if the engagement force exerted by the blades 54
on one shaft 36' against the adjacent blades on the other shaft 39
is limited so as not to exceed the force appropriate for smooth
cutting engagement between the adjacent blades.
It is also advantageous that with the adjacent blades in engagement
along one face, the maximum gap between adjacent blades along the
opposite face is not so large that the material will be stuffed and
chocked down between the faces, but is limited to a gap size
appropriate to break up the material without choking down the
machine.
To these ends, the bearing cap 29' has a threaded axial hole 131
which receives a set screw 132 having a locking nut 133
thereon.
The end of the set screw abuts and presses against a spacer 134
which, in turn, presses against the outer ring of a bearing 136
supported in the bearing cap 29'. The bearing 136 supports the end
pin 135 of gear shaft 31. The shaft 36' is supported in gear box 16
by bearing 130 which is supported by a seal ring 138. A spacer ring
137 is secured to the seal ring by screws 137 one of which is
shown. The spacer ring surrounds the cylindrical portion 34 of the
shaft and is spaced slightly from the gear 48.
Tightening the set screw 132 against the spacer 134 reduces the
play and movement of the bearing 136 to the left as shown in FIG.
14 and limits and controls the play of the shaft 36' to the left
and hence the cutting force and space between the blades in that
direction.
As in the embodiment of FIG. 4, the play of the shaft 36' to the
right is limited by movement of the blades 54 on the shaft 36'
against the blade 54 on the shaft 39' which limits and controls the
cutting force and the space between the blades in that direction.
Hence, the setting of the set screw 132 in relation to the blades
54 on the fixed shaft 39 controls the degree of axial play of the
shaft 36' to limit the force of engagement between the blades on
one shaft 36' and the adjacent blades on the other shaft 39 to a
smooth cutting force and the space between adjacent blades along
their opposite faces to a space advantageous for comminuting the
material, in this embodiment about 0.2 mm.
The setting of the set screw 132 can also be used to adjust the
degree of axial play on the shaft 36' as may be necessary from time
to time.
* * * * *