Abstrict The object of the present invention is to provide a crusher, which
is capable of efficiently crushing materials or scraps, and a crushing
mechanism for the crusher. To achieve the object, the crusher of
the present invention comprises: a fixed member having a first blade
portion for crushing a material to be crushed into pieces; a movable
member being capable of moving to and away from the fixed member,
the movable member having a second blade portion, which crushes
the material into pieces with the first blade portion when the movable
member is moved toward the fixed member; and a driving mechanism
for moving the movable member to and away from the fixed member.
Claims What is claimed is:
1. A crusher, comprising:
a fixed member having a first blade portion for crushing a material
to be crushed into pieces;
a movable member being capable of moving to and away from said
fixed member, said movable member having a second blade portion,
which crushes the material into pieces with said first blade portion
when said movable member is moved toward said fixed member;
a driving mechanism for moving said movable member to and away
from said fixed member; and
a preparatory crushing section which includes a rotary blade member,
wherein the material is preparatorily crushed by said preparatory
crushing section and introduced to said fixed member and said movable
member.
2. A crusher, comprising:
a fixed member having a first blade portion for crushing a material
to be crushed into pieces;
a movable member being capable of moving to and away from said
fixed member, said movable member having a second blade portion,
which crushes the material into pieces with said first blade portion
when said movable member is moved toward said fixed member;
a driving mechanism for moving said movable member to and away
from said fixed member;
said first blade portion including:
a first shearing section for primarily shearing the material; and
a second shearing section for secondarily shearing the material;
which has been primarily sheared, and
said second blade portion including:
a third shearing section, which primarily shears the material with
said first shearing section when said movable member is moved toward
said fixed member; and
a fourth shearing section, which secondarily shears the material
with said second shearing section when said movable member is further
moved toward said fixed member and as said third shearing section
is moved away from said first shearing section.
3. The crusher according to claim 2 wherein,
a fixed member proper and a movable member proper are formed into
block shapes,
said first shearing section comprises a plurality of groove-blades,
which are formed with parts of an edge of said fixed member proper
and side sections of a plurality of projected sections, which are
projected from the edge thereof,
said second shearing section comprises a plurality of concave sections,
which are formed in fixed end portions of the projected sections,
said third shearing section comprises a plurality of projected
blades, which are arranged in said movable member proper so as to
engage with the groove-blades of said first shearing section, and
said fourth shearing section comprises a plurality of projections,
which are arranged in said movable member proper so as to fit into
the concave sections of said second shearing section.
4. The crusher according to claim 3
wherein the side sections of the projected sections are perpendicular
to the edge of said fixed member proper.
5. The crusher according to claim 3 wherein,
the concave sections of said second shearing section are formed
in said fixed member proper, and
each concave section has an inclined inner bottom face, which is
formed deeper toward the edge of said fixed member proper.
6. The crusher according to claim 3 wherein,
said movable member has a discharge hole through which the pieces
crushed are discharged outside, and
said third shearing section has an opening section, which is connected
to the discharge hole.
7. A crushing mechanism, comprising:
a first member;
a second member capable of moving to and away from said first member;
a first shearing section having a plurality of groove-blades, which
are formed with parts of an edge of said first member and side sections
of a plurality of projected sections, which are projected from the
edge thereof;
a second shearing section having a plurality of concave sections,
which are formed in fixed end portions of the projected sections;
a third shearing section having a plurality of projected blades,
which are arranged in said second member so as to engage with the
groove-blades of said first shearing section; and
a fourth shearing section having a plurality of projections, which
are arranged in said second member so as to fit into the concave
sections of said second shearing section.
8. The crushing mechanism according to claim 2
wherein the side sections of the projected sections are perpendicular
to the edge of said first member.
9. The crushing mechanism according to claim 2 wherein,
the concave sections of said second shearing section are formed
in said first member, and
each concave section has an inclined inner bottom face, which is
formed deeper toward the edge of said first member.
10. The crushing mechanism according to claim 2
wherein the projections of said fourth shearing section are formed
thicker toward front ends.
11. The crushing mechanism according to claim 2 wherein,
said second member has a discharge hole through which the pieces
crushed are discharged outside, and
said third shearing section has an opening section, which is connected
to the discharge hole.
Description BACKGROUND OF THE INVENTION
The present invention relates to a crusher and a crushing mechanism
for the same, more precisely relates to a crusher, which is capable
of crushing scraps, e.g., resin runners formed during plastic molding
processes, rubber materials, metals, so as to reuse them.
Various types of crushers have been known, e.g., Japanese Utility
Model Publication Gazette No. 61-3461. One of conventional crushers,
which crushes plastic scraps, e.g., resin runners, into pieces for
a reuse, is shown in FIGS. 16 and 17. FIG. 16 is a side sectional
view of the conventional plastic crusher; FIG. 17 is a plan view
thereof. In the conventional plastic crusher, there are provided
a plurality of blade members 5 on a shaft 4 at regular intervals.
A fixed member 7 has a plurality of blades 8 which are arranged
like comb-teeth. Each blade member 5 has a plurality of blades 6
which are arranged in the circumferential direction of the blade
member 5 at regular intervals. The blades 6 of each blade member
5 are capable of passing through a gap 8 between the blades with
the rotation of the shaft 4 so that materials or plastic scraps
can be crushed by them.
Though there are various types of crushers, all of them have the
rotary blade members 5 for crushing materials or scraps as an essential
element.
However, the conventional crushers having the rotary blade members
have following disadvantages.
1 It is difficult to make pieces crushed in a uniform size. Some
materials can be passed through gaps between the blades 6 and 8
without being crushed, so that they are discharged with large sizes.
2 The blade members 5 must hold materials to crush them. But the
materials will be free from the blade members 5 when the blade members
5 insufficiently hold them, so that the crushing efficiency cannot
be raised.
3 If crushing is continued without discharging pieces crushed,
the crusher is overheated by frictional heat among the materials.
4 Some materials are not crushed by the blades 6 and they stay
between the blades 8.
5 If crushing is continued without discharging the pieces crushed,
minute resin particles are scattered so that work environment will
be worse.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a crusher, which
is capable of efficiently crushing materials or scraps, and a crushing
mechanism for the crusher.
To achieve the object, the crusher of the present invention comprises:
a fixed member having a first blade portion for crushing a material
to be crushed into pieces;
a movable member being capable of moving to and away from the fixed
member, the movable member having a second blade portion, which
crushes the material into pieces with the first blade portion when
the movable member is moved toward the fixed member; and
a driving mechanism for moving the movable member to and away from
the fixed member.
In the crusher, for example, the first blade portion may include:
a first shearing section for primarily shearing the material; and
a second shearing section for secondarily shearing the material,
which has been primarily sheared. And the second blade portion may
include: a third shearing section, which primarily shears the material
with the first shearing section when the movable member is moved
toward the fixed member; and a fourth shearing section, which secondarily
shears the material, which has been primarily shears by the first
shearing section and the third shearing section, with the second
shearing section when the movable member is further moved toward
the fixed member. In this case, a fixed member proper and a movable
member proper may be formed into block shapes; the first shearing
section may have a plurality of groove-blades, which are formed
with parts of an edge of the fixed member proper and side sections
of a plurality of projected sections, which are projected from the
edge thereof like comb-teeth; the second shearing section may have
a plurality of concave sections, which are formed in fixed end portions
of the projected sections; the third shearing section may have a
plurality of projected blades, which are arranged in the movable
member proper so as to engage with the groove-blades of the first
shearing section; and the fourth shearing section may have a plurality
of projections, which are arranged in the movable member proper
so as to fit into the concave sections of the second shearing section.
On the other hand, the crushing mechanism of the present invention
comprises:
a first member being formed into a block;
a second member being formed into a block, the second member being
capable of moving to and away from the first member;
a first shearing section having a plurality of groove-blades, which
are formed with parts of an edge of the first member and side sections
of a plurality of projected sections, which are projected from the
edge thereof like comb-teeth;
a second shearing section having a plurality of concave sections,
which are formed in fixed end portions of the projected sections;
a third shearing section having a plurality of projected blades,
which are arranged in the second member so as to engage with the
groove-blades of the first shearing section; and
a fourth shearing section having a plurality of projections, which
are arranged in the second member so as to fit into the concave
sections of the second shearing section.
In the crusher of the present invention, materials are crushed
by the fixed blade portion and the movable blade portion with the
reciprocative movement of the movable member, so that they are sufficiently
held and crushed. Especially, materials are pinched and held by
the fixed blade portion and the movable blade, so that crushing
power directly and effectively works to the materials. Thus, the
energy consumption can be reduced and the crushing efficiency can
be raised. With higher crushing efficiency, a small and light crusher
having high performance can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way
of examples and with reference to the accompanying drawings, in
which:
FIG. 1 is a side sectional view of a crusher of an embodiment of
the present invention;
FIG. 2 is a view in the direction of an arrow A shown in FIG. 1;
FIG. 3 is a view in the direction of an arrow B shown in FIG. 1;
FIG. 4 is a side sectional view of a crusher of another embodiment;
FIG. 5 is an explanation view of a driving mechanism of the embodiment
shown in FIG. 4;
FIG. 6 is a perspective view of a fixed member and a movable member;
FIG. 7 is a perspective view, with portions broken away for clarity,
of the fixed member;
FIG. 8 is a perspective view, with portions broken away for clarity,
of the movable member;
FIG. 9 is a view in the direction of an arrow X shown in FIG. 6;
FIG. 10 is an explanation view showing positions of the fixed member
and the movable member prior to crushing;
FIG. 11 is a plan view of a material to be crushed;
FIG. 12 is an explanation view showing a state of a primary crushing;
FIG. 13 is a plan view of the material, which has been primarily
crushed;
FIG. 14 is an explanation view showing a state of a secondary crushing;
FIG. 15 is a plan view of the material, which has been secondarily
crushed;
FIG. 16 is a side sectional view of the conventional crusher; and
FIG. 17 is a plan view of the conventional crusher.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described
in detail with reference to the accompanying drawings.
FIG. 1 is a side sectional view of a crusher of the embodiment,
FIG. 2 is a view in the direction of an arrow A shown in FIG. 1
and FIG. 3 is a view in the direction of an arrow B shown therein.
In the crusher of the present invention, the process of crushing
materials to be crushed, e.g., plastic scraps, is characterized
in that the materials are preparatorily crushed into medium size
pieces by a preparatory crushing section having rotary blade members,
then they are crushed into small pieces by a crushing section.
In FIG. 1 the preparatory crushing section C has the rotary blade
members 10 for preparatorily crushing plastic scraps into medium
size pieces. The crushing section D crushes the medium size pieces
into small pieces, e.g., pellets.
The rotary blade members 10 are provided in a casing 13 whose
upper face is opened. Receiving sections 12 and 14 are provided
on both sides of the rotary blade members 10. The receiving sections
12 and 14 are capable of receiving the scraps, which have been put
into the casing 13 and collecting them onto the rotary blade members
10. Therefore, inner edges of the receiving sections 12 and 14 are
lowered.
The rotary blade members 10 are fixed on a horizontal drive shaft
16 with a proper clearance (see FIG. 2). Fact rotary blade member
10 has two blades 10a and 10b, which are symmetrically provided
with respect to the drive shaft 16 (see FIG. 1). The receiving section
12 has fixed blades 12a and 12b, which cooperate with the blades
10a and 10b to crush scraps.
The blades 10a and 10b are extended relatively long with respect
to the drive shaft 16 so as to efficiently catch scraps. Furthermore,
there are fixed three small rotary blade members 18 on the drive
shaft 16 and they are provided between the rotary blade members
10 and on outer side of each rotary blade member 10. The small rotary
blade members 18 are capable of transferring and collecting scraps
onto the receiving section 12 so that the scraps can be crushed
by the blades 10a and 10b of the rotary blade members 10. As described
above, the scraps are preparatorily crushed into medium size pieces
by the rotary blade members 10 and the small rotary blade members
18 in the preparatory crushing section C, and fall into the crushing
section D.
As clearly shown in FIG. 2 a gear 19 is fixed at an end of the
drive shaft 16. A gear 22 which is fixed to an output shaft of
a motor 20 is engaged with the gear 19. The gear ratio between
the gears 22 and 19 is 1:2 so that the drive shaft 16 is made a
half turn for each full turn of the gear 22.
The crushing process of the preparatory crushing section C with
the rotary blade members 10 is basically the same as that of the
conventional crusher. On the other hand, the crushing process of
the crushing section D is very unique. As shown in FIG. 1 the scraps,
which have been crushed into medium size pieces in the preparatory
crushing section C, fall in the crushing section D. A duct 23 connecting
the sections C and D is formed like a hopper. There are provided
a fixed member 30a and a movable member 30b at a lower end of the
duct 23. The fixed member 30a has a first blade portion the movable
member 30b has a second blade portion, which is capable of slidably
engaging with the first blade portion of the fixed member 30a. By
the first and the second blade portions, the medium-sized scraps
(pieces) can be crushed smaller.
The movable member 30b is linearly and reciprocatively moved in
the direction of an arrow E (see FIG. 1) along a bottom face of
the fixed member 30a for crushing scraps. Note that, the fixed member
30a and the movable member 30b are inclined with respect to the
vertical line so as to introduce the scraps to an engaging portion
of the fixed member 30a and the movable member 30b. With this structure,
the movable member 30b is diagonally moved in the direction E for
crushing.
In the present embodiment, a driving mechanism for reciprocatively
moving the movable member 30b has a cam mechanism. Namely, the movable
member 30b is fixed to a movable board 32; the movable board 32
is fixed to a cam board 34 having a window 36; a roller 38 is rotatably
fitted in the window 36; the roller 38 is eccentrically fixed to
a rotary plate 39; and the rotary plate 39 is connected to a gear
40 which is engaged with the gear 22. Note that, the gear ratio
between the gears 22 and 40 is 1:1.
The cam mechanism including the cam board 34 the rotary plate
39 etc. is shown in FIG. 3. The rotary plate 39 is connected to
a gear shaft 42 of the gear 40. The gear shaft 42 is rotatably held
by bearings. The reciprocative movement of the cam board 34 is guided
by guide shafts 44.
When the gear 22 is rotated by the motor 20 the rotary plate 39
rotates and the roller 38 moves with a circular track. By the circular
movement of the roller 38 the cam board 34 and the movable board
32 are reciprocatively moved along the guide shafts 44. Thus, the
movable member 30b is reciprocatively moved, and the scraps are
crushed by the fixed member 30a and the movable member 30b.
In the present embodiment, by said gear ratio, the rotary blade
members 10 are made a half turn for preparatory crushing with respect
to each reciprocative movement of the movable member 30b. Note that,
the reciprocative movement of the movable member 30b is designed
to start after the rotary blade members 10 complete the preparatory
crushing. By shifting the timing of the movable member 30b with
respect to that of the rotary blade members 10 load of the driving
mechanism can be reduced.
Though many of plastic scraps such as runners have complex shapes,
the crushing section D of the present embodiment is designed to
crush scraps having simple shapes, e.g., rod shape. Thus, the preparatory
crushing section C crushes scraps into simple shapes with medium
sizes before crushing by the crushing section D.
Another embodiment will be explained with reference to FIGS. 4
and 5. In this embodiment, each rotary blade member 10 has blades
10c and 10d, which are different from the blades 10a and 10b (see
FIG. 1) in shape, and the drive mechanism has a cam 45 instead of
the roller 38. The circumferential width of base portions of the
blades 10c and 10d is wider than that of the blades 10a and 10b.
If the circumferential width of the base portions of the blades
10c and 10d is narrow, scraps are allowed to pass downward through
gaps between the blades 12a after the blades 10c and 10d pass through
said gaps. By making the blades 10c and 10d wide, it takes the blades
10c and 10d a long time to pass through the gaps, so that scraps
can be held on the blades 12a and they are prevented from falling
down without being preparatorily crushed.
Moreover, since front end portions of the blades 10c and 10d are
made sharp, scraps can be caught and introduced to inner portions
of the blades 10c and 10d, so that effective crushing can be executed.
In the driving mechanism for reciprocatively moving the movable
member 30b, the gear 40 is engaged with the gear 22 which is driven
by the motor 20 (see FIGS. 1 and 3); the gear 40 is fixed to the
gear shaft 42; the cam 45 is fixed to the gear shaft 42; and a roller
46 always contacts an outer circumferential face of the cam 45.
With this structure, the roller 46 is pushed and moved by the rotation
of the cam 45. As clearly shown in FIG. 4 the roller 46 is rotatably
held on the movable board 32 which holds the movable member 30b.
The driving mechanism of the present invention the movable board
32 is linearly moved along the guide shafts 44 as well as the driving
mechanism shown in FIGS. 1-3. The movable board 32 is always biased
upward by springs 47 so that the roller 46 can contact the outer
circumferential face of the cam 45.
The cam 45 is formed into an oval shape as shown in FIG. 4 so
the cam 45 is capable of cyclically pushing the roller 46 downward.
By the downward force of the cam 45 and the upward elasticity of
the springs 47 the roller 46 is capable of linearly and reciprocatively
moving with a prescribed stroke, so that the movable member 30b
can be reciprocatively moved.
Next, the fixed member 30a and the movable member 30b of the crushing
section D will be explained.
FIG. 6 is a perspective view of the fixed member 30a and the movable
member 30b; FIG. 7 is a perspective view, with portions broken away
for clarity, of the fixed member 30a; FIG. 8 is a perspective view,
with portions broken away for clarity, of the movable member 30b;
and FIG. 9 is a view in the direction of an arrow X shown in FIG.
6.
In FIG. 6 a fixed member proper is formed into a block shape and
has edge sections 310 in one side. There are formed inclined concave
sections 311 whose depth is made deeper toward front ends, between
the adjacent edge sections 310.
Projected sections 312 are projected between the adjacent edge
sections 310 like comb-teeth. Namely, the projected sections 312
are projected from the front end portions of the inclined concave
sections 311 in the fixed member proper toward the movable member
30b. As shown in FIGS. 6 and 7 the edge sections 310 and the front
end portions of the inclined concave sections 311 are linearly arranged,
and the projected sections 312 are projected outward from them.
Front ends of the projected sections 312 have rectangular faces.
Both side faces 313 and 314 and an upper faces 315 of the projected
sections 312 are shearing blade faces. A plurality of groove-blades,
each of which comprises the edge section 310 and the corresponding
blade faces 313 and 314 are a first shearing section 318 (see FIG.
12). Furthermore, a plurality of inclined concave sections 311 including
the blade faces 315 are a second shearing section 320 (see FIG.
14). Thus, the fixed member 30a has a plurality of groove-blades
as the first shearing section 318 at regular intervals and a plurality
of the inclined concave sections 311 as the second shearing section
320 between said adjacent groove-blades. Note that, faces 316 of
the projected sections 312 which face to the movable member 30b
slidably contact the movable member 30b.
In FIG. 8 the movable member 30b has a third shearing section
330 which is provided on an upper face of a movable member proper.
The third shearing section 330 has a plurality of projected blades,
which are capable of slidably engaging with the groove-blades of
the first shearing section 318 for shearing scraps. Each projected
blades of the third shearing section 330 has shearing blade faces
332 and 333. Front ends of the projected blades have rectangular
faces. The projected blades of the third shearing section 330 slidably
come into the groove-blades of the first shearing section 318 when
the movable member 30b is moved to the fixed member 30a.
The movable member 30b also has a fourth shearing section 340.
The fourth shearing section 340 has a plurality of projections,
each of which is arranged between the adjacent projected blades
of the third shearing section 330 like comb-teeth. The projections
of the fourth shearing section 340 are located rearwardly with respect
to the projected blades of the third shearing section 330. The projections
of the fourth shearing section 340 are capable of fitting into the
inclined concave sections 311. The projections are diagonally formed
thinner toward front ends.
As clearly shown in FIG. 8 the projected blades of the third shearing
section 330 are provided on the movable member proper at regular
intervals, so there are formed grooves between the adjacent projected
blades. There are formed opening sections 350 at rear ends of said
grooves. The opening sections 350 are communicated to a discharge
hole 360 for discharging crushed pieces outside, which is formed
downward in the movable member 30b.
As described above, the fixed member 30a has the first and the
second shearing members 318 and 320; the movable member 30b has
the third and the fourth shearing members 330 and 340. With this
structure, the first and the third shearing members 318 and 330
crush the scraps, which have been preparatorily crushed by the preparatory
crushing section C, as primary crush, then the second and the fourth
shearing sections 320 and 340 further crush the scraps, which have
been primarily crushed by the first and the third shearing members
318 and 330 as secondary crush.
To manufacture the fixed member 30a and the movable member 30b,
forming materials, e.g., steel, may be selected on the basis of
hardness of scraps, etc. For example, the shearing sections of the
fixed member 30a and the movable member 30b may be made from cemented
carbide, and rests may be made of stainless steel. In the example
shown in FIGS. 6-8 the fixed member 30a and the movable member
30b are assembled with a plurality of members.
The fixed member 30a and the movable member 30b have many small
blades, so it is very difficult to machine so as to form many small
blades if the cemented carbide is employed as a blade material.
Furthermore, manufacturing cost must be increased. To avoid these
disadvantages, the blades may be separately manufactured and adhered
onto the fixed member proper and the movable member proper with
adhesives having higher adhering force. By adhering the blades,
it is very easy to arrange the blades onto the fixed member proper
and the movable member proper, so that manufacturing time and cost
can be reduced.
Successively, the action of crushing scraps will be explained with
reference to FIGS. 10-15.
In FIG. 10 the fixed member 30a and the movable member 30b are
in a state of before crushing a scrap 50. Namely, the movable member
30b is located at uppermost position. Note that, the scrap 50 is
a rod-shaped resin runner (see FIG. 11).
The scrap 50 has been preparatorily crushed by the preparatory
crushing section C, then it has fallen onto the engaged portion
of the fixed member 30a and the movable member 30b. The faces 316
of the projected sections 312 of the fixed member 30a slidably contact
the movable member 30b so as to support the scrap 50.
In the state shown in FIG. 10 the movable member 30b is moved
diagonally downward, then the scrap 50 is crushed between the first
shearing section 318 and the third shearing section 330 (the primary
crush). The state of the primary crush is shown in FIG. 12. The
scrap 50 is pinched and sheared by the first shearing section 318
and the third shearing section 330 and the scrap 50 sheared has
an uneven shape shown in FIG. 13. To described in detail, the scrap
50 is pinched between the projected sections 312 the third shearing
section 330 and an edge portion of the fixed member proper, and
faces of the projected sections 312 and the third shearing section
330 which are capable of pinching the scrap 50 have V-groove,
so that the scrap 50 can be reliably pinched and held therebetween.
In FIG. 12 crushed pieces 50a, which are formed by the primary
crush, are ejected by the third shearing section 330 with the downward
movement of the movable member 30b. The ejected pieces 50a fall
down from there.
In the state shown in FIG. 14 the movable member 30b has been
further moved downward, and the scrap 50 is crushed between the
second shearing section 320 and the fourth shearing section 340
(the secondary crush). The projections of the fourth shearing section
340 are fitted into the inclined concave sections 311 of the second
shearing section 320 so that the scrap 50 which have been primarily
crushed, is further crushed. By the secondary crush, projected parts
52 of the scrap 50 which has been primarily crushed, are sheared.
The edge sections 310 of the first shearing section 318 and the
second shearing section 320 are linearly arranged as described above,
a sheared face of the scraps 50c, which has been secondarily crushed
by the second shearing section 320 and the fourth shearing section
340 is formed flat (see FIG. 15). Namely, the scrap 50 (FIG. 11)
is once formed into the uneven shape (FIG. 50) by the primary crush,
then the projected parts 52 are sheared by the secondary crush,
so that the scrap 50 is formed into the shape 50c (FIG. 15).
After the primary crush, the third shearing section 330 bites the
scrap 50 while the movable member 30b is moved downward. And the
secondary crush is executed immediately after the primary crush.
Thus, the scrap 50 is securely held, so that only the projected
parts 52 are sheared by the second and the fourth shearing sections
320 and 340.
The crushed pieces 50b (the projected parts 52), which has sheared
by the secondary crush, are introduced into the the discharge hole
360 via the opening sections 330 of the third shearing section 330
and discharged outside.
Upon completing the secondary crush, the movable member 30b is
returned to the position shown in FIG. 10 for the next crush. When
the movable member 30b is returned to the initial position, next
scrap 50 to be crushed is allowed to move to the engaged portion
of the fixed and the movable members 30a and 30b for the next crush.
The scrap 50c left (FIG. 15) will be crushed into the pieces 50a
and 50b in the next crushing process.
In the present embodiment, scraps are continuously crushed into
small pieces with the linear reciprocative movement of the movable
member 30b. Parts of a scrap are crushed into small pieces by the
primary crush, then the rest parts of the scrap are crushed into
small pieces by the secondary crush, so that the scrap can be reliably
crushed. Even if scraps have complex shapes, they can be crushed
into small pieces, whose sizes are smaller than prescribed size,
by repeating the primary crush and the secondary crush.
In the present embodiment, the first and the second shearing sections
are provided in the fixed member and the third and the fourth shearing
sections are provided in the movable member. But the first and the
second shearing sections may be provided in the movable member and
the third and the fourth shearing sections may be provided in the
fixed member. Moreover, the both members may be movable.
Since the crusher of the present invention is capable of partially
and repeatedly crushing scraps (materials), scraps having various
sizes can be crushed into small pieces smaller than a prescribed
size. The size of the crushed pieces can be defined by the sizes
of the shearing sections. Namely, if small sized pieces are desired,
the sizes of the shearing sections will be small; if large sized
pieces are desired, the sizes thereof will be large. The sizes of
the shearing sections can be designed on the basis of the reuse
of scraps.
With the crusher of the present embodiment, plastic scrap pieces
having almost uniform size can be gained. Since they can be used
as resin pellets for plastic molding, the crusher is very useful
for reuse of plastic scraps.
Since scraps are crushed by pinching and shearing with the fixed
member and the movable member, the crusher of the present invention
is able to more efficiently crush scraps than conventional crushers,
which crush scraps with rotary blade members. Thus, in the present
invention, the driving mechanism need not have great power.
In the present embodiment, the width of the fixed and the movable
members 30a and 30b is around 80 mm, so the present invention is
able to provide a compact crusher having higher crushing performance.
Note that, in case of large amount of scraps, the width of the fixed
and the movable members may be larger so as to increase the number
of shearing points, so that mass crushing of scraps can be executed
in a short time.
Since the crusher of the present invention can be compact, so it
can be assembled, for example, in an injection molding machine.
Resin scraps, e.g., runners, formed in the injection molding machine
can be immediately crushed by the crusher assembled. In this case,
resin molding and scrap crushing can be executed in one machine.
Note that, the crusher for crushing plastic (resin) scraps has
been described above but the crusher of the present invention is
not limited to the plastic crusher. Of course, many kinds of materials,
e.g., rubber, glass, can be crushed by the crusher of the present
invention.
The invention may be embodied in other specific forms without departing
from the spirit or essential characteristics thereof. The present
embodiments are therefore to be considered in all respects as illustrative
and not restrictive, the scope of the invention being indicated
by the appended claims rather than by the foregoing description
and all changes which come within the meaning and range of equivalency
of the claims are therefore intended to be embraced therein. |