Abstrict An improved crusher with first, second and third curtain assemblies.
Each curtain assembly mounts a series of crusher plates and the
plates of its curtain assemblies are distributed circumferentially
above a rotor in the crusher. The three curtain assemblies pivot
or swing about a common pivot axis. Gravity biases the third curtain
assembly whereby the breaker plates are urged toward the rotor of
the crusher. Springs and curtain rods are part of structure additionally
biasing the third curtain assembly.
Claims It is claimed and desired to secure by Letters Patent:
1. In an impact crusher having a frame and a rotor rotatably supported
on the frame for rotation about a rotor rotation axis, with hammers
on the rotor for striking material, the improvement comprising:
primary and secondary curtain assemblies disposed above the rotor
at locations spaced circumferentially thereabout,
a tertiary curtain assembly extending downwardly beyond the secondary
curtain assembly,
said tertiary curtain assembly including a breaker plate structure
spaced outwardly of the rotor and for contacting material moved
thereagainst by the rotor and a pivot arm structure mounting the
breaker plate structure, and
a pivot mounting for the tertiary curtain assembly pivotally supporting
the pivot arm structure for movement about a pivot axis disposed
above the breaker plate structure and spaced in a horizontal direction
toward a vertical line perpendicular to the rotation axis of the
rotor from the center of gravity of the tertiary curtain assembly,
whereby a gravity biasing of the tertiary curtain assembly toward
the rotor is produced.
2. The crusher of claim 1 wherein the primary and secondary curtain
assemblies each include pivot arms pivotally mounting the assembly
for pivotal movement about said pivot axis.
3. The crusher of claim 1 and further including stop structure
defining a lower limit position for the tertiary curtain assembly,
gravity serving to bias the tertiary curtain assembly to said limit
position.
4. The crusher of claim 3 wherein said pivot axis for the tertiary
curtain assembly is a fixed pivot axis, and the tertiary curtain
assembly is freely pivotable about said pivot axis at least to enable
doubling of the spacing between the breaker plate structure and
the rotor.
5. The crusher of claim 3 wherein the stop structure is adjustable,
with adjustment of the stop structure serving to adjust the location
of said lower limit position.
6. The crusher of claim 3 wherein the stop structure comprises
an elastomer bumper and a stop shoulder engaged by the bumper and
the bumper is freely movable away from the stop shoulder with movement
of the tertiary curtain assembly away from the rotor.
7. The impact crusher of claim 3 which further includes biasing
spring means operatively connected to the tertiary curtain assembly
urging the assembly to said limit position.
8. The impact crusher of claim 3 and which further comprises plural
curtain rods pivotably connected to the tertiary curtain assembly
at points distributed in a direction paralleling the pivot axis
of the curtain assembly, a bar interconnecting ends of the curtain
rods, and coil springs interposed between the frame and said bar
biasing the tertiary curtain assembly in a direction towards said
limit position.
9. In an impact crusher:
a frame,
a rotor journaled on the frame for rotation about a horizontal
rotor rotation axis and the rotor having a perimeter,
first, second and third curtain assemblies, each including breaker
plate means, and the curtain assemblies being disposed with their
said breaker plate means distributed circumferentially about the
perimeter of the rotor, the rotor having a top and the breaker plate
means of said first curtain assembly being adjacent the top of the
rotor, the breaker plate means of said second curtain assembly being
disposed downwardly from the breaker plate means of the first assembly,
and the breaker plate means of the third assembly being disposed
downwardly from the breaker plate means of the second assembly,
and pivot arms pivotally mounting each of the curtain assemblies
for pivotal movement about a horizontal pivot axis, and this pivot
axis being the same for all the curtain assemblies, said pivot axis
being located in a horizontal direction toward a vertical line perpendicular
to the rotation axis of the rotor from the center of gravity of
each curtain assembly.
Description BACKGROUND OF THE INVENTION
This invention relates to an impact crusher. More particularly,
the invention concerns an impact crusher which includes primary
and secondary curtain assemblies, each of which includes breaker
plates which material impacts or is thrown against during the crushing
operation, and which additional includes a tertiary curtain assembly
acting on material after the material passes the primary and secondary
assemblies.
A general object of the invention is to provide an improved impact
crusher which incorporates primary, secondary and tertiary curtain
assemblies, and which features a construction accommodating clearance-establishing
movement in the tertiary curtain assembly as desirably should occur
when an overloaded or jammed condition exists.
Yet another object is to provide an improved impact crusher, with
a tertiary or exit curtain assembly, where release movement is established
with pivoting of the curtain assembly about a suitably located pivot
axis.
Yet a further object is to provide a construction where a tertiary
curtain assembly is part of the curtain system, and where gravity
is relied upon, at least in part, for biasing of the curtain assembly
to establish a lowered operative position for the assembly.
A related object is to provide a construction which provides for
adjustability in the lowered position for a curtain assembly.
Another related object is to provide a construction wherein biasing
may be supplemented by springs acting in concert with gravity.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages are attained by the invention,
which is described hereinbelow in conjunction with the accompanying
drawings, wherein:
FIG. 1 is a side elevation, partially broken away, of a crusher
constructed according to an embodiment of the invention;
FIG. 2 is a view of faces of curtain assemblies in the crusher
as they appear viewing from right to left in FIG. 1;
FIG. 3 is a view looking downwardly at rear portions of the crusher
illustrated in FIG. 1;
FIG. 4 illustrates the tertiary curtain assembly in the crusher,
looking at the back of the assembly and with the assembly removed
from the crusher; and
FIG. 5 is an enlarged view, with portions broken away, showing
a part of curtain rod structure provided in the tertiary curtain
assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and initially to FIG. 1 an impact
crusher constructed pursuant to the invention is indicated generally
at 10. The crusher includes a frame 12 with a hood 12a of the frame
that extends about the top and sides of the crusher. The frame suitably
supports the crusher on the ground. Material is fed into the crusher
through infeed opening 14. Material exits the crusher through a
discharge opening 16 at the base of the crusher.
Supported within the crusher is a rotor 20. The rotor includes
a horizontal shaft or spindle 24 extending axially through its center,
and this shaft has it ends suitably rotatably supported in bearings,
such as those shown at 26. The rotor is rotated under power, through
a suitable power-drive system connected to an end of the shaft.
Rotation of the shaft is about its axis 25.
Suitably supported at points distributed circumferentially about
the rotor are hammers 30. Rock or aggregate fed into the crusher
through opening 14 cascades downwardly onto the rapidly rotating
rotor, thence to be struck by the hammers which are moving in circular
orbits about the axis of shaft 24. This material is thrown outwardly
by the rotor.
The interior of the hood assembly which forms the frame forms a
chamber essentially surrounding the rotor. The interior of this
chamber is lined with the usual liner plates, which are conventional,
and thus not illustrated.
Supported within the hood structure of the frame is a primary curtain
assembly 40 which includes what is referred to herein as a curtain
collectively formed by rows of breaker plates 42a, 42b, 42c, 42d,
42e. Also supported within the hood assembly of the frame is a secondary
curtain assembly 44 supporting a curtain formed collectively of
rows of breaker plates 44a, 44b. A tertiary or exit curtain assembly
is illustrated at 50 which mounts rows of plates 50a, 50b forming
a curtain assembly adjacent the base of the hood interior.
With operation of the crusher, as already discussed, material fed
into the crusher cascades downwardly against the rotor and thence
is impacted and thrown outwardly on being struck by the hammers
in the rotor. Much of such material initially is thrown outwardly
against the primary curtain assembly, with impacting of material
and particle size reduction. Such is returned to the rotor, by rebounding
off the curtain assembly. Material on working past the primary curtain
assembly, usually of a smaller size on being impacted by the hammers
in the rotor, is thrown outwardly against the secondary curtain
assembly and its rows of breaker plates 44a, 44b. This material,
again, rebounds or falls by gravity to return to the rotor.
It will be noted, and with continued reference to FIG. 1 that
the faces of the breaker plates in tertiary or exit curtain assembly
50 and in particular faces 52 of plates in row 50b, incline at
a much slighter angle relative to horizontal then do faces 54 and
56 in the rows of breaker plates in the primary and secondary curtain
assemblies. Further, as compared to the breaker plates in the primary
and secondary curtain assemblies, the breaker plates in the tertiary
curtain assembly are relatively low in the housing. Further explaining,
row 50a of the plates in assembly 50 is approximately at the level
of the axis of shaft 24 in the rotor, and row 50b in assembly 50
is below this level. It should further be remembered that material
on being operated upon by the tertiary curtain assembly has already
been reduced in size to a substantial extent by impacting of the
hammers in the rotor and striking the curtains in the primary and
secondary curtain assemblies. As a consequence, the kinetic energy
of material thrown against the breaker plates of the tertiary curtain
assembly is substantially less than that of material being operated
upon in regions higher in the crusher. All these factors contribute
to an operation, in the tertiary curtain assembly, which in many
respects resembles a grinding operation, in comparison to the impacting
type of action of the primary and secondary curtain assemblies.
Considering details of the construction of exit or tertiary curtain
assembly 50 and referring to FIGS. 1 and 4 such includes on opposite
sides of the assembly, a pair of elongate pivot arms 70 72. These
arms, which constitute arm structure in the assembly, have pivot
mountings 74 pivotally supporting the arms for pivotal movement
about a horizontal axis, indicated at 76. This axis parallels rotor
rotation axis 25 and is directly adjacent the upper margin of intake
opening 14 for material being fed into the crusher. These arms,
together with strong backs 78 and weldments 80 are all joined together
to provide a rigid unit supporting the plates in rows 50a, 50b.
Curtain rods 86 88 are pivotably mounted at 90 92 to the back
of the arm structure in the curtain assembly. Referring now also
to FIG. 5 these extend out through holes, such as hole 94 in the
hood structure. Each curtain rod is provided with a guide bushing,
which may be made of nylon and is shown at 96 mounted adjacent
hole 94. Encasing the guide bushing is a washer 98 and a cylinder
segment 100. These are welded to each other, and segment 100 is
secured, as by welding, to the hood structure on its under side.
A retaining plate 103 is suitably secured to hood 12a, and this
retaining plate confines the upwardly facing side of guide bushing
96.
A dust cover 104 has one end anchored to cylinder segment 100 and
its opposite end anchored to the curtain rod adjacent where the
rod is pivotably connected to the arm structure of the curtain assembly.
The curtain rod is threaded as at 106. Snugly mounted on the curtain
rod, but moveable along the rod, is an elastomer (such as a polyurethane)
bumper 110. Encasing the bumper are a washer 112 and cylinder segment
114. The cylinder segment and washer are joined together, as by
welding.
Screwed onto the threaded end of the curtain rod is a nut 116.
This nut may be joined, as by welding, to washer 112. The structure
described functions as an adjustable stop structure, with the position
of nut 116 on the curtain rod determining the relative position
of the bumper on the rod, and the position of the bumper when it
comes up against retaining plate 103 to define the lower limit position
for the curtain rod. This defined lower limit positioned for the
curtain rod determines the defined lower limit position for the
tertiary curtain assembly.
A lock nut is shown at 118. Curtain rod cover 120 secured to the
locked nut serves to cover and protect the protruding end of the
curtain rod.
The center of gravity of the tertiary curtain assembly just described
is approximately midway along the length of the arms between the
pivot mountings for the curtain rods and pivot axis 76 for the assembly.
Thus, the pivot mounting for the curtain assembly, in a horizontal
direction is spaced well toward the rotor from the center of gravity
for the curtain assembly. As a consequence, gravity functions to
bias the curtain assembly, urging the same to swing downwardly and
in a counterclockwise direction in FIG. 1. Gravity thus urges the
assembly to its lower limit position as determined by the stop structure
just described.
The curtain assembly is yieldable, however, with the rows of breaker
plates swinging rearwardly and upwardly from their lowered position,
and with swinging of the curtain assembly about the fixed pivot
axis 76 provided by pivot mounting 74. Such yieldable movement in
the curtain assembly is desirable, as when overloading of rows of
breaker plates 50a, 50b occurs, such as might occur, for instance,
by reason of excessive accumulation of material on the breaker plates,
or by reason of oversized material reaching the region between the
rows of plates and the rotor. With an overloaded condition eliminated,
the arm structure and rows of breaker plates making up the exit
curtain assembly may freely swing downwardly about axis 76 with
return of the exit curtain assembly to its lower limit position.
Assisting gravity in biasing the curtain assembly to its lower
limit position is spring mechanism shown at 130. Specifically, and
referring to FIGS. 1 and 3 secured to the upper ends of rod covers
120 and spanning the space between them, is an elongate bar 132.
Multiple spring anchors 134 are secured to this bar. Operatively
secured to the hood structure are bars 136. Interspersed between
spring anchors 134 and bars 136 are multiple coil springs 140.
The tension in the coil springs functions to draw bar 132 downwardly
and toward the hood structure. This produces a corresponding movement
in the curtain rod covers, with urging of stop nut 116 downwardly
to move bumper 110 firmly against retaining plate 103.
Secondary curtain assembly 44 includes support arms such as arm
150 extending along opposite sides of the apparatus within the interior
of the hood structure. These support arms, together with suitable
strong backs and weldments, provide a unified support for the breaker
plates in rows of breaker plates 44a, 44b.
The upper ends of arms 150 are pivotably mounted by pivot mounts
adjacent the top of the machine and the upper margin of the entrance
opening to the apparatus. The pivot axis provided by these pivot
mounts coincides with axis 76 provided for the pivoting of the tertiary
curtain assembly.
Curtain rods, exemplified by rod 168 have one set of ends pivotably
mounted on the arm structure. The rods project rearwardly from the
arm structure and outside of the hood. A nut 170 joined to a washer
172 and cylindrical segment 174 position a bumper similar to bumper
110 that defines a lower limit position for the curtain assembly.
A lock mount is shown at 178 and a rod cover at 180 which is secured
to the lock nut.
The center of gravity of the secondary curtain assembly is located,
in a horizontal direction, well toward the rotor from rows of breaker
plates 44a, 44b. As a consequence, gravity functions to urge the
secondary curtain assembly in a counterclockwise direction in FIG.
2 to place it in its lower limit position.
The primary curtain assembly, like the secondary assembly, includes
opposed support arms as exemplified by arm 190. These arms, together
with suitable strong backs, are joined together and form a unified
structure providing support for rows of plates 42a, 42b, 42c, 42d,
42e.
Curtain rods, such as rod 210 pivotally supported in the arm structure
project rearwardly and through the hood. Screwed onto each of these
rods is a nut 212. This nut, together with washer 214 and cylindrical
segment 216 and an enclosed bumper, define a lower limit position
for the curtain assembly.
The support arms 190 in the curtain assembly are pivotally mounted
by pivot mounts for pivotal movement about an axis which coincides
with axis 76. Thus, pivotal movement occurs, as in the case of the
other curtain assemblies, about a pivot axis disposed upwardly from
the rotor and forwardly in the hood structure adjacent the upper
margin of the entrance opening to the apparatus.
As in the case of the secondary curtain assembly, the pivot mounting
for the primary curtain assembly is disposed, in a horizontal direction,
well forwardly toward the rotor from the center of gravity of the
curtain assembly. Thus, gravity functions to bias the curtain assembly
downwardly to its lower position defined by bumpers striking frame
structure of the hood.
Operation of the impact crusher should be obvious. Material to
be processed is introduced into the crusher through infeed opening
14. This material cascades downwardly inside the apparatus to fall
upon the power-driven rotating rotor which is rotated under power,
and in a counterclockwise direction as the rotor is illustrated
in FIG. 1.
Such material is struck by the hammers which are moved by the rotor
in circular orbits about the axis of the rotor. Crushing occurs,
together with the material being thrown outwardly to impact the
breaker plates of the primary curtain assembly and, on progressing
further downwardly in the machine, the breaker plates of the secondary
curtain assembly.
Final pulverizing of the material occurs as the material progresses
downwardly to be thrown against rows of plates 50a, 50b of the exit
or tertiary curtain assembly. More than with the other curtain assemblies,
pulverizing of material with the tertiary curtain assembly occurs
by reason of a grinding action occurring as the material is collected
on the rows of breaker plates and forced downwardly by the rotating
rotor.
In the event of overloading of the tertiary curtain assembly, by
reason of oversized material forced between the rotor and the rows
of breaker plates, or for any other reason, the curtain assembly
may swing rearwardly and upwardly about pivot axis 76 with this
movement resisted by gravity and also the biasing action of coil
springs. During this movement, the bumpers which limit downward
movement of the curtain assembly are free to move rearwardly and
away from the hood structure of the machine. With passage of the
oversized material in the curtain assembly, the curtain assembly
is free to return to its lower limit position as defined by the
bumpers striking the rear of the hood structure.
The apparatus described is reliable in operation and operates to
produce a consistently sized material rapidly and efficiently.
While a particular embodiment of the invention has been described,
obviously variations and modifications are possible. It is desired
to cover all such modifications and variations that come within
the scope of the invention.
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