Abstrict The invention concerns a rebound crusher having at least one rotor
provided with hammers which is mounted rotatably in a crusher housing
and cooperates with at least one rebound mechanism which is arranged
swingable against spring force within the crusher housing and the
distance of which from the hammers of the rotor is adjustable. In
order, in a space-saving development, to permit remote adjustment
of the nip between hammers and rebound mechanism, the rebound mechanism
is pivotally connected to the piston rod of a damping piston which
rests against the crusher housing and the front end position of
which is infinitely variable via an adjustment piston of a setting
cylinder.
Claims We claim:
1. A rebound crusher comprising
a crusher housing, a rebound mechanism disposed within said housing,
and at least one rotor provided with hammers and being rotatably
mounted in said crusher housing, said rotor cooperating with said
rebound mechanism, said rebound mechanism being supported swingably
against spring force within the crusher housing, the distance from
said rebound mechanism to the hammers of the rotor being adjustable;
and wherein
said crusher further comprises
adjustment means secured to said crusher housing, and having an
adjustment piston and a setting cylinder enclosing said piston,
damping means interconnecting said adjustment means with said rebound
mechanism, said adjustment means adjusting the distance between
the hammers and said rebound mechanism, said damping means damping
a motion of said rebound mechanism during a crushing of bodies of
material placed within said housing; and wherein
said setting cylinder is secured to said housing; and
said damping means comprises a damping cylinder positioned by said
adjustment piston, said damping means further comprising a damping
piston enclosed within said damping cylinder and being articulated
to a part of said rebound mechanism distant from a point of pivot
of said rebound mechanism, said damping piston being moveable independently
of a movement of said adjustment piston for operation of said damping
means and said adjustment means independently of each other.
2. In an impact crusher comprising
a crusher housing and at least one impact mechanism;
at least one rotor which is provided with hammer arms, said rotor
being mounted rotatably in the crusher housing and operative with
said at least one impact mechanism, said impact mechanism being
mounted swingably in the crusher housing so as to move away upon
the presence of large pieces of material to be crushed and particularly
foreign bodies;
distance means for adjusting the distance of the impact mechanism
from the hammer arms of the rotor, the impact mechanism including
a setting cylinder, and a piston rod and a setting piston connected
together and disposed in the setting cylinder; the impact mechanism
being connected continuously displaceable in articulated fashion
with the piston rod, the piston resting against the crusher housing;
the improvement wherein:
said crusher further comprises
a damper cylinder and a damping piston connected to said piston
rod, said piston rod serving also as a piston rod for the damping
piston; and wherein
a front end position of the damping piston is continuously displaceable
via the setting piston of the setting cylinder; and
said setting piston is moveable within said setting cylinder, said
damping piston being moveable within said damper cylinder independently
of movement of said setting piston within said setting cylinder
for operation of said setting piston and said damping piston independently
of each other.
3. A rebound crusher according to claim 2 wherein
the damper cylinder encloses a damping space filled with an elastomer.
4. A rebound crusher according to claim 2 wherein
the damper cylinder encloses a damping space filled with a pressure
liquid, there being a storage connected to the damping space and
having a variable pretensioning pressure.
5. A rebound crusher according to claim 4 wherein
the storage is arranged outside the damping cylinder.
6. A rebound crusher according to claim 2 wherein
the damping cylinder is simultaneously developed as an adjustment
piston and is arranged displaceably within the setting cylinder.
7. A rebound crusher according to claim 6 wherein
the damping cylinder extends in sealed manner out of the rear of
the setting cylinder, and
the adjustment piston rests against the cylinder bottom of the
setting cylinder via an annular surface surrounding the damping
cylinder.
8. A rebound crusher according to claim 6 wherein
the damping cylinder extends in sealed manner out of the front
of the setting cylinder, and
the adjustment piston rests via its piston bottom against the cylinder
bottom of the setting cylinder.
9. A rebound crusher according to claim 2 further comprising
a stop for limiting movement of the rebound mechanism in a direction
towards the rotor, the setting cylinder terminating in a rod which
extends in sealed manner out of the rear of the setting cylinder,
the stop being disposed on the rod which extends out of the rear
of the setting cylinder.
10. A rebound crusher according to claim 2 wherein
said damping cylinder rests directly against the crusher housing
and the setting piston and is developed as a double piston, one
of the pistons of which is arranged in the damping position while
the other piston of which is arranged adjustably in the setting
cylinder which is developed as an extension of the damping cylinder.
11. A rebound crusher according to claim 2 further comprising
a pressure-limiting valve connected to the damping cylinder.
12. A rebound crusher according to claim 2 further comprising
a pressure-limiting valve connected to the setting cylinder.
Description FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a rebound crusher having at least
one rotor provided with hammers which is mounted for rotation in
a crusher housing and cooperates with at least one rebound mechanism
which is arranged swingable against spring force in the crusher
housing and the distance between which and the hammers of the rotor
is adjustable.
Rebound crushers of the above-described type whose rebound mechanisms
are mounted under spring action with respect to the housing are
known. The spring mounting permits the rebound mechanism to move
away upon the encountering of large pieces to be crushed, and particularly
in the case of foreign bodies such as pieces of metal, in order
to avoid damage to the rebound mechanism and the rotor with its
hammers. In order to be able to adjust the fineness of the crushed
material it is know to adjust the starting position of the rebound
mechanism with respect to the hammers of the rotor by means of spindles.
In addition to this adjustment of the nip, the spring characteristic
of the springs is also selected as a function of the specific material
to be crushed.
In the case of rebound crushers of relatively large capacity, the
dimensioning and arrangement of the springs and spindles affords
problems. Furthermore, it is difficult and time-consuming to adjust
the nip in each case. Such an adjustment is, however, not only necessary
if wear of the hammers and of the armor plates of the rebound mechanism
must be compensated for by readjustment but also if different material
is charged in succession into the rebound crusher and/or if different
particle sizes of the crushed material are desired.
SUMMARY OF THE INVENTION
The object of the present invention is so to further develop a
rebound crusher of the aforementioned type that, with a compact
development of the springs and displacement elements, remote adjustment
of the nip between hammers and rebound mechanism is made possible.
The solution of this problem by the present invention is characterized
by the fact that the rebound mechanism is pivotally connected to
the piston rod of a damping piston which rests against the crusher
housing and the front end position of which is capable of infinitely
variable adjustment via an adjustment piston of a setting cylinder.
By the use of a damping cylinder instead of mechanical springs,
high spring forces and spring paths can be obtained in a minimum
space; the use of an adjustment cylinder via which the damping piston
rests against the housing of the crusher permits an infinitely variable
remote adjustment of the nip between the hammers of the rotor and
the armor plates of the rebound mechanism.
In order to avoid sealing problems with a given spring force and
damping, the interior of the damping cylinder can, in accordance
with another feature of the invention, be filled with an elastomer.
This elastomer is compressible and flowable but it can be sealed
against emergence at considerably little structural expense.
In an alternative embodiment, the interior of the damping cylinder
is filled with a pressure liquid and connected with a storage the
pretensioning pressure of which is variable so as to adapt the damping
characteristic to the specific purpose of use. In accordance with
the invention, the storage can be arranged outside the damping cylinder
so that protected arrangement at a given place is possible.
In a preferred further development of the invention, the damping
cylinder is, at the same time, developed as adjustment piston and
arranged displaceably within the setting cylinder. In this way a
compact, space-saving construction is obtained which is capable
of absorbing high pressure.
The damping cylinder can, in accordance with the invention, be
extended in sealed manner out of the rear of the setting cylinder,
in which case the adjustment piston rests, via an annular surface
surrounding the damping cylinder, against the cylinder bottom of
the setting cylinder. This development permits simple connection
of a storage to the damping cylinder and easy filling of the damping
cylinder with an elastomer.
As an alternative to this, the damping cylinder can also be extended
in sealed manner out of the front side of the setting cylinder,
in which case the adjustment piston rests via its piston bottom
against the cylinder bottom of the setting cylinder. This embodiment
results in large supporting surfaces and is therefore suitable for
the taking up of large forces.
In order to limit the form-locked fashion the possibility of movement
of the rebound mechanism in the direction towards the rotor so that
entrance of the rebound mechanism into the beating circle of the
hammers is prevented, it is proposed by the invention that a top
for the limiting of the movement of the rebound mechanism in the
direction towards the rotor be arranged on a rod which is extended
in sealed manner out of the rear of the cylinder housing. In the
case of a damping cylinder which extends out of the rear of the
setting cylinder, this stop can be arranged directly on the damping
cylinder. If the damping cylinder is extended out of the front of
the setting cylinder, then the stop is arranged on a rod which connects
the setting piston with the storage and is conducted in sealed manner
out of the cylinder bottom of the setting cylinder.
In accordance with another feature of the invention, for the creation
of a preferred embodiment the damping cylinder can rest directly
on the crusher housing and the setting piston can be developed as
a double piston, one of the pistons of which is arranged in the
damping piston while the other is adjustably arranged in the setting
cylinder which is developed as an extension of the damping cylinder.
In this embodiment also there is obtained a compact structure capable
of taking up high forces and which permits, aside from the variation
of the damping characteristic, remote adjustment of the nip between
hammers of the rotor and rebound mechanism.
It is finally proposed by the invention that a pressure-limiting
valve be connected both to the damping cylinder and to the displacement
cylinder. The pressure-limiting valve arranged on the damping cylinder
releases pressure liquid when an adjustable pressure is reached,
so that the damping piston then displaces pressure liquid without
additional loading of the storage, whereby overloading of the damping
system can be avoided, particularly in the event of the occurrence
of large foreign bodies. In these cases, as a result of the pressure-limiting
valve which is arranged alternatively or additionally on the displacement
cylinder, the result is obtained that the adjustment path of the
nip adjustment is also utilized for the moving away of the rebound
mechanism upon the occurrence of large foreign bodies, so that maximum
escape paths are present.
BRIEF DESCRIPTION OF THE DRAWINGS
Several embodiments of the rebound crusher of the invention are
shown in the drawing, in which:
FIG. 1 is a diagrammatic longitudinal section through a rebound
crusher with a first possible embodiment, shown diagrammatically,
of the damping and setting cylinder of the invention,
FIG. 2 is a diagrammatic longitudinal section through a second
embodiment, in which the damping cylinder, which is developed at
the same time as adjustment piston, is extended out of the rear
of the setting cylinder,
FIG. 3 is another embodiment, corresponding to FIG. 2 with damping
cylinder extending out of the front of the setting cylinder, and
FIG. 4 is a longitudinal section through another embodiment with
setting piston developed as double piston.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 diagrammatically shows a rebound crusher within the crusher
housing 1 of which a rotor 2 provided with hammers 2a is rotatably
mounted. The material to be crushed which is charged into the rotor
1 is thrown by the crusher arms 2a in the embodiment of FIG. 1 against
two rebound mechanisms 3 which are provided on their front surface
with armor plates 3a. Each rebound mechanism 3 is swingably mounted
in the crusher housing 1 around a pin 3b and rests via a link rod
4 against the piston rod 5a of a damping piston 5 which, in its
turn, rests against the crusher housing 1 and the front end position
of which is adjustable in infinitely variable manner by an adjustment
piston 7 of a setting cylinder 8.
FIG. 1 shows diagrammatically the association of the damping piston
5 arranged within a damping cylinder 6 with the setting cylinder
8. This figure shows that the damping piston 5 arranged within the
damping cylinder 6 is acted on by a spring 5b or an elastomer 5c,
and that the position of the damping cylinder 6 relative to the
crusher housing 1 is infinitely variable by means of the adjustment
piston 7 which, in its turn, is guided displaceably within the setting
cylinder 8. In this way, the operating position of the rebound mechanism
3 can be displaced infinitely variably by means of the adjustment
piston 7 so that the nip between the hammers 2a and the armor plates
3a of the rebound mechanism 3 is adjustable without the actuating
of threaded spindles. Starting from this adjustment, the movement
of the rebound mechanism 3 is damped by a movement of the damping
piston 5 within the damping cylinder 6 against the force of the
spring 5b when material to be crushed comes against the armor plates
3a.
FIG. 2 shows diagrammatically a first structural embodiment. In
this construction, the setting cylinder 8 is fastened to the crusher
housing 1 and is provided with a sealed passage opening for the
piston rod 5a of the damping piston 5. The damping cylinder 6 is,
at the same time, developed as adjustment piston 7 and is accordingly
displaceable within the setting cylinder 8. The rear end of the
damping cylinder 6 is extended in sealed manner out of the setting
cylinder 8 and provided with a stop 9 which limits the movement
of the damping cylinder 6 and thus of the damping piston 5 as well
as of the rebound mechanism 3 connected by the link rod 4 in the
direction towards the rotor 2. In this way, assurance is had that
the armor plates 3a of the rebound mechanism 3 cannot come into
the circle of movement of the hammers 2a of the rotor 2.
In order to reduce the distance of the rebound mechanism 3 from
the hammers 2a in the position of the individual parts shown in
FIG. 2 pressure liquid in conducted by a pump 10 from a storage
container 11 into the annular space 8a of the setting cylinder 8.
For this purpose, the multi-way valve 12 is switched in such a manner
that the pressure liquid passes via the openable non-return valve
13 into the annular space 8a. The pressure which builds up in this
case in the annular space 8a and its feed lines opens a combined
blocking-braking valve 14 via a control line so that pressure liquid
can flow back from the piston space 8b of the setting cylinder 8
via the blocking-braking valve 14 and the multi-way valve 12 into
the storage container 11. As soon as the desired position of the
setting piston 7 has been reached, the blocking-braking valve 14
and the non-return valve 13 close off the feed to and discharge
from the setting cylinder 7 without leakage oil, so that said piston
remains in its position. The blocking-braking valve 14 furthermore
prevents the swinging of the rebound mechanisms 3 as a result of
its own weight around the axis 3b.
In order to act with the necessary initial tension on the damping
piston which, due to blows against the rebound mechanism 3 can
move within the damping space 6a of the damping cylinder 6 pressure
liquid is conducted, via a second pump 15 and a multi-way valve
16 as well as a non-return valve 17 into the damping space 6a.
The pressure and thus the initial tensioning force are limited by
an adjustable pressure-limiting valve 18.
If the forces acting on the rebound mechanism 3 exceed the pretensioning
force set, then the damping piston 5 moves into the damping space
6a. The pressure liquid which is displaced thereby flows into a
storage 19. If the force exerted on the rebound mechanism 3 drops,
then the pressure liquid flows back from the storage 19 into the
damping space 6a. The rebound mechanism 3 accordingly assumes its
previous starting position since the setting piston 7 has remained
unchanged in its position.
Since the pressure prevailing in the system increases upon the
displacement of the damping piston 5 another pressure-limiting
valve 20 is provided which discharges pressure liquid into the storage
container 11 if the maximum pressure set is exceeded, so as to prevent
damage to the system. If in such a case the load has again dropped,
a pressure switch 21 reports the decrease in the initial tensioning
pressure, which is again increased to the set value by means of
the pump 15 in the manner described above. Another pressure-limiting
valve 22 serves as safety valve for the storage 19 in order to protect
it from overload. Complete draining of the storage circuit is possible
by means of a valve 23.
If the distance between the rebound mechanism 3 and the hammers
2a (not shown) of the rotor 2 is to be increased in the embodiment
shown in FIG. 2 then, by a suitable position of the multi-way valve
12 and blocking-braking valve 14 pressure liquid is pumped from
the storage container 11 by means of the pump 10 into the piston
space 8b of the setting cylinder 8. The increasing pressure opens
the openable non-return valve 13 so that the pressure liquid present
in the annular space 8a can flow back into the storage container
11 via the non-return valve 13 and the multi-way valve 12 in an
amount corresponding to the quantity forced into the piston space
8b. This is followed by the above-described locking of the position
assumed by the adjustment piston 7 within the setting cylinder 8.
The further embodiment shown in FIG. 3 differs from the construction
of FIG. 2 which has been described above, in the manner that the
damping cylinder 6 which is at the same time developed as adjustment
piston 7 is extended in sealed manner out of the front of the setting
cylinder 8. As a result of this, the piston space 8b is on the side
opposite the rebound mechanism 3 so that a larger piston area is
available to take up the forces exerted on the rebound mechanism
3. In this construction also the same adjustments and displacement
are possible as described with respect to FIG. 2. The limiting of
the force is effected by means of a pressure-limiting valve 24.
If this force is exceeded, pressure liquid flows out of the piston
space 8b of the setting cylinder 8 via the pressure limiting valve
24 and a pretensioning valve 25 into the storage container 11.
A part of the pressure liquid flows in this case over a non-return
valve 26 to the annular space 8a of the setting cylinder 8. In this
way, the latter is completely filled and cavitation is avoided.
Since in the case of the construction described above the adjustment
cylinder 7 has left its position, it must be newly adjusted either
by path-measurement or a stop. In order to limit the displacement
of the adjustment piston 7 in the direction towards the rebound
mechanism 3 a stop 9 is again provided, arranged on a rod 27. This
rod 27 is fastened on the adjustment piston 7 and extends in sealed
manner out of the cylinder bottom of the setting cylinder 8. It
serves also for the connecting of the storage 19 to the damping
space 6a of the damping cylinder 6.
Finally, the further embodiment shown in FIG. 4 shows a damping
cylinder 6 which is fastened directly to the crusher housing 1 and
in which the damping piston 5 is displaceably guided. The front
part 7b of the adjustment piston 7 developed as double piston,
extends into said damping piston 5. The rear part 7a of this adjustment
piston 7 lies in the setting cylinder 8 which adjoins the damping
cylinder 6.
Also in the case of this embodiment a storage 19 is connected to
the damping space 6a of the damping cylinder 6. The annular space
6b present on the rod side of the damping piston 5 is in communication
with the atmosphere via a vent hole in the case of the construction
shown in FIG. 4. The piston spaces 8a and 8b of the setting cylinder
8 are each connected via a non-return valve 28 to a multi-way valve
29 which, in its turn, is in communication with the pump 10 and
with the storage container 11 respectively.
In order to decrease the position of the adjustment piston 7 in
the sense of a decrease of the distance between the rebound mechanism
3 and the rotor 2 pressure liquid is pumped by the pump 10 via
the multi-way valve 29 and an openable non-return valve 28 into
the piston space 8a of the setting cylinder 8. Via the other openable
non-return valve 28 pressure liquid discharges from the piston
space 8b through the corresponding position of the multi-way valve
29 into the storage container 11. In order that the front part 7b
of the adjustment piston 7 can shift within the damping cylinder
5 in the direction towards the rebound mechanism 3 the piston space
30 in the damping piston 5 is in communication with the atmosphere
via a bore 31.
If the distance between rotor 2 and rebound mechanism 3 is to be
increased, then pressure liquid is forced by the pump 10 via the
multi-way valve 29 into the piston space 8b of the setting cylinder
8. The pressure liquid flows from the piston space 8a via the openable
non-return valve 28 and the multi-way valve 29 back into the storage
container 11. At the same time, the annular piston space 33 in the
damping piston 5 is connected via a bore 32 and via the multi-way
valve 34 to the storage container 11.
For purpose of servicing, the distance between rotor 2 and rebound
mechanism 3 can be further increased. For this purpose, the annular
piston space 33 is connected to the pump 10 via the multi-way valve
34. At the same time, the damping space 61 is connected with the
storage container 11 as shown in FIG. 2.
In this construction also, the movements of the damping piston
5 are damped by pressure liquid in the damping space 6a which is
connected to the storage 19. Since upon the movement of the damping
piston 5 the annular piston space 33 is enlarged or reduced in size,
pressure liquid can either be drawn out through the bore 32 or pushed
out into the storage container 11.
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