Abstrict A jaw crusher unit for use in crushing stone and other crushable
material has a fixed jaw and a movable jaw which define a crushing
zone therebetween. A drive mechanism coupled with the movable jaw
operates to rock the movable jaw to and fro to crush material in
the crushing zone. A link mechanism sets a space between the lower
end of the movable jaw and the fixed jaw and thereby controls the
discharge of crushed material from the lower end of the crushing
zone. A removable wear plate is mounted on a mounting face of at
least one of the jaws by a wedge arrangement coupled with a power-operated
linear actuator. The linear actuator moves the wear place into and
out of engagement with the mounting face to facilitate replacement
of the wear plate.
Claims What is claimed is:
1. A jaw crusher unit for use in crushing stone and other crushable
material and comprising: a fixed jaw and a moveable jaw which define
a crushing zone therebetween, a drive mechanism coupled with the
moveable jaw and operative to rock the moveable jaw to and fro in
order to crush material in the crushing zone, a link mechanism connected
to a lower end of the moveable jaw and serving to set any required
space between the lower end of the moveable jaw and the fixed jaw
and thereby control the discharge of crushed material from the lower
end of the crushing zone, and a removable wear plate mounted on
a mounting face of at least one of said jaws by a wedge arrangement
coupled with a power-operated linear actuator which is operative
in one direction to pull the wear plate into engagement with the
mounting face in order to mount the wear plate on the jaw and which
is operative in an opposite direction in order to move the wear
plate away from the mounting face and thereby allow the wear plate
to be lifted out of the crusher unit when it is required to be replaced.
2. A jaw crusher unit according to claim 1 in which the removable
wear plate is mounted on the fixed jaw.
3. A jaw crusher unit according to claim 2 in which a removable
wear plate is mounted on the movable jaw, and is retained in position
by a wedge carried on one end of a rod which is manipulatable, in
order to mount of de-mount the wear plate relative to the mounting
face of the moveable jaw.
4. A jaw crusher unit according to claim 2 in which the power
operated linear actuator comprises a device which can apply a linear
force to the wear plate which generates a pulling force in the case
of mounting a replacement wear plate in position, and a pushing
force in the case of de-mounting a worn plate.
5. A jaw crusher unit according to claim 4 in which the linear
actuator comprises a piston/cylinder device which is coupled with
a wear plate/securing wedge, and which is hydraulically or pneumatically
operable.
6. A jaw crusher unit according to claim 5 including a lifting
tool engageable with a wear plate, for the purposes of mounting
and demounting the wear plate relative to the corresponding jaw.
7. A jaw crusher unit according to claim 1 in which the removable
wear plate is mounted on the movable jaw.
8. A jaw crusher unit according to claim 7 in which the power
operated linear actuator comprises an externally threaded rotary
spindle and follower.
9. A jaw crusher unit according to claim 7 in which the power
operated linear actuator comprises a device which can apply a linear
force to the wear plate which generates a pulling force in the case
of mounting a replacement wear plate in position, and a pushing
force in the case of de-mounting a worn plate.
10. A jaw crusher unit according to claim 9 in which the linear
actuator comprises a piston/cylinder device which is coupled with
a wear plate/securing wedge, and which is hydraulically or pneumatically
operable.
11. A jaw crusher unit according to claim 10 including a lifting
tool engageable with a wear plate, for the purposes of mounting
and demounting the wear plate relative to the corresponding jaw.
12. A jaw crusher unit according to claim 1 in which the power
operated linear actuator comprises a device which can apply a linear
force to the wear plate which generates a pulling force in the case
of mounting a replacement wear plate in position, and a pushing
force in the case of de-mounting a worn plate.
13. A jaw crusher unit according to claim 12 in which the linear
actuator comprises a piston/cylinder device which is coupled with
a wear plate/securing wedge, and which is hydraulically or pneumatically
operable.
14. A jaw crusher unit according to claim 1 including a lifting
tool engageable with a wear plate, for the purposes of mounting
and demounting the wear plate relative to the corresponding jaw.
Description This invention relates to a jaw crusher unit for use in crushing
stone and other crushable material and comprising a fixed jaw and
a movable jaw which define a crushing zone therebetween, and a drive
mechanism operative to rock the movable jaw to and fro in order
to crush material in the crushing zone.
The crushing zone defined between the fixed jaw and the movable
jaw is usually generally convergent towards its lower discharge
end, so that crushable material can be fed to the upper and wider
end of the zone, and then fall downwardly under gravity while being
subjected to repeated cycles of crushing movement and relieving
movement of the movable jaw. This breaks down the material, and
crushed material finally falls under gravity through the narrower
lower discharge end of the crushing zone.
In existing machines, the drive mechanism usually takes the form
of an eccentric drive mechanism, and the "throw" of the
mechanism has an influence on the crushing action, and so also has
the width of the crushing zone at the lower discharge end.
It is also usual to provide an adjustable link mechanism which
is connected to a lower end of the movable jaw, and which can be
adjusted in order to set any required spacing apart of the lower
end of the movable jaw from the lower end of the fixed jaw.
It is also usual to provide removable wear plates, mounted on each
of the fixed jaw and the movable jaw, and which exert a working
action on the crushable material, and therefore must be robustly
constructed, so as to be able to exert mechanical crushing action,
and also to resist the inevitable wearing action as the wear plates
engage the material. Wear plates have a working life which will
depend upon the material being crushed, and as the wear plates become
worn, this increases the width of the crushing zone, and therefore
it is known to provide means for adjusting the spacing apart of
the fixed jaw and the movable jaw, to compensate for wear. However,
when the wear on one or both wear plates reaches an unacceptable
level, it is then necessary to stop the operation of the jaw crusher
unit, to unfasten the or each wear plate which requires replacement,
to remove it, and then to install replacement wear plates.
In existing machines, it is usual to employ wedges which engage
wedging recesses, or holding shoulders provided on the wear plates,
and to provide bolts which engage the wedges and which, upon tightening,
cause the wedges to pull the wear plates into clamped engagement
with the adjacent mounting surface of the jaw on which the wear
plate is mounted. Use of wedges and bolts is presently used in order
to mount, and de-mount wear plates on both fixed jaws and also movable
jaws.
The use of bolts and wedges does provide reliable clamping of the
wear plates in position on the mounting faces of the fixed and movable
jaws, but the use of threaded fasteners, such as bolts, is a time
consuming operation, as far as assembly is concerned, and also gives
rise to further problems upon de-mounting of worn wear plates. In
the case of assembly, the operation is reasonably straightforward,
in that a replacement wear plate is lowered into position, the wedges
are engaged with the wear plate, and then the bolts are tightened.
The only serious drawback, with regard to existing use of wedges
and bolts, as far as assembly is concerned, therefore is the time
consuming nature of the job, and the need to inter-fit the wedges
with the wear plates. However, with regard to de-mounting of worn
plates, in practice this is often a difficult task, since crusher
dust and small crushed particles can become trapped or lodged between
the wear plate and the jaw on which it is mounted, and also between
the wear plate and adjacent parts of the crusher unit. Therefore,
even although the bolts are untightened, and release the wear plates,
in practice the wear plates often remain fully engaged with the
mounting surfaces of the jaws, by reason of the trapped material.
The frictional forces arising can be very substantial, and it is
a matter of practical experience, with existing machines using bolts
and wedges, that the use of usual lifting tools to attempt to lift
out released wear plates is ineffective, since application of a
lifting load to the wear plate merely results in the entire jaw
crusher unit being lifted, which typically might be in the order
of 13 tons in weight, and the application of such a lifting force
is insufficient to cause the de-mounting of the wear plate from
the jaw.
The present invention has therefore been developed primarily with
a view to provide an improved means for effecting disengagement
of a wear plate from a jaw, so that a worn plate can be easily lifted
out, and such means also being capable of operating more speedily
than existing bolt and wedge action, to effect mounting in position
of the wear plates on the jaws (fixed jaw and/or movable jaw).
According to the invention there is provided a jaw crusher unit
for use in crushing stone and other crushable material and comprising
a fixed jaw and a movable jaw which define a crushing zone therebetween,
a drive mechanism coupled with the movable jaw and operative to
rock the movable jaw to and fro in order to crush material in the
crushing zone, a link mechanism connected to a lower end of the
movable jaw and serving to set any required space between the lower
end of the movable jaw and the fixed jaw and thereby control the
discharge of crushed material from the lower end of the crushing
zone, and a removable wear plate mounted on a mounting face of at
least one of said jaws by a wedge arrangement coupled with a power-operated
linear actuator which is operative in one direction to pull the
wear plate into engagement with the mounting face in order to mount
the wear plate on the jaw and which is operative in an opposite
direction in order to move the wear plate away from the mounting
face and thereby allow the wear plate to be lifted out of the crusher
unit when it is required to be replaced.
A jaw crusher unit according to the invention therefore is able
to mount a replacement wear plate on a crusher jaw more quickly,
than in existing machines using known bolts and wedges. Also, by
application of a separating force to the wear plate via the linear
actuator and wedge, it can assist in de-mounting of a wear plate
even when there is crushed material jamming the wear plate in position.
Preferably, the removable wear plate is mounted on the fixed jaw.
However, as an alternative, or in addition, the same wear-plate
mounting and de-mounting arrangement may be provided for the movable
jaw.
The power operated linear actuator may comprise any suitable device
which can apply a linear force to the wear plate (a pulling force
in the case of mounting a replacement wear plate in position, and
a pushing force in the case of de-mounting a worn plate). Preferably,
a piston/cylinder device is coupled with a wear plate-securing wedge,
and which may be hydraulically or pneumatically operable. However,
it is within the scope of the invention to use other types of power
operated linear actuator, such as an externally threaded rotary
spindle and follower.
A preferred embodiment of jaw crusher unit according to the invention
will now be described in detail, by way of example only, with reference
to the accompanying drawing, in which:
FIG. 1 is a side view of a jaw crusher unit to which the invention
may be applied;
FIG. 2 illustrates successive stages in the removal, and mounting
of a wear plate on a fixed jaw of the crusher unit shown in FIG.
1; and
FIG. 3 shows successive stages in the mounting, and de-mounting,
of a removable wear plate on a movable jaw of the crusher unit shown
in FIG. 1.
Referring now to the drawings, a jaw crusher unit according to
the invention is designated generally by reference 10 and is intended
for use in crushing stone and other crushable material, comprising
a fixed jaw 11 and a movable jaw 12 which define a crushing zone
13 there-between. An eccentric drive mechanism (not shown in detail)
is coupled with the movable jaw 12 and is operative to rock the
movable jaw 12 to and fro in order to crush material in the crushing
zone. A link mechanism (not shown) is connected to a lower end of
the movable jaw 12 and serves to set any required space between
the lower end of the movable jaw 12 and the fixed jaw 11 and thereby
control the discharge of crushed material from the lower end of
the crushing zone 13.
It is usual to provide de-mountable wear plates on both the fixed
jaw 11 and the movable jaw 12 and when they become excessively
worn, they must be de-mounted, and replacement wear plates mounted
in their position.
FIG. 2 shows successive stages in the mounting, and de-mounting
of a removable wear plate 14 relative to the fixed jaw 11. Therefore
the jaw 11 has a forward mounting face 15 on which wear plate 14
can be mounted, and it will be noted from the right hand illustration
of FIG. 2 in particular that the mounting face 15 includes projections
16 and 17 which can inter-fit snuggly in matching recesses 18 and
19 in the rear face of the wear plate 14. The left hand illustration
of FIG. 2 shows snug inter-fit between the projections 16 and 17
and the recesses 18 and 19.
A linearly displaceable wedge 20 is mounted in an upper portion
11a of the fixed jaw 11 being carried at one end of a (power operated)
linearly displaceable actuator 21. The series of illustrations in
FIG. 2 show successive stages in mounting, and de-mounting wear
plate 14. Evidently, the actuator 21 will be operated in one direction
in order to pull the wear plate 14 into engagement with the mounting
face 15 (see the middle illustration) in order to mount the wear
plate on the jaw 11. However, it is operative in an opposite direction,
in order to move i.e. push the wear plate 14 away from the mounting
face 15 and thereby allow the wear plate 14 to be lifted out of
the crusher unit 10 when the wear plate is required to be replaced.
Reference 22 illustrates schematically use of a lifting tool which
can hook into engagement with an upper end of the wear plate 14
both for mounting and de-mounting purposes.
Any suitable power operated linear actuator device may be provided
to function as actuator 21 though preferred means is a piston/cylinder
unit, preferably hydraulically operated. Evidently, a substantial
separating force can be applied to the rear face of the wear plate
14 when it is required to be removed, and the application of such
a strong force can easily overcome any jamming of the wear plate
which may occur in practice, due to the presence of crushed material
tightly trapped alongside the wear plate i.e. between the sides
of the wear plate and the sides of the crusher unit.
It is particularly preferred to provide a wedge arrangement coupled
with a power operated linear actuator for mounting and de-mounting
a wear plate on the fixed jaw (11) of a crusher unit. However, as
an alternative, or in addition, a similar mounting and de-mounting
arrangement may be provided for a movable jaw of a crusher unit.
However, it is particularly suitable for the fixed jaw 11 where
there is greater risk of the wear plate becoming jammed in position
in service.
FIG. 3 shows a different type of mounting and de-mounting arrangement
for removable wear plate 23. A wedge 24 is carried on one end of
a rod 25 and by suitable manual or other manipulation, wedge 24
can move towards the mounting face of the jaw 12 to the position
shown in the right hand illustration of FIG. 3 and in order to
mount the wear plate 23 on the mounting face. FIG. 3 also shows
use of lifting tool 22 for the purposes of mounting and de-mounting
the wear plate 23. |