Abstrict A gyrasphere crusher includes a crusher frame, a crushing head,
and a crusher bowl which is selectively locked to and released from
the crusher frame via operation of a bowl lock assembly including
a clamping ring or locknut and an inflatable bladder device. The
bladder device, which preferably is formed from a plurality of discrete
bladder segments mounted on an axial end of the locknut, applies
sufficient clamping forces to the locknut when it is fully inflated
to prevent rotation of the locknut and bowl, and can be partially
deflated to permit precisely controlled rotation of the bowl and
thus adjustment of the crushing gap under load. The bladder operated
bowl lock assembly is simple, reliable, and operates at a fraction
of the pressures typically required for conventional mechanically
applied/fluid-pressure released lock assemblies.
Claims We claim:
1. A crusher for crushing stones, said crusher comprising:
(A) a crusher frame:
(B) a crushing head rotatably mounted on said crusher frame;
(C) a crusher bowl mounted on said crusher frame above said head
with a crushing gap formed therebetween, said bowl being adjustable
with respect to said crusher frame and said head upon the imposition
of a designated rotational force on said bowl so as to adjust the
thickness of said gap;
(D) a lock assembly which normally locks said bowl in position
but which selectively permits adjustment of said bowl on said crusher
frame, said lock assembly including
(1) a locknut which is connected to said bowl and which is threadedly
mounted on said crusher frame, and
(2) an inflatable elastomeric bladder device which, when inflated,
applies clamping forces to said locknut and prevents rotation of
said locknut relative to said crusher frame and which, when deflated,
at last partially releases said clamping forces and permits rotation
of said locknut relative to said crusher frame; and
(E) means for (a) selectively inflating said bladder device and
for (b) selectively partially deflating said bladder device to just
below a pressure at which the clamping forces applied by said bladder
device can be overcome by the designated rotational force on said
bowl, thereby permitting bowl adjustment while said crusher is crushing
stone.
2. A crusher as defined in claim 1 wherein said lock assembly
lacks mechanical spring devices applying biasing forces to said
locknut.
3. A crusher as defined in claim 1 further comprising a bowl adjuster
mechanism, and wherein said locknut is annular and comprises a lower
threaded portion, an upper clamping portion on which is mounted
said bladder device, and a vertical portion connecting said clamping
portion to said threaded portion, said lock assembly further including
(A) a clamp ring disposed above said bladder device;
(B) a plurality of threaded studs which extend through said clamp
ring and said threaded portion and clamping portion of said locknut
and which extend into tapped bores in said bowl, thereby connecting
said locknut to said bowl; and
(C) a cylindrical locknut cover which is mounted on an outer radial
periphery of said locknut and which is selectively rotated by said
bowl adjuster mechanism to rotate said locknut and said bowl relative
to said crusher frame.
4. A crusher as defined in claim 3 further comprising a hose assembly
communicating with said bladder device, wherein said clamp ring
presents a plurality of ribs which extend axially upwardly from
an upper axial surface thereof, each of said ribs being generally
U-shaped and presenting a pair of legs defining a passage therebetween,
said hose assembly being supported by said ribs and being disposed
in said passages in said ribs.
5. A crusher as defined in claim 4 further comprising an annular
guard mounted on the upper axial surface of said clamp ring and
overlying said hose assembly.
6. A crusher as defined in claim 5 further comprising a feed hopper
which is supported on said crusher frame and which feeds stones
to be crushed into said crusher bowl, and wherein said guard comprises
(1) an annular plate which overlies said clamp ring and which rests
on said ribs and (2) an inner cylinder which forms a portion of
said feed hopper.
7. A crusher comprising:
(A) a crusher frame:
(B) a crushing head rotatably mounted on said crusher frame;
(C) a crusher bowl mounted on said crusher frame above said head
with a crushing gap formed therebetween, said bowl being adjustable
with respect to said crusher frame and said head so as to adjust
the thickness of said gap; and
(D) a lock assembly which normally locks said bowl in position
but which selectively permits adjustment of said bowl on said crusher
frame, said lock assembly including
(1) a locknut which is connected to said bowl and which is threadedly
mounted on said crusher frame, and
(2) an inflatable elastomeric bladder device which, when inflated,
applies clamping forces to said locknut and prevents rotation of
said locknut relative to said crusher frame and which, when at least
partially deflated, at last partially releases said clamping forces
and permits rotation of said locknut relative to said crusher frame,
wherein
said locknut is annular, wherein
said bladder device is mounted on an upper axial end surface of
said locknut and extends around essentially the entire circumference
of said locknut, and wherein
when pressurized, said bladder device biases said locknut downwardly.
8. A crusher as defined in claim 7 wherein said locknut has a
plurality of arcuate cavities formed in an axial surface thereof,
and wherein said bladder device is formed from a plurality of independently
pressurizeable arcuate bladder segments each of which is mounted
in a respective one of said cavities.
9. A crusher as defined in claim 8 further comprising a hydraulic
pressure source and a plurality of valve stems, each of which has
an inlet connected to said hydraulic pressure source and an outlet
opening into one of said bladder segments.
10. A crusher as defined in claim 7 wherein said lock assembly
further comprises (1) a locknut clamp ring mounted in axial alignment
with said bladder device and (2) a plurality of studs which extend
through said clamp ring and said locknut and which are threadedly
received in said bowl beneath said locknut.
11. A crusher comprising:
(A) a crusher frame:
(B) a crushing head rotatably mounted on said crusher frame and
presenting an upper concave surface;
(C) a crusher bowl which includes a bowl frame threadedly mounted
on said crusher frame above said head and which presents a lower
convex surface facing said concave surface of said head with a crushing
gap formed therebetween, said bowl being vertically adjustable with
respect to said crusher frame and said head so as to adjust the
thickness of said gap;
(D) a hydraulic pressure source;
(E) a bowl adjuster mechanism; and
(F) a lock assembly which normally locks said bowl in position
but which selectively permits adjustment of said bowl relative to
said crusher frame and said head, said lock assembly including
(1) an annular locknut which includes a lower threaded portion
which engages a mating threaded portion on said crusher frame, an
upper clamping portion, and a vertical portion connecting said clamping
portion to said threaded portion, said clamping portion having a
plurality of arcuate cavities formed in an upper axial end surface
thereof which collectively extend around essentially the entire
circumference of said locknut and which are separated by one another
by dividers,
(2) an inflatable elastomeric bladder device including a plurality
of arcuate bladder segments each of which is mounted in a respective
one of said cavities and which is connected to said hydraulic pressure
source, said bladder device (a) being pressurized by said hydraulic
pressure source to force said locknut upwardly, thereby locking
said locknut and said bowl from rotation, and (b) being selectively
partially deflatable,
(3) an annular clamp ring disposed above said bladder device, said
clamp ring presenting a plurality of ribs which extend upwardly
from an upper axial surface thereof, each of said ribs being generally
U-shaped and presenting a pair of legs defining a passage therebetween.
(4) a plurality of threaded studs which extend through said clamp
ring and said threaded portion and said dividers of said clamping
portion of said locknut and which extend into a tapped bore in said
bowl frame, thereby attaching said locknut to said bowl,
(5) a cylindrical locknut cover which is mounted on an outer radial
periphery of said locknut and which is selectively rotatable by
said bowl adjuster mechanism (a) while said crusher is performing
a crushing operation, and (b) when said bladder device is partially
deflated to just below a pressure at which forces applied by said
bladder device can be overcome by a designated rotational force
applied to said locknut cover, thereby rotating said locknut relative
to said crusher frame and vertically adjusting said locknut relative
to said crusher frame and said head and adjusting the thickness
of said gap,
(6) a guard which is disposed above said clamp ring, said guard
comprising (1) an annular plate which overlies said clamp ring and
rests on said ribs and (2) an inner cylinder, and
(7) a hose assembly communicating with said pressure source and
said bladder segments, said hose assembly being supported by said
ribs and being disposed in said passages in said ribs.
12. A method comprising:
(A) feeding rocks into a crushing gap formed between a rotatable
crushing head of a crusher and a crusher bowl located above said
head, said bowl being threadedly mounted on a crusher frame, the
thickness of said gap being adjustable by rotating said bowl on
said crusher frame;
(B) eccentrically rotating said head to crush rocks in said gap;
(C) normally preventing adjustment of said gap by applying a clamping
force to a locknut attached to said bowl and threadedly mounted
in said crusher frame, said clamping force being applied by inflating
an elastomeric bladder device coupled to said locknut; and
(D) periodically adjusting the thickness of said gap, said adjusting
step including
(1) partially deflating said bladder device, thereby relieving
said clamping force sufficiently to permit rotation of said bowl
with respect to said crusher frame, then
(2) rotating said locknut and said bowl with respect to said crusher
frame, thereby vertically moving said bowl and adjusting said gap
thickness, and then
(3) re-inflating said bladder device, thereby reapplying said clamping
force and locking said bowl in position, wherein said adjusting
step takes place without stopping said crushing step.
13. A method as defined in claim 12 wherein said preventing step
comprises inflating said bladder device to no more than about 500
psi.
14. A method as defined in claim 13 wherein said preventing step
comprises inflating said bladder device to no more than about 250
psi.
15. A method as defined in claim 12 wherein said bladder device
comprises a plurality of bladder segments mounted in respective
arcuate cavities formed in an axial surface of said locknut, and
wherein said inflating step comprises supplying hydraulic fluid
to all of said bladder segments from a common hydraulic pressure
source.
16. A method comprising:
(A) feeding rocks into a crushing gap formed between a rotatable
crushing head of a crusher and a crusher bowl located above said
head, said bowl being threadedly mounted on a crusher frame, the
thickness of said gap being adjustable by rotating said bowl on
said crusher frame;
(B) eccentrically rotating said head to crush rocks in said gap;
(C) normally preventing adjustment of said gap by applying a clamping
force to a locknut attached to said bowl and threadedly mounted
in said crusher frame, said clamping force being applied by inflating
an elastomeric bladder device coupled to said locknut; and
(D) periodically adjusting the thickness of said gap, said adjusting
step including
(1) partially deflating said bladder device, thereby relieving
said clamping force sufficiently to permit rotation of said bowl
with respect to said crusher frame, then
(2) rotating said locknut and said bowl with respect to said crusher
frame, thereby vertically moving said bowl and adjusting said gap
thickness, and then
(3) re-inflating said bladder device, thereby reapplying said clamping
force and locking said bowl in position, wherein said adjusting
step takes place without stopping said crushing step wherein
said adjusting step takes place without stopping said crushing
step, and wherein
said step of rotating said bowl comprises applying a designated
rotational force to said locknut and wherein said deflating step
comprises deflating said bladder device to just below a pressure
at which the clamping forces applied by said bladder device can
be overcome by said designated rotational force.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to gyrasphere crushers and, more particularly,
relates to gyrasphere crushers having a crushing head, a crusher
bowl which is vertically adjustable relative to the head, and a
bowl lock assembly which normally prevents vertical adjustment of
the bowl relative to the head but which selectively permits such
adjustment.
2. Discussion of the Related Art
Gyrasphere crushers typically include a stationary frame, a generally
conical crushing head mounted in the frame for rotation about an
eccentric shaft and including an upwardly facing convex crushing
surface, and an annular crusher bowl that is mounted on the frame
above the head so as to define a crushing gap therebetween forming
an annular crushing chamber. Material to be crushed is fed downwardly
into the crushing chamber and is crushed by gyration of the head
about the eccentric.
The particle size of the output from the crusher is dependent upon
the thickness of the crushing gap. Particle size adjustment and/or
compensation for wear on the opposed surfaces of the head and the
bowl is thus possible by mounting the bowl on the crusher frame
for vertical movement with respect thereto whereby the crushing
gap is widened by raising the bowl or narrowed by lowering it. To
permit such adjustment, the frame of the bowl is threadedly connected
to an upper portion of the crusher frame, and the bowl is vertically
adjusted by rotating it in the appropriate direction relative to
the crusher frame.
When satisfactorily adjusted, the bowl must be locked or prevented
from rotating relative to the crusher frame in response to the tangential
forces imposed upon it by the gyrating head. This locking is typically
performed via a threaded locknut or clamping ring which is located
just above the threaded portion of the bowl frame and which is threadedly
connected to the crusher frame so as to be selectively operable
as a conventional locknut or jam nut. A substantial clamping force
is normally exerted between the bowl and the locknut to urge them
axially towards one another. For adjusting rotation of the bowl,
this clamping force must of course be released.
Various arrangements or lock assemblies have been proposed for
providing the necessary clamping force between the bowl and the
locknut and for selectively releasing this clamping force. Early
crushers employed a complex system of wedges for applying the clamping
force, and these wedges had to be removed to permit adjustment.
Such lock assemblies, an example of which is disclosed in U.S. Pat.
No. 2881981 to Rumpel, proved complex and difficult to operate
and soon were replaced with mechanically applied/fluid-pressure
released lock assemblies which remain in wide use today.
Mechanically applied/fluid-pressure released lock assemblies typically
employ a system of Belleville washers or other mechanical springs
to apply clamping forces to the locknut. These forces are released
by action of a plurality of single or double-acting hydraulic cylinders
spaced around the locknut. Examples of mechanically applied/fluid-pressure
released lock assemblies and their variants are disclosed, e.g.,
in U.S. Pat. Nos. 3341138 to Allen, 3797760 to Davis et al.,
3951348 to Davis et al., 4198003 to Polzin et al., and 4478373
to Gieschen.
Mechanically applied/fluid-pressure released lock assemblies for
gyrasphere crushers exhibit several drawbacks and disadvantages.
Most notably, adjusting "on the fly," i.e., when the crusher
is crushing rock (typically referred to as operating "under
load") is difficult or impossible. Adjusting under load is
desirable because crushers typically form but one component of a
relatively large quarrying system with the crusher continuously
receiving stone from upstream devices such as screens and supplying
the crushed stone to downstream devices. Shutting down the crusher
for adjustment therefore requires that the feed be shut down, thereby
significantly increasing down time and operating costs. Adjusting
under load is as a practical matter made difficult with crushers
employing mechanically applied/fluid pressure released lock assemblies
because there is a high amount of uncertainty as to the release
point of such systems, (The release point is defined as that point
at which the net clamping force applied by the mechanical springs
as offset by the release forces supplied by the fluid actuated cylinders
produces a rotational locking force which is just below the rotational
forces supplied by bowl adjuster mechanisms). Uncertainty exists
because spring forces vary from system to system and actually vary
in a given crusher over the life of the springs because the spring
rate decreases as the springs age. Given this uncertainty, it is
typically necessary to fully or nearly fully release the clamping
forces each time adjustment is required thereby preventing "feathering,"
i.e., relatively minute adjustments which do not significantly affect
the current operation of the crusher. The need has therefore arisen
to provide a lock assembly the net clamping forces imposed by which
can be precisely controlled to permit adjustment of the bowl under
load.
Another disadvantage associated with conventional mechanically
applied/fluid-pressure released lock assemblies is that the cylinders
apply the release forces over a very small area and thus must operate
under extremely high pressures, typically on the order of 7000 psi
or more. Operating under such high pressures requires the use of
relatively expensive high pressure fittings and hoses and renders
the system more prone to leaks. The need has therefore arisen to
permit the release of lock assemblies for crushers using relatively
low fluid pressures.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a gyrasphere
crusher the bowl of which can be precisely adjusted under load,
thereby decreasing down time and operating costs.
Another object of the invention is to provide a gyrasphere crusher
the clamping ring or locknut of which can be operated using relatively
low fluid pressures.
Yet another object of the invention is to provide a gyrasphere
crusher which has one or more of the characteristics discussed above
but which is relatively simple to manufacture and assemble.
In accordance with a first aspect of the invention, these objects
are achieved by providing a crusher comprising a crusher frame,
a crushing head rotatably mounted on the crusher frame, a crusher
bowl mounted on an upper crusher frame above the head with a crushing
gap formed therebetween, the bowl being adjustable with respect
to the upper crusher frame and the head so as to adjust the thickness
of the gap, and a lock assembly which normally locks the bowl in
position but which selectively permits adjustment of the bowl on
the upper crusher frame. The lock assembly includes a locknut which
is connected to the bowl and which is threadedly mounted on the
upper crusher frame, and an inflatable elastomeric bladder device
which, when inflated, applies clamping forces to the locknut and
prevents rotation of the locknut relative to the crasher frame and
which, when at least partially deflated, at last partially releases
the clamping forces and permits rotation of the locknut relative
to the crusher frame. Because the bladder device applies all clamping
forces, the lock assembly lacks mechanical spring devices applying
biasing forces to the locknut.
Preferably, the locknut is annular and the bladder device is mounted
on an axial end surface of the locknut and extends around essentially
the entire circumference of the locknut. The locknut has a plurality
of arcuate cavities formed in an axial surface thereof, and the
bladder device is formed from a plurality of independently pressurizeable
arcuate bladder segments each of which is mounted in a respective
one of the cavities.
Yet another object of the invention is to provide a method of precisely
adjusting the gap between the crushing head and crusher bowl of
a gyrasphere crusher.
In accordance with another aspect of the invention, this object
is achieved by providing a method comprising feeding rocks into
a crushing gap formed between a rotatable crushing head of a crusher
and a crusher bowl located above the head, the bowl being threadedly
mounted on a crusher frame, and the thickness of the gap being adjustable
by rotating the bowl on the crusher frame. The rocks are then crushed
in the gap by eccentrically rotating the head. Maintaining the gap
is normally accomplished by applying a clamping force to a locknut
attached to the bowl and threadedly mounted in the crusher frame,
the clamping force being applied by inflating an elastomeric bladder
device coupled to the locknut. However, the thickness of the gap
is periodically adjusted by: (1) at least partially deflating the
bladder device, thereby relieving the clamping force sufficiently
to permit rotation of the bowl with respect to the crusher frame;
then (2) rotating the locknut and the bowl with respect to the crusher
frame, thereby vertically moving the bowl and adjusting the gap
thickness; and then (3) re-inflating the bladder device, thereby
reapplying the clamping force and locking the bowl in position.
Because bladder release can be controlled to apply clamping forces
which are just below the release point of the lock assembly, the
adjusting step can take place without stopping the crushing step,
thereby reducing downtime and operating costs.
In addition, because the bladder device operates over a relatively
large area, relatively low pressures can be used to lock the bowl
in place. Indeed, the preventing step comprises inflating the bladder
device to no more than about 500 psi, and typically to no more than
about 250 psi.
Other objects, features, and advantages of the present invention
will become apparent to those skilled in the art from the following
detailed description and the accompanying drawings. It should be
understood, however, that the detailed description and specific
examples, while indicating preferred embodiments of the present
invention, are given by way of illustration and not of limitation.
Many changes and modifications may be made within the scope of the
present invention without departing from the spirit thereof, and
the invention includes all such modifications .
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred exemplary embodiment of the invention is illustrated
in the accompanying drawings in which like reference numerals represent
like parts throughout, and in which:
FIG. 1 is a side elevation view of a gyrasphere crusher employing
a bowl lock assembly constructed in accordance with a preferred
embodiment of the present invention;
FIG. 2 is a partially cut-away sectional plan view taken generally
along the lines 2--2 in FIG. 1;
FIG. 2A is a sectional plan view generally corresponding to FIG.
2 but illustrating only the bladder device, hydraulic pressure source,
and associated hoses and fittings;
FIG. 3 is a sectional elevation view of the gyrasphere crusher
illustrated in FIG. 1;
FIGS. 4 and 5 are enlarged fragmented views of portions of FIG.
3;
FIG. 6 is a top plan view of one of the bladder segments illustrated
in FIG. 2A; and
FIG. 7 is a sectional elevation view taken along the lines 7--7
in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
1. Resume
Pursuant to the invention, a gyrasphere crusher is provided the
bowl of which is selectively locked to and released from the crusher
frame via operation of a bowl lock assembly including a locknut
and an inflatable bladder device. The bladder device, which preferably
is formed from a plurality of discrete bladder segments mounted
on an axial end of the locknut, applies sufficient clamping forces
to the locknut when it is fully inflated to prevent rotation of
the locknut and bowl, and can be partially deflated to permit precisely
controlled rotation of the bowl and thus adjustment of the crushing
gap under load. The bladder operated bowl lock assembly is simple,
reliable, and operates at a fraction of the pressures typically
required for conventional mechanically applied/fluid-pressure released
lock assemblies.
2. System Overview
Referring now to the drawings and to FIGS. 1-3 in particular, a
gyrasphere crusher 10 is illustrated and includes a main crusher
frame 12 having upper and lower portions 14 and 16 a crushing head
18 mounted in the crushing frame lower portion 16 and a crusher
bowl 20 mounted in the crusher frame upper portion 14 above the
crushing head 18. The bowl 20 is normally held fast from rotation
with respect to the crusher frame upper portion 14 by a bowl lock
assembly 22 but the lock assembly 22 is selectively at least partially
releasable to permit vertical adjustment of the bowl 20 relative
to the head 18 by a bowl adjuster mechanism 24 as detailed below.
The crushing head 18 is mounted in the crusher frame lower portion
16 by an eccentric shaft 26 rotatably journaled in the crusher frame
lower portion 16 and connected to a drive pulley 28 by a conventional
torque transfer system 30. The head 18 also presents an upper generally
frusto conical convex crushing surface 32 formed from a replaceable
liner. The head 18 and its drive system 28 30 are conventional
and, accordingly, will not be described in further detail.
The crusher bowl 20 includes a body or frame 34 an upper uncrushed
and/or precrushed rock feed hopper 36 and a hardened lower concave
surface 38 which is formed from a replaceable liner. Concave surface
38 surrounds the convex crushing surface 32 of the crushing head
18 and is spaced above it to define a crushing gap G forming an
annular crushing cavity. In order to permit vertical adjustment
of the crusher bowl 20 relative to the crusher frame 12 and thus
to permit adjustment of the thickness of gap G, a helically threaded
connection is provided between the bowl 20 and the frame 12 in the
form of an internal helical thread 42 on the crusher frame upper
portion 14 and an external helical thread 44 on the frame 34 of
bowl 20.
The crusher frame upper portion 14 is supported on the frame lower
portion 16 by a plurality of tramp relief cylinders 40 which can
be selectively actuated for tramp relief purposes in a manner which
is, per se, well known and which forms no part of the present invention.
The gyrasphere crusher 10 as thus far described, save for the lock
assembly 22 and the mating features of the bowl 20 and crusher frame
upper portion 14 is conventional.
3. Construction of Lock Assembly
The bowl 20 is normally locked from rotation with respect to the
frame 12 by the lock assembly 22 which includes an annular locknut
or clamping ring 46 a bladder device 48 mounted on an axial end
surface of the locknut 46 and extending around essentially the entire
circumference thereof, a clamp ring 50 mounted on the bladder device
48 and a plurality of studs 52. A locknut cover 54 is mounted on
the outer radial periphery of the locknut 46 and an annular guard
56 is mounted on the upper surface of the clamp ring 50. Each of
these devices will now be described in turn.
The locknut 46 is designed to lock the bowl 20 from rotation when
it receives sufficient clamping forces from the bladder device 48
and to permit rotation of the bowl 20 in the absence of such clamping
forces. To this end, the locknut 46 is fixed to the bowl frame 34
by the studs 52 as detailed below and has threads 58 formed on its
outer radial periphery so as to be rotatable in the threads 42 of
the crusher frame upper portion 14. Locknut 46 is generally C-shaped
and includes a lower portion 60 having the threads 58 mounted thereon,
an upper clamping portion 62 and a vertical portion 64 located
near the inner radial edge of the locknut 46 and connecting the
clamping portion 62 to the threaded portion 60. A generally annular
flange 66 extends radially inwardly frown the inner edge of the
vertical portion 64 for receiving an upwardly projecting annular
flange 68 (see FIG. 4.) of the bowl 20. A sealing ring 69 is provided
between the inner surface of the locknut 46 and the annular flange
68. The clamping portion 62 has a plurality (6 in the illustrated
embodiment) of arcuate cavities 70 formed in the upper axial end
surface thereof for receiving the bladder segments 80 (described
in more detail below). Each of the cavities 70 has a depth which
is generally equal to the fully deflated thickness of the bladder
segments 80 such that, when the bladder segments 80 are inflated,
they extend above the uppermost surface of the locknut 46 to engage
the clamp ring 50 and apply clamping forces to the locknut 46. Adjacent
cavities 70 are separated by radial dividers 72 each of which has
a hole 74 bored therethrough for the passage of a stud 52. Mating
holes 76 are formed in the lower threaded portion 60 and these
holes are aligned with tapped bores 78 in the bowl frame 34.
The bladder device 48 is formed from a plurality (6 in the illustrated
embodiment) of rubber or other elastomeric segments 80 which are
mounted in the cavities 70 in the upper axial end surface of the
upper clamping portion 62 of locknut 46. The bladder device 48 is
segmented in this manner to avoid interference with the studs 52
where they pass through the clamp ring 50 and locknut 46 and to
help each segment 80 hold its shape. Each bladder segment 80 has
a hollow interior 82 and a central upper aperture 84 which sealingly
receives a valve stem 86. Valve stem 86 has an outlet opening into
the bladder segment interior 82 and an inlet connected to a T-fitting
88 which is in turn connected to a generally circular hose assembly
90. The hose assembly 90 is connected to a conventional hydraulic
pressure source 92 which can be operated to permit the simultaneous
pressurization or depressurization of all of the bladder segments
80.
The primary purposes of the clamp ring 50 are to clamp the bladder
segments 80 in the cavities 70 and to provide a reaction member
via which clamping forces created upon inflation of the bladder
device 48 are imparted to the locknut 46. To this end, the clamp
ring 50 has a lower surface 94 which is planar in the vicinity of
the cavities 70 so as to provide a uniform engagement surface for
the bladder device 48. Clamp ring 50 also presents a plurality of
generally U-shaped radial ribs 96 which extend upwardly from the
upper axial surface thereof so as to support the upper guard 56
while providing a passage for the hose assembly 90 between the legs
of the "U." In addition, a plurality of apertures 98 are
formed through the clamp ring 50 between the apertures 74 for the
studs 52 for receiving the valve stems 86.
The upper guard 56 protects the hose assembly 90 and forms part
of the hopper 36. To this end, upper guard 56 is formed from a unitary
metal member and includes (1) an annular plate 100 which overlies
the clamp ring 50 and rests on ribs 96 and (2) an inner cylinder
102 forming the upper or cylindrical portion of the hopper 36.
Each of the studs 52 extends through one of the holes 74 in the
clamp ring 50 and a mating hole 76 in the locknut 46 and threadedly
engages a tapped bore 78 in the bowl frame 34 thereby nonrotatably
connecting the locknut 46 to the bowl 20. The studs 52 also connects
the clamp ring 50 to the locknut 46 to hold the bladder device 48
therebetween, thereby assuring that inflation of the bladder device
48 will result in the application of clamping forces to the locknut
46.
The primary purpose of the locknut cover 54 is to provide a mechanism
via which tangential or rotational forces applied by the bowl adjuster
mechanism 24 are translated into rotational forces tending to rotate
the locknut 46 and the bowl 20 on the crusher frame 12. To this
end, locknut cover 54 is connected to the locknut 46 by a plurality
of bolts 104 extending (1) through axial bores 106 formed in the
outer radial portion of the locknut 46 and (2) into axial taps 108
formed in the upper portions of the locknut cover 54. An annular
recess 110 is formed in the lower axial surface of the clamp ring
50 to provide clearance for the heads of bolts 104. A sealing ring
112 is disposed between the inner radial surface of the locknut
cover 54 and the outer radial surface of the upper frame 14 and
a plurality of axial lugs or ribs 114 are formed on the outer axial
surface of the locknut cover 54 and extend radially outwardly for
cooperation with the adjuster mechanism 24.
The bowl adjuster mechanism 24 may comprise any device capable
of imparting rotational forces of designated magnitudes through
designated strokes to the locknut cover 54 and preferably comprises
a hydraulically actuated mechanism applying tangential forces to
the lugs or ribs 114. A suitable adjuster mechanism is disclosed
in U.S. Pat. No. 3396915 to Allen, the subject matter of which
is hereby incorporated by reference.
4. Operation of Crusher
During normal operation of the crusher 10 rocks or stones are
fed to the hopper 36 from a screen or the like and fall into the
crushing cavity, where they are crushed between the concave surface
38 of the crusher bowl 20 and the convex surface 32 of the crushing
head 18 upon eccentric rotation of the head 18 about shaft 26. The
particle sizes of the: crushed rock thus produced are defined by
the thickness of the gap G formed between the head 18 and the bowl
20.
The crusher bowl 20 is locked in place at this time by inflating
the bladder segments 80 through the supply of pressurized hydraulic
fluid to the segment interiors 82 from the hydraulic pressure source
92 and the hose assembly 90. It should be noted that because the
area over which the hydraulic pressure is applied to the locknut
46 from bladder segments 80 is dramatically larger than that over
which conventional hydraulic cylinders act, dramatically lower pressures
can be employed. Most conventional fluid pressure-applied or released
lock assemblies require hydraulic pressures in the range of 5000
to 10000 psi to lock or release locknuts. The lock assembly 22
employing the inflatable bladder device 48 on the other hand, applies
the same clamping forces using hydraulic pressures of no more than
500 psi and typically no more than about 200-250 psi. A lower-power
and less expensive pressure source 92 can therefore be employed
along with less expensive and more reliable low pressure hoses and
fittings.
Assuming now that it is desired to adjust vertically the crusher
bowl 20 relative to the upper crushing frame 14 and crushing head
18 the bladder segments 80 are partially deflated to relieve a
portion of the clamping forces applied to the locknut 46 and the
adjuster mechanism 24 is actuated to drive the lugs 114 on the locknut
cover 54 tangentially, thereby rotating the locknut cover 54 and
hence rotating the locknut 46. Rotational motion of locknut 46 is
transferred to the bowl 20 through the studs 52 so that the locknut
46 and bowl 20 rotate about the threads 42 44 58 to vertically
adjust the bowl 20 thereby adjusting the thickness of the crushing
gap G. Unlike in mechanically applied/fluid-pressure released lock
assemblies, the net clamping force applied by the bladder device
48 can be controlled via suitable operation of the hydraulic pressure
source 92 to be just below the release point of the lock assembly
22 (defined as that point at which the net clamping forces applied
by the bladder device 48 are just below the rotational forces imparted
by the adjuster mechanism 24). Assuredly, operating the adjuster
mechanism 24 with significant but not excessive resistance from
the lock assembly 22 permits adjustment at a relatively slow, controlled
rate, thereby permitting adjustment under load. This obviates the
need to shut down the quarry plant to adjust the bowl 20 thereby
significantly reducing downtime and operating costs.
Of course, many changes and modifications could be made to the
invention as disclosed without departing from the spirit thereof,
and the scope of such changes will become apparent from the appended
claims. |