Abstrict A jaw crusher where the tension rod includes an electronically-controlled
hydraulic pre-load and an automatically releasable pre-load whenever
adjustments to the size of the material output are made, together
with a remote visual indicator of the setting of the size of the
material output.
Claims 1. A jaw rock crusher comprising: a first jaw; a pitman; an eccentric
shaft coupled to said pitman; a toggle plate disposed adjacent said
pitman on an opposite side from said first jaw; a means for adjusting
a location of said pitman so as to control a maximum size of material
which is permitted to pass between said fixed jaw and said pitman;
a spring tension rod comprising a spring and a rod coupled to said
pitman and configured to create a force which is biased toward increasing
contact between said pitman and said toggle plate; said spring tension
rod having a hydraulic piston coupled thereto for pre-loading said
spring, so that said force may be maintained at a predetermined
level irrespective of a setting location of said pitman as determined
by said means for adjusting; said hydraulic piston having coupled
thereto a path of hydraulic fluid to a source of hydraulic fluid
at an adjustable pressure; and a pressure sensor configured to measure
a fluid pressure characteristic which is indicative of a pressure
in said path of hydraulic fluid.
2. A crusher of claim 1 further comprising a source of variable
pressure hydraulic fluid and said path of hydraulic fluid being
free from any accumulator disposed between said hydraulic piston
and said source of variable pressure hydraulic fluid.
3. A crusher of claim 2 wherein said source of variable pressure
hydraulic fluid comprises a pump and an electronic pump controller.
4. A crusher of claim 3 wherein said electronic pump controller
is an electronic controller which commands pump activity in response
to a measurement of said fluid pressure characteristic, which measurement
is below a predetermined lower limit.
5. A crusher of claim 4 wherein said electronic controller generates
a signal which results in termination of rotation of said eccentric
shaft in response to said measurement of said fluid pressure exceeding
a predetermined upper limit.
6. A crusher of claim 1 further comprising a means for automatically
releasing pressure in said path of hydraulic fluid in response to
an initiation of an adjustment of said means for adjusting.
7. A crusher of claim 6 wherein said means for automatically releasing
pressure is responsive to an increase in hydraulic pressure which
causes a manipulation of a location of said toggle plate.
8. A crusher of claim 7 wherein said means for automatically releasing
pressure is a pressure-relieving device which is responsive to a
high pressure in a line other than said path of hydraulic fluid.
9. A crusher of claim 8 further comprising a check valve in said
line other than said path of hydraulic fluid, where said check valve
applies a high pressure to manipulate a pilot to open check valve
and flow diverting valve when said means for adjusting moves a wedge.
10. A crusher of claim 9 further comprising: a pressure sensor
configured to measure a fluid pressure characteristic which is indicative
of a pressure in said path of hydraulic fluid and a source of variable
pressure hydraulic fluid; wherein said source of variable pressure
hydraulic fluid comprises a pump and an electronic pump controller;
wherein said electronic pump controller is a microprocessor which
commands pump activity in response to a measurement of said fluid
pressure characteristic which measurement is below a predetermined
lower limit; wherein said microprocessor generates a signal which
terminates rotation of said eccentric shaft in response to said
measurement of said fluid pressure exceeding a predetermined upper
limit; and an indicator disposed remotely with respect to a gap
between said first jaw and a bottom portion of said pitman, said
indicator configured to provide an indication of a separation distance
between said first jaw and said bottom portion of said pitman.
11. A jaw crusher comprising: means for limiting a movement of
a rock to be crushed; means for crushing a rock by pressing the
rock against said means for limiting; an eccentric shaft coupled
to said means for crushing, where rotation of said shaft results
in motion of said means for crushing; means for adjusting permissible
motion of said means for crushing; means solely for remotely indicating
a separation distance between a portion of said means for limiting
and a portion of said means for crushing, wherein said means for
solely remotely indicating provides a visual indication of an output
material size setting which is determined by said means for adjusting.
12. A jaw crusher of claim 11 wherein said means solely for remotely
indicating comprises an elongated rod having a free end which moves
in unison with a portion of said means for crushing.
13. A jaw crusher of claim 12 wherein movement of said elongated
rod results in relative movement between a series of graduated marks
and an adjacent reference mark.
14. A method of crushing rock with a jaw crusher comprising the
steps of: providing a first jaw; providing a pitman coupled to an
eccentric shaft; providing a toggle plate disposed adjacent to said
pitman; providing a hydraulically actuated means to limit a location
of the toggle plate; manipulating, from an output control location,
the output material size setting of the material output between
the first jaw and the pitman by manually actuating the hydraulically
actuated means to limit movement of the toggle plate, while simultaneously
viewing relative movement between graduated markings and a reference,
from the output control location, on a visual indicator, which relative
movement is representative of changes in a remotely located variable
gap between the pitman and the first jaw.
15. A method of crushing rock of claim 14 further comprising the
steps of: providing a tension device which comprises a spring and
a hydraulic device to apply a pre-load to said spring.
16. A method of crushing rock of claim 14 further comprising the
steps of automatically reducing a tension between said pitman and
said toggle plate when manually actuating the hydraulically actuated
means to limit movement of the toggle plate so as to move said pitman
closer to said first jaw.
17. A jaw rock crusher comprising: a first jaw; a pitman; a toggle
plate; a tension device configured to increase contact between said
pitman and said toggle plate; and an automatic pressure reducing
apparatus configured to automatically reduce pressure created by
said tension device when an adjustment of a gap between said first
jaw and said pitman is attempted.
18. A crusher of claim 17 wherein said automatic pressure reducing
apparatus comprises an apparatus to relieve pressure in a tension
rod assembly hydraulic line when pressure in a toggle plate adjusting
hydraulic line increases.
19. A crusher of claim 18 further comprising a pressure sensing
device to measure a pressure characteristic which is indicative
of a pressure in said tension rod assembly hydraulic line.
20. A crusher of claim 19 further comprising a movable member responsive
to movement of bottom of said pitman, where movement of said member
results in relative movement between a reference and a graduated
scale which is representative of a separation gap between said pitman
and said first jaw.
21. A jaw rock crusher comprising: a first jaw; a pitman; a toggle
plate; a tension device configured to increase contact between said
pitman and said toggle plate; and said tension device having a pitman
end and terminal end opposite said pitman end, said tension device
being supported at said terminal end and at said pitman end.
22. A system of claim 21 wherein said tension device is free from
any support members centrally disposed between said opposite end
and said pitman end.
23. A jaw rock crusher comprising: a first jaw; a pitman; a toggle
plate; a tension device configured to increase contact between said
pitman and said toggle plate; and said tension device comprising
a tension rod assembly outside enclosure which covers a spring,
wherein said tension device is incapable of functioning to increase
contact between said pitman and toggle plate if said tension rod
assembly outside enclosure has been removed so as to no longer cover
said spring.
24. A system of claim 23 wherein said tension rod assembly outside
enclosure is a load-bearing enclosure which experiences static forces
thereon which are equal in magnitude to static forces existing at
a connection between the pitman and the tension device.
Description FIELD OF THE INVENTION
[0001] The present invention generally relates to jaw-type rock
crushers, and more particularly relates to jaw crushers having a
toggle plate and spring tension rod, and even more particularly
relates to such spring tension rods with hydraulics.
BACKGROUND OF THE INVENTION
[0002] In the past, rock crusher designers have endeavored to improve
the ease of operating and adjustment of jaw-type rock crushers.
While many improvements have been made to reduce the effort associated
with adjusting such crushers, adjustment of such crushers often
remains a non-trivial task. Most jaw-type crushers usually have
a fixed jaw and a large heavy movable jaw known as a pitman which
is driven by an eccentric shaft which causes the pitman to move
along a non-circular path.
[0003] Typically, the bottom of the pitman is supported by a piece
of metal called the toggle plate. It serves the purpose of allowing,
within limits, the bottom of the pitman to move up and down with
the motion of the eccentric shaft, as well as serve as an overload
protection mechanism for the entire crusher. Should a piece of non-crushable
material such as a steel loader tooth (sometimes called "tramp
iron") enter the jaw of the crusher and be larger than the
maximum allowed size for passing through the jaw (the output material
size setting), it can't be crushed nor pass through the jaw. In
this case, the toggle plate is designed to collapse and prevent
further damage to the rest of the crusher.
[0004] Adjustment of the location of the toggle plate effectively
adjusts the output material size setting. A common approach to adjusting
the location of the toggle plate is to use a pair of reversed overlapping
wedges which are hydraulically actuated so that when maximum overlap
occurs, the output material size setting is at a minimum.
[0005] A tension rod is typically included to maintain contact
between the pitman and the movable toggle plate in an effort to
reduce wear on these components.
[0006] These tension rods have various types of construction. One
type of tension rod used in the past has been a spring coupled to
a threaded rod and nut combination. Adjustment of the nut can adjust
the tension applied. Others have used hydraulic cylinders with an
accumulator to essentially effectuate an adjustable "hydraulic
spring." Other hybrid designs have used hydraulic or pneumatic
power to maintain a constant pressure applied to a spring.
[0007] While these and other types of tension rods have improved
the operation of a jaw crusher, they do have several drawbacks.
[0008] First of all, all types of spring-loaded tension rods generally
make it more difficult to manipulate the overlapping wedges due
to the high spring forces.
[0009] The hydraulic cylinder with an accumulator often results
in leakage at the hydraulic seal owing to the very rapid movement
of the tension rod.
[0010] The hybrid types of tension rods may require a manual release
of the hydraulic pressure therein to reduce the pressure, thereby
making it easier to manipulate the overlapping wedges.
[0011] Consequently, there exists a need for improved methods and
systems for tensioning a toggle plate and a pitman in an efficient
manner.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a system
and method for adjusting the output material size setting and maintaining
the tension between a pitman and a toggle plate of a jaw-type rock
crusher in an efficient manner.
[0013] It is a feature of the present invention to utilize a hydraulic
pre-loaded spring tension rod.
[0014] It is an advantage of the present invention to provide an
easily adjustable spring tension rod that provides a constant (within
limits) tension between the toggle plate and the pitman irrespective
of the output material size setting of the crusher.
[0015] It is another feature of the present invention to include
a pressure sensing device to create an electronically controlled
hydraulic system which maintains the pressure within the hydraulic
cylinder portion of the tension rod within predetermined limits.
[0016] It is another advantage to permit automatic re-pressurization
of the hydraulic pre-load within predetermined limits.
[0017] It is yet another advantage of the present invention to
permit automatic shutdown of the crusher if the pressure of the
hydraulic pre-load is improperly set to an excessively high level.
[0018] It is another feature of the present invention to include
an automatic reduction in the hydraulic pre-load pressure whenever
the overlapping wedges are being manipulated to change the output
material size setting of the crusher.
[0019] It is another advantage of the present invention to permit
easier adjustment of the output setting of the crusher, thereby
allowing smaller and more compact hydraulic cylinders to manipulate
the overlapping wedges.
[0020] It is yet another feature of the present invention to include
a remote visual indicator of the separation between the fixed jaw
and the bottom of the pitman, which determines the output material
size setting.
[0021] It is another advantage of the present invention to provide
for quick, easy and accurate hydraulic adjustment of the output
material size setting.
[0022] The present invention is a hydraulically pre-loaded spring
apparatus and method for adjusting the output material size setting
of jaw-type crushers, designed to satisfy the aforementioned needs,
provide the previously stated objects, include the above-listed
features, and achieve the already articulated advantages. The present
invention is carried out in a "wasted time-less" manner
in a sense that the time required to manually release pressure on
the tension rod hydraulic cylinder and the time required to check
and maintain the proper pressure in the tension rod hydraulics,
has been eliminated. The invention is also an accumulator-less system
in the sense that a typical hydraulic accumulator which creates
a "hydraulic spring" is not employed.
[0023] Accordingly, the present invention is a system and method
including a jaw crusher which utilizes at least one of the following:
an electronically controlled and/or automatically releasable hydraulic
pre-loaded spring tension rod together, and a remote visual indicator
of the output material size setting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention may be more fully understood by reading the
following description of the preferred embodiments of the invention,
in conjunction with the appended drawings wherein:
[0025] FIG. 1 is a cross-sectional elevation view of a jaw crusher
of the prior art, employing a spring-type tension rod and nut locking
assembly.
[0026] FIG. 2 is a close-up elevational view of a hydraulic adjusting
tension rod assembly of the prior art which shows an accumulator
coupled to the tension rod by a hose or pipe.
[0027] FIG. 3 is a perspective view of the jaw crusher of the present
invention.
[0028] FIG. 4 is a close-up cross-sectional view of the lower portion
of the jaw crusher of FIG. 3.
[0029] FIG. 5 is a partially cut-away perspective view of the lower
portion of the jaw crusher of FIG. 3.
[0030] FIG. 6 is a schematic circuit diagram of the hydraulic and
electrical systems of the present invention.
DETAILED DESCRIPTION
[0031] Now referring to the drawings wherein like numerals refer
to like matter throughout, and more specifically referring to FIG.
1 there is shown a jaw rock crushing system of prior art generally
designated 100 including a fixed jaw 102 which typically is firmly
mounted to a support structure. Pitman 104 is shown disposed next
to fixed jaw 102. Pitman 104 is well known, and it moves around
eccentric shaft 106. It is possible that a cam may be used instead
of an eccentric shaft. It is also possible that in some situations,
the fixed jaw 102 may be replaced with a second pitman. The discussion
herein is focused upon a single pitman jaw crusher, but novel aspects
of the present invention are intended to apply to crushers having
multiple pitmans.
[0032] Pitman 104 is adjacent to toggle plate 108 which is adjacent
to output material size setting adjusting wedge mechanism 120. Also
shown is a tension rod assembly 110 having a tension rod to pitman
connection 112 a tension rod 114 a tension rod spring 116 a tension
rod end cap 117 and a tension rod adjusting nut 118.
[0033] Now referring to FIG. 2 there is shown a lower portion
of a jaw crusher of the prior art, such as one made by Automatic
Welding Machine and Supply Co. of Kitchener, Ontario Canada. FIG.
2 shows a pitman 204 and a toggle plate 208 which are believed to
be functionally very similar to pitman 104 and toggle plate 108
respectively of FIG. 1. Also shown in FIG. 2 is a hydraulic spring
tension rod assembly 210 which includes an accumulator 230 and
an accumulator connection line 232. Note that this device has an
attachment at one end to the pitman 204 and at a midpoint support
211 while the spring and hydraulic elements are located outside
of the two support points for the hydraulic spring tension rod assembly
210.
[0034] Now referring to FIG. 3 there is shown a jaw crusher of
the present invention, generally designated 300 which includes
a fixed jaw 302 and pitman 304. As stated above, the fixed jaw 302
may be replaced in some situations with a second pitman to achieve
a dual pitman jaw crusher. It is the intention of the present invention
to apply to multiple pitman jaw crushers as well. The pitman 304
is coupled to eccentric shaft 306 in a well-known manner. Also shown
is toggle plate 308 as well as the outside end of the hydraulically
preloaded spring tension rod assembly 310 which is shown below
the output material size setting adjusting wedge mechanism 320.
The hydraulically preloaded spring tension rod assembly 310 is shown
having a tension rod assembly retaining pin 342 which is shown
at the terminal end of hydraulically preloaded spring tension rod
assembly 310. The location of the support of hydraulically preloaded
spring tension rod assembly 310 at both ends thereof provides for
some of the advantages of the present invention. The motion of the
terminal end of the prior art device shown in FIG. 2 may be considered
to be excessive. In the prior art design of FIG. 2 the terminal
end will swing significantly because of the significant distance
between its terminal end and the support 211. Shown adjacent to
the hydraulically preloaded spring tension rod assembly 310 is remote
visual indicator of output setting 340. The end of the rod of remote
visual indicator of output setting 340 is shown protruding from
the support structure at the end of the hydraulically preloaded
spring tension rod assembly 310. The amount that this end protrudes
indicates the crusher material gap or the output material size setting.
This rod may have markings thereon which aid in measuring the extent
of the protrusion and, therefore, the output material size setting.
Also shown is hydraulic output adjusting controls 350 which are
located in a position that the remote visual indicator of output
setting 340 is easily visible when the hydraulic output adjusting
controls 350 are being manipulated.
[0035] Now referring to FIG. 4 there is shown a close-up cross-sectional
view of the lower portion of the crusher of the present invention,
generally designated 400. The hydraulically preloaded spring tension
rod assembly 310 is shown having a tension rod connecting rod 402
which couples to the pitman 304 and to the tension rod hydraulic
pre-load piston 408. Also shown is the spring 404 which provides
the desired tension force. The hydraulically preloaded spring tension
rod assembly 310 has a tension rod assembly outside enclosure 406
which is coupled at one end via tension rod assembly retaining pin
342 to the frame of the crusher or in some embodiments, to the toggle
plate 308 or the output material size setting adjusting wedge mechanism
320 or its support structure. Tension rod assembly outside enclosure
406 is a load bearing member as it structurally couples the pitman
to a fixed location on the crusher, through the hydraulically preloaded
spring tension rod assembly 310. Since the tension rod assembly
outside enclosure 406 is a load bearing structure, the hydraulically
preloaded spring tension rod assembly 310 would be inoperable if
the tension rod assembly outside enclosure 406 were removed. This
results in an advantageous increase in safety. Hydraulically preloaded
spring tension rod assembly 310 includes a tension rod hydraulic
pre-load mechanism 407 which is essentially a hydraulic cylinder
which is adjusted to accommodate the differing location of the bottom
of the pitman 304 when it is adjusted to different output material
size settings by the toggle plate 308 and output material size setting
adjusting wedge mechanism 320. The tension rod hydraulic pre-load
mechanism 407 is capable of being released when necessary to facilitate
ease of use of the output material size setting adjusting wedge
mechanism 320.
[0036] The hydraulically preloaded spring tension rod assembly
310 is supported at one end by the pitman 304 and at the other
end, by tension rod assembly retaining pin 342. The entirety of
the hydraulically preloaded spring tension rod assembly 310 is located
between these supports, and this eliminates any large protrusions
which extend substantially beyond the end of the support structure
associated with the hydraulically preloaded spring tension rod assembly
310.
[0037] Remote visual indicator of output setting 340 is shown coupled
at visual indicator connection point 440 to the tension rod connecting
rod 402. The displacement of the spring does not affect the location
of the end of the rod of the remote visual indicator of output setting
340.
[0038] Now referring to FIG. 5 there is shown an alternate view
of the crusher of the present invention, generally designated 500.
In FIG. 5 the tension rod assembly outside enclosure 406 has been
removed, as well as a cover on output material size setting adjusting
wedge mechanism 320 so as to expose the underlying mechanisms. Shown
are output material size adjusting first wedge 502 and output material
size adjusting second wedge 504. The cylinder to actuate these wedges
is smaller than in many prior art crushers and is located with the
structure labeled as output material size setting adjusting wedge
mechanism 320.
[0039] One of the advantages of the present invention is achieved
by the use of tension rod assembly deformable retaining clip 506
which couples to tension rod assembly retaining pin 342 and fits
in a slot in the support structure. Tension rod assembly deformable
retaining clip 506 has a tension rod assembly deformable retaining
clip back end 508 which extends behind the support structure. However,
if the toggle plate 308 is collapsed and excessive forces are applied
to hydraulically preloaded spring tension rod assembly 310 the
tension rod assembly deformable retaining clip back end 508 will
bend straight, and the hydraulically preloaded spring tension rod
assembly 310 will drop out of the slot. This dropping out of the
slot will prevent expensive damage to the hydraulically preloaded
spring tension assembly 310 and also will be apparent to the operator,
who can shut down the crusher and make necessary repairs and replacements.
[0040] Now referring to FIG. 6 there is shown a schematic diagram
of the hydraulics of the present invention, generally designated
600. Hydraulic output adjusting controls 350 are shown, as well
as high pressure sensitive check valves 604 which are hydraulically
coupled to pilot to open check valve 606 and flow diverting valve
608 which are triggered by the pressure associated with high pressure
sensitive check valve 604 but release the pressure associated with
the tension rod hydraulic pre-load mechanism 407. The wedge manipulating
hydraulic cylinder 602 is shown as well. It can be readily seen
that when the wedge manipulating hydraulic cylinder 602 is actuated
by hydraulic output adjusting controls 350 the high pressure associated
with that actuation is applied via high pressure sensitive check
valves 604 to the pilot to open check valve 606 and flow diverting
valve 608 which release the pressure on the tension rod hydraulic
pre-load mechanism 407 thereby making it easier for wedge manipulating
hydraulic cylinder 602 to move the wedges.
[0041] Also shown is the optional accumulator 610 which performs
the function of providing for a more constant pressure in line 611
as a result of leaks, etc. without the need to command the pump
630 to adjust for every detected pressure drop. The structure which
performs this function may be a hydraulic/pneumatic accumulator
as is well known in the art or a suitable substitute.
[0042] Also shown is the accumulator isolating check valve 612
which performs the function of allowing the accumulator 610 to maintain
the pressure in line 611 without bleeding the pressure in the accumulator
610 out to the pump 630. The structure which performs this function
may be a simple check valve with a predetermined pressure level
needed to keep it closed or open depending upon the particular arrangement
of components or a suitable substitute.
[0043] Also shown is the manual pressure release valve 614 which
performs the function of releasing pressure in the cylinder of mechanism
407 during servicing. The structure which performs this function
may be a plunger operated check valve or a suitable substitute.
[0044] Also shown is the adjustable pressure reducing valve 616
which performs the function of setting the desired pre-load on tensioning
mechanism 407. The structure which performs this function may be
a pressure reducing valve or a suitable substitute.
[0045] Also shown is the unloading valve 618 which performs the
function of diverting pump flow, after the tensioning cylinder is
loaded, instead of continuing to build pressure, so as to reduce
horsepower requirements. The structure which performs this function
may be a pilot actuated spool valve or a suitable substitute.
[0046] Also shown is the pressure sensing device 620 which performs
the function of measuring and aiding in the reporting of the pressure
in the hydraulic line 611. The structure which performs this function
may be a pressure transducer which generates an electronic signal
representative of the pressure in line 611 or it may be a similar
sensing apparatus or it may even be a pressure gauge which provides
a visual indication of the pressure in line 611 to a human operator
of the system of the present invention.
[0047] The pressure sensing device 620 provides its electronic
output signal on line 622 to electronic controller 640.
[0048] Electronic controller 640 performs the function of receiving
information relating to the pressure in line 611 and other lines
if so desired, and generating a command on line 642 to drive the
pump 630 to increase the pressure in line 611.
[0049] Electronic controller 640 may be the microprocessor as mentioned
herein, or it may be an electronic device with more limited capabilities
such as a gate array or other dedicated circuitry to perform the
limited functions of maintaining pressure in line 611 within certain
predetermined limits and disabling the entire jaw crusher if so
desired.
[0050] It should be understood that not all of the advantages of
the present invention require the use of an electronic controller
640. Indeed some of the advantages of the present invention can
be achieved with an embodiment where the pressure sensing device
is a gauge and a human operator inspects the gauge and controls
a pump in response to the pressure indicated by the gauge.
[0051] The linkages herein are described as being hydraulic linkages;
however, it is contemplated that other types of linkages could be
substituted such as mechanical, electrical, pneumatic, or a combination
thereof.
[0052] The term "pre-load" is used herein to refer to
the application of hydraulic forces to address the differing location
of the hydraulically preloaded spring tension rod assembly 310
depending upon the output material size setting.
[0053] The term "pitman" is used herein to refer, as
it is well known in the rock crushing industry, to mean the moving
jaw in a jaw crusher which moves around in an eccentric path. This
definition is not necessarily intended to be consistent with the
usage of the term in the automotive industry, where it often refers
to a connecting rod.
[0054] It is thought that the method and apparatus of the present
invention will be understood from the foregoing description and
that it will be apparent that various changes may be made in the
form, construct steps, and arrangement of the parts and steps thereof,
without departing from the spirit and scope of the invention or
sacrificing all of their material advantages. The form herein described
is merely a preferred exemplary embodiment thereof. |