Abstrict A pipeline padding machine is provided comprising a crushing mechanism
for crushing large pieces of excavated material into smaller pieces
of material that are suitable for use in padding a pipeline or underground
cable. In preferred embodiments, the crusher comprises two parallel
rollers that are arranged with a selected gap between them. The
rollers are driven toward each other, such that excavated material
that is fed onto the rollers is drawn into the gap, and pieces that
are too large to fall through the gap are crushed by the rollers.
The crusher mechanism may be installed on a known type of padding
machine, preferably at the end of the transverse conveyor over the
trench. Alternatively, the crusher may be mounted on the padding
machine frame. The output material from the crusher may be screened
or otherwise processed, or it may be delivered directly to the trench.
Claims We claim:
1. A pipeline padding system for processing at least a portion
of the excavated material into a final processed padding material,
the excavated material positioned along the side of a ditch in which
a pipeline has been laid, the system having:
a pipeline padding machine, including:
a means for engaging the excavated material and elevating a portion
of said excavated material to a first position located on said machine;
a separator for separating the elevated excavated material into
a coarse portion and a padding portion, said coarse portion deposited
away from the open ditch;
a crusher assembly mounted on said padding machine for receiving
substantially all of said padding portion of said elevated excavated
material and crushing said padding portion into said final processed
padding material having a maximum predetermined size without further
processing of said final processed padding material.
2. The padding system of claim 1 wherein the padding machine includes
a transverse conveyor for conveying the padding portion to a location
lateral to the padding machine, and wherein the crusher assembly
is located at a distal end of the transverse conveyor to receive
the padding portion from the transverse conveyor.
3. The padding machine of claim 1 wherein the crusher assembly
is selectively adjustable to alter the maximum predetermined size.
4. A pipeline padding system for processing at least a portion
of the excavated material into a final processed padding material,
the excavated material positioned along the side of an open ditch
in which a pipeline has been laid, the system having:
a pipeline padding machine, including:
a means for engaging the excavated material and elevating a portion
of said excavated material to a first position located on said machine;
a separator for receiving and separating the elevated excavated
material into a coarse portion and a padding portion, said coarse
portion deposited away from the open ditch;
a crusher assembly mounted on said padding machine for receiving
at least a portion of said padding portion of said elevated excavated
material and crushing said at least a portion of said padding portion
into said final processed padding material having a maximum predetermined
size, said crusher assembly having a pair of crushing rollers that
are spaced from one another, the rollers rotatable about their longitudinal
axis toward one another such that the material which is received
by the crusher assembly is dram between the rollers and crushed,
said final processed padding material being deposited into said
open ditch about the pipeline without further processing.
5. The padding system of claim 4 wherein the padding machine includes
a transverse conveyor for conveying said at least a portion of the
padding portion to a location lateral to the padding machine, and
wherein the crusher assembly is located at a distal end of the transverse
conveyor to receive said at least a portion of the padding portion
from the transverse conveyor.
6. The padding machine of claim 4 wherein the crusher assembly
is selectively adjustable to alter the maximum predetermined size.
7. The padding system of claim 4 wherein the rollers have textured
outer surfaces adapted to engage the material that is deposited
into the crusher and to pull that material downwardly between the
rollers.
8. A pipeline padding system for processing at least a portion
of the excavated material into a final processed padding material,
the excavated material positioned along the side of an open ditch
in which a pipeline has been laid, the system comprising:
a pipeline padding machine having:
a means for receiving a portion of said excavated material at a
first position located on said machine;
a separator for separating the received excavated material into
a coarse portion and a padding portion, said coarse portion deposited
away from the open ditch;
a crusher assembly mounted on said padding machine for receiving
at least a portion of said padding portion of said received excavated
material and crushing said at least a portion of said padding portion
into said final processed padding material having a maximum predetermined
size without further processing of said final processed padding
material.
9. The padding system of claim 8 wherein the padding machine includes
a transverse conveyor for conveying said at least a portion of the
padding portion to a location lateral to the padding machine, and
wherein the crusher assembly is located at a distal end of the transverse
conveyor to receive the material from the transverse conveyor.
10. The padding machine of claim 8 wherein the crusher assembly
is selectively adjustable to alter the maximum predetermined size.
Description BACKGROUND OF THE INVENTION
The present invention relates to earth moving and handling machinery,
and more particularly to machinery for preparing and depositing
padding material in a trench during installation of a pipeline or
underground cable.
An underground pipelines or cable is generally installed by placing
it in a prepared trench and then filling the trench to cover the
pipeline or cable and to restore the surface of the ground to the
desired condition. Pipelines often have coatings for corrosion control
that are subject to damage by rocks and other hard or sharp objects.
Pipelines exhibit some amount of motion with respect to the surrounding
soil after they are installed, primarily due to thermal expansion
and contraction, and they must be protected from direct contact
with rocks and other hard or sharp objects than may cause damage
both during and after installation. Buried cables, including fiber
optic cables, are also susceptible to damage if not properly padded
by fine or soft material. It is therefore often desirable to place
a layer of sand or soil that is free of large rocks and other undesirable
material in the trench immediately adjacent a pipeline or cable
to provide uniform support and to protect the pipeline or cable
from damage caused by rocks and other objects. In many applications
two layers of padding are required, one below the pipe and another
above the pipe, so that the pipeline is completely surrounded by
padding material.
Although this patent specification will refer primarily to the
use of the present invention with respect to installation pipelines,
it is to be understood that the invention is equally applicable
for use in installation and repair of underground cables.
The sand or soil that is used to pad pipelines or cables is called
padding material. Padding material may be hauled to the trench from
a remote location. This is a difficult and expensive way to provide
padding material, because a source of material must be identified
and then the material must be purchased, hauled to the pipeline
site, and properly deposited around the pipe. Furthermore, there
are other disadvantages to using non-native soil for padding material
that are know in the art, including increased problems with corrosion
under some circumstances.
Alternatively, padding material may be produced or selected from
the excavated material that is removed from the pipeline trench
when it is dug. Typically, when a pipeline trench is excavated the
removed material, including soil and rocks, is deposited along one
side of the trench. That material may be screened or sorted to separate
the rocks from the fines, and the fines may be collected and used
for padding material. After the fines are placed around the pipe,
the remainder of the unsorted excavated material, including larger
rocks that are not suitable for padding material, may be placed
in the trench to fill it to grade level.
A number of integrated pipe padding machines have been developed
for picking up excavated material from alongside a pipeline trench,
sorting it into padding material and residual material, and placing
the padding material into the trench. These machines typically employ
a transverse conveyor that extends to a position over the trench
for carrying the padding material from a separator mechanism in
the machine to the trench. The following U.S. Patents illustrate
and describe such machines: 4633602; 4912862; 4948299; 5084991;
5097610; 5120433 and 5261171. The disclosure of each of those
patents is hereby incorporated into this application by reference.
The separating and padding machines known in the prior art, including
those described in the above-referenced patents, rely on screening
or sifting means for separating padding material from residual excavated
material. Under some circumstances it is difficult or impossible
to efficiently generate an adequate quantity of padding material
from the material removed from the trench using such means. In very
rocky conditions, there may not be enough soil and other fine material
in the excavated material. In wet conditions or in areas with high
clay content, the soil may tend to clump and not pass through the
screen of the padding machine. Sometimes it may be necessary to
use a larger screen size than desired in order to produce a required
mount of padding material under particular circumstances. Pipeline
constructors typically specify the maximum particle size that is
acceptable in the padding material, and using larger screen sizes
may not be acceptable to the owner of the pipeline. It is therefore
desirable to provide a more active method of producing padding material
from various types of excavated material so as to be assured of
an adequate supply of padding material that can be predictably and
efficiently manufactured at the pipeline site from the native materials
removed from the trench.
SUMMARY OF THE INVENTION
The present invention provides an active means for producing padding
material from excavated material, regardless of whether the excavated
material initially contains sufficient fine material suitable for
padding. The present invention also permits the padding machine
operator to preselect the size (degree of fineness) of the padding
material that is to be produced for a particular job, regardless
of the condition of the excavated material that is generated when
the trench is dug.
The present invention comprises a crushing mechanism that may be
added to an integrated padding machine to replace or supplement
the screening means that are shown by the prior art. Alternatively,
the crushing mechanism of the present invention may be attached
to an excavating machine for producing padding material while the
trench is being dug, or the crushing mechanism may be used independently
of an excavating or padding machine. In presently preferred embodiments,
the crushing mechanism comprises a pair of parallel power-driven
rollers, cones, jaws or impact members with a preselected, preferably
adjustable spacing between them. As the excavated material passes
between the rollers, the fine material fails through the space between
the rollers and the larger material is crushed into finer material
by the rollers. Alternatively, the fine material may be removed
by a screen mechanism before the larger material is placed in the
crushing mechanism.
A crusher according to this invention may be installed on padding
machines of the type described in the patents listed above. It may
be attached to the end of the transverse conveyor, operably located
over the trench. Alternatively, the crusher may be positioned on
the machine frame, and the output from the crusher may be conveyed
to the trench by the transverse conveyor or other means. The crusher
may replace the screens used on padding machines shown in the prior
art, or it may supplement those screens. It may be desirable to
place a sifting or sorting mechanism upstream of the crusher to
keep boulders and other undesirable materials from reaching the
crusher. It may also be desirable to remove fines from the excavated
material before it is fed into the crusher, to avoid choking or
clogging the crushing mechanism.
The present invention therefore provides an improved machine which
allows efficient production of padding material from excavated material
during installation or maintenance of a pipeline or buried cable,
particularly where conventional screening means are not adequate.
The crushing mechanism of the present invention eliminates reliance
on the presence of an adequate supply of separable fine material
for padding in the raw excavated material. These and other advantages
of the present invention will be further appreciated from the drawings
and from the detailed description provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the herein described advantages and
features of the present invention, as well as others which will
become apparent, are attained and can be understood in detail, more
particular description of the invention summarized above may be
had by reference to the embodiment thereof which is illustrated
in the appended drawings, which drawings form a part of this specification.
It is to be noted, however, that the appended drawings illustrate
only exemplary embodiments of the invention and are therefore not
to be considered limiting of its scope, for the invention may admit
to other equally effective embodiments.
FIG. 1A shows that prior art pipeline padding machine with which
the present invention may be used.
FIG. 1B shows a different type of prior art pipeline padding machine
with which the present invention may be used.
FIG. 2 shows a plan view of a padding crusher according to the
present invention operatively coupled to a transverse conveyor from
a padding machine and disposed over a pipeline trench.
FIG. 3 is a schematic illustration of an arrangement of conveyors
and a crusher according to this invention.
FIG. 4 is a schematic illustration of an alternative arrangement
of conveyors and a crusher according to this invention, including
a screen disposed upstream from the crusher.
FIG. 5 is a schematic illustration of yet another alternative arrangement
of conveyors and a crusher according to this invention including
a screen disposed downstream from the crusher.
FIG. 6 illustrates a crushing mechanism according to the present
invention mounted on a vehicle that is not a padding machine.
FIG. 7 is an elevation view of a preferred embodiment of a padding
crusher mechanism according to the present invention.
FIG. 8 is an elevation view of a padding crusher according to the
present invention, illustrating details of the crushing mechanism.
FIG. 9 is a cross-sectional view of a crushing roller assembly
and supporting structure according to a preferred embodiment of
the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
In its presently preferred embodiment, the present invention is
an improvement to an "E-Z Pipe Paddler" padding machine,
as described in U.S. Pat. No. 5084991 which is incorporated herein
by reference. An illustration from the '991 patent is reproduced
as FIG. 1 of the present patent. Referring to FIG. 1 the "E-Z
Pipe Paddler" is attached to the yoke 24 of bulldozer 20 which
during operation supports the padding machine and moves it along
the elongated pile of excavated material 48 that is alongside and
parallel to trench 50 containing pipe 158. The machine operates
by rotating drum 52 around a horizontal axis transverse to the trench
in a manner to engage and lift the excavated material. When the
excavated material reaches the top of the drum, it falls from the
scoops onto bars and/or screens which are arranged around the periphery
of the drum. Relatively fine material falls through spaces in the
bars/screens and is received by transverse conveyor 68 for deposit
into trench 50. Boulders and other objects that are too large to
pass through the screens or bars are carried over the top of the
drum as it rotates and deposited back on the ground behind the padding
machine.
The present invention comprises a crushing mechanism that is mounted,
in preferred embodiments, at the distal end of lateral conveyor
68. It is not necessary to place screens around the periphery of
drum 52 so that only bars having relatively larger spaces between
them are used to remove boulders and large rocks. (Of course, screens
may be used to reduce the size of the material collected, if desired.)
The remaining material, which includes rocks and clumps of material
that are larger than is acceptable for padding material, falls through
the bars and onto lateral conveyor 68.
Referring to FIG. 2 in a preferred embodiment crusher 200 is mounted
at the discharge end of conveyor 68. (On some padding machines,
the discharge conveyor is adjustable to discharge padding material
to either side of the padding machine. A crusher according to this
invention could be selectably mounted on either end of the transverse
conveyor.) One embodiment of crusher 200 comprises a pair of parallel
rollers 202 204 having a variable gap 206 between them. The rollers
202 204 are rotated toward one another by motor 208. The dirt and
rocks that are deposited onto lateral conveyor 68 by drum 52 are
discharged from conveyor 68 into crusher 200 and more particularly
into hopper 210. As rollers 202 204 turn toward one another they
draw dirt and rocks from hopper 210 through gap 206 between the
rollers, crushing any pieces that are larger than the gap dimension
into material that is suitably fine for use as padding material.
In this embodiment, the padding material falls from gap 206 between
rollers 202 204 into trench 50. Rollers 202 204 may be driven
by hydraulic motors 208. Other types of motors, such as electric
or gasoline motors may alternatively be employed to power the crusher.
Suitable gearing mechanisms and other power transfer apparatus may
be incorporated as needed. A skilled engineer with the benefit of
this disclosure could design a suitable drive means for the crusher,
guided by the speed, torque and power requirements of the particular
implementation. Hydraulic motor 208 may be powered by pressurized
hydraulic fluid supplied from the padding machine or from the host
vehicle through hydraulic lines 212. The outer surfaces of rollers
202 204 may be textured, as for example with small weld deposits,
to more efficiently draw dirt and rocks from hopper 210 and through
gap 206 between rollers 202 204.
The suitable size, type and number of rollers may depend on the
particular characteristics of the material being crushed as well
as the desired characteristics of the desired padding material.
It is believed that any suitable alloy material such as alloy steel
which has been adequately hardened may be used for rollers 202
204. While two rollers are shown, it is believed that multiple,
progressive pairs of rollers may be used.
Crusher 200 according to this invention may be used with equal
beneficial effect at the end of the lateral or transverse conveyor
on other types of padding machines, such as those described in U.S.
Pat. Nos. 4948299 4633602 4912862 5120433 5097610
and 5261171 all of which are incorporated herein by reference.
FIGS. 3 through 5 illustrate alternative configurations in which
the crusher 200 of this invention may be utilized. FIG. 3 shows
crusher 200 relocated from the distal end of transverse conveyor
68 to the proximal end of transverse conveyor 68 crushing the excavated
material prior to depositing it on transverse conveyor 68. In this
embodiment, excavated material is raised from ground level by conveyor
220 and deposited into crusher 200. The crushed material is deposited
on transverse conveyor 68 which conveys it to trench 50 for placement
over pipe 158. In the type of padding machine illustrated and described
in U.S. Pat. No. 5084991 which is incorporated herein by reference,
the crusher may be positioned inside of the rotating drum to receive
excavated material that is lifted by the drum and to crush that
material before it is deposited onto the transverse conveyor for
placement in the ditch or trench.
FIG. 4 shows a schematic representation of another embodiment wherein
excavated material is carried by conveying means 220 and deposited
on screen 222. Screen 222 separates material into relatively fine
material that passes through screen 222 and into crusher 200 and
relatively course material that is too large to pass through screen
222. The course material is deposited on waste conveyor 226 and
placed at a desired location. The material which enters crusher
200 is crushed and deposited on conveyor 68 which carries it to
trench 50 for placement over pipe 158. An additional screen and
conveyor or chute may be employed to separate fine material and
bypass it around the crusher, so as to avoid overloading the crusher
with fine material.
FIG. 5 shows yet another embodiment in schematic form. Conveyor
220 carries excavated material and deposits it into crusher 200.
The crushed material is subsequently screened by screen 224. The
fine material which falls through the screen is placed on transverse
conveyor 68 for placement in trench 50. The courser material which
does not pass through screen 224 is deposited on conveyor 226 for
placement as desired, which may be in trench 50 after the fine material
has been placed over the pipe, onto the ground adjacent trench 50
or returned to crusher 200 for reprocessing.
FIG. 6 shows yet another embodiment of the present invention. Crusher
200 may be mounted on bulldozer 230 or other vehicle, or it may
be mounted on a stand or skid. A hopper 210 may be provided for
receiving a supply of excavated material to be crushed and placed
in a pipeline trench. As in the previously described embodiment,
crushing rollers 202 and 204 are driven by hydraulic motor 208
utilizing power delivered through hydraulic lines 212 from the bulldozer.
The hopper may be filled by a front-end loader or other means, and
then positioned over the pipeline trench. The operator may then
activate hydraulic motor 208 to cause rollers 202 204 to deposit
crushed padding material into the trench. Such a crusher mechanism
may be used on other types of equipment as well. For example, a
front-end loader could be equipped with a crushing mechanism attached
to a bucket. The bucket could be used to pick up excavated material
from the ground, and then the crusher operated to deposit crushed
material into the trench.
A crusher according to this invention may also be used in conjunction
with a ditching or trenching machine. All or a portion of the rock
and soil excavated to dig the trench may be crushed and returned
to the ground along the right-of-way. The crushed material may than
be gathered and screened by a conventional padding machine and the
resulting padding material may be deposited in the trench to surround
the pipe or cable that is to be disposed therein. The crusher according
to the present invention is well suited for padding operations in
areas where the native excavated material does not contain sufficient
amounts of suitable material that can be obtained by screening.
FIG. 7 shows a preferred embodiment of a padding crusher according
to this invention mounted on the end of a conveyor belt structure
that typically extends from a padding machine, as shown in the above
listed patents. A padding machine, ditching machine, or other source
of excavated material is presumed to be to the right of the structure
as shown in FIG. 7. The excavated material is conveyed to the left
on conveyor belt 302 which is supported by conveyor supporting
structure 304. In the prior art, the material placed on conveyor
302 was suitable padding material that had already been screened,
and it was deposited into the trench directly off of the end of
conveyor 302. The present invention may be suspended from the end
of conveyor supporting structure 305 as illustrated, to receive
the material conveyed by conveyor belt 302 and further process it
prior to depositing it in the trench.
The crusher according to the embodiment of the present invention
shown in FIG. 7 comprises a hopper 300 for receiving excavated material
from conveyor 302 and a pair of crushing rollers 306 304 for receiving
material from the hopper 300 crushing any of the material that
is too large to fit between the rollers, and depositing the resulting
material into the trench.
In the illustrated embodiment, a screen 308 is disposed between
the end of conveyor belt 302 and hopper 300. The screen mesh size
is selected to permit those pieces of the excavated material that
are smaller than a preselected size to pass through the screen and
bypass the crusher, while retaining those pieces that are larger
than the preselected size and depositing them into hopper 300. Guide
walls 310 may be positioned along the sides of screen 308 to retain
excavated material on screen 308 and to guide material that is too
large to pass through the openings in screen 308 into hopper 300.
A shaking or vibrating mechanism may be employed to shake screen
308 during operation. The material that passes through screen 308
is directed into the trench by slide or chute 312 which is supported
by suitable structural members below screen 308. The purpose of
screen 308 is to reduce the volume of material that is introduced
into crushing mechanism 314 in order to avoid overloading or choking
crusher 314 and to increase the capacity and speed of the apparatus.
With screen 308 in place, only the material that needs to be crushed
or broken up is introduced into hopper 300 and fed through crusher
314. Ramp 316 may be positioned between screen 308 and hopper 300
to support the material that passes between those two components.
Ramp 316 may include sidewalls to prevent material from falling
off of ramp 316 during operation of the padding mechanism.
Crusher mechanism 314 along with hopper 300 and screen 308 may
be suspended from conveyor supporting structure 305 by an adjustable
frame 317 as shown in FIG. 7. The elevation of crusher 314 above
the trench or ground level may be adjusted by operation of hydraulic
cylinder 318. The particular arrangement of the supporting structure
is not considered part of this invention, and is a matter of design
choice in any particular implementation of the invention. In some
applications, there may be no need for an adjustable frame, and
a fixed frame may be employed.
FIG. 8 illustrates further details of a presently preferred embodiment
of crusher mechanism 314 of this invention, complete with hopper
300. Crushing rollers 304 306 are supported at each end by bearing
assemblies 324 326. Semicylindrical housing members 328 330 are
suspended below hopper 300 and arranged to cover the outwardly facing
surfaces of rollers 304 306. Semicylindrical housing members 328
330 have end plates 332 334 attached thereto that at least partially
cover the ends of rollers 304 306. The hopper and housing members
may be attached to and supported by a suitable structural frame.
Bearing assemblies 324 326 are attached to and supported by end
plates 332 334.
In the illustrated embodiment of FIG. 8 the right-hand housing
member 330 and cylinder 306 are fixed in position with respect to
hopper 300 and the frame of crusher 314. The left-hand housing 328
and roller 304 are pivotally movable with respect to the right-hand
roller 306 permitting the crush gap 336 between the rollers 304
306 to be adjusted by the operator of the machine. In a preferred
embodiment, the movable left-hand housing member 328 is pivotally
mounted to the frame by pivot bolts 338. The width of crush gap
336 may be adjusted and maintained by adjusting eye-bolt 340 which
threadably engages socket 342 which is pivotally attached to the
stationary position of housing 330. Eye bolt 340 may be disconnected
from movable portion of housing 328 and its extension from socket
342 may be adjusted by rotating it around its longitudinal axis.
Eye bolt 340 may then be re-attached to the movable portion of housing
328 thus establishing a selected and fixed crush gap 336 between
rollers 304 306. A similar eye bolt and socket arrangement may
be positioned at the other end of crusher 314.
Alternatively, the rollers 304 306 may be spring biased (not shown)
toward one another, permitting the rollers to move apart if something
hard enough to overcome the spring force without being crushed is
drawn between the rollers. In the presently contemplated preferred
applications for this invention it is impermissible to allow objects
larger than the selected crush gap to fall into the trench, so the
crush gap 336 is rigidly fixed rather than being spring biased.
A screening apparatus may be placed downstream of a spring biased
crusher to prevent oversized material from being placed in the trench,
such as in the arrangement shown in FIG. 5.
It is preferable to direct excavated material from hopper 300 onto
the "feed zone" of rollers 304 306 without permitting
any dirt or rocks to fall around the outside of crushing rollers
304 306. The "feed zone" is that portion of the upper
surfaces of the rollers proximate the crush gap 336 that is designed
to accept material for crushing. Hopper 300 is therefore provided
with chute 344 which directs excavated material onto the rollers
proximate crush gap 336. Chute 344 has front and rear walls 346
348 and lateral walls 350. The lateral walls 350 are disposed inwardly
spaced from the ends of rollers 304 306 so as to prevent excavated
material from entering the spaces between the ends of rollers 304
306 and end plates 332 334. Pivotally movable housing member 328
has a diverter plate 352 affixed thereto which slidably engages
lateral wall 350 of chute 344 to direct excavated material into
the feed zone on top of rollers 304 306 and away from the space
between roller 304 and moveable end plate 332 regardless of the
selected crush gap 336.
It may sometimes be necessary to reverse the direction of rotation
of rollers 304 and 306 for example to dislodge a hard object or
to clear a clogging or choking condition in crush gap 336. It is
therefore desirable to ensure that no oversized excavated material
is carried around the back sides of rollers 304 and 306 when they
are rotated backwards (away from one another). Guard bars 356 358
are provided to define the front and rear limits of the feed area.
They extend the length of rollers 304 306 between end plates 332
334 on each side of the machine. Guard bars 356 358 are positioned
closely spaced from the outer surfaces of rollers 304 306 so that
no oversized material can pass between guard bars 356 358 and rollers
304 306.
FIG. 9 shows a front elevation cross section of a presently preferred
embodiment of the present invention. (Section IX--IX in FIG. 8).
Axle 362 is supported by bearing assemblies 324 at each end. Hydraulic
motor 360 is mounted on mounting plate 333 and operatively coupled
to axle 362. One hydraulic motor is provided for each of the two
rollers 304 306. The two hydraulic motors 360 may be hydraulically
arranged in series or in parallel, depending on the power requirements
of the application. If necessary, motors can be placed at both ends
of each roller. The specific construction of the bearing assemblies,
e.g., 324 will be recognized by those of skill in the art as a
matter of design choice to accommodate the anticipated load, considering
the desired speed, torque and crushing force. The present invention
is not intended to be limited to particular drive and bearing arrangements.
Also, different sorts of crusher mechanisms may be used in implementing
this invention. For example and without limitation, apparatus including
cone crushers, jaw crushers, and impact hammers may be employed
in place of or in conjunction with the roller crusher described
in connection with the presently preferred embodiments of the invention.
Rollers 304 306 may be sections of heavy walled tube. Roller end
plates 363 are connected to the ends of roller 304 preferably by
welding and then keyed to axle 362. When hydraulic motor 360 is
operated, it transmits power to the axle via coupling 366 which
causes the roller to turn. Hydraulic power may be provided from
an external hydraulic power unit, which may be mounted on the padding
machine to which the crusher of this invention is attached. The
crusher is operated by hydraulic or electrical controls that are
positioned within reach of the padding machine operator. The elevation
of the crusher above the trench may be controlled by manipulation
of valves that provide hydraulic power to cylinder 318 which is
shown in FIG. 7. The direction and speed of rotation of crushing
rollers 304 306 may be controlled by manipulation of valves that
provide hydraulic power to hydraulic motors 360 which are operably
coupled to rollers 304 306.
Further modifications and alternative embodiments of this invention
will be apparent to those skilled in the art in view of this description.
Accordingly, this description is to be construed as illustrative
only and is for the purpose of teaching those skilled in the art
the manner of carrying out the invention. It is to be understood
that the forms of the invention herein shown and described are to
be taken as the presently preferred embodiments. Various changes
may be made in the shape, size, and arrangement of parts. For example,
equivalent elements or materials may be substituted for those illustrated
and described herein, and certain features of the invention may
be utilized independently of the use of other features, all as would
be apparent to one skilled in the art after having the benefit of
this description of the invention.
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