Note: Descriptions are shown in the official language in which they were submitted.
CA 02828008 2013-09-20
ROPE SHOVEL
BACKGROUND
[0001] The present invention relates to rope shovels used for example in
the mining and the
construction industries.
[0002] In the mining field, and in other fields in which large volumes of
materials must be
collected and removed from a work site, it is typical to employ a power shovel
including a large
dipper for shoveling material from the work site. After filling the dipper
with material, the
shovel swings the dipper to the side to dump the material into a material
handling unit, such as a
dump truck or a local handling unit (e.g., crusher, sizer, or conveyor).
Generally, the shovels
used in the industry include hydraulic shovels and electric rope shovels.
Electric rope shovels
typically include a shovel boom that supports a pulling mechanism that pulls
the shovel dipper
thereby producing efficient dig force to excavate the bank of material.
Conventional electric
rope shovels include a relatively straight boom that is mounted at forty five
degrees with respect
to a horizontal plane (e.g., the ground).
SUMMARY
[0003] In some aspects, the invention provides a digging assembly for a
mining shovel. The
assembly includes a generally V-shaped boom including a lower connection point
for attachment
to the mining shovel. A first portion of the boom extends generally upwardly
from the lower
connection point, and a second portion of the boom is angled with respect to
and extends
upwardly and forwardly from the first portion. The second portion includes a
distal end defining
a sheave support, and a pivot element is positioned generally at a connection
area between the
first portion and the second portion. The assembly also includes a boom
attachment (also known
as a boom handle) having a first end that is pivotally supported by the pivot
element and a
second end that is connected to a dipper.
[0004] In other aspects, the invention provides a digging assembly for a
mining shovel. The
assembly includes a generally V-shaped boom including a lower connection point
for attachment
to the mining shovel. A first portion of the boom extends generally upwardly
from the lower
connection point, and a second portion of the boom is angled with respect to
and extends
CA 02828008 2013-09-20
upwardly and forwardly from the first portion. The second portion includes a
distal end defining
a sheave support, and a pivot element is positioned between about zero degrees
and about 10
degrees from a vertical line extended directly upwardly from the lower
connection point. The
assembly also includes a boom attachment having a first end that is pivotally
supported by the
pivot element and a second end that is connected to a dipper.
[0005] In still other aspects, the invention provides a mining shovel that
includes a lower
base and an upper base rotatably mounted on the lower base for rotation
relative to the lower
base. A generally V-shaped boom includes a lower connection point for
attachment to the upper
base, a first portion extending generally upwardly from the lower connection
point, and a second
portion angled with respect to and extending upwardly and forwardly from the
first portion. The
second portion includes a distal end defining a sheave support. A pivot
element is positioned
generally at a connection area between the first portion and the second
portion. A sheave is
rotatably supported by the sheave support. A boom attachment has a first end
that is pivotally
supported by the pivot element and a second end that is connected to a dipper.
A rope extends
from the upper base, over the sheave, and is connected to the dipper for
support thereof.
[0006] In still other aspects, the invention provides a mining shovel that
includes a lower
base and an upper base rotatably mounted on the lower base for rotation
relative to the lower
base. A generally V-shaped boom includes a lower connection point for
attachment to the upper
base, a first portion extending generally upwardly from the lower connection
point, and a second
portion angled with respect to and extending upwardly and forwardly from the
first portion. The
second portion includes a distal end defining a sheave support. A pivot
element is positioned
between about zero degrees and about 10 degrees from a vertical line extended
directly upwardly
from the lower connection point. A sheave is rotatably supported by the sheave
support. A
boom attachment has a first end that is pivotally supported by the pivot
element and a second end
connected to a dipper. A rope extends from the upper base, over the sheave,
and is connected to
the dipper for support thereof.
[0007] In still other aspects, the invention provides a mining shovel that
includes a flat
bottom boom and a strut mechanism for supporting the boom in an upright
position relative to a
base of the shovel.
2
CA 02828008 2013-09-20
[0008] In still other aspects, the invention provides a mining shovel
including a base, a
boom, an elongated member movably coupled to the boom, and a support member.
The base
includes a first portion and a second portion. The first portion includes
tracks for supporting the
shovel on a support surface, and the second portion is rotatable relative to
the first portion about
an axis of rotation. The boom includes a first end pivotably coupled to the
second portion of the
base and a second end positioned away from the base. The boom is pivotable
about a pivot axis
extending transversely to the boom proximate the first end. The elongated
member is pivotable
relative to the boom. The support member biases the boom against pivoting
movement about the
pivot axis. The support member includes a pair of struts. Each strut is
positioned on an opposite
side of the axis of rotation and includes a first end coupled to the second
portion of the base and
a second end coupled to the boom.
[0009] In still other aspects, the invention provides a support member for
a mining shovel
including a base and a boom. The base has a first portion and a second portion
supported for
rotation relative to the first portion about a rotational axis. The boom has a
first end pivotably
coupled to the second portion. The support member includes a strut and a
damper for dampening
a pivoting movement of the boom relative to the second portion of the base.
The strut includes a
first end and a second end. The first end is adapted to be coupled to the
boom, and the second
end is adapted to be coupled to the second portion of the base. The damper
includes a first end
coupled to the strut and a second end adapted to be coupled to the boom.
[0010] In still other aspects, the invention provides a mining shovel
including a base for
supporting the shovel on a support surface, a boom, an elongated member
movably coupled to
the boom, and a support member. The boom includes a first end pivotably
coupled to the base
and a second end positioned away from the base. The boom is pivotable about a
pivot axis
extending transversely to the boom proximate the first end. The elongated
member is pivotable
about a shaft positioned between the first end and the second end of the boom.
The support
member biases the boom against pivoting movement about the pivot axis. The
support member
extending between the base and the boom.
[0011] Other aspects of the invention will become apparent by consideration
of the detailed
description and accompanying drawings.
3
CA 02828008 2013-09-20
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an electric rope shovel.
[0013] FIG. 2 is a side view of the electric rope shovel of FIG. 1 with
some portions
removed and showing a reach comparison between a conventional boom A and a
curved boom
B.
[0014] FIG. 3 is a side view of the electric rope shovel of FIG. 1 with
additional portions
removed and illustrating relative locations of the centers of gravity of
certain components of the
shovel.
[0015] FIG. 4 is a perspective view of a rope shovel according to another
embodiment.
[0016] FIG. 5 is a perspective view of a shovel according to another
embodiment.
[0017] FIG. 5A is a perspective view of a shovel according to another
embodiment.
[0018] FIG. 6 is a side view of the shovel of FIG. 5.
[0019] FIG. 7 is a side view of a portion of the shovel of FIG. 5.
[0020] FIG. 8 is a perspective view of a base, boom, and support member.
[0021] FIG. 9 is a top view of the base, boom, and support member of FIG.
8.
[0022] FIG. 10 is a side view of a portion of a shovel according to another
embodiment.
[0023] FIG. 11 is a rear perspective view of a portion of the shovel of
FIG. 10.
[0024] FIG. 12 is an enlarged perspective view of a coupling between a
strut and a boom.
[0025] FIG. 13 is an enlarged side view of the portion of the shovel of
FIG. 11.
[0026] FIG. 14 is an enlarged side view of a portion of a shovel according
to another
embodiment.
[0027] FIG. 15 is a perspective view of a saddle block.
4
CA 02828008 2013-09-20
[0028] FIG. 16 is a rear perspective view of the saddle block of FIG. 15
coupled to the boom
and supporting a handle.
[0029] FIG. 17 is a side view of the shovel of FIG. 5 illustrating relative
locations of centers
of gravity of certain components of the shovel.
[0030] It is to be understood that the invention is not limited in its
application to the details
of the construction and the arrangements of components set forth in the
following description or
illustrated in the drawings. The present invention is capable of other
embodiments and of being
practiced or being carried out in various ways. Also, it is to be understood
that the phraseology
and terminology used herein is for the purpose of description and should not
be regarded as
limiting.
DETAILED DESCRIPTION
[0031] FIGS. 1-4 illustrate an electric rope shovel 10 including a lower
base 15 that is
supported on drive tracks 20. The electric shovel 10 further includes an upper
base 25 (also
called a deck) positioned on a rotational structure 30 that is mounted to the
lower base 15. The
rotational structure 30 allows rotation of the upper base 25 relative to the
lower base 15. The
rotational structure defines a center line of rotation 27 of the shovel 10
(FIG. 4). The center line
of rotation 27 is perpendicular to a plane 28 defined by the lower base 15 and
generally
corresponding to the grade of the ground. In one embodiment, the upper base 25
includes,
among other elements, an operating area 33 used by an operator or a driver to
operate the electric
rope shovel 10. As used herein, the terms "above," "upwardly," "vertically,"
and the like assume
the drive tracks 20 are positioned on level ground such that the center line
of rotation 27 is
substantially vertical.
[0032] The electric rope shovel 10 further includes a boom 45 extending
upwardly from the
upper base 25. The boom 45 includes a first end 46 coupled to the upper base
25 and a second
end 47. The boom 45 is curved and has "banana" or a "V" shape. The boom 45 is
coupled to the
upper base 25 at a point 26 via pin joints or other suitable attachment
mechanisms. In some
embodiments, the boom 45 comprises a generally vertical first portion 31 that
extends generally
upwardly from the base 25, and a second portion 32 that extends at an angle
from the first
CA 02828008 2013-09-20
portion 31 toward the second end 47. The second end 47 of the boom 45 is
remote from the base
25. In one embodiment, the boom 45 comprises a one-piece construction
combining the first and
the second portions of the boom. In other embodiments, the boom 45 comprises
two pieces,
where the two portions of the boom 45 are securely attached to one another via
welding, pin
joints, fasteners, or any other attachment mechanisms.
[0033] The first portion 31 of the boom 45 is angled with respect to the
second portion 32 of
the boom. In some embodiments, the angle between the first portion 31 and the
second portion
32 of the boom can be between about one hundred and twenty degrees and about
one hundred
and sixty degrees. More specifically, the angle between the first portion 31
and the second
portion 32 can be between approximately one hundred and sixty degrees. In
other words, the
second portion 32 of the boom 45 is offset between abut twenty and about sixty
degrees from the
first portion 31 of the boom 45. In particular, the offset between the second
portion 32 of the
boom 45 and the first portion 31 can be twenty degrees.
[0034] The electric rope shovel 10 also includes a digging attachment
comprising a boom
attachment 50 (also called a boom handle) pivotally and slidably coupled to
the boom 45 and a
dipper 55 rigidly coupled to an end 39 of the boom attachment 50. In other
embodiments, the
dipper 55 can be moveably (e.g., pivotally) attached to the boom handle 50.
Together the boom
45, the boom attachment 50, and the dipper 55 define a digging assembly of the
shovel 10. The
dipper 55 includes dipper teeth 56 and is used to excavate the desired work
area, collect material,
and transfer the collected material to a desired location (e.g., a material
handling vehicle).
[0035] A pulling mechanism 58 is mounted on a second end 47 of the boom 45
and partially
supports the boom handle 50 and the dipper 55. In some embodiments, the
pulling mechanism
58 comprises a pulley or boom sheave 60 and a flexible hoist rope 62 that
extends from the base
25, upwardly along the boom 45 and over the boom sheave 60, and downwardly to
an attachment
point on the dipper 55. The flexible hoist rope 62 is wrapped around a hoist
drum 63 mounted
on the upper base 25 of the electric shovel 10. The hoist drum 63 is powered
by an electric
motor (not shown) that provides turning torque to the drum 63 through a geared
hoist
transmission (not shown).
6
CA 02828008 2013-09-20
[0036] The sheave 60 is rotatably coupled to the second end 47 of the boom
45 between a
pair of sheave support members 37 located at the second end 47 of the boom 45.
A rod or a load
pin 34 extends between the sheave support members 37 and through the sheave
60, thereby
rotatably coupling the sheave 60 to the boom 45. Thus, the sheave 60 rotates
about the rod or the
load pin 34. In other embodiments, alternative mechanisms for connecting the
sheave 60 to the
boom 45 can be used. Rotation of the hoist drum 63 reels in and pays out the
hoist rope 62,
which travels over the sheave 60 and raises and lowers the dipper 55.
[0037] The electric shovel 10 also includes a strut mechanism 48 for
supporting the boom 45
in an upright position relative to the base 25. In one embodiment, the strut
48 includes two
parallel strut legs 49 coupled by rigid-connect members 51. One end 52 of the
strut 48 is rigidly
mounted on the base 25 at a location spaced apart from the first end 46 of the
boom 45. A
second end 53 of the strut 48 is coupled to the boom 45 by connecting each
strut leg 49 to a
depending portion 54 of the boom 45. In some embodiments, the second end 53 of
the strut 48 is
coupled to the general area where the first portion 31 and the second portion
32 of the boom 45
connect or intersect. The strut 48 supports the boom 45 in the upright
position. The strut 48 of
the shovel 10 allows the elimination of a major structural member used in a
conventional shovel
(i.e., the gantry structure) and the suspension ropes also used in a
conventional shovel.
100381 In some embodiments, the strut 48 is pivotally connected to the base
25 and to the
boom 45 via moving pin joints or other types of connectors. The strut 48 can
be provided with
shock absorbing connectors (FIG. 11, described below) - such as various types
of spring
assemblies and/or fluid dampers incorporated into the pinned attachment joints
between the strut
48, the base 25, and the boom 45. These shock absorbing connectors can reduce
the overall
stiffness of the strut assembly when compression and tension forces are acting
on the strut,
thereby reducing shock loading and in turn reducing the overall stresses
experienced by the
various components and the major structures.
100391 The curved boom 45 can be used with a variety of differently
configured boom
handles 50. For example, in the embodiments of FIGS. 1-3 the boom handle 50
includes two
substantially straight and parallel elongated handle members 61 positioned on
either side of the
boom 45. On the other hand, in the embodiment of FIG. 4, the boom handle 50
includes an
7
CA 02828008 2013-09-20
upper arm 64 and a lower arm 65. The upper arm 64, and consequently the boom
handle 50, is
pivotally attached to a portion of the boom 45 generally where the first
portion 31 and the second
portion 32 of the boom 45 connect or intersect. In the illustrated embodiment,
the upper arm 64
includes parallel upper arm members 43, such that one upper arm member 43
extends to each
side of the boom 45. The lower arm 65 of the boom handle 50 is mechanically
connected to the
upper arm 64, and is driven by the upper arm 64. In some embodiments, the
lower arm 65 is
connected to the upper arm 64 via free moving pin joints, but other mechanical
connections such
as cams, linkages, gear sets, and the like may also be used to achieve the
desired relative
movement between the upper arm 64 and the lower arm 65.
100401 With continued reference to the embodiment of FIG. 4, the boom
handle 50 is driven
by one or more hydraulic cylinders 66 that extend between at least one of the
upper aini 64 and
the lower arm 65 and at least one of the boom 45 and the base 25. In the
illustrated construction,
two hydraulic cylinders 66 are used, with one cylinder 66 positioned on each
side of the boom
45. The hydraulic cylinders 66 pivot the upper arm 64 with respect to the boom
45 and thrust the
lower arm 65 and the dipper 55 into the bank of material that is being
excavated. The dipper 55
is moveably (e.g., pivotally) connected to the distal end of the lower arm 65.
At least one
actuator 71 in the form of a hydraulic cylinder extends between the dipper 55
and the lower arm
65 and is operable to move the dipper 55 relative to the lower arm. Other
types of actuators can
be used and can alternatively be coupled to the upper arm 64 or to an
intermediate structure (not
shown) coupled to one or both of the upper arm 64 and the lower arm 65.
100411 Regardless of whether the shovel has the boom attachment 50 of FIGS.
1-3 or the
boom attachment 50 of FIG. 4, the boom attachment 50 is also supported by the
sheave 60 via
the hoist rope 62. For that purpose, the boom attachment includes a connecting
mechanism that
engages the hoist rope 62 and connects the boom attachment with the sheave 60
(FIG. 4). In one
embodiment, the connecting mechanism comprises an equalizer 73 coupled to the
lower arm 65.
In alternative embodiments (e.g., when the hydraulic cylinders driving the
dipper are attached to
the upper portion of the dipper), the equalizer 73 is positioned near the
pivot point of the lower
arm 65 and the dipper, and the hoist rope 62 passes between the actuators 71
to reach the
equalizer. Where more than one hoist rope is used, the equalizer 73 can sense
the tension
applied on each hoist rope 62 and is operable to equalize the tension in the
two hoist ropes 62. In
8
CA 02828008 2013-09-20
other embodiments, different types of connecting mechanisms can be used to
connect the sheave
60 and the boom attachment 50 and the dipper 55.
[0042] As shown in FIGS. 1-4, the boom 45 includes a pivot element or pivot
point 59 (e.g.,
a shipper shaft or a pin depending on the type of boom handle 50) that
pivotally supports the
boom handle 50. The pivot point 59 of the curved boom 45 is located
significantly closer to the
center line of rotation 27 of the shovel 10 when compared to the pivot point
location for a
conventional straight boom. For example, in some embodiments, the pivot point
59 is about nine
feet closer to the axis of rotation 27 that it would be if the boom 45 was a
conventional straight
boom. Thus, as shown in FIG. 2, the maximum reach of the dipper 10 (shown as
B) is closer to
the base and to the center line of rotation 27 when compared to the reach of
the convectional
dipper (shown as A). The center of gravity 83 of the curved boom 45 is also
closer to the center
line of rotation 27 than the center of gravity of a conventional boom.
Consequently, less
counterweight is required to support the digging attachment and the overall
machine weight and
swing inertia is reduced.
[0043] In some embodiments, the pivot point 59 of the boom handle is
positioned
approximately at the general area where the first portion 31 and the second
portion 32 of the
boom 45 connect or intersect. In some embodiments, the pivot point 59 is
positioned
substantially directly above the point of connection 26 between the first
portion 31 of the boom
45 and the upper base 25. For example, depending on the particular
construction of the boom,
the pivot point 59 can be positioned between about zero degrees and about ten
degrees from a
vertical line drawn directly upwardly from the point of connection 26. In
other embodiments,
the pivot point 59 can be positioned between about zero degrees and about five
degrees from a
vertical line drawn upwardly from the point of connection 26.
[0044] Because of the curved shape of the boom 45, the pivot point 59 of
the boom handle
45 is moved substantially towards the base 25 and the center line of rotation
27 of the shovel 10.
The relationship of different points along the boom 45 relative to the axis of
rotation 27 and
relative to one another are illustrated in and discussed with respect to FIG.
3. The relevant points
or locations along the boom 45 include the pivot point 59, the center of
gravity 83 of the boom
45, a geometric center 82 of the second boom portion 32, and a pulley
connection point 81 where
9
CA 02828008 2013-09-20
the pulley 60 is rotatably coupled to the second boom portion 42. A pulley
reference distance 79
is defined as the perpendicular distance from the axis of rotation 27 to the
pulley connection
point 81. A pivot point distance 80 is defined as the perpendicular distance
from the axis of
rotation 27 to the pivot point 59. A CG distance 90 is defined as the
perpendicular distance from
the axis of rotation 27 to the center of gravity 83 of the boom 45. A second
portion center
distance 91 is defined as the perpendicular distance from the axis of rotation
27 to the geometric
center 82 of the second boom portion 32.
100451 In some embodiments, the pivot point distance 80 is between about 20
percent and
about 40 percent of the pulley reference distance 79. In other embodiments the
pivot point
distance 80 is between about 25 percent and about 35 percent of the pulley
reference distance 79.
In still other embodiments the pivot point distance 80 is about thirty percent
of the pulley
reference distance 79.
[0046] In some embodiments, the CG distance 90 is between about 35 percent
and about 55
percent of the pulley reference distance 79. In other embodiments the CG
distance 90 is between
about 40 percent and about 50 percent of the pulley reference distance 79. In
still other
embodiments the CG distance 90 is about 45 percent of the pulley reference
distance 79.
[0047] In some embodiments, the second portion center distance 91 is
between about 55
percent and about 75 percent of the pulley reference distance 79. In other
embodiments the
second portion center distance 91 is between about 60 percent and about 70
percent of the pulley
reference distance 79. In still other embodiments the second portion center
distance 91 is about
65 percent of the pulley reference distance 79.
[0048] With continued reference to FIG. 3, reference line 84 extends
between point 26 (i.e.,
the point of connection between the first portion 31 of the boom 45 and the
upper base 25) and
pulley connection point 81. Reference line 85 extends through the pivot point
59 and is
perpendicular to reference line 84. In some embodiments, the length of
reference line 85 is
between about 1/4 and about 1/8 of the length of reference line 84. In other
embodiments the
length of reference line 85 is between about 1/5 and about 1/7 of the length
of reference line 84.
In still other embodiments the length of reference line 85 is about 1/6 of the
length of reference
line 84.
CA 02828008 2013-09-20
100491 Reference line 86 extends from point 26 to the pivot point 59. In
some embodiments,
an angle 0 between reference line 86 and reference line 84 is greater than
about 10 degrees. In
other embodiments, the angle 0 is greater than about 20 degrees. In still
other embodiments, the
angle 0 is greater than about 30 degrees.
100501 Thus, the features of the curved boom 45 help the shovel 10 to
increase its dipper dig
forces up to 15% compared to the shovel having a straight boom. Specifically,
the height of the
pivot point 58 in relation to the plane 28, the position of the pulley
connection point 81 relative
to the pivot point 59, and the length of the handle 50 help to increase the
dipper dig forces. This
increase in digging force and efficiency allows manufacturers to downsize the
hoist motor and
the drive train of the shovel, thereby lowering the cost of the shovel.
100511 Due to the curved shape of the boom 45, the electric shovel 10
significantly improves
the direct line of sight of the shovel operator who wants to view parked dump
trucks as he or she
swings the shovel to side opposite to the operator's area 33 (i.e., the
operator's blind side).
Compared to the conventional straight boom, the curved boom 45 is shifted
above and behind the
line of sight of the operator as he or she looks to target the truck bed with
a full dipper in order to
adjust the location of the dipper over the waiting truck bed. Further, the
curved boom 45 opens
up the area in front and below the boom for greater dipper accommodation in
the tuck back
areas.
100521 FIGS. 5-9 illustrate a shovel 410 according to another embodiment.
The shovel 410
includes components similar to the components of shovel 10 described above
with respect to
FIGS. 1-4, and similar features are indicated with similar reference numbers,
plus 400.
100531 As shown in FIG. 5, the shovel 410 includes a frame having a first
portion or lower
base 415 that is supported on drive tracks 420. The frame of the shovel 410
further includes a
second portion or an upper base 425 (also called a deck) positioned on a
rotational structure 430
that is mounted on the lower base 415. The rotational structure 430 allows
rotation of the upper
base 425 relative to the lower base 415. The rotational structure defines a
center line or axis of
rotation 427 of the shovel 410. The axis of rotation 427 is perpendicular to a
plane 428 (FIG. 6)
defined by the lower base 415 and generally corresponding to the grade of the
ground or support
surface. In one embodiment, the upper base 425 supports a machine house 429
including, among
11
CA 02828008 2013-09-20
other elements, an operating area 433 used by an operator or a driver to
operate the shovel 410.
As used herein, the terms "above," "upwardly," "vertically," and the like
assume the drive tracks
420 are positioned on level ground such that the axis of rotation 427 is
substantially vertical.
[0054] As shown in FIGS. 5 and 6, the shovel 410 includes a boom 445
extending upwardly
from the upper base 425. The boom 445 includes a first end 446 coupled to the
upper base 425
and a second end 447 distant from the upper base 425. Further, the boom 445
includes a top area
423 and a bottom area 424. The top area 423 of the boom 445 includes two
portions 423A and
423B, which are generally positioned on either side of an area where a pair of
saddle blocks 421
couple a boom attachment or handle 450 to the boom 445. The bottom area 424
defines a single
portion between the first end 446 arid the second end 447 of the boom 445. The
boom 445
illustrated in FIGS. 5-9 is a "flat bottom" boom. In other words, the bottom
area 424 of the
boom 445 between the first end 446 and the second end 447 has a flat surface.
In other
embodiments, the boom 445 can have a different form (e.g., a curved shape,
etc.).
[00551 Referring to FIGS. 5 and 6, the handle 450 is pivotally and slidably
coupled to the
boom 445. A shipper shaft 442 extends transversely through the boom 445 and
rotatably
supports a pair of saddle blocks 421. An end of the handle 450 is received in
the saddle blocks
421 such that the handle 450 can move translationally with respect to the
saddle blocks 421 and
can rotate about the shipper shaft 442, which defines a pivot axis 459 about
which the handle 450
pivots. The saddle blocks 421 connect the boom handle 450 to the boom 445 and
allows for
secure movement of the handle 450. The operation of the shipper shaft 442 and
saddle blocks
421 are described in more detail below.
[0056] The shovel 410 also includes a digging attachment coupled to another
end of the
boom handle 450 opposite the end that is received within the saddle blocks
421. In the
embodiment of FIGS. 5 and 6, the digging attachment is a clamshell bucket 455
that is pivotably
coupled to the end of the handle 450. The bucket 455 is pivoted by one or more
actuators, such
as hydraulic cylinders for example that are in fluid communication with a pump
via one or more
fluid conduits (not shown). The shovel 410 includes a mechanism 468 (FIG. 5)
for supporting
the fluid conduit throughout the motion of the handle 450. In the illustrated
embodiment, the
mechanism 468 is a hose reel that reels in and pays out fluid conduit based on
the extension of
12
CA 02828008 2013-09-20
the handle. The bucket 455 includes a digging edge 456 having teeth and is
used to excavate the
desired work area, collect material, and transfer the collected material to a
desired location (e.g.,
a material handling vehicle). In other embodiments (FIG. 5A), the digging
attachment is a
dipper 457 rigidly attached to the end of the handle 450 such that the dipper
457 does not move
relative to the handle 450 during a digging operation. The combination of the
boom 445, the
boom handle 450, and the bucket 455 define a digging assembly of the shovel
410.
100571 Referring again to FIGS. 5 and 6, a boom sheave 460 is rotatably
coupled to the
second end 447 of the boom 445 similar to the manner described above with
respect to FIGS. 1-
3. A hoist drum 463 is coupled to the upper base 425 and is powered by a motor
487 that
provides turning torque to the drum 463 through a geared hoist transmission
(not shown). The
hoist drum 463 reels in and pays out a hoist rope 462, which extends upwardly
along the boom
445, over the boom sheave 460, and downwardly to an attachment point on the
bucket 455.
Rotation of the hoist drum 463 reels in and pays out the hoist rope 462,
thereby raising and
lowering the bucket 455, respectively.
[00581 The boom handle 450 and the bucket 455 are supported by the hoist
rope 462
extending over the boom sheave 460. More specifically, a connecting mechanism
473 engages
the hoist rope 462 and connects the boom handle 450 and the bucket 455 with
the sheave 460. In
one embodiment, the connecting mechanism 473 comprises an equalizer coupled to
the bucket
455. In one embodiment, the equalizer senses the tension applied on each hoist
rope 462 and is
operable to equalize the tension in the hoist ropes 462. In other embodiments
(for example,
when hydraulic cylinders driving the bucket 455 are attached to the upper
portion of the bucket
455 as described in FIG. 4), an equalizer is positioned near the pivot point
of the lower arm and
the bucket, and the hoist rope 462 passes between the actuators to reach the
equalizer. In still
other embodiments, other types of connecting mechanisms 473, such as a bail,
can be used to
connect the sheave 460 with the handle 450 and the bucket 455.
100591 Referring now to FIG. 6, the first end 446 of the boom 445 is
coupled to the upper
base 425 via pin joints or other suitable attachment mechanisms and defines a
boom pivot axis
426. In some embodiments, the boom 445 comprises a first portion 431 that
extends generally
upwardly from the base 425, and a second portion 432 that extends at an angle
from the first
13
CA 02828008 2013-09-20
portion 431 toward the second end 447. Specifically, the angle between the
first portion 431 and
the second portion 432 of the boom is defined between the first portion 423A
and second portion
423B of the top area of the boom 445. Generally, the saddle block 421
supporting the handle
450 is positioned at an area where the first portion 423A and second portion
423B of the top area
423 intersect. A pivot axis 459 of the boom handle 450 is defined by the
position of the shipper
shaft 442. The area below the pivot axis 459 of the handle 450 (i.e., the area
below the shipper
shaft 442) has an extended diameter also referred to as an "extended belly."
As described in
more detail below, the extended diameter of the area below the pivot axis 459
allows for the
incorporation of a three-piece saddle block 421. In one embodiment, the boom
445 comprises a
one piece construction combining the first and the second portions of the
boom.
[0060] As shown in FIG. 6, the first portion 431 of the boom 445 is angled
with respect to
the second portion 432 of the boom. Since the bottom portion 24 of the boom is
flat, an angle
434 is defined between the first portion 423A and the second portion 423B of
the top area of the
boom 445. In the illustrated embodiment, the angle 434 is between
approximately 130 degrees
and approximately 140 degrees. More specifically, the angle 434 is
approximately 134 degrees.
In other words, the second portion 432 of the boom 445 is offset from the
first portion 431 by an
angle 435. In the illustrated embodiment, the angle 435 is between
approximately 40 degrees
and approximately 50 degrees. In particular, the offset angle 435 is
approximately 46 degrees.
[0061] The described flat bottom boom 445 provides improved support for the
handle 450
during swing load operations in the tuck back position of the shovel 410.
Additional support to
the handle 450 is provided by guide rails 441 (FIG. 6) that can extend further
outwardly from the
boom 445 parallel to the pivot axis 459 of the handle 450. Therefore, the flat
bottom geometry
of the boom 445 creates additional support and allows the proposed design to
eliminate weight
from the handle 450.
[0062] As shown in FIGS. 7-9, the shovel 410 also includes a support member
in the form of
a pair of struts 448 for supporting the boom 445 in an upright position
relative to the base 425.
In the illustrated embodiment, the struts 448 are positioned parallel to one
another and are not
connected to each other. In other embodiments, the struts 448 are coupled by
rigid-connect
members (not shown).
14
CA 02828008 2013-09-20
[0063] As shown in FIG. 7, each strut 448 includes a first end 452 coupled
to the upper base
425 at a location between the hoist drum 463 and the first end 446 of the boom
445. Each strut
448 also includes a second end 453 coupled to a depending portion of the boom
445. In the
illustrated embodiment, the struts 448 are positioned forward of the hoist
drum 463. In other
embodiments, the first end 452 of each strut 448 can extend behind the hoist
drum 463. The
second end 453 of each strut 448 is rigidly coupled to the general area where
the first portion 431
and the second portion 432 of the boom 445 connect or intersect.
[0064] As best shown in FIGS. 8 and 9, the struts 448 straddle the axis of
rotation 427, and
the couplings between the first ends 452 and the upper base 425 are positioned
on an opposite
side of the axis 427 from the boom 445. More specifically, the upper base 425
defines a first or
front end 436 proximate the first end 446 of the boom 445 and a second or rear
end 438 opposite
the front end 436. A frame axis 444 extends from the front end 436 to the rear
end 438. The
base 425 also includes a first or left side 451 extending generally parallel
to and offset from the
frame axis 444, and a second or right side 469 parallel to the left side 451
and positioned on an
opposite side of the frame axis 444. In general, the area of the base 425
between the axis of
rotation and the front end 436 is a front portion, while the area between the
axis of rotation 427
and the rear end 438 is a rear portion. Also, the area of the base 425 between
the axis of rotation
427 and the left side 451 is a left portion, and the area between the axis of
rotation 427 and the
right side 469 is a right portion. One of the first ends 452 of the struts 448
is positioned
proximate the left side 451 in the left portion, while the other first end 452
is positioned
proximate the right side 469 in the right portion. In addition, the first ends
452 are coupled to the
base 425 proximate the rear end 438 (i.e.,in the rear portion), while the
first end 446 of the boom
445 is coupled to the base 425 proximate the front end 436 (i.e., in the front
portion). Therefore,
the main support points for the boom 445 (i.e., the first ends 452 of the
struts 448 and the first
end 446 of the boom 445) are generally positioned around the axis of rotation
427, providing a
more even load distribution on the base 425 and the rotation mechanism 430.
This improves the
load flow of the bucket 455 through the boom 445 and struts 448, providing a
direct path through
the rotational structure 430 and reduces the bending stress in the frame 425.
[0065] The position of the struts 448 provides greater stability of the
boom 45 and also
allows easier access to the hoist drum 463 (FIG. 7) and the other machinery
elements of the
CA 02828008 2013-09-20
shovel 410 when maintenance is required. Specifically, positioning the struts
48 forward of the
hoist drum 463 allows the hoist drum 463 to be easily accessed from the top of
the shovel 410
(e.g., by a crane). The struts 448 eliminate the need for a gantry structure,
a major structural
member of conventional shovels that generally includes a compression member, a
tension
member, and suspensions ropes for supporting the boom 445. Further, the struts
448 eliminate
the need for a separate boom stabilizer in compression.
[0066] In some embodiments, the struts 448 are pivotally connected to the
upper base 425
and to the boom 445 via moving pin joints or other types of connectors. The
struts 448 can be
provided with shock absorbing connectors such as various types of spring
assemblies and/or
fluid dampers incorporated into the pinned attachment joints between the
struts 448, the upper
base 425, and the boom 445. These shock absorbing connectors reduce the
overall stiffness of
the strut assembly when compression and tension forces are acting on the strut
448, thereby
reducing shock loading and in turn reducing the overall stresses experienced
by the various
components and the major structures.
[0067] In the embodiment shown in FIGS. 10-13, the strut 448 is movably
connected to the
boom 445 by a sliding pin joint. As shown in FIGS. 11 and 12, the strut 448
includes a slot 465
that receives a pin 466 coupled to the boom 445. The sliding pin joint permits
the boom 445 to
pivot relative to the base 425 toward the axis of rotation 427 (counter-
clockwise in FIG. 13).
The slot 465 permits the boom 445 to pivot within a predetermined angular
range 488, and the
slot 465 provides an ultimate stop for the pivoting movement. In the
illustrated embodiment, the
slot 465 is sized so that the boom 445 can pivot through an angle 488 of five
degrees. In another
embodiment, shown in FIG. 14, the slot 465 is sized so that the boom 445 can
pivot through an
angle 488 of ten degrees.
[0068] Referring again to FIG. 11, the pivoting movement of the boom 445 is
dampened by
fluid dampers 467 coupled between the strut 448 and the boom 445. In the
illustrated
embodiment, the fluid dampers 467 are pressurized cylinders. Each cylinder
includes a relief
valve (not shown) that opens when the force on the cylinder exceeds a
predetermined level to
permit the boom 445 to pivot toward the axis of rotation 427 (i.e., counter-
clockwise in FIG. 13).
In addition, the cylinders are double-acting so that the cylinders dampen the
movement of the
16
CA 02828008 2013-09-20
boom 445 as it pivots back toward its normal position (i.e., clockwise in FIG.
13) after the
overload event. In one embodiment, the relief valves do not open until the
force exerted on the
boom 445 exceeds a maximum allowable dynamic impact load, and a signal or
alarm is
transmitted to a control system when the relief valves open.
100691 The three-piece saddle block 421 is shown in FIGS. 15 and 16. The
saddle block
421 includes a first side portion 495, a second side portion 496 parallel to
the first side portion
495, and a top portion 497 connecting the two side portions 495 and 496. Each
of the side
portions 495 and 496 includes an aperture 498, both of which are aligned with
one another. The
shipper shaft 442 or another mechanism extends through the apertures 498 to
pivotally support
the handle 450 that is connected to the boom 445. As illustrated in FIG. 16,
the shovel 410
includes two saddle blocks 421 coupled to the boom 445 for receiving an end of
the handle 450.
Pinion gears 489 are coupled to the shipper shaft 442 and positioned between
the side portions
495, 496 of each saddle block 421. The pinion gears 489 engage a rack (not
shown) on each
handle member 461 to extend and retract the handle 450.
[0070] As described above, the area below the pivot axis 459 of the boom
445 has an
extended diameter (i.e., "extended belly"). The extended diameter of the area
below the pivot
axis 459 allows for the incorporation of the saddle block 421. Specifically,
the saddle block 421
rotates without hitting the guide rail 441 (FIG. 16). This permits a more
compact and lighter
design of the shovel 410 and also allows for easier removal of the saddle
block 421 (as compared
to a two-piece saddle block).
[0071] Referring now to FIG. 17, the boom 445 includes a pivot element or
pivot axis 459
(e.g., defined by the shipper shaft 442 or a pin depending on the type of
handle 450) that
pivotally supports the handle 450. The pivot axis 459 of the flat bottom boom
445 is located
significantly closer to the axis of rotation 427 of the shovel 410 when
compared to the pivot axis
location for a conventional straight boom. For example, in some embodiments,
the pivot axis
459 is about nine feet closer to the axis of rotation 427 than it would be if
the boom 445 was a
conventional straight boom. Thus, the maximum reach of the bucket 455 is
closer to the base
425 and to the center line of rotation 427 when compared to the reach of a
conventional dipper.
Therefore, a center of gravity 483 of the boom 445 is also closer to the axis
of rotation 427 than
17
CA 02828008 2013-09-20
the center of gravity of a conventional boom. Consequently, less counterweight
is required to
support the digging attachment and the overall machine weight and swing
inertia is reduced.
[0072] In some embodiments, the pivot axis 459 of the handle 450 is
positioned
approximately where the first portion 423A and the second portion 423B of the
top area of the
boom 445 connect or intersect. In some embodiments, the pivot axis 459 is
positioned
substantially directly above a point of connection 426 between the first
portion 431 of the boom
445 and the upper base 425. For example, depending on the particular
construction of the boom
445, the pivot axis 459 can be positioned up to approximately 10 degrees in
either direction from
a vertical line drawn directly upwardly from the boom pivot axis 426. In other
embodiments, the
pivot axis 459 can be positioned up to approximately 5 degrees in either
direction from a vertical
line drawn upwardly from the boom pivot axis 426.
[0073] The geometry of the boom 445 and the configuration of the saddle
block 421 causes
the pivot axis 459 of the handle 450 to be positioned substantially towards
the upper base 425
and toward the axis of rotation 427 of the shovel 410. The relationship of
different points along
the boom 445 relative to the axis of rotation 427 and relative to one another
are illustrated in and
discussed with respect to FIG. 17. The relevant points or locations along the
boom 445 include
the pivot axis 459, the center of gravity 483 of the boom 445, a geometric
center 482 of the
second boom portion 432, and a boom sheave connection point 481 where the boom
sheave 460
is rotatably coupled to the second boom portion 432. A boom sheave reference
distance 479 is
defined as a perpendicular distance from the axis of rotation 427 to the boom
sheave connection
point 481. A pivot axis distance 480 is defined as a perpendicular distance
from the axis of
rotation 427 to the pivot axis 459. A CG distance 490 is defined as a
perpendicular distance
from the axis of rotation 427 to the center of gravity 483 of the boom 445. A
second portion
center distance 491 is defined as a perpendicular distance from the axis of
rotation 427 to the
geometric center 482 of the second boom portion 432.
[0074] In the illustrated embodiment, the pivot axis distance 480 is
between approximately
18 percent and approximately 40 percent of the boom sheave reference distance
479. For
example, the pivot axis distance 480 is approximately 19.7 percent of the boom
sheave reference
distance 479. In other embodiments the pivot axis distance 480 is between
approximately 25
18
CA 02828008 2013-09-20
percent and approximately 35 percent of the boom sheave reference distance
479. In still other
embodiments the pivot axis distance 480 is approximately thirty percent of the
boom sheave
reference distance 479.
[0075] In the illustrated embodiment, the CG distance 490 is between
approximately 35
percent and approximately 55 percent of the boom sheave reference distance
479. For example,
the CG distance 490 is approximately 43.7 percent of the boom sheave reference
distance 479.
In other embodiments the CG distance 490 is between approximately 40 percent
and
approximately 50 percent of the boom sheave reference distance 479. In still
other embodiments
the CG distance 490 is approximately 45 percent of the boom sheave reference
distance 479.
[0076] In the illustrated embodiment, the second portion center distance
491 is between
approximately 55 percent and approximately 75 percent of the boom sheave
reference distance
479. For example, the second portion center distance 491 is approximately 62
percent of the
boom sheave reference distance 479. In other embodiments the second portion
center distance
491 is between approximately 60 percent and approximately 70 percent of the
boom sheave
reference distance 479. In still other embodiments the second portion center
distance 491 is
approximately 65 percent of the boom sheave reference distance 479.
[0077] With continued reference to FIG. 17, a boom longitudinal axis or
reference line 484
extends between the boom pivot axis 426 (i.e., the point of connection between
the first portion
431 of the boom 445 and the upper base 425) and the boom sheave connection
point 481. A
reference distance 485 is defined as the perpendicular offset of the pivot
axis 459 with respect to
the reference line 484 (i.e., a distance measured from the pivot axis 459 to
the reference line 484
in a direction perpendicular to the reference line 484). In some embodiments,
the length of
reference line 485 is between approximately 1/4 and approximately 1/8 of the
length of reference
line 484. In other embodiments the length of reference line 485 is between
approximately 1/5
and approximately 1/7 of the length of reference line 484. In still other
embodiments the length
of reference line 485 is approximately 1/6 of the length of reference line
484. For example, in
the illustrated embodiment the length of reference line 485 is approximately
0.1587 of the length
of reference line 484.
19
[0078] Reference line 486 extends from boom pivot axis 426 to the pivot
axis 459. In some
embodiments, an angle 0 between reference line 486 and reference line 484 is
greater than
approximately 10 degrees. In other embodiments, the angle 0 is greater than
approximately 20
degrees. In still other embodiments, the angle 0 is greater than approximately
30 degrees. For
example, in the illustrated embodiment the angle 0 between reference line 486
and reference line
484 is approximately 34.5 degrees.
[0079] Thus, the features of the flat bottom boom 445 increase dig forces
by as much as to
15% compared to the shovel having a straight boom. Specifically, the height of
the pivot axis
459 in relation to the plane 428, the position of the boom sheave connection
point 481 relative to
the pivot axis 459, and the length of the handle 450 help to increase the
dipper dig forces. This
increase in digging force and efficiency allows manufacturers to downsize the
hoist motor and
the drive train of the shovel 410, thereby lowering the cost of the shovel
410. Alternatively, the
size and payload of the bucket 455 can be increased while maintaining the
cutting force at the
teeth 456.
[0080] Due to the shape of the boom 445 and the pivot axis 459 moved closer
to the axis of
rotation 427, the shovel 410 significantly improves the direct line of sight
of the shovel operator
who wants to view parked dump trucks as he or she swings the shovel to side
opposite to the
operator's area 433 (FIG. 5) that is, the operator's blind side. Compared
to the conventional
boom, the boom 445 is shifted above and behind the line of sight of the
operator, allowing the
operator to more easily position a full bucket 455 over a waiting truck or
haulage vehicle.
Further, the positioning of the boom 445 opens up the area in front and below
the boom 445 for
greater bucket 455 accommodation in tuck-back areas.
[0081] Thus, the invention provides, among other things, a mining shovel.
Although the
invention has been described in detail with reference to certain preferred
embodiments,
variations and modifications exist within the scope of one or more independent
aspects of the
invention as described.
CA 2828008 2018-10-02
