Patent Application
20190292746
The present disclosure relates to excavator buckets and, more particularly, to an excavator bucket for minimizing bucket overlap and maintaining accuracy on sloped surfaces.
Excavators are typically used in construction and reclamation or cleanup projects for the grading of land and dredging operations. Known excavators will have a clamshell bucket mounted to the end of a stretchable arm. The stretchable arm is normally defined by a two-member linkage. One of the linkages, called a boom, is pivotally mounted to a machine base of the excavator, and extends outwardly in an upward direction. The other linkage, called a stick arm, is pivotally mounted at one end to the outer end of the boom and extends downwardly from a boom pivot. Normally, the clamshell bucket is pivotally mounted to the outer end of the stick arm.
In operation, hydraulic cylinders of the excavator are typically used to move the boom, the stick, and the bucket independently under the control of an operator or a machine control system. The clamshell bucket itself is openable and closable by means of fluid pressure applied by a hydraulic cylinder. Another hydraulic cylinder may be used to rotate the machine base relative to a set of tracks. This permits a repositioning of the clamshell bucket for operations like cutting of the land and dumping to a desired location.
Most excavating projects involve creating surfaces that are substantially planar, either horizontal or sloped. Operating an excavator efficiently requires a skilled operator, especially when the excavator is being used to excavate sloped surfaces. Operator skill is especially critical because the couplings between the machine base, boom, stick arm, and bucket are pivots, and therefore extending or retracting any single hydraulic cylinder or actuator causes the digging edge of the bucket to move in an arc. The clamshell bucket will also usually have a rectangular-shaped footprint. For these reasons, excavating operations for the formation of sloped surfaces usually require approaching the surface to be excavated from suitable locations relative to the sloped surface, and precise use of the clamshell bucket.
However, even with the most skilled operators, use of conventional clamshell buckets has been found to result in an undesirable degree of bucket overlap when cutting a sloped surface. This is wasteful and not environmentally sensitive. Maintaining the optimal orientation of the bucket to the sloped surface with conventional clamshell buckets has also proven difficult, especially with the rectangular-shaped footprint associated with conventional clamshell buckets.
There is also a particular need for a clamshell bucket to meet the stringent requirements associated with environmental dredging. Such environmental dredging work includes the removal of polychlorinated biphenyl (PCB) contaminated sediment, transportation of sediment, and disposal of the sediment into an existing Confined Aquatic Disposal (CAD) cell. The bucket required position accuracy for such projects is +/− four (4) inches vertically and +/− six (6) inches horizontally. The work is required to be conducted in a two-pass approach. The first pass removes the material up to one (1) foot above the required design. The second pass removes the final one (1) foot of material to the required design. The dredging is also required to be conducted from the top-down (shallow to deep) in order to minimize residuals.
There is a continuing need for an excavator bucket that facilitates the cutting of a sloped surface, and minimizes bucket overlap when cutting the sloped surface. Desirably, the excavator bucket also permits the maintenance of a predetermined orientation of the bucket to the sloped surface and allows for compliance with stringent environmental dredging requirements.
In concordance with the instant disclosure, an excavator bucket that facilitates the cutting of a sloped surface, minimizes bucket overlap when cutting the sloped surface, which permits the maintenance of a predetermined orientation of the bucket to the sloped surface, and which allows for compliance with stringent environmental dredging requirements, is surprisingly discovered.
In one embodiment, a slope-level-cut bucket has a first bucket half pivotably connected to a second bucket half. The first bucket half and the second bucket half are movable about a first axis between a closed position and an opened position. Each of the first bucket half and the second bucket half have a top wall, a front wall, a rear wall, a side wall and a cutting wall. The cutting wall has a plurality of steps. The first bucket half and the second bucket half have a rim defined by the top wall, the front wall, the rear wall, and the cutting wall. The rim of each cutting wall defines an excavating edge of the respective bucket half.
In another embodiment, the rear wall of each of the first bucket half and the second bucket half is on a first plane, and the excavating edge of the first bucket half is on a second plane. The first plane is oriented transverse to the second plane, defining a first angle therebetween. The first angle is between about 72 degrees and about 79 degrees. A planar surface of the side wall of each of the first bucket half and the second bucket half is on a third plane and the top wall of each of the first bucket half and the second bucket half is on fourth plane. The third plane is oriented transverse to the fourth plane, defining a second angle therebetween. The second angle between about 25 degrees and about 45 degrees.
In a further embodiment, the first bucket half and the second bucket half each have a distal end and a proximal end. The side wall and the cutting wall of the first bucket half and the second bucket half each taper toward the distal end of their respective bucket half.
The above, as well as other advantages of the present disclosure, will become readily apparent to those skilled in the art from the following detailed description, particularly when considered in the light of the drawings described hereafter.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. In respect of the methods disclosed, the order of the steps presented is exemplary in nature, and thus, is not necessary or critical unless otherwise disclosed.
In
As shown in
As a non-limiting example, the actuator 5 may be a hydraulic actuator in communication with a controller (not shown) used by an operator of the bucket 2. However, other suitable types of actuators 5 including electric and pneumatic actuators are also contemplated and considered within the scope of the present disclosure.
In certain embodiments, as shown in
With continued reference to
In certain embodiments, the cutting wall 20 and the side wall 18 of each bucket half 4, 6 may taper toward the distal end 24. Also, the side wall 18 of the bucket half 4, 6 may have both a curvilinear surface 25 and a planar surface 27. The curvilinear surface 25 is disposed adjacent the proximal end 22 of the bucket half 4, 6 and the planar surface 27 is disposed adjacent the distal end 24. In certain embodiments, each bucket half 4, 6 may also have rounded corners 28 defined by a portion of the curvilinear surface 25 adjacent to and disposed between the top wall 12 and the side wall 18.
With reference to
With further attention to
In certain embodiments, also shown in
With renewed reference to
Referring now to
In certain embodiments, a contour of the cutting wall 20 may be selected so as to be optimized for creation of differently angled slope cuts in the excavating surface 43. For example, as shown in
With reference to
For example, the excavating edge 40 of each bucket half 4, 6 may be adapted to create a 5H:1V slope (not shown, where the angle α is about 79 degrees), a 4H:1V slope (not shown, where the angle α is about 76 degrees); or a 3H:1V slope (shown in
In particular embodiments, the cutting wall 20 of the bucket half 4, 6 has a plurality of steps 44, which in turn define the contour of the excavating edge 40 of the bucket half 4, 6. As shown in
Furthermore, it should be understood that the use of discrete steps 44 also provides better cutting performance than a continuous, uninterrupted curved edge, as the stepped 44 excavating edge 40 has been found to better hold in material having been cut from the excavating surface 43, where the bucket is in the closed position. The length (L), the width (W), and the depth (D) of each of the steps 44 may be selected by the skilled artisan to correspond with the desired end use of the slope-level-cut bucket 2, within the scope of the present disclosure. For example, the slope-level-cut bucket 2 may have seven (7) steps formed in the cutting wall 20 that are configured to be of the length (L), the width (W), and/or the depth (D) to create a 3H:1V slope cut in the excavating surface 43, for example, as shown in
With renewed reference to
In certain embodiments, as shown in
In particular embodiments, with further reference to
In operation, the slope-level-cut bucket 2 may be attached to a movable arm of an excavator (not shown) and may be both pivoted and rotated by an actuator 5 with at least one hydraulic piston to be presented in an orientation substantially perpendicular to the sloped excavating surface 43 to be cut. This selective orientation of the sloped-level-cut bucket 2, together with the excavating edge 40 of the cutting wall 20, has been found to minimize bucket overlap due to an optimized interaction of each bucket half 4, 6 with the sloped excavating surface 43, as shown
In certain excavating processes, for example, where dredging, the operator may open and close the slope-level-cut bucket 2 on a waterline to conduct a visual check of how level each stair-step 44 cuts. This ensures that the slope cutting operation will be optimized for the slope being cut in a body of water.
It should be appreciated that first bucket half 4, the second bucket half 6, and the support structure 26 may be manufactured using any method or material chosen by a skilled artisan. As a non-limiting example, the slope-level-cut bucket 2 may be manufactured using metal (such as steel, titanium, aluminum), plastic, carbon-fiber, or wood. In a specific embodiment, the slope-level-cut-bucket 2 may be formed using corresponding casting molds to create an integrally molded first bucket half 4 and second bucket half 6. In another embodiment, the first bucket half 4 and the second bucket half 6 may be created by joining a plurality of pieces or parts together, for example, by welding or other suitable manufacturing processes.
In one example, an excavator was outfitted with a five (5) cubic yard slope-level-cut bucket 2 according to the present disclosure. The excavator was a CAT 385, having a thirty-two-foot and ten-inch (32′-10″) boom, and an eighteen-foot and one-inch (18′-1″) stick. The slopes cut with the slope-level-cut bucket 2 ranged from average of 5H:1V to as steep as 3H:1V. The excavator then used the slope-level-cut bucket 2 to dredge material from within the body of water.
The slope-level-cut bucket 2 had the contoured footprint 42 (e.g., trapezoidal or pyramidal) as shown in
The slope-level-cut bucket 2 was employed in digging operations relative to a conventional flat-level-cut bucket as a control. Production comparisons relative to the conventional flat-level-cut bucket are shown below in TABLES 1 and 2.
Advantageously, the slope-level-cut bucket 2 of the present disclosure has been found to dig slopes with a greater accuracy and efficiency than conventional flat-level-cut buckets having a rectangular footprint. The slope-level-cut bucket 2 has achieved required design depths and leaves an accurately sloped excavating surface 43.
With reference to
It has also been found that there is reduced water collection with the slope-level-cut bucket 2 of the present disclosure. In particular, the number of buckets to complete a single boom set over a fifty-foot (50′) wide cut-lane was shown to decrease from twenty-six (26) buckets to nine (9) buckets (i.e., a sixty-five percent (65%) increase in efficiency). The stair-stepped 44 design of the present disclosure increased bucket fill, resulting in more material and less water. The increased bucket fill significantly reduced the amount of water generation needing to be processed at a dewatering plant, once the excavated material was hauled away for processing.
The slope-level-cut bucket 2 of the present disclosure has also been shown to reduce suspension by minimizing buckets taken. In other words, the reduction in required buckets also reduced resuspension by limiting the number of times the bucket came into contact with the bottom excavating surface 43. It should be appreciated that by reducing suspension, the slope-level-cut bucket 2 is able to more efficiently remove materials than other bucket designs. The more efficient removal of materials results in fewer particles unwantedly dispersed into the body of water. Accordingly, the slope-level-cut bucket 2 of the present disclosure is able to reduce the amount of PCB contaminated sediment that is unwantedly dispensed in the water during the dredging process
Finally, it has been discovered that there is no sacrifice to production with the slope-level-cut bucket 2 of the disclosure. Production between the slope-level-cut bucket 2 and the flat-level-cut bucket was observed to be almost identical. Both buckets removed approximately sixty (60) net cubic yards per operating hour. Thus, use of the slope-level-cut bucket 2 is deemed to result in no sacrifice to net production in operation.
Advantageously, the slope-level-cut bucket 2 facilitates the cutting of a sloped surface, minimizes bucket overlap where cutting the sloped surface, and allows for compliance with stringent environmental dredging requirements.
While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the disclosure, which is further described in the following appended claims.
This application claims the benefit of U.S. Provisional Application 62/647,176, filed on Mar. 23, 2018. The entire disclosure of the above application is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62647176 | Mar 2018 | US |
