A. Field of the Invention
The present invention relates to digging implements, and in particular a backhoe.
B. Background of the Art
Backhoes are used extensively for excavating and for carrying objects from one area to another. Backhoes have typically been used to dig holes in the ground for trenches and for the placement of building structural components, road substructures, cables, pipes, etc.
Heretofore, backhoes have included a first arm pivotally attached to a tractor and a second arm pivotally attached to the first arm in a scissors-like manner. A bucket is attached to the second arm for digging. Separate hydraulic actuators have typically been used to move each of the arms and the bucket. Some of these backhoes have included an extendable second arm. Furthermore, some backhoes have included a gripping device positioned opposite the bucket for gripping objects between the gripping device and the bucket. One of the gripping devices has included a gripping device statically attached to an arm of the backhoe that does not rotate relative to the arm. These gripping devices have been difficult to use because the arm and the bucket have to properly position relative to the gripping device before the gripping device can be used to pick up objects. Another gripping device includes a separate hydraulic actuator for moving only the gripping device. These backhoe are expensive to manufacture because of the cost for the extra hydraulic actuator and the cost for connecting the gripping device to the controls in the tractor. A third gripping device includes thumbs that rotate simultaneously with the bucket. These backhoes are also difficult to use because the bucket and the gripping device must be properly positioned before the gripping implement can be used. Furthermore, these backhoes are difficult to operate because the rotating gripping implement can get in the way of the rotating bucket, thus making the ground difficult to dig.
In a digging implement of the present invention, a thumb assembly is configured for connection to an extendable linkage having a bucket for holding materials in the bucket. The thumb assembly is also configured to rotate as the linkage extends, wherein both the bucket and the thumb assembly are independently operable.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification and claims.
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in
The reference number 10 (
In the illustrated example, the digging implement 10 is pivotally connected at a first pivot point 11 to a boom 18 in a scissors-like manner. The boom 18 is configured for pivotal attachment to the rear end of a mobile powered tractor (not shown) for moving the digging implement 10 to various locations. A combination of the tractor, the digging implement 10 and the boom 18 are commonly referred to as a “backhoe.” The bucket 14 connected to the digging implement 10 can be extended away from the tractor by rotating the boom 18 downward relative to the tractor and rotating the digging implement 10 upward relative to the boom 18. The digging implement 10 includes the extendable linkage 12, which comprising a first telescoping body 20 and a second telescoping body 22 in which the second telescoping body 22 can be slid relative to the first telescoping body 20 to vary the effective length of the linkage 12 and thus the reach of the bucket 14. The illustrated first telescoping body 20 and the second telescoping body 22 are a pair of concentric telescoping tubes. Although the first telescoping body 20 and the second telescoping body 22 are shown as being hollow and substantially rectangular, it is contemplated that the first telescoping body 20 and the second telescoping body 22 could have any geometric cross-section and the second telescoping body 22 could be solid throughout its cross-section. A telescoping hydraulic actuator (not shown) within the second telescoping body 22 telescopes the second telescoping body 22 outward from the first pivot point 11 within the first telescoping body 20 in order to extend the linkage 12.
The illustrated extendable linkage 12 includes the bucket 14 and a telescoping hydraulic actuator 26 for rotating the bucket 14. The illustrated bucket 14 is pivotally attached to an end 28 of the second telescoping body 22 at a second pivot point 30. An open mouth 28 of the bucket 14 faces the tractor such that the boom 18 and the extendable linkage 12 can move the bucket 14 towards the tractor in order to scoop up dirt or other objects adjacent the tractor. The telescoping hydraulic actuator 26 is connected to a pivot sleeve 31 attached to a top surface 32 of the first telescoping body 20 near the first pivot point 11. The telescoping hydraulic actuator 26 is also pivotally connected to a first arm 33 and a second arm 35. The first arm 33 is further pivotally connected the second telescoping body 22 between the second pivot point 30 and the first telescoping body 20. Likewise, the second arm 35 is further pivotally connected to the bucket 14 at a point offset the second pivot point 30. The telescoping hydraulic actuator 26, the first arm 33 and the second arm 35 are configured to rotate the bucket 14 about the second pivot point 30 greater than 90° around the end 28 of the second telescoping body 22. The telescoping hydraulic actuator 26 can be operated such that the telescoping hydraulic actuator 26 will extend with the second telescoping body 22 while the second telescoping body 22 telescopes within the first telescoping body 20. Therefore, during this operation, the bucket 14 will not rotate relative to the second telescoping body 22 as the linkage 12 extends. Likewise, the telescoping hydraulic actuator 26 can be operated such that the telescoping hydraulic actuator 26 will extend while the second telescoping body 22 remains stationary relative to the first telescoping body 20. Therefore, during this operation, the bucket 14 will rotate towards the tractor and the boom 18. Furthermore, the telescoping hydraulic actuator 26 can be extended at a rate faster or slower than the rate that the second telescoping body 22 telescopes within the first telescoping body 20 such that the linkage 12 will extend and the bucket 14 will rotate relative to the second telescoping body 22.
The illustrated thumb assembly 16 (
The illustrated arm 36 is an elongated shaft with a through hole 58 a first end and a pair of sleeves 60 at a second end. The sleeves 60 each include an opening 62 having a common axis that is parallel to the through hole 58 at the first end of the arm 36. A pin 64 (
In operation, the thumb 34 is pivoted relative to the second telescoping body 22 about the second pivot point 30 by extending the linkage 12. As seen in
The illustrated bucket 14 and thumb assembly 16 of the digging implement 10 can be used to grasp objects between the bucket 14 and the thumb 34 of the thumb assembly 16 by first creating an opening 100 (as seen in
An advantage of the illustrated thumb assembly 16 is that the thumb assembly 16 can be retrofitted to operate on a backhoe already having the extendable linkage 12 and the bucket 14. First, the shoulder 66 can be welded or otherwise attached to the first telescoping body 20. Second, a pin connecting the bucket 14 to the second telescoping body 22 could be removed and a new pin 50 could be inserted through the thumb 34, the bucket 14 and the second telescoping body 22 to replace the old pin. Third, the arm 36 can be connected to the thumb 34 and the shoulder 66 by inserting the pin 64 though the opening 65 in the shoulder 66 and the through hole 58 of the arm 36 to pivotally connect the arm 36 to the first telescoping body 20. Finally, the pin 66 is inserted through the sleeves 60 of the arm 36 and the opening 68 in the pair of sleeves 56 on the second cross beam 42 of the thumb 34 to pivotally connect the arm 36 to the thumb 34. It is noted that the order of the steps for connecting the thumb assembly 16 to the linkage 12 can be rearranged.
Another advantage of the thumb assembly 16 is that the thumb 34 and the arm 36 can be easily attached and removed from the extendible linkage 12. As seen in
The above description is that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. For example, it is contemplated that the extendible linkage 12 could include a pair of bodies that extend in a manner other than telescoping (e.g., the bodies of the extendible linkage could slide relative to one another wherein one of the bodies is not located within the other body). Therefore, it is understood that the embodiment described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/US00/20687 | 7/31/2000 | WO | 00 | 9/16/2003 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO02/10522 | 2/7/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2044624 | Morgan | Jun 1936 | A |
3275172 | Smith | Sep 1966 | A |
3353285 | Murray | Nov 1967 | A |
3422975 | Oris | Jan 1969 | A |
3477602 | Peterson | Nov 1969 | A |
3807589 | Shovick | Apr 1974 | A |
4285628 | Jankowski | Aug 1981 | A |
4375345 | Hanson | Mar 1983 | A |
4407626 | Bruckner | Oct 1983 | A |
4466494 | Hanson | Aug 1984 | A |
4761113 | Smith et al. | Aug 1988 | A |
4803788 | Sorenson | Feb 1989 | A |
4932832 | McCasland et al. | Jun 1990 | A |
4996830 | Davison | Mar 1991 | A |
5088213 | Raimondo et al. | Feb 1992 | A |
5092733 | Kishi | Mar 1992 | A |
5111602 | Risch | May 1992 | A |
5267824 | Kishi | Dec 1993 | A |
5375348 | Kishi | Dec 1994 | A |
5494395 | Raunisto | Feb 1996 | A |
5553408 | Townsend | Sep 1996 | A |
5638616 | Kishi | Jun 1997 | A |
5649377 | Tanada | Jul 1997 | A |
5678332 | Hawkins | Oct 1997 | A |
5851101 | Kim | Dec 1998 | A |
5927933 | Tucker | Jul 1999 | A |
6120237 | Cummings et al. | Sep 2000 | A |
6203267 | Heiple et al. | Mar 2001 | B1 |
6260294 | Pitcher | Jul 2001 | B1 |
6640471 | Desrochers | Nov 2003 | B1 |
6655053 | Cummungs | Dec 2003 | B1 |
Number | Date | Country |
---|---|---|
2364936 | Jun 2005 | CA |