US20040261301A1

US20040261301A1 - High rotation linkage assembly

Info

Publication number: US20040261301A1
Application number: US10/610,289
Authority: US
Inventors: Andrew Vering; John Tate
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2003-06-30
Filing date: 2003-06-30
Publication date: 2004-12-30
Also published as: CN1576469A

Abstract

The addition of a thumb to a bucket of a work machine allows more uses for the work machine than having only the bucket. These uses, however, are often limited to the capabilities of the linkage of the thumb and its ability to rotate the thumb with the bucket. An attachment arrangement for a load-bearing member of a work machine for attaching the implement to the load-bearing member, comprises an implement, an actuator, and a high rotation linkage assembly rotatably attaching the implement to the load-bearing member and to the actuator, the high rotation linkage assembly structured and arranged to allow the implement to have a range of rotation of at least 190 degrees.

Description

TECHNICAL FIELD

This invention relates generally to a high rotation linkage assembly, and, more particularly, to a high rotation linkage assembly rotatably attached to a thumb that allows full rotation of the thumb.

BACKGROUND

Work machines such as backhoe loaders, excavators, or other similar work machines use counteracting thumbs and buckets to grasp, hold, and lift odd-shaped articles such as pipes, structural components, and the like, similar to the thumb of a human hand. When used to perform this grasping, holding, or lifting function, a counteracting thumb is normally rotatably attached to a stick, lift arm assembly, or a bucket of the work machine to accomplish the grasping, holding, and lifting function. The high rotation linkage assembly used to rotate the thumb dictates the thumb's ability to retract fully to allow normal operation of the bucket and the thumb's ability to fully rotate so as to follow the bucket path throughout the range of rotation of the bucket.

One known linkage design is disclosed in U.S. Pat. No. 4,283,866 issued to Ogawa on Aug. 18, 1981. It discloses a convertible bucket attachment having a pair of brackets, each to which the joining portions of the bucket proper, the sub-bucket, and the lower pivot of the sub-link member are rotatably attached. The high rotation linkage assembly of this design will not allow the sub-bucket to follow the full rotation of the bucket proper from the dump cycle to the curl cycle while applying clamping force on the bucket proper throughout this rotation. More specifically, the high rotation linkage assembly of this design will not allow the sub-bucket to rotate more than 190 degrees.

The present invention is directed to overcoming one or more of the problems as set forth above.

SUMMARY OF THE INVENTION

In one aspect of the present invention, an attachment arrangement for a load-bearing member of a work machine comprises an implement rotatably attached to the load-bearing member, an actuator attached to the load-bearing member, and a high rotation linkage assembly rotatably attaching the implement to the load-bearing member and to the actuator, the high rotation linkage assembly structured and arranged to allow the implement to have a range of rotation of at least 190 degrees.

In another aspect of the present invention, an attachment arrangement for a load-bearing member of a work machine comprises a first implement rotatably attached to the load-bearing member, a second implement rotatably attached to the load-bearing member, an actuator attached to the load-bearing member, and a high rotation linkage assembly rotatably attaching one of the first implement and the second implement to the load-bearing member, the high rotation linkage assembly structured and arranged to allow the first implement and the second implement to have substantially the same range of rotation.

In the present invention, an attachment arrangement for a load-bearing member of a work machine comprises an implement rotatably attached to the load-bearing member, an actuator attached to the load-bearing member, and a high rotation linkage assembly rotatably attaching the implement to the load-bearing member and to the actuator, the high rotation linkage assembly structured and arranged to allow the implement to have a range of rotation of at least 190 degrees. Rotation of greater than 190 degrees of the implement produces a more useful implement that can function in positions it may not otherwise had been able to function.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, reference may be made to the accompanying drawings in which: [0008]
FIG. 1 is a diagrammatic side view of a high rotation linkage assembly for a thumb rotatably attached with a bucket of a work machine, the bucket being in the open position and the thumb being disengaged from the bucket; [0009]
FIG. 2 is a diagrammatic side view, in perspective, of a first link; and [0010]
FIG. 3 is a diagrammatic side view, in perspective, of a second link.[0011]

DETAILED DESCRIPTION

Referring to the drawings, FIG. 1 shows a load-bearing [0012] member 100, for example a boom, stick, lift arm or the like, of a work machine (not shown) having an end portion 105 and having a lower surface 115. A pair of implements comprising, for exemplary purposes herein, a first implement being a bucket 120 and a second implement being a thumb 125, is rotatably attached in proximity to the end portion 105 of the load-bearing member 100 by means of a pin 130. In addition, at least one of the implements 120 or 125 is shown attached to the load-bearing member 100 by an attachment arrangement 134 of the present invention. The attachment arrangement 134 includes a high rotation linkage assembly 135 that is rotatably attached to the thumb 125 by means of a pin 140 at a first rotatable attachment point 142, and is rotatably attached to the load-bearing member 100 by means of a pin 145 at a second rotatable attachment point 150. The attachment arrangement 134 further includes an actuator, such as a hydraulic cylinder 155, attached to the lower surface 115 of the load-bearing member 100, having a rod end 160 that is rotatably attached to the high rotation linkage assembly 135 by means of a pin 165 at a third rotatable attachment point 167. The hydraulic cylinder 155 is adapted to be extended and retracted to rotate and thereby curl and uncurl the thumb 125.
The high [0013] rotation linkage assembly 135 includes a pair of first links (one shown), each designated herein as 170, and a second link 175. Each first link 170 has a first-end portion 180, a second-end portion 185, and an extension portion 190 extending from the first-end portion 180. The first-end portion 180 is rotatably attached to the rod end 160 of the hydraulic cylinder 155 at the third rotatable attachment point 167, and the second-end portion 185 is rotatably attached to the load-bearing member 100 at the second rotatable attachment point 150. The second link 175 has a first-end portion 192 and a second-end portion 195. The first-end portion 192 is rotatably attached to the extension portion 190 of the first link 170 by a pin 196 at a fourth rotatable attachment point 198, and the second-end portion 195 is rotatably attached to the thumb 125 at the first rotatable attachment point 164. As shown in FIG. 1, the second rotatable attachment point 150, the third rotatable attachment point 167, and the fourth rotatable attachment point 198 define non-co-linear rotatable attachment points irrespective of the location of the high rotation linkage assembly 135 in its rotation.
With reference to FIG. 2, further details of the [0014] first link 170 will now be described. It should be understood that each first link 170 is substantially identical, and, as such, only one will be described. The first link 170 includes a long member 210 having a long member long axis 211, an aperture 225 provided in the first-end portion 180, and another aperture 230 provided in the second-end portion 185. The extension portion 190 has an extension portion long axis 233, a first-end portion 240, and a second-end portion 245. Each such respective end portion 240 and 245 has an aperture 250 and 255 provided therein, respectively.
The first-[0015] end portion 180 of the long member 210 is attached to the first-end portion 240 of the extension portion 190 by a hollow connection member, such as a tubular member 260, sized to receive the pin 165. The tubular member 260 is rigidly attached, by welding or other suitable process, to both the long member 210 and the extension portion 190 such that the tubular member 260 is in concentric alignment with apertures 225 and 250. As shown, the long member 210 and extension portion 190 of the first link 170 are attached such that the long member long axis 211 is oriented in a non-parallel relationship with the extension portion long axis 233. Such a showing, however, is for exemplary purposes only and it is contemplated that other geometries may be used without deviating from the spirit of the present invention.
In FIG. 3, the [0016] second link 175 includes a pair of elements 300 and 305 of substantially equal length and a pair of hollow connection members, such as tubular members 310 and 315, of substantially equal length. Each element 300 and 305 has first- end portions 320 and 325, respectively, and second- end portions 330 and 335, respectively. Each end portion 320, 325, 330, and 335 having respective apertures 340, 345, 350, and 355 provided therein. The tubular member 310 is inserted through the apertures 340 and 345 to attach the elements 300 and 305 together at the first- end portions 320 and 325 thereof to form the first-end portion 192 of the second link 175. Once the tubular member 310 is inserted into the apertures 340 and 345, the tubular member 310 is rigidly attached, by welding or other suitable process, to the elements 300 and 305 at the apertures 340 and 345, respectively, such that the tubular member 310 is in concentric alignment with apertures 340 and 345. Further, the tubular member 315 is inserted through apertures 350 and 355 to attach the elements 300 and 305 together at the second- end portions 330 and 335 thereof to form the second-end portion 195 of the second link 175. Once the tubular member 315 is inserted into apertures 350 and 355, the tubular member 315 is rigidly attached, by welding or other suitable process, to elements 300 and 305 at the apertures 350 and 355, respectively such that the tubular member 315 is in concentric alignment with apertures 350 and 355.
Finally, the [0017] second link 175 has a geometry that is substantially non-linear. As shown in FIG. 3, the second link 175 has a generally convex shape that bends away from the load-bearing member 100 when the second link 175 is attached to the load-bearing member 100 in the intended manner. Such a showing, however, is for exemplary purposes only and it is contemplated that other geometries, such as a straight line, may be used without deviating from the spirit of the present invention. The appropriate geometry depends upon the location of the second rotatable attachment point 150, the length of the load-bearing member 100, the length of the hydraulic cylinder 155, the type of thumb 125 that is used, the particular work machine on which the thumb 125 is attached, or other factors. As used herein, convex is to be understood to not be limited to a curved shape, but is intended to encompass curved, angular, or other like shapes.

INDUSTRIAL APPLICABILITY

Thumbs are often attached to buckets to create a gripper, grapple, or the like to grasp, hold, and lift odd-shaped items such as logs, pipes, and structural components. During this sort of operation, the thumb's rotation must follow that of the bucket's to maintain a gripping force on the item between the thumb and the bucket throughout rotation thereof. The high [0018] rotation linkage assembly 135 of the present invention is structured and arranged to allow the thumb 125 to have substantially the same range of rotation as the bucket 120 so that the thumb 125 can stay in contact with the bucket 120 throughout the bucket's 120 range of rotation, or, at least, to allow the thumb 125 to rotate more than 190 degrees relative to the load-bearing member 100.
More particularly and with reference to FIG. 1, one or more of the following factors allows the [0019] second link 175 to be unencumbered by the load-bearing member 100 as the high rotation linkage 135 rotates the thumb 125: (i) the distance D₁between the second rotatable attachment point 150 and the third rotatable attachment point 167 relative to the distance D₂between the second rotatable attachment point 150 and the end portion 105 of the load-bearing member 100, (ii) the distance D₃between the first rotatable attachment point 142 and the fourth rotatable attachment point 198 relative to the distance D₂between the second rotatable attachment point 150 and the end portion 105 of the load-bearing member 100, and (iii) the non-linear geometry of the second link 175.
The aforementioned factors and how they allow the [0020] thumb 125 to have the range of rotation will now be discussed. The distance D₁being greater than D₂allows the second link 175 to extend beyond the end portion 105 of the load-bearing member 100 as the thumb 125 rotates past the load-bearing member 100 such that it is unencumbered by the load-bearing member 100 during such rotation. In addition, or alternatively, the distance D₃being greater than D₂allows the second link 175 to extend beyond the end portion 105 of the load-bearing member 100 as the thumb 125 rotates past the load-bearing member such that it is unencumbered by the load-bearing member 100 during such rotation. Furthermore, the non-linear geometry of the second link 175 allows the second link 175 to be unencumbered by the load-bearing member 100 while also allowing the thumb 125 to remain in contact with the bucket 120 as the thumb 125 rotates past the end portion 105 of the load-bearing member 100.
Other aspects, objects and advantages of the invention can be obtained from a study of the drawings, the disclosure and the appended claims. [0021]

Claims

1. An attachment arrangement for a load-bearing member of a work machine, comprising:

an implement rotatably attached to the load-bearing member;

an actuator attached to the load-bearing member; and

a high rotation linkage assembly rotatably attaching the implement to the load-bearing member and to the actuator, the high rotation linkage assembly structured and arranged to allow the implement to have a range of rotation of at least 190 degrees.

2. The attachment arrangement of claim 1 wherein the implement is a thumb.

3. The attachment arrangement of claim 1 wherein the high rotation linkage assembly comprises:

a first link having first and second-end portions and an extension portion extending from the first-end portion, the first-end portion of the first link being rotatably attached to the load-bearing member at a second rotatable attachment point, and the second-end portion of the first link being rotatably attached to the actuator at a third rotatable attachment point; and

a second link having first and second-end portions, the first-end portion of the second link being rotatably attached to the implement at a first rotatable attachment point, the second-end portion of the second link being rotatably attached to the extension portion of the first link at a fourth rotatable attachment point.

4. The attachment arrangement of claim 3 wherein the extension portion further has an extension portion long axis and the first link further comprises a long member having a long member long axis oriented in a non-parallel relationship with the extension portion long axis.

5. The attachment arrangement of claim 3 wherein a distance between the first rotatable attachment point and the fourth rotatable attachment point is greater than a distance between the second rotatable attachment point and the end portion of the load-bearing member.

6. The attachment arrangement of claim 3 wherein a distance between the second rotatable attachment point and the third rotatable attachment point is greater than a distance between the second rotatable attachment point and the end portion of the load-bearing member.

7. The attachment arrangement of claim 3 wherein the second link has a convex shape bent away from the load-bearing member when attached with the load-bearing member.

8. An attachment arrangement for a load-bearing member of a work machine, comprising:

a first implement rotatably attached to the load-bearing member;

a second implement rotatably attached to the load-bearing member;

an actuator attached to the load-bearing member; and

a linkage assembly rotatably attaching the second implement to the load-bearing member, the linkage assembly structured and arranged to allow the first implement and the second implement to have substantially the same range of rotation.

9. The attachment arrangement of claim 8 wherein the first implement is a bucket and the second implement is a thumb.

10. The attachment arrangement of claim 8 wherein the rotation linkage assembly comprises:

a first link having first- and second-end portions and an extension portion extending from the first-end portion, the first-end portion of the first link being rotatably attached to the actuator at a third rotatable attachment point, the second-end portion of the first link being rotatably attached to the load-bearing member at a second rotatable attachment point; and

a second link having first and second-end portions, the first-end portion of the second link being rotatably attached to the extension portion of the first link at a fourth rotatable attachment point and the second-end portion of the second link being rotatably attached to the second implement at a first rotatable attachment point.

11. The attachment arrangement of claim 10 wherein the extension portion further has an extension portion long axis and the first link further comprises a long member having a long member long axis oriented in a non-parallel relationship with the extension portion long axis.

12. The attachment arrangement of claim 10 wherein a distance between the second rotatable attachment point and the third rotatable attachment point is greater than a distance between the second rotatable attachment point and the end portion of the load-bearing member.

13. The attachment arrangement of claim 10 wherein a distance between the first rotatable attachment point and the fourth rotatable attachment point is greater than a distance between the second rotatable attachment point and the end portion of the load-bearing member.

14. The attachment arrangement of claim 10 wherein the second link has a convex shape bent away from the load-bearing member when attached with the load-bearing member.

15. The attachment arrangement of claim 10 wherein the second implement has a range of rotation of at least 190 degrees.

16. An attachment arrangement for an implement of a work machine, the attachment arrangement comprising:

a load-bearing member having an end portion;

an implement attached to the load-bearing member in proximity to the end portion;

a first link having first and second-end portions and an extension portion extending from the first-end portion, the first-end portion of the first link being rotatably attached to an actuator at a third rotatable attachment point, the second-end portion of the first link being rotatably attached to the load-bearing member at a second rotatable attachment point a predetermined distance from the end portion of the load-bearing member; and

a second link having first and second-end portions, the second-end portion being rotatably attached to the implement at a first rotatable attachment point, the second-end portion being rotatably attached to the extension portion of the first link at a fourth rotatable attachment point, the second, third, and fourth rotatable attachment points defining non-co-linear attachment points.

17. The attachment arrangement of claim 16 wherein the implement is a thumb.

18. The attachment arrangement of claim 16 wherein the predetermined distance is less than a distance between the second and third rotatable attachment points.

19. The attachment arrangement of claim 16 wherein the first link and the second link are structured and arranged to allow the implement to have a range of rotation of at least 190 degrees.

20. The attachment arrangement of claim 16 wherein the extension portion further has an extension portion long axis and the first link further comprises a long member having a long member long axis oriented in a non-parallel relationship with the extension portion long axis.

21. An attachment arrangement for a load-bearing member of a work machine comprising:

a load-bearing member;

a first implement rotatably attached to the load-bearing member;

a first actuator attached to the load-bearing member applying a force to the first implement to move the first implement relative to the load-bearing member;

a second implement rotatably attached to the load-bearing member;

a second actuator attached to the load-bearing member applying a force to the second implement to move the second implement relative to the load-bearing member, the second actuator moving the second implement independently of the first implement; and

a linkage assembly rotatably attaching the second implement to the load-bearing member, the linkage assembly allowing each of the first implement and the second implement to have a range of rotation of at least approximately 190 degrees.

22. An attachment arrangement according to claim 21 wherein:

the first implement is an earth-excavating bucket; and

the second implement is a thumb which can move under force of the second actuator in an opposite direction of the bucket to apply a pinching force to an object between the bucket and the thumb.

23. An attachment arrangement for a load-bearing member of a work machine comprising:

a load-bearing member;

a bucket rotatably attached to the load-bearing member;

a first actuator operatively attached to and applying a force to the bucket to rotate the bucket relative to the load-bearing member;

a thumb rotatably attached to the load-bearing member and adapted to produce a pinching between the bucket and the thumb;

a second actuator applying a force to the thumb to rotate the thumb relative to the load-bearing member;

a linkage assembly connecting the second actuator to the thumb, the linkage assembly comprising:

a first link; and

a second link;

wherein the first link is attached at a first end thereof to the load-bearing member and the first link is attached at a second end thereof opposite its first end to a first end of the second link, the second link is attached at a second end thereof opposite its first end to the thumb; and

wherein the second actuator is attached to the first link at a point in between the first end and second end of the first link.

24. An attachment arrangement according to claim 23 wherein the thumb has a range of motion of at least approximately 190 degrees relative to the load-bearing member.