EXCAVATOR THUMB ASSEMBLY

• US 20120328400A1
• Filed: 06/24/2011
• Published: 12/27/2012
• Est. Priority Date: 06/24/2011
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Seljestad, Gregory A.
• Granted Patent: US 8,920,106 B2
• Time in Patent Office: Days
• US Class Current: 414/724
• CPC Class Codes: E02F 3/404 comprising two parts movable relative to each other, e.g. for gripping
• CPC Class Codes: Y10S 37/903 Scoop or scraper attachments
• CPC Class Codes: Y10T 29/49817 with other than ancillary treating or assembling

Abstract

A thumb assembly mountable to a lifting arm of an excavator includes a base member mountable to the lifting arm, the base member having a link mounting aperture, a thumb member pivotally connected to the base member, a link member having a base mounting aperture in a first end for coupling to the base member and a thumb mounting aperture in a second end for coupling to the thumb member, a removable pin receivable through the link mounting aperture and the base mounting aperture to connect the link member to the base member, and a connection-assist system disposed on at least one of the link member and base member, the connection-assist system configured to provide a visual indication that the thumb member and the link member are in a position such that the removable pin can be received through both the link mounting aperture and the base mounting aperture.

Claims

1. A thumb assembly for an excavator having a lifting arm, the thumb assembly comprising:

a base member mountable to the lifting arm, the base member having a link mounting aperture;

a thumb member pivotally connected to the base member;

a link member having a base mounting aperture in a first end for coupling to the base member and a thumb mounting aperture in a second end for coupling to the thumb member;

a removable pin receivable through the link mounting aperture and the base mounting aperture to connect the link member to the base member; and

a connection-assist system disposed on at least one of the link member and the base member, the connection-assist system configured to provide a visual indication that the thumb member and the link member are in a position such that the removable pin can be received through both the link mounting aperture and the base mounting aperture.

2. The thumb assembly of claim 1 wherein the connection-assist system includes a projection on one of the link member and the base member and a catch on the other of the link member and the base member.

3. The thumb assembly of claim 1 wherein base member comprises

two spaced apart, link member mounting plates, each mounting plate having a first link mounting apertures and a second link mounting apertures, and

a catch on at least one of the link mounting plates corresponding to each of the apertures.

4. The thumb assembly of claim 1 wherein the base member includes a first link mounting aperture and a second link mounting aperture, and wherein the connection-assist system is configured to provide a visual indication that the thumb member and the link member are in a first position such that the removable pin can be received through both the first link mounting aperture and the base mounting aperture and provide a visual indication that the thumb member and the link member are in a second position such that the removable pin can be received through both the second link mounting aperture and the base mounting aperture.

5. The thumb assembly of claim 4 wherein the base member includes a pair of coaxial first link mounting apertures and a pair of coaxial second link mounting apertures.

6. The thumb assembly of claim 4 wherein the connection-assist system includes a projection on one of the link member and the base member and a catch on the other of the link member and the base member.

7. The thumb assembly of claim 6 wherein the projection is adjacent the base mounting aperture on the link member.

8. The thumb assembly of claim 4 wherein in the first position, the link mounting aperture and the base mounting aperture are misaligned.

9. The thumb assembly of claim 8 wherein insertion of the removable pin through the link mounting aperture and the base mounting aperture substantially aligns the apertures coaxially.

10. The thumb assembly of claim 1 wherein the link member further comprises a storage position aperture disposed between the base mounting aperture and the thumb mounting aperture.

11. The thumb assembly of claim 1 wherein the connection-assist system supports at least a portion of the weight of the thumb member and link member are in a position such that the removable pin can be received through both the link mounting aperture and the base mounting aperture.

12. A method for changing working positions of an excavator stiff link thumb assembly having a link member coupled to a thumb member and a base member, the method comprising:

disconnecting the link member from the base member;

rotating the thumb member to the desired working position;

positioning a detent lock into a detent to provide a visual indication that the thumb member and the link member are in a position such that the link member may be reconnected to the base member; and

reconnecting the link member to the base member.

13. The method of claim 12 wherein the step of positioning a detent lock into a detent further comprises engaging a projection on one of the link member and base member with a detent on the other of the link member and base member.

14. The method of claim 13 wherein the step of positioning a detent lock into a detent further comprises engaging a projection on the link member with a detent on the base member.

15. The method of claim 14 wherein the step of rotating the thumb to the desired working position further comprises moving a detent lock on the link member from a first detent on the base member to a second detent on the base member.

16. The method of claim 12 wherein the step of positioning a detent lock into a detent further comprises positioning a base mounting aperture on the link member adjacent a link mounting aperture on the base member such that the apertures are axially misaligned but sufficient overlapping to receive a mounting pin therethrough.

17. The method of claim 16 wherein the step of reconnecting the link member to the base member further comprises inserting the mounting pin through both the base mounting aperture and the link mounting aperture.

18. The method of claim 17 wherein the step of reconnecting the link member to the base member coaxially aligns the apertures.

19. An excavator comprising:

a lifting pivotally coupled to a bucket;

a thumb assembly pivotally coupled to the lifting arm, the thumb assembly comprising;

a base member mountable to the lifting arm, the base member having a link mounting aperture;

a thumb member pivotally connected to the base member;

a link member having a base mounting aperture in a first end for coupling to the base member and a thumb mounting aperture in a second end for coupling to the thumb member;

a removable pin receivable through the link mounting aperture and the base mounting aperture to connect the link member to the base member; and

a connection-assist system disposed on at least one of the link member and the base member, the connection-assist system configured to provide a visual indication that the thumb member and the link member are in a position such that the removable pin can be received through both the link mounting aperture and the base mounting aperture.