Milling machine with re-entering back wheels

• US 20040135421A1
• Filed: 10/27/2003
• Published: 07/15/2004
• Est. Priority Date: 04/27/2001
• Status: Active Grant

• Current Assignee: Caterpillar Power Systems Incorporated (Caterpillar Incorporated)
• Original Assignee: Caterpillar Power Systems Incorporated (Caterpillar Incorporated)
• Inventors: Sansone, Dario, Orefice, Michele, Dubay, Gregory Henry
• Granted Patent: US 7,140,693 B2
• Time in Patent Office: Days
• US Class Current: 299/10
• CPC Class Codes: B60G 2300/09 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60G 2300/37 Vehicles having steerable wheels mounted on a vertically moving column
• CPC Class Codes: B60G 3/01 the wheel being mounted for sliding movement, e.g. in or on a vertical guide camber maintaining means B60G3/26
• CPC Class Codes: E01C 23/088 Rotary tools, e.g. milling drums for forming recesses to receive marking materials E01C23/0946

Abstract

A work machine includes a frame (2) supported by a plurality of wheels or tracks (5), at least some of which are associated with respective lifting columns (32) adapted to raise and lower the frame (2) relative to the respective wheels or tracks (5). A work tool is supported by the frame (2), and a drive mechanism is adapted to rotate the work tool and at least one of the wheels or tracks (5). An articulation apparatus (10) uses a first actuator (20) and a pivoting support arm (11) to move one of the wheels or tracks (5) between a projecting position and a retracted position relative to the frame (2). The articulation apparatus (10) further includes a second actuator (21) adaped to rotate the wheel or track (5) about a vertical axis (Z).

Claims

1. A work machine (1) comprising:

a frame (2) supported by a plurality of wheels or tracks (4, 5), at least one of which is associated with a respective lifting column (32) adapted to raise and lower said frame (2) relative to the respective wheel or track (5);

a work tool (6) supported by said frame (2);

a drive mechanism adapted to rotate said work tool (6) and at least one of said wheels or tracks (4, 5);

an articulation apparatus (10) adapted to pivotally move said one of said wheels or tracks (5) associated with said lifting column (32) between a projecting position (60) and a retracted position (70) relative to said frame (2), said articulation apparatus including;

a support arm (11) pivotally connecting said frame (2) to the lifting column (32) associated with said one wheel or track (5);

a first actuator (20) connected to said support arm (11) and operable to pivot said support arm (11) relative to said frame (2);

a second actuator (21) adapted to rotate said at least one wheel or track (5) about a vertical axis (Z).

2. The machine (1) of claim 1, wherein said second actuator (21) is connected between said support arm (11) and said lifting column (32) and is adapted to controllably cause relative rotation between said lifting column (32) and said support arm (11).

3. The machine (1) of claim 1 or 2, wherein said second actuator (21) is connected to a coupling member (13) which is in rotary engagement with said lifting column (32).

4. The machine (1) of claim 3, wherein said support arm (11) includes a fork-shaped end (11a) providing with respect to the vertical axis (Z) of the lifting column (32) an axially and radially extending space adapted to receive said coupling member (13).

5. The machine (1) of one of claims 3 or 4, wherein said second actuator (21) includes a first rigid link member (14) pivotably connected to said coupling member (13) and a second rigid link member (16) pivotably connected to said support arm (11), both said first and second link members (14, 16) being also pivotably connected to each other, said second actuator (21) further including an extendable actuation member (21a, 21b) pivotably connected on one end to said support arm (11) and on the other end to said second rigid link member (16).

6. The machine (1) of one of the preceding claims 3 to 5, wherein said coupling member comprises a ring (13a) arranged coaxial with and coupled to said lifting column (32) via at least one longitudinally extending groove (32b).

7. The machine (1) of claim 6, wherein said ring (13a) is coupled to said at least one groove (32b) by at least one key (33) adapted to be in engagement with said groove (32b), said groove (32b) being in a sleeve (132) of said lifting column (32) and having fixedly attached at its lower end a generally U-shaped bracket (32a) adapted to receive said at least one wheel or track (5).

8. The machine (1) of one of the preceding claims, wherein said first actuator (20) comprises an extendable actuation member (20b, 20a) being on one end pivotably connected to said support arm (11) and at the other end pivotably connected to said frame (2).

9. The machine (1) of one of the preceding claims, further including a control device (53) adapted to independently control said first and second actuators (20, 21).

10. The machine (1) of claim 9, wherein said control device (53) is adapted to coordinate said first and second actuators (20, 21) so as to maintain the orientation of a vertical rotation plane +6(α

) of said one wheel or track (5) relative to said frame (2) during pivoting movement of said support arm (11).

11. The machine (1) of claim 9 or 10, wherein said control device (53) includes at least one movement detector (36) associated with said articulation apparatus (10).

12. The machine (1) of claim 11, wherein said movement detector (36) is adapted to detect relative movement between said coupling member (13) and said support arm (11).

13. The machine (1) of claim 12, wherein said support arm (11) comprises a seat (34) formed adjacent said coupling member (13) and receiving said movement detector (36), and wherein said detector (36) received in said seat (34) has a sensor element (37) in contact with said coupling member (13).

14. The machine (1) of one of the preceding claims, wherein said support arm (11) includes an actuator (50, 51) adapted to lock said support arm (11) in its projecting position (60) and retracted positon (70), respectively.

15. The machine (1) of claim 14, wherein said actuator (50) includes a stem (51) adapted to come into engagement with a first hole (52) in said frame (2) when said support arm (11) is in its projecting position (60) and with a second hole (52a) in said frame (2) when the support arm (11) is in its retracted position (70).

16. A method of controlling the position of at least one wheel or track (5) of a plurality of wheels or tracks (4, 5) supporting a frame (2) of a work machine (1), said at least one wheel or track (5) being connected to a respective lifting column (32) adapted to raise and lower said frame (2) relative to the respective wheel or track (5), said method comprising the steps of:

pivoting said at least one wheel or track (5) relative to said frame (2) to position said wheel or track (5) between a projecting or retracted position (60, 70) relative to said frame (2), and

positioning said wheel or track (5) in a selected rotational direction (β

) about a vertical axis (Z) of said wheel or track (5).

17. The method of claim 16, wherein pivoting of said wheel or track (5) relative to said frame (2) includes pivoting of a support arm (11) relative to said frame (2), said support arm (11) being connected to said lifting column (32) associated with said one wheel or track (5).

18. The method of claim 17, wherein pivoting of said support arm (11) includes extending or retracting an extendable actuation member (20b, 20a) of a first actuator (20) being on one end pivotably connected to said support arm (11) and at the other end pivotably connected to said frame (2).

19. The method of one of the claims 16 to 18, wherein positioning said wheel or track (5) in said rotational direction (β

) includes rotating said lifting column (32).

20. The method of one of the claims 16 to 19, wherein positioning said wheel or track (5) in said selected rotational direction (β

) includes rotating a sleeve (132) of said lifting column (32) having fixedly attached at its lower end a generally U-shaped bracket (32a) adapted to receive said at least one wheel or track (5).

21. The method of claim 19 or 20, wherein positioning said wheel or track (5) in said rotational direction (13) includes extending or retracting an extendable actuation member (21a, 21b) of a second actuator (21) pivotably connected on one end to said support arm (11) and on the other end connected to a coupling member (13) which is in rotary engagement with said lifting column (32).

22. The method of one of the claims 19 to 21, wherein positioning of said wheel or track (5) in said rotational direction (β

) is determined by detecting a rotational position of said lifting column (32) about said vertical axis (Z) of said wheel or track (5) relative to said support arm (11).

23. The method of claim 22, wherein said detecting the rotational position of said lifting column (32) includes detecting a position of said coupling member (13) relative to said support arm (11).

24. The method of one of the claims 16 to 23, wherein positioning said wheel or track (5) in said rotational direction (13) is controlled dependent on pivoting of said wheel or track (5) relative to said frame (2).

25. The method of claim 24, wherein said controlling further includes coordinating positioning of said wheel or track (5) in said selected rotational direction (β

) and pivoting of said wheel or track (5) relative to said frame (2) so as to maintain a predetermined orientation (α

) of said one wheel or track (5) relative to said frame (2) during pivoting of said one wheel or track (5) relative to said frame (2).

26. The method of one of the claims 16 to 25, further including locking of said support arm (11) in its projecting position (60) and retracted positon (70), respectively, by means of an actuator (50, 51).

27. The method of claim 26, wherein said locking includes engaging of an actuatable stem (51) provided on said support arm (11) with a first hole (52) in said frame (2) when said support arm (11) is in its projecting position (60) and with a second hole (52a) in said frame (2) when the support arm (11) is in its retracted position (70).

28. The method of one of the claims 16 to 27, wherein positioning said wheel or track (5) in said rotational direction (β

) about the vertical axis (Z) is coordinated with the steering of at least one of the other of the plurality of wheels or tracks (4, 5).