SINGLE PEDAL PROPULSION SYSTEM FOR STRAIGHT TRAVEL OF WORK VEHICLE

• US 20150315769A1
• Filed: 07/13/2015
• Published: 11/05/2015
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Boyle, Michael J., Shook, Justin R., Wall, Mark K., Friebel, Jeffrey A.
• Granted Patent: US 9,643,648 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B62D 11/005 Hydraulic control systems
• CPC Class Codes: B62D 11/02 by differentially driving ground-engaging elements on opposite vehicle sides
• CPC Class Codes: B62D 11/04 by means of separate power sources
• CPC Class Codes: B62D 11/06 by means of a single main power source
• CPC Class Codes: E02F 9/225 Control of steering, e.g. for hydraulic motors driving the vehicle tracks steering in general B62D
• CPC Class Codes: F16D 1/00 Couplings for rigidly connecting two coaxial shafts or other movable machine elements attachment of wheels to axles for railway carriages B60B; for attachment of cranks to their shafts F16C3/10

Abstract

A work vehicle is disclosed with a propulsion system that is selectively operable in a first, turning mode or a second, straight mode. The vehicle includes a first traction device, a second traction device, a first steering input, and a second steering input. In the first, turning mode, an operator is able to steer the vehicle left, right, or straight by independently operating the first and second traction devices via the first and second steering inputs. In the second, straight mode, the operator is able to steer the vehicle straight by operating both the first and second traction devices together via one of the first and second steering inputs.

Claims

1. A work vehicle that is selectively operable in a first steering mode and a second steering mode, the work vehicle comprising:

a chassis;

a first traction device supporting the chassis;

a second traction device supporting the chassis;

a first steering input device that is configured to control movement of the first traction device in the first steering mode; and

a second steering input device configured to control movement of (i) the second traction device in the first steering mode and (ii) the first traction device and the second traction device in the second steering mode,

wherein the work vehicle is configured to enter the first steering mode by default in response to the work vehicle restarting.

2. The work vehicle of claim 1, wherein the first traction device is configured to move independently of the second traction device in the first steering mode.

3. The work vehicle of claim 2, wherein the first traction device is configured to move faster than the second traction device in the first steering mode to turn the work vehicle right or left.

4. The work vehicle of claim 1, wherein the first traction device is configured to move together with the second traction device in the second steering mode to steer the work vehicle straight.

5. The work vehicle of claim 1, wherein the work vehicle is configured to switch from the second steering mode to the first steering mode in response to a manipulation of the first steering input device.

6. The work vehicle of claim 5, wherein the first steering input device is configured to be disconnected from the first traction device and the second traction device in the second steering mode.

7. The work vehicle of claim 6, wherein the first steering input device and the second steering input device comprise foot pedals.

8. The work vehicle of claim 1, further comprising a mode selector operable to switch between the first steering mode and the second steering mode.

9. The work vehicle of claim 1, further comprising a hydraulic circuit operatively coupled to the first traction device and the second traction device, the hydraulic circuit configured to divide a supply of a hydraulic fluid equally between the first traction device and the second traction device in the second steering mode.

10. The work vehicle of claim 9, wherein the hydraulic circuit comprises:

a first directional control valve that is configured to direct the hydraulic fluid to drive the first traction device and the second traction device in the first steering mode; and

a second directional control valve that is configured to direct the hydraulic fluid to drive the first traction device and the second traction device in the second steering mode.

11. The work vehicle of claim 10, wherein:

the first directional control valve is configured to direct the hydraulic fluid to a tank in the second steering mode; and

the second directional control valve is configured to direct the hydraulic fluid to the tank in the first steering mode.

12. A work vehicle including:

a chassis;

at least one left traction device supporting the chassis;

at least one right traction device supporting the chassis;

a left steering input device;

a right steering input device; and

a mode selector operable to switch between a first steering mode and a second steering mode, wherein;

in the first steering mode, the at least one left traction device is configured to be operated by the left steering input device and the at least one right traction device is configured to be operated by the right steering input device to steer the work vehicle to steer the work vehicle left, right, or straight, and

in the second steering mode, the at least one left traction device and the at least one right traction device are configured to be operated together by one of the left steering input device or the right steering input device to steer the work vehicle straight,

wherein the work vehicle is configured to enter the first steering mode by default in response to the work vehicle restarting.

13. The work vehicle of claim 12, wherein the work vehicle is configured to switch from the second steering mode to the first steering mode in response to a manipulation of the left steering input device.

14. The work vehicle of claim 13, wherein the left steering input device includes a left foot pedal and the right steering input device includes a right foot pedal.

15. The work vehicle of claim 14, wherein the work vehicle lacks a third foot pedal operatively coupled to either of the at least one left traction device and the at least one right traction device.

16. The work vehicle of claim 12, wherein the at least one left traction device includes a single left track and the at least one right traction device includes a single right track.

17. A method comprising:

operating a work vehicle in a first steering mode by controlling a first traction device and a second traction device together in response to manipulation of one of a first steering input device or a second steering input device; and

operating the work vehicle in a second steering mode by default in response to the work vehicle restarting, wherein operating the work vehicle in the second steering mode comprises controlling the first traction device in response to manipulation of the first steering input device and controlling the second traction device in response to manipulation of the second steering input device.

18. The method of claim 17, further comprising equally dividing a supply of hydraulic fluid between the first traction device and the second traction device to steer the work vehicle straight.

19. The method of claim 17, further comprising switching from the second steering mode to the first steering mode in response to a manipulation of a mode selector input.

20. The method of claim 17, further comprising switching from the first steering mode to the second steering mode in response to a manipulation of the first steering input device, wherein the first steering input device is disconnected from the first traction device and the second traction device while the work vehicle is in the first steering mode.