Boom lock system for work machine

1. A work vehicle comprising:

a frame including generally upwardly extending laterally spaced side members;

a boom structure including a pair of arms pivotably connecting the boom structure to the frame;

a pressurized fluid system operably associated with the boom structure for raising and lowering jointly each of the arms along a path of travel adjacent a corresponding side member;

a stop member selectably extending outwardly from at least one of the side members between a locking position and a retracted position, the locking position extending at least a portion of the stop member into the path of travel of a corresponding arm of the boom structure to prevent a lowering movement of the boom structure beyond a predetermined height; and

a boom lock system for preventing the fluid system from applying a fluid force to lower the boom structure when the stop member is in the locking position;

wherein the boom lock system comprises a selectably actuatable switch between a first position and a second position, the first position corresponding to the stop member being in the locking position;

wherein the boom lock system comprises an electrical circuit comprising the switch and a valve in fluid communication with the boom structure, wherein in response to the switch being in the first position, the electrical circuit is open, preventing the fluid system from applying a fluid force to lower the boom structure.

2. The work vehicle of claim 1 , wherein the boom lock system permits the fluid system to apply a fluid force to raise the boom structure.

3. The work vehicle of claim 2 , wherein the boom lock system comprises an electrical circuit comprising the switch and a controller operably connected to the fluid system, wherein in response to the switch being in the first position, the electrical circuit is open, preventing operation of operator controls associated with lowering the boom structure.

4. The work vehicle of claim 2 , wherein the boom lock system comprises an electrical circuit comprising the switch and a controller operably connected to the fluid system, wherein in response to the switch being in the second position, the electrical circuit is closed, permitting operation of operator controls associated with lowering the boom structure.

5. The work vehicle of claim 1 , wherein the stop member is actuable to the locking position when a corresponding arm of the boom structure is positioned at or above the predetermined height.

6. The work vehicle of claim 1 , wherein the boom lock system comprises an electrical circuit comprising the switch and a valve in fluid communication with the boom structure, wherein in response to the switch being in the second position, the electrical circuit is closed, permitting the fluid system to apply a fluid force to raise and lower the boom structure.

7. The work vehicle of claim 6 , wherein the valve is a solenoid control valve.

8. The work vehicle of claim 1 , wherein the valve is a solenoid control valve.

9. The work vehicle of claim 1 , wherein the boom lock system comprises an operator actuated linkage connected to the switch and the stop member.

10. The work vehicle of claim 9 , wherein the linkage is actuatable from inside a cab of the work vehicle.

11. The work vehicle of claim 1 , wherein the stop member is actuatable to the locking position when a corresponding arm of the boom structure is positioned at or above the predetermined height.

12. A work vehicle comprising:

a frame including generally upwardly extending laterally spaced side members;

a boom structure including a pair of arms pivotably connecting the boom structure to the frame;

a pressurized fluid system operably associated with the boom structure for raising and lowering jointly each of the arms along a path of travel adjacent a corresponding side member;

a stop member selectably extending outwardly from at least one of the side members between a locking position and a retracted position, the locking position extending at least a portion of the stop member into the path of travel of a corresponding arm of the boom structure to prevent a lowering movement of the boom structure beyond a predetermined height; and

a boom lock system for preventing the fluid system from applying a fluid force to lower the boom structure, while permitting the fluid system to apply a fluid force to raise the boom structure, when the stop member is in the locking position;

wherein the boom lock system comprises a selectably actuatable switch between a first position and a second position, the first position corresponding to the stop member being in the locking position;

wherein the boom lock system comprises an electrical circuit comprising the switch and a valve in fluid communication with the boom structure, wherein in response to the switch being in the first position, the circuit is open, preventing the fluid system from applying a fluid force to lower the boom structure.

13. The work vehicle of claim 12 , wherein the boom lock system comprises an electrical circuit comprising the switch and a controller operatively connected to the fluid system, wherein in response to the switch being in the first position, the circuit is open, preventing operation of operator controls associated with lowering the boom structure.

14. The work vehicle of claim 12 , wherein the boom lock system comprises an electrical circuit comprising the switch and a controller operatively connected to the fluid system, wherein in response to the switch being in the second position, the circuit is closed, permitting operation of operator controls associated with lowering the boom structure.

15. The work vehicle of claim 12 , wherein the stop member is actuatable to the locking position when a corresponding arm of the boom structure is positioned at or above the predetermined height.

16. A method for operating a work vehicle comprising:

providing a frame including generally upwardly extending laterally spaced side members; a boom structure including a pair of arms pivotably connecting the boom structure to the frame; a pressurized fluid system operably associated with the boom structure for raising and lowering jointly each of the arms along a path of travel adjacent a corresponding side member; a stop member selectably extending outwardly from at least one of the side members between a locking position and a retracted position, the locking position extending at least a portion of the stop member into the path of travel of a corresponding arm of the boom structure to prevent a lowering movement of the boom structure beyond the predetermined height; and

preventing the fluid system from applying a fluid force to lower the boom structure when the stop member is in the locking position with a boom lock system;

wherein the boom lock system comprises a selectably actuatable switch between a first position and a second position, the first position corresponding to the stop member being in the locking position;

wherein the boom lock system comprises an electrical circuit comprising the switch and a valve in fluid communication with the boom structure, wherein in response to the switch being in the first position, the electrical circuit is open, preventing the fluid system from applying a fluid force to lower the boom structure.