Roll center for attachment frame control arms

1. A harvesting header for an agricultural harvesting machine, the header comprising:

a first frame portion;

a second frame portion moveably connected to the first frame portion;

an upper control arm pivotally connected to the first frame portion and pivotally connected to the second frame portion; and

a lower control arm pivotally connected to the first frame portion and pivotally connected to the second frame portion,

wherein, when the harvesting header is attached to a harvesting machine, the connection between the first frame portion, second frame portion, upper control arm, and lower control arm creates a roll center of the second frame portion positioned at or below ground level over which the machine is configured to travel and behind the second frame portion relative to a direction of travel.

2. The harvesting header of claim 1 , wherein the upper control arm is connected to the first frame portion at a first contact point and connected to the second frame portion at a second contact point, and the lower control arm is connected to the first frame portion at a third contact point and connected to the second frame portion at a fourth contact point.

3. The harvesting header of claim 2 , wherein an upper control arm axis is defined by a line passing through a first planar representation of the first contact point and the second contact point and a lower control arm axis is defined by a line passing through a second planar representation of the third contact point and the fourth contact point, and wherein the roll center is positioned at an intersection between the upper control arm axis and the lower control arm axis, and wherein the first planar representation and the second planar representation are coincident planes orthogonal to the ground level and extending along the chassis axis.

4. The harvesting header of claim 2 , wherein the first contact point is positioned closer to a central axis than the second contact point and wherein the fourth contact point is positioned closer to the central axis than third contact point.

5. The harvesting header of claim 1 , wherein the first frame portion is configured to connect to an agricultural harvesting vehicle.

6. The harvesting header of claim 1 , wherein the roll center is positioned below ground level.

7. The harvesting header of claim 1 , wherein the second frame portion supports a cutter bar.

8. The harvesting header of claim 7 , wherein the second frame portion supports a conveyor.

9. A harvesting header for an agricultural harvesting machine, the header comprising:

a first frame portion;

a second frame portion moveably connected to the first frame portion;

an upper control arm connected to the first frame portion at a first contact point and connected to the second frame portion at a second contact point; and

a lower control arm connected to the first frame portion at a third contact point and connected to the second frame portion at a fourth contact point,

wherein, when the harvesting header is attached to a harvesting machine, an upper control arm axis is defined by a line passing through a first planar representation of the first contact point and the second contact point and a lower control arm axis is defined by a line passing through a second planar representation of the third contact point and the fourth contact point, and wherein a roll center is defined by the intersection between the upper control arm axis and the lower control arm axis, and wherein the roll center is positioned at or below ground level over which the machine is configured to travel and positioned behind the second frame portion relative to a direction of travel, and wherein the first planar representation and the second planar representation are coincident planes orthogonal to the ground level and extending along the chassis axis.

10. The harvesting header of claim 9 , wherein the first contact point is positioned closer to a central axis than the second contact point and wherein the fourth contact point is positioned loser to the central axis than third contact point.

11. The harvesting header of claim 9 , wherein the first frame portion is configured to connect to an agricultural harvesting vehicle.

12. The harvesting header of claim 9 , wherein the roll center is located below ground level.

13. The harvesting header of claim 9 , wherein the second frame portion supports a cutter bar.

14. The harvesting header of claim 9 , wherein the upper control arm and the lower control arm are pivotally connected to the first frame portion and pivotally connected to the second frame portion.

15. An agricultural harvesting machine comprising:

a chassis;

ground engaging members for moving the chassis;

a feederhouse connected to the chassis for receiving agricultural material;

a harvesting header for cutting and gathering agricultural material and delivering it to the feederhouse, the harvesting header including;

a first frame portion;

a second frame portion moveably connected to the first frame portion;

an upper control arm pivotally connected to the first frame portion and pivotally connected to the second frame portion; and

a lower control arm pivotally connected to the first frame portion and pivotally connected to the second frame portion,

wherein, when the harvesting header is attached to a harvesting machine, the connection between the first frame portion, second frame portion, upper control arm, and a lower control arm forms a roll center positioned at or below ground level over which the machine is configured to travel and behind the second frame portion relative to a direction of travel.

16. The agricultural harvesting machine of claim 15 , wherein the upper control arm is connected to the first frame portion at a first contact point and connected to the second frame portion at a second contact point, and the lower control arm is connected to the first frame portion at a third contact point and connected to the second frame portion at a fourth contact point.

17. The agricultural harvesting machine of claim 16 , wherein an upper control arm axis is defined by a line passing through a first planar representation of the first contact point and the second contact point and a lower control arm axis is defined by a line passing through a second planar representation of the third contact point and the fourth contact point, and wherein the roll center is positioned at an intersection between the upper control arm axis and the lower control arm axis, and wherein the first planar representation and the second planar representation are coincident planes orthogonal to the ground level and extending along the chassis axis.

18. The agricultural harvesting machine of claim 15 , wherein the roll center is positioned below ground level.

19. The agricultural harvesting machine of claim 15 , wherein the roll center is positioned beneath the chassis.

20. The agricultural harvesting machine of claim 15 , wherein the harvesting head includes a cutter bar and a conveyor.