Exercise machines for facilitating elliptical striding motion

1. An exercise machine for performing a striding exercise motion, the exercise machine comprising:

a longitudinally extending frame;

first and second pedal members;

first and second foot pads on the first and second pedal members, respectively, each of the first and second foot pads being movable along an elliptical path during said striding exercise motion; and

first and second rocker arms each having a first end that is pivotable with respect to the frame about a rocker arm pivot axis and further having a second end that is pivotable relative to one of the first and second pedal members about a pedal lever hub axis;

the frame comprising a front frame portion and a rear frame portion located longitudinally rearwardly of the front frame portion, the front frame portion supporting the first and second rocker arms and being pivotable about a frame pivot axis upwardly and rearwardly relative to the rear frame portion while the rear frame portion remains stationary, the frame configured so that pivoting the front frame portion relative to the rear frame portion about the frame pivot axis while the rear frame portion remains stationary adjusts a position of the rocker arm pivot axis, which changes a shape of said elliptical path.

2. The exercise machine according to claim 1 , wherein adjusting the position of the rocker arm pivot axis changes a fore aft range of motion through which the first and second rocker arms pivot during the striding exercise motion but does not substantially change a horizontal length of said elliptical path.

3. The exercise machine according to claim 2 , further comprising an adjustment mechanism that facilitates pivoting of the front frame portion relative to the rear frame portion about the frame pivot axis.

4. The exercise machine according to claim 3 , wherein the front frame portion and the rear frame portion each extend from a front to a rear and are located below the first and second pedal members, and further comprising a support column extending upwardly from the front frame portion and supporting the first and second rocker arms along the rocker arm pivot axis.

5. The exercise machine according to claim 4 , wherein the adjustment mechanism comprises a linear actuator having a first end that is pivotably coupled to the front frame portion and having an opposite second end that is pivotably coupled to a base plate for being supported by a surface.

6. The exercise machine according to claim 5 , wherein the first end of the linear actuator is pivotably coupled to a forward portion of the front frame portion.

7. The exercise machine according to claim 6 , wherein operation of the linear actuator pivots the support column and the front frame portion upwardly and rearwardly together relative to the rear frame portion about the frame pivot axis which adjusts said position of said rocker arm pivot axis.

8. The exercise machine according to claim 3 , wherein the adjustment mechanism is manually actuatable.

9. The exercise machine according to claim 3 , further comprising a controller configured to automatically actuate the adjustment mechanism based on a user input to a user input device.

10. The exercise machine according to claim 3 , further comprising a controller configured to automatically actuate the adjustment mechanism based on a stored program.

11. The exercise machine according to claim 2 , wherein the front frame portion and the rear frame portion each extend from a front to a rear and are located below the first and second pedal members, and further comprising a support column extending upwardly from the front frame portion and supporting the first and second rocker arms along the rocker arm pivot axis.

12. The exercise machine according to claim 11 , wherein said support column is fixed to the front frame portion at a fixed joint located forwardly of said frame pivot axis.

13. The exercise machine according to claim 12 , wherein the frame pivot axis is located rearwardly of the support column.

14. The exercise machine according to claim 11 , wherein the support column is coupled to the front frame portion such that the support column and the front frame portion are pivotable upwardly and rearwardly together relative to the rear frame portion about the frame pivot axis while the rear frame portion remains stationary, which adjusts said position of said rocker arm pivot axis.

15. The exercise machine according to claim 2 , further comprising a frame pivot joint that facilitates pivoting of the front frame portion relative to the rear frame portion about the frame pivot axis, the frame pivot joint located longitudinally between the front frame portion and the rear frame portion.

16. The exercise machine according to claim 1 , wherein the frame is configured so that pivoting the front frame portion relative to the rear frame portion about the frame pivot axis while the rear frame portion remains stationary adjusts an incline of said elliptical path.

17. The exercise machine according to claim 16 , wherein said elliptical path has a horizontal length that remains substantially constant when the position of the rocker arm pivot axis is changed.

18. The exercise machine according to claim 1 , wherein said elliptical path has a horizontal length that remains substantially constant when the position of the rocker arm pivot axis is changed.

19. The exercise machine according to claim 1 , wherein the front frame portion and the rear frame portion are each configured to support the exercise machine relative to a surface, the front frame portion being pivotable about the frame pivot axis upwardly and rearwardly relative to the surface.

20. The exercise machine according to claim 1 , further comprising a support column extending upwardly from the front frame portion and supporting the first and second rocker arms along the rocker arm pivot axis, the support column pivoting with the front frame portion about the frame pivot axis upwardly and rearwardly relative to the rear frame portion.