Linkage assemblies for exercise devices

1. An exercise device comprising:

a driving member;

a driven member; and

a linkage assembly that links the driving member to the driven member such that rotation of the driving member causes rotation of the driven member;

wherein the linkage assembly comprises a linking member, a base member that connects the driving member and the driven member, a first crank arm that connects the driving member to the linking member such that rotation of the driving member causes motion of the linking member, a second crank arm that connects the linking member to the driven member such that the motion of the linking member causes rotation of the driven member, and a third crank arm that is separate and spaced apart from the first and second crank arms, wherein the third crank arm connects the linking member to the base member such that the motion of the linking member causes the third crank arm to rotate with respect to the base member; and

wherein the driving member comprises a first rotatable shaft, the driven member comprises a second rotatable shaft, and the base member is connected to and extends between the first and second rotatable shafts.

2. The exercise device according to claim 1 , wherein the first, second, and third crank arms extend in a common plane.

3. The exercise device according to claim 2 , wherein the first and second crank arms remain parallel to each other as the driving member is rotated.

4. The exercise device according to claim 2 , wherein the first crank arm is connected to the driving member at a driving member rotational axis, wherein the second crank arm is connected to the driven member at a driven member rotational axis, and wherein the driving member rotational axis and the driven member rotational axis are parallel and spaced apart with respect to each other.

5. The exercise device according to claim 4 , wherein rotation of the driving member causes the first crank arm to rotate about the driving member rotational axis, the linking member to move relative to the driving member rotational axis and the driven member rotational axis, and the second crank arm to rotate about the driven member rotational axis.

6. The exercise device according to claim 5 , wherein the driving member rotational axis and the driven member rotational axis remain at a fixed distance from each other during said rotation of the driving member.

7. The exercise device according to claim 2 , wherein the first crank arm is connected to the linking member at a first crank arm rotational axis, wherein the second crank arm is connected to the linking member at a second crank arm rotational axis, and wherein the first crank arm rotational axis and second crank arm rotational axis are parallel and spaced apart with respect to each other.

8. The exercise device according to claim 7 , wherein the third crank arm is connected to the linking member at a third crank arm rotational axis, and wherein the third crank arm rotational axis is laterally offset from a straight line extending through the first and second crank arm rotational axes.

9. The exercise device according to claim 2 , wherein the base member supports rotation of the driving member, driven member, first crank arm, second crank arm, and third crank arm and motion of the linking member.

10. The exercise device according to claim 9 , wherein said motion of the linking member is translation along a circular path with respect to the base member.

11. The exercise device according to claim 8 , further comprising a fourth crank arm that connects the linking member to the base member, wherein the fourth crank arm is connected to the linking member at a fourth crank arm rotational axis, wherein said rotation of the linking member causes the fourth crank arm to rotate with respect to the base member, and wherein the first, second, third, and fourth crank arms extend in a common plane.

12. The exercise device according to claim 11 , wherein the third crank arm rotational axis and fourth crank arm rotational axis are located between the first and second crank arm rotational axes and are laterally offset on opposite sides of a straight line extending through the first and second crank arm rotational axes.

13. The exercise device according to claim 12 , wherein the base member comprises a plurality of bearing housings for supporting rotation of the driving member, driven member, first crank arm, second crank arm, third crank arm, and fourth crank arm with respect to the base member.

14. The exercise device according to claim 1 , further comprising a driving crank arm that drives rotation of the driving member.

15. The exercise device according to claim 1 , further comprising a resistance member that resists rotation of the driven member.

16. An exercise device comprising:

a driving member;

a driven member;

a linkage assembly that links the driving member to the driven member such that rotation of the driving member causes rotation of the driven member;

wherein the linkage assembly comprises a linking member, a base member that connects the driving member and the driven member, a first crank arm that connects the driving member to the linking member at a first crank arm rotational axis such that rotation of the driving member causes motion of the linking member, a second crank arm that connects the linking member to the driven member at a second crank arm rotational axis such that rotation of the linking member causes rotation of the driven member, and a third crank arm that is separate and spaced apart from the first and second crank arms, wherein the third crank arm connects the linking member to the base member at a third crank arm rotational axis such that the motion of the linking member causes the third crank arm to rotate with respect to the base member;

wherein the first, second, and third crank arms extend in a common plane and remain parallel to each other as the driving member rotates; and

wherein the third crank arm rotational axis is laterally offset from a straight line extending through the first and second crank arm rotational axes; and

a driving crank arm that drives rotation of the driving member;

wherein the driving member comprises a first rotatable shaft, the driven member comprises a second rotatable shaft, and the base member is connected to and extends between the first and second rotatable shafts.

17. The exercise device according to claim 16 , further comprising a resistance member that resists rotation of the driven member.

18. An exercise device comprising:

a frame;

a pedal member having a first portion and a second portion;

a base member having a first portion and a second portion, wherein the second portion of the base member is pivotally coupled to the frame via a driven member;

a crank arm that has a first portion that is pivotally coupled to the first portion of the pedal member and a second portion that is pivotally coupled to the first portion of the base member via a driving member; and

wherein the crank arm is rotatable in a circular path entirely around the first portion of the base member as the base member pivots back and forth with respect to the frame such that the pedal member is movable along user defined paths of differing dimensions; and

a linkage assembly that links the driving member to the driven member such that rotation of the driving member causes rotation of the driven member;

wherein the linkage assembly comprises a linking member, a first crank arm that connects the driving member to the linking member at a first crank arm rotational axis such that rotation of the driving member causes motion of the linking member, a second crank arm that connects the linking member to the driven member at a second crank arm rotation axis such that rotation of the linking member causes rotation of the driven member, and a third crank arm that connects the linking member to the base member at a third crank arm rotational axis such that the motion of the of the linking member causes the third crank arm to rotate with respect to the base member;

wherein the first, second, and third crank arms extend in a common plane and remain parallel to each other as the driving member rotates;

wherein the third crank arm rotational axis is laterally offset from a line extending through the first and second crank arm rotational axes; and

wherein the driving member comprises a first rotatable shaft, the driven member comprises a second rotatable shaft, and the base member is connected to and extends between the first and second rotatable shafts.

19. The exercise device according to claim 18 , further comprising a rocker arm having a first portion that is pivotally coupled to the pedal member between the first and second portions of the pedal member wherein the rocker arm further has a second portion that is pivotally coupled to the frame.

20. The exercise device according to claim 19 , further comprising a resistance member that resists rotation of the driven member.