EXERCISE MACHINES HAVING DAMPENER FOR REDUCING ACTUATOR BACKLASH

1 . An exercise machine comprising:

a frame,

a rocker arm operable to perform a striding exercise motion relative to the frame,

an actuator coupling the rocker arm to the frame, the actuator being configured to adjust a position of the rocker arm relative to the frame to adjust an incline of the striding exercise motion, and

a dampener configured to apply a preload force on the actuator to dampen reversing loads from the rocker arm and reduce backlash in the actuator.

2 . The exercise machine according to claim 1 , wherein said preload force includes a tension force.

3 . The exercise machine according to claim 1 , wherein said preload force includes a compression force.

4 . The exercise machine according to claim 1 , wherein said dampener includes a spring.

5 . The exercise machine according to claim 4 , wherein said spring includes an elastomer.

6 . The exercise machine according to claim 4 , wherein said spring includes a first spring member and a second spring member coupled to the first spring member.

7 . The exercise machine according to claim 1 , wherein said preload force includes at least one of a tension force and a compression force, and said dampener is configured to apply the at least one of the tension force and the compression force on the actuator.

8 . The exercise machine according to claim 7 , wherein said actuator is configured to extend and retract, and said dampener is configured to apply the compression force when the actuator is extended and to apply the tension force when the actuator is retracted.

9 . The exercise machine according to claim 7 , wherein said dampener includes a first spring configured to apply the tension force on the actuator and a second spring configured to apply the compression force on the actuator.

10 . The exercise machine according to claim 1 , wherein said actuator includes a linear actuator having a first end pivotably coupled to the frame and a second end pivotably coupled to the rocker arm.

11 . The exercise machine according to claim 10 , further including an incline link pivotably coupling the rocker arm to the frame, the second end of the linear actuator being pivotably coupled to the rocker arm via the incline link.

12 . The exercise machine according to claim 11 , wherein said dampener including a spring configured to bias the incline link relative to the frame to apply said preload force as a tension force on the actuator.

13 . The exercise machine according to claim 11 , wherein said dampener including a spring configured to bias the incline link relative to the frame to apply said preload force as a compression force on the actuator.

14 . The exercise machine according to claim 1 , said dampener including a first spring and a second spring, said first spring and said second spring being configured to abut each other to apply the preload force.

15 . The exercise machine according to claim 14 , wherein one of the first spring and the second spring travels along a non-linear path relative to the other one of the first spring and the second spring, and wherein at least one of the first spring and the second spring has a shape configured to generally maintain alignment between the first spring and the second spring as the first spring and the second spring are compressed along the non-linear path.

16 . The exercise machine according to claim 1 , wherein said dampener is configured to apply said preload force throughout movement into and between a low-incline configuration and a high-incline configuration.

17 . An exercise machine comprising:

a frame,

a rocker arm operable to perform a striding exercise motion relative to the frame,

an incline link pivotably coupling the rocker arm to the frame,

a linear actuator having a first end pivotably coupled to the frame and a second end pivotably coupled to the incline link, the linear actuator being extendible and retractable to adjust a position of the rocker arm relative to the frame, and

a dampener configured to apply at least one of a tension force and a compression force on the linear actuator that dampens reversing loads from the rocker arm to thereby reduce backlash in the linear actuator.

18 . The exercise machine according to claim 17 , wherein said dampener is configured to apply both the tension force and the compression force on the linear actuator.

19 . The exercise machine according to claim 17 , wherein said linear actuator is configured to extend and retract, and said dampener is configured to apply the compression force when the linear actuator is extended and to apply the tension force when the linear actuator is retracted.

20 . The exercise machine according to claim 17 , wherein said dampener includes a first spring configured to apply the tension force on the linear actuator and a second spring configured to apply the compression force on the linear actuator.

21 . The exercise machine according to claim 17 , wherein the dampener includes a spring that is compressed between the incline link and the frame upon retraction of the linear actuator, which applies the tension force on the linear actuator.

22 . The exercise machine according to claim 17 , further comprising a pivot linkage coupled to the frame and to the incline link, wherein the dampener includes a spring, and wherein the dampener is configured to compress the spring between the pivot linkage and the frame when the linear actuator is in an extended position to apply the compression force on the linear actuator.

23 . The exercise machine according to claim 22 , wherein the pivot linkage includes a spring arm and a connecting link that are pivotably coupled together.

24 . The exercise machine according to claim 17 , further comprising a pivot linkage coupled to the frame and the incline link, the dampener comprising a first spring and a second spring, the dampener configured to compress the first spring between the incline link and the frame when the linear actuator is in a retracted position to apply the tension force on the linear actuator, the dampener configured to compress the second spring between the pivot linkage and the frame when the linear actuator is in an extended position to apply the compression force on the linear actuator.

25 . The exercise machine according to claim 17 , wherein said dampener includes a low-incline dampener configured to dampen the reversing loads when the exercise machine is in a low-incline configuration and a high-incline dampener configured to dampen the reversing loads when the exercise machine is in a high-incline configuration.

26 . The exercise machine according to claim 25 , wherein said low-incline dampener is configured to apply the tension force and said high-incline dampener being configured to apply the compression force.

27 . The exercise machine according to claim 25 , wherein said dampener is configured to apply at least one of said tension force and said compression force throughout movement into and between a low-incline configuration and a high-incline configuration.

28 . The exercise machine according to claim 17 , wherein the dampener comprises a first spring supported on the frame and a second spring supported on a movable member, wherein the first spring and the second spring are compressed between the frame and the movable member to generate at least one of the tension force and the compression force; and

wherein the second spring travels along a non-linear path relative to the frame, and at least one of the first spring and the second spring has a shape configured to generally maintain alignment between the first spring and the second spring as the first spring and the second spring are compressed along the non-linear path.