Active roll control system for a vehicle suspension system

1. An actuator assembly adapted for use in a vehicle suspension system for selectively controlling the position of a stabilizer bar of the vehicle suspension system comprising:

an actuator having a first rack and a second rack;

a rotatable drive pinion in operative engagement with the first and second racks wherein substantially linear movement of the first and second racks in opposite directions causes rotational movement of the drive pinion; and

a locking mechanism selectively moveable between a first position, wherein the locking mechanism prevents rotation of the drive pinion and linear movement of the first and second racks toward a retracted position and an extended position, and a second position, wherein the locking mechanism allows rotation of the drive pinion and linear movement of the first and second racks.

2. The actuator assembly defined in claim 1 wherein movement of the first rack and second rack causes the actuator to move between any one of an infinite number of positions defined between a fully extended position and a fully retracted position.

3. The actuator assembly defined in claim 2 wherein the locking mechanism comprises a scroll that is in operative engagement with the drive pinion for rotation therewith, and a pin that is configured to be selectively engaged in a cavity provided in the scroll to prevent rotation of the scroll.

4. The actuator assembly defined in claim 3 wherein the locking mechanism further comprises a solenoid, wherein the solenoid is selectively operable between a first actuated position and a second non-actuated position.

5. The actuator assembly defined in claim 4 wherein the pin is in one of an extended position and a partially extended position when the solenoid is in the non-actuated position and the pin is in a retracted position when the solenoid is in the actuated position.

6. The actuator assembly defined in claim 5 wherein the cavity is located on the scroll such that the pin engagement with the cavity locks the actuator in a position that is substantially at a mid-point between the extended position and the retracted position.

7. The actuator assembly defined in claim 6 wherein the solenoid is actuated to retract the pin from engagement with the scroll and to unlock the actuator.

8. The actuator assembly defined in claim 3 wherein the scroll further includes a plurality of cavities such that the pin can engage a selected one of the plurality of cavities to lock the actuator in one of a selected plurality of positions.

9. The actuator assembly defined in claim 8 wherein the plurality of cavities are located on the scroll such that pin engagement with one of the cavities will lock the actuator in one of a mid-position, an extended position, and a retracted position.

10. A vehicle suspension system comprising:

a vehicle body;

a chassis;

a stabilizer bar connecting the vehicle body to the chassis;

an actuator assembly operatively connected between the stabilizer bar and the vehicle body for selectively controlling the position of the stabilizer bar, the actuator assembly being operable to selectively lock and unlock the stabilizer bar in position relative to the vehicle chassis and vehicle body to provide structural support, the actuator assembly including,

an actuator having a first rack and a second rack,

a rotatable drive pinion in operative engagement with the first and second racks wherein substantially linear movement of the first and second racks in opposite directions causes rotational movement of the drive pinion; and

a locking mechanism selectively moveable between a first position, wherein the locking mechanism prevents rotation of the drive pinion and linear movement of the first and second racks toward a retracted position and an extended position, and a second position, wherein the locking mechanism allows rotation of the drive pinion and linear movement of the first and second racks.

11. The vehicle suspension system defined in claim 10 wherein the actuator has a first rack and a second rack that are movable in opposite directions, and are configured to move the actuator between any one of an infinite number of positions defined between a fully extended position and a fully retracted position.

12. The vehicle suspension system defined in claim 11 wherein the locking mechanism comprises a scroll that is in operative engagement with the drive pinion for rotation therewith; and

a pin that is configured to be selectively engaged in a cavity provided in the scroll to prevent rotation of the scroll.

13. The vehicle suspension system defined in claim 12 wherein the locking mechanism further comprises a solenoid, wherein the solenoid is selectively operable between a first actuated position and a second non-actuated position.

14. The vehicle suspension system defined in claim 13 wherein the pin is in one of an extended position and a partially extended position when the solenoid is in the non-actuated position and the pin is in a retracted position when the solenoid is in the actuated position.

15. The vehicle suspension system defined in claim 14 wherein the cavity is located on the scroll such that the pin engagement with the cavity locks the actuator in a position that is substantially at a mid-point between the extended position and the retracted position.

16. The vehicle suspension system defined in claim 15 wherein the solenoid is actuated to retract the pin from engagement with the scroll and to unlock the actuator.

17. The vehicle suspension system defined in claim 15 wherein locking the actuator locks the stabilizer bar in place relative to the vehicle chassis.

18. The vehicle suspension system defined in claim 17 wherein unlocking the scroll allows the actuator to move substantially unrestrained between the fully extended position and the fully retracted position.

19. An actuator assembly comprising:

an actuator having a first rack and a second rack configured for substantially linear movement relative to each other in opposite directions;

a rotatable drive pinion in operative engagement with the first and second racks wherein the substantially linear movement of the first and second racks in opposite directions causes rotational movement of the drive pinion;

a rotatable scroll in operative engagement with the drive pinion for rotation therewith, the scroll having a cavity formed therein; and

a locking mechanism including a pin, the locking mechanism being selectively moveable between a first position, wherein the pin of the locking mechanism engages the cavity of the scroll to prevent rotation of the scroll, the drive pinion, and linear movement of the first and second racks, and a second position, wherein the pin of the locking mechanism disengages from the cavity of the scroll to allow rotation of the scroll, the drive pinion, and linear movement of the first and second racks.