Failsafe actuator

• US 6,942,227 B2
• Filed: 07/19/2002
• Issued: 09/13/2005
• Est. Priority Date: 07/19/2001
• Status: Expired due to Term

• Current Assignee: Stoneridge Control Devices, Inc. (Stoneridge Incorporated)
• Original Assignee: Stoneridge Control Devices, Inc. (Stoneridge Incorporated)
• Inventors: Fort, William H., Heller, Joe
• Primary Examiner(s): Dunn, David R.
• Application Number:
  US10/267,090
• Publication Number:
  US 20030116928A1
• Time in Patent Office: 1,152 Days
• Field of Search: 280/5.501, 280/5.502, 280/5.506, 280/5.507, 280/5.508, 280/5.509, 280/124.106, 280/124.137, 280/124.149, 280/5.511, 280/124.107
• US Class Current: 280/5.502
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/0185 for failure detection
• CPC Class Codes: B60G 21/0555 including an actuator inducing vehicle roll
• CPC Class Codes: B60G 21/0556 including a releasable coupling B60G21/0555 takes precedence
• CPC Class Codes: B60G 2202/135 Stabiliser bar and/or tube
• CPC Class Codes: B60G 2202/413 Hydraulic actuator
• CPC Class Codes: B60G 2202/42 Electric actuator
• CPC Class Codes: B60G 2202/442 Rotary actuator
• CPC Class Codes: B60G 2204/46 Means for locking the suspension
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2600/26 Electromagnets; Solenoids
• CPC Class Codes: B60G 2600/73 Electrical control
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/80 Detection or control after a system or component failure

Abstract

A failsafe actuator for returning an actuator driven element to a failsafe position in case of a failure condition is provided. The failsafe actuator may include mechanical or electrical means to provide a failsafe function. Such a failsafe actuator may be used in a stabilizer bar system of a vehicle to ensure that at least one stabilizer bar is returned to a failsafe or engaged condition should a failure condition occur when the stabilizer bar is disengaged. Various failure conditions can include loss of electrical power to the actuator or some internal actuator failures.

Claims

1. A vehicle stabilizer bar system comprising:

at least one vehicle stabilizer bar; and

an actuator comprising;

a drive assembly comprising a motor configured to drive an output member from a first position to a second position;

said vehicle stabilizer bar being responsive to said output member such that vehicle stabilizer bar is in a first stabilizer bar state when said output member is in said first position and is in a second stabilizer bar state when said output member is in said second position;

a return mechanism configured to drive said output member from said second position to said first position; and

an electromechanical mechanism configured to maintain said output member in said second position and further configured to release said output member upon interruption of electrical power to said electromechanical mechanism thereby permitting said return mechanism to drive said output member to said first position.

2. The system of claim 1, wherein said output member comprises a plunger.

3. The system of claim 1, wherein said return mechanism comprises a spring.

4. The system of claim 1, wherein said motor comprises an output shaft coupled to said output member through a gear train, said gear train comprising a clutch configured to release when said output member is in said second position.

5. The system of claim 1, wherein said electromechanical mechanism comprises a solenoid having a solenoid shaft configured to maintain said output member in said second position.

6. The system of claim 5, wherein said solenoid shaft is configured to move to a retracted position upon interruption of electrical power to said electromechanical mechanism to thereby release said output member from said second position.

7. The system of claim 1, wherein said first stabilizer bar state is an engaged state of said stabilizer bar and said second stabilizer bar state is a disengaged state of said stabilizer bar.

8. An actuator comprising:

a drive assembly comprising a motor configured to drive an output member from a first position to a second position, said motor comprising an output shaft coupled to said output member through a near train, said gear train comprising a clutch configured to release when said output member is in said second position;

a return mechanism configured to drive said output member from said second position to said first position; and

an electromechanical mechanism configured to maintain said output member in said second position and further configured to release said output member upon interruption of electrical power to said electromechanical mechanism thereby permitting said return mechanism to drive said output member to said first position.

9. The actuator of claim 8, wherein said output member comprises a plunger.

10. The actuator of claim 8, wherein said return mechanism comprises a spring.

11. The actuator of claim 8, wherein said electromechanical mechanism comprises a solenoid having a solenoid shaft configured to maintain said output member in said second position.

12. The actuator of claim 11, wherein said solenoid shaft is configured to move to a retracted position upon interruption of electrical power to said electromechanical mechanism to thereby release said output member from said second position.

13. A method of operating an actuator to drive

vehicle stabilizer bar comprising:

energizing a motor to drive an actuator output member from a first position to a second position to thereby move said vehicle stabilizer bar from a first stabilizer bar state to a second stabilizer bar state;

energizing an electromechanical mechanism to maintain said output member in said second position;

releasing said output member from said second position upon interruption of electrical power to the actuator; and

driving said output member from said second position to said first position to thereby move said vehicle stabilizer bar from said second stabilizer bar state to said first stabilizer bar state.

14. The method of claim 13, wherein said output member is driven from said second position to said first position by a return mechanism.

15. The method of claim 14, wherein said return mechanism comprises a spring.

16. The method of claim 13, wherein said first stabilizer bar state is a disengaged state of said stabilizer bar and said second stabilizer bar state is a disengaged state of said stabilizer bar.