ACTIVE MATERIAL HEAD RESTRAINT ASSEMBLY

• US 20080252113A1
• Filed: 03/27/2008
• Published: 10/16/2008
• Est. Priority Date: 04/12/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Browne, Alan L., Johnson, Nancy L., Alexander, Paul W., Berger, Leigh A., Carpenter, Michael G., Khoury, James Y.
• Granted Patent: US 7,883,148 B2
• Time in Patent Office: Days
• US Class Current: 297/216.12
• CPC Class Codes: B60N 2/832 movable to an inoperative or stowed position
• CPC Class Codes: B60N 2/888 with arrangements for protecting against abnormal g-forces, e.g. by displacement of the head-rest

Abstract

A head restraint assembly includes a support member and a deployable member selectively movable between a retracted position and a deployed position. At least a portion of the deployable member is farther from the support member in the deployed than in the retracted position. A latch system is configured to releasably retain the deployable member in its retracted position. An active material member is actuatable to release the latch system, to release the deployable member.

Claims

1. A head restraint assembly for a seat comprising:

a support member;

a deployable member selectively movable between a retracted position and a deployed position;

at least a portion of said deployable member being farther from the support member in the deployed position than in the retracted position;

a latch system configured to releasably retain the deployable member in its retracted position; and

an active material member that is actuatable to release the latch system to thereby release the deployable member.

2. The head restraint assembly of claim 1, wherein actuation of the active material also causes the movement of the deployable member from its retracted position to its deployed position.

3. The head restraint assembly of claim 1, wherein at least a portion of the deployable member is in a different angular orientation relative to the support member in the deployed position than in the retracted position.

4. The head restraint assembly of claim 1, wherein the active material member comprises at least one of a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological elastomer, an electrorheological elastomer, an electroactive polymer, and a piezoelectric material.

5. The head restraint assembly of claim 1, wherein the active material member is a wire.

6. The head restraint assembly of claim 1, wherein the active material is configured to be activated by an activation signal that comprises at least one of a thermal activation signal, an electric activation signal, a magnetic activation signal, a chemical activation signal, and a mechanical load.

7. The head restraint assembly of claim 6, further comprising an activation device configured to provide the activation signal to the active material.

8. The head restraint assembly of claim 1, wherein the active material member changes in at least one of shape, stiffness and a dimension in proportion to an applied external signal.

9. The head restraint assembly of claim 1, wherein actuation of the active material allows a stored potential energy device to aid the movement of the deployable member from its retracted position to its deployed position.

10. A head restraint assembly comprising:

a support member;

a deployable member selectively movable between a retracted position and a deployed position;

at least a portion of said deployable member being farther from the support member in the deployed position than in the retracted position;

a clutch operatively interconnecting the support member and the deployable member and configured for a first mode of operation in which the clutch permits movement of the deployable member toward its deployed position and prevents movement of the deployable member toward its retracted position, and a second mode of operation in which the clutch permits movement of the deployable member toward its retracted position; and

an active material member that is actuatable to cause the clutch to operate in its second mode of operation.

11. The head restraint assembly of claim 10, wherein the active material member comprises at least one of a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological elastomer, an electrorheological elastomer, an electroactive polymer, and a piezoelectric material.

12. The head restraint assembly of claim 10, wherein the active material member is a wire.

13. The head restraint assembly of claim 10, wherein the active material is configured to be activated by an activation signal that comprises at least one of, a thermal activation signal, an electric activation signal, a magnetic activation signal, a chemical activation signal, and a mechanical load.

14. The head restraint assembly of claim 13, further comprising an activation device configured to provide the activation signal to the active material member.

15. The head restraint assembly of claim 10, wherein the active material member changes in at least one of shape, stiffness and a dimension in proportion to an applied external signal.

16. A head restraint assembly comprising:

a support member;

a deployable member selectively movable in first and second directions between a retracted position and a deployed position;

said deployable member being at least one of farther from and in a different angular orientation relative to the support member in the deployed position than in the retracted position;

a deployment mechanism configured to move the deployable member from its retracted position to its deployed position upon actuation;

an active material member; and

a lock system configured to limit motion of the deployable member in both directions and disengageable by the active material during actuation of the deployment mechanism.

17. The head restraint assembly of claim 16, wherein the active material member comprises at least one of a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological elastomer, an electrorheological elastomer, an electroactive polymer, and a piezoelectric material.

18. The head restraint assembly of claim 16, wherein the active material member is a wire.

19. The head restraint assembly of claim 16, wherein the active material is configured to be activated by an activation signal that comprises at least one of a thermal activation signal, an electric activation signal, a magnetic activation signal, a chemical activation signal, and a mechanical load.

20. The head restraint assembly of claim 19, further comprising an activation device configured to provide the activation signal to the active material.

21. The head restraint assembly of claim 165, wherein the active material member changes in at least one of shape, stiffness and a dimension in proportion to an applied external signal.