Active material actuated headrest assemblies

• US 20070246979A1
• Filed: 04/17/2007
• Published: 10/25/2007
• Est. Priority Date: 04/17/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Johnson, Nancy, Khoury, James, Browne, Alan, Chernoff, Adrian, Glaser, Rainer, Ukpai, Ukpai, Zavattieri, Pablo
• Granted Patent: US 7,448,678 B2
• Time in Patent Office: Days
• US Class Current: 297/216.120
• CPC Class Codes: A47C 7/38 for the head adjustable coupled to reclining or easy chairs A47C1/036
• CPC Class Codes: B60N 2/806 movable or adjustable
• CPC Class Codes: B60N 2/865 providing a fore-and-aft movement with respect to the occupant's head
• CPC Class Codes: B60N 2/885 provided with side-rests
• CPC Class Codes: B60N 2002/981 Warning systems, e.g. the seat or seat parts vibrates to warn the passenger when facing a danger

Abstract

Active material actuated headrest assemblies and their methods of operation are described herein. The headrests include an active material incorporated in a frame member, a bag, gear device, or the like, wherein the active material actuates upon receipt of an activation signal.

Claims

1. A headrest positioned to be aligned with a seated occupant'"'"'s head, the headrest comprising:

a post extending from a seatback;

a padded covering having a surface configured to contact the occupant'"'"'s head;

a frame disposed within the padded covering; and

an active material disposed within the padded covering in operative communication with a portion of the headrest surface, wherein the active material is configured to undergo a change in at least one property upon receipt of an activation signal, wherein the change in at least one property is effective to change a position of the headrest surface relative the occupants head or a modulus property.

2. The headrest of claim 1, wherein the active material comprises a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological elastomer, an electrorheological elastomer, an electroactive polymer, a piezoelectric material, a magnetorheological fluid, an electrorheological fluid, a shear thickening fluid, a shear thinning fluid, or combinations comprising at least one of the foregoing active materials.

3. The headrest of claim 1, wherein the padded covering is formed at least in part of one or more active material.

4. The headrest of claim 1, wherein the change in the at least one property comprises a change in a shape, a dimension, a phase, a shape orientation, a stiffness, a shear strength and/or viscosity or combinations comprising at least one of the foregoing properties.

5. The headrest of claim 1, wherein the activation signal comprises a thermal activation signal, an electric activation signal, a magnetic activation signal, a chemical activation signal, a mechanical load, or a combination comprising at least one of the foregoing activation signals.

6. The headrest of claim 1, further comprising an activation device configured to provide the activation signal to the active material.

7. The headrest of claim 1, wherein the active material defines one or more framing members of the frame.

8. The headrest of claim 1, wherein the headrest further comprises wing portions extending from a central portion, wherein the change in the at least one property of the active material is effective to selectively orient the wing portions relative to the central portion.

9. The headrest of claim 1, further comprising a bladder in operative communication with the headrest surface, wherein the active material comprises a fluid disposed within the bladder, and wherein the change in at least one property is effective to change the resistance of the headrest surface to deformation by increasing or decreasing the effective viscosity and/or shear strength of the fluid and/or volume of the bladder.

10. A method for selectively reconfiguring a shape or modulus property of a headrest extending from a seatback, the method comprising:

activating an active material with an activation signal, wherein the active material is in operative communication with a headrest surface and is configured to undergo a change in at least one property upon receipt of the activation signal; and

reconfiguring the headrest by changing a position or modulus property of the headrest surface in response to the change in the at least one property.

11. The method of claim 10, further comprising deactivating the active material to reverse the change in at least one property.

12. The method of claim 10, wherein activating the active material with the activation signal comprises continuously applying the activation signal to the active material and maintaining change in at least one feature of the headrest surface.

13. The method of claim 10, wherein changing the position or the modulus property comprises changing a shape, a dimension, a phase, a shape orientation, a stiffness, a viscosity and/or shear strength or combinations thereof to the active material.

14. The method of claim 10, wherein activating the active material with the activation signal comprises applying a selected one of a thermal activation signal, an electric activation signal, a magnetic activation signal, a chemical activation signal, and a mechanical load.

15. The method of claim 10, further comprising locking the headrest in the position, location, shape, etc. resulting from the change in at least one property of the active material so as to hold the change in the headrest after deactivating the active material.

16. The method of claim 10, further comprising applying the activation signal to change the at least one property in the active material in response to a sensor input, wherein the sensor input is a detected condition.

17. A headrest assembly comprising:

a central portion;

a first wing portion coupled to one side of the central portion;

a second wing portion coupled to an other side of the central portion;

a frame for supporting and defining the wing and central portions, wherein the frame has interconnecting members formed of an active material, wherein the active material is configured to selectively change a position of the wing and/or central portions or change a modulus property of the wing portions relative to the central portion.

18. The headrest of claim 17, wherein the interconnecting members are plates.

19. The headrest of claim 17, wherein the active material comprises a shape memory alloy, a ferromagnetic shape memory alloy, a shape memory polymer, a magnetorheological elastomer, an electrorheological elastomer, an electroactive polymer, a piezoelectric material, a magnetorheological fluid, an electrorheological fluid, a shear thickening fluid, a shear thinning fluid, or combinations comprising at least one of the foregoing active materials.

20. The headrest of claim 17, further comprising a sensor configured to detect a condition and activate the active material.