Magnetorheological nanocomposite elastomer for releasable attachment applications

• US 20040194261A1
• Filed: 04/15/2004
• Published: 10/07/2004
• Est. Priority Date: 10/19/2002
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Ulicny, John C., Golden, Mark A., Ottaviani, Robert A.
• Granted Patent: US 7,020,938 B2
• Time in Patent Office: Days
• US Class Current: 24/442
• CPC Class Codes: A44B 18/0003 Fastener constructions A44B18/0023, A44B18/0046 take precedence
• CPC Class Codes: A44B 18/0096 Shape memory materials
• CPC Class Codes: A44D 2203/00 Fastening by use of magnets
• CPC Class Codes: C08L 2201/12 Shape memory
• CPC Class Codes: F16B 2200/77 Use of a shape-memory material
• CPC Class Codes: F16B 2200/81 Use of a material of the hooks-and-loops type
• CPC Class Codes: F16F 1/3605 characterised by their material F16F1/362, F16F1/364, F16F1/366, F16F1/37 take precedence; composition of macromolecular compounds in general C08L
• CPC Class Codes: F16F 2224/045 magnetorheological
• CPC Class Codes: Y10T 24/27 including readily dissociable fastener having numerous, protruding, unitary filaments randomly interlocking with, and simultaneously moving towards, mating structure [e.g., hook-loop type fastener]
• CPC Class Codes: Y10T 428/24017 Hook or barb

Abstract

A releasable fastener system comprises a loop portion and a hook portion. The loop portion includes a support and a loop material disposed on one side thereof whereas the hook portion includes a support and a plurality of closely spaced upstanding hook elements extending from one side thereof. When the hook portion and loop portion are pressed together they interlock to form a releasable engagement. The resulting joint created by the engagement is relatively resistant to shear and pull forces and weak in peel strength forces. The hook elements are formed of a magnetorheological elastomer that provides a change in shape orientation and/or flexural modulus of the hook elements. In this manner, the shape orientation and/or flexural modulus of the hook elements can be remotely changed to provide a reduction or magnification in the shear and/or pull-off forces in addition to providing variable damping capabilities to the fastener system.

Claims

1-17. -17. (Canceled)

18. A hook portion for a releasable fastener system comprising:

a support and

a plurality of hook elements disposed on a surface of the support, wherein the plurality of hook elements comprise a magnetorheological elastomer adapted to change a shape orientation and/or a flexural modulus upon receipt of a magnetic signal.

21. A releasable fastener system comprising:

a loop portion comprising a support and a loop material disposed on a surface thereon;

a hook portion comprising a support and a plurality of hook elements disposed on a surface, wherein the plurality of hook elements comprises a magnetorheological elastomer adapted to change a shape orientation and/or flexural modulus; and

means for changing the shape orientation and/or flexural modulus to reduce a shear force and/or a pull-off force of an engaged hook and loop portion and to provide a variable damping capability to the fastener system.