Releasable fastener system

• US 20040074068A1
• Filed: 02/05/2003
• Published: 04/22/2004
• Est. Priority Date: 10/19/2002
• 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 L., Browne, Alan Lampe
• Granted Patent: US 7,140,081 B2
• Time in Patent Office: Days
• US Class Current: 24/442
• CPC Class Codes: A41D 2300/326 using hooks and eyelets
• CPC Class Codes: A44B 18/0003 Fastener constructions A44B18/0023, A44B18/0046 take precedence
• CPC Class Codes: A44B 18/0007 in which each part has similar elements
• CPC Class Codes: A44B 18/0096 Shape memory materials
• CPC Class Codes: A44D 2203/00 Fastening by use of magnets
• CPC Class Codes: B64C 33/02 Wings; Actuating mechanisms therefor
• 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: F16B 2200/83 Use of a magnetic material
• CPC Class Codes: F16B 5/07 by means of multiple interengaging protrusions on the surfaces, e.g. hooks, coils,
• 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]

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 material or have configurations that provide a shape changing capability and/or change in flexural modulus property to the hook elements. In this manner, the shape and/or flexural modulus of the hook elements can be remotely changed to provide a reduction in the shear and/or pull forces.

Claims

1. A releasable fastener system comprising:

a loop portion comprising a loop support and a loop material attached or supported by the support;

a hook portion comprising a support, at least one hook element attached to the support, wherein the at least one hook element comprises a hollow interior region in fluid communication with the at least one perforation; and

means for increasing or decreasing a pressure within the hollow interior region upon receipt of an activation signal to provide the at least one hook element with a change in shape orientation, a change in flexural modulus property, or a combination of a change in the shape orientation and the flexural modulus property.

2. The releasable fastener system of claim 1, wherein the activation signal comprises a pneumatic signal, a thermal signal, a mechanically activating signal, or combinations comprising at least one of the foregoing signals.

3. The releasable fastener system of claim 1, wherein the at least one hook element comprises a shape comprising a J-shaped orientation, a mushroom shape, a knob shape, a multi-tined anchor shape, a T-shape, a spiral shape, or combinations comprising at least one of the foregoing shapes.

4. The releasable fastener system of claim 1, wherein the loop material comprises a shape adapted to be engaged with the hook elements when the hook portion is pressed into face-to-face engagement with the loop portion.

5. The releasable fastener system of claim 1, wherein the activation signal pneumatically or hydraulically introduces fluid into the hollow interior region of the at least one hook element.

6. The releasable fastener system of claim 1, wherein the at least one hook element comprises a hollow tube, wherein each hollow tube comprises an open end in fluid communication with a perforation disposed in the support and a closed end, wherein the activation signal pneumatically or hydraulically introduces fluid through the perforation and into the open end to change the shape orientation and/or flexural modulus property of the at least one of hook element.

7. The releasable fastener system of claim 1, wherein the shape orientation to the at least one hook element changes from an inverted J-shaped orientation to a substantially straightened shape orientation upon pressurization.

8. The releasable fastener system of claim 1, wherein the at least one hook element comprises a knob like shape, and wherein the loop portion comprises at the least one complementary opening adapted to receive the knob like shape.

9. A releasable fastener system comprising:

a loop portion comprising a loop support and a loop material attached or supported by the loop support;

a hook portion comprising a support, at least one hook element attached to an upper surface of the support, a containment vessel coupled to a lower surface of the support, and at least one perforation through the support, wherein the at least one hook element comprises a hollow interior region in fluid communication with the at least one perforation, and wherein the containment vessel comprises a slidably engageable plunger; and

an activation device in operative communication with the hook portion, the activation device being operable to selectively provide an activation signal to slidably engage the plunger within the containment vessel and cause a pressure change in the at least one hook element.

10. The releasable fastener system according to claim 9, further comprising a spring coupled to the plunger and the lower surface of the hook portion support.

11. The releasable fastener system according to claim 10, wherein the spring is fabricated from a shape memory material responsive to a thermal activation signal to slidably engage the plunger and cause the pressure change in the at least one hook element.

12. The releasable fastener system according to claim 9, further comprising a rigid element disposed in the hollow interior region of the at least one hook element, wherein the rigid element is dimensioned to provide a hook-like shape orientation to the at least one hook element in a relaxed state and a straightened shape orientation upon receipt of the activation signal.

13. The releasable fastener system according to claim 9, wherein the containment vessel comprises a diaphragm adapted to cause a pressure change in the at least one hook element upon receipt of the activation signal.

14. A process for operating a releasable fastener system, the process comprising:

contacting a loop portion to a hook portion to form a releasable engagement, wherein the loop portion comprises a support and a loop material disposed on a surface thereon, and wherein a hook portion comprising a support, at least one hook element attached to the support, wherein the at least one hook element comprises a hollow interior region in fluid communication with at least one perforation and is adapted to change a shape orientation, a flexural modulus property, or a combination thereof, upon receipt of an activation signal;

maintaining constant shear and pull forces in the releasable engagement without introducing the activation signal;

selectively introducing the activation signal to the hook portion, wherein the activation signal is effective to change the shape orientation, the flexural modulus property, or the combination thereof to the plurality of hook elements; and

reducing shear and/or pull forces in the releasable engagement.

15. The process according to claim 14, wherein the activation signal comprises pressurizing the at least one hook element.

16. The process according to claim 14, wherein the activation signal comprises sliding a rigid element into the hollow interior region of the at least one hook element.

17. The process according to claim 14, wherein the hook elements comprise a shape comprising a J-shaped orientation, a mushroom shape, a knob shape, a multi-tined anchor shape, a T-shape, a spiral shape, or combinations comprising at least one of the foregoing shapes.

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

a support comprising an upper surface, a lower surface and at least one perforation through the support;

at least one hook element attached to the upper surface of the support, wherein the at least one hook element comprises a hollow interior region in fluid communication with the at least one perforation; and

a containment vessel coupled to the lower surface of the support, and wherein the containment vessel comprises a slidably engageable plunger.

19. The hook portion according to claim 18, wherein the support comprises a metal, a plastic, a fabric, or a combination comprising at least one of the foregoing materials.

20. The hook portion according to claim 18, wherein the at least one hook element comprises a shape comprising a J-shaped orientation, a mushroom shape, a knob shape, a multi-tined anchor shape, a T-shape, a spiral shape, and combinations comprising at least one of the foregoing shapes.

21. The hook portion according to claim 18, further comprising an activation device adapted to provide an activation signal to the plurality of hook elements to sidably engage the plunger.

22. The hook portion according to claim 18, further comprising a rigid element disposed in the hollow interior region of the at least one hook element, wherein the rigid element is dimensioned to provide a hook-like shape orientation to the at least one hook element in a relaxed state and a straightened shape orientation upon receipt of the activation signal.

23. The hook portion according to claim 18, wherein the containment vessel comprises a diaphragm.