Magnetic closures

Abstract

A releasable closure having a first structure that encapsulates a magnetic composition based on magnetic particles, such as a smart fluid of the group electrorheological fluid, magnetorheological fluid, ferrofluid, or that is formed of a printable composition with dispersed magnetic particles. The first structure is magnetically attracted and thereby joinable to an opposing, second structure, with the first and second structures forming the releasable closure.

1 .- 38 . (canceled) 
     
     
         39 . A releasable closure for inhibiting access to an opening, comprising:
 a. a substrate material defining an opening;   b. an overlying material that can inhibit access to the opening; and   c. a closure element coupled to the overlying material, the closure element having a smart fluid therein wherein the closure element is relatively rigid when the smart fluid is magnetized and access to the opening is more inhibited, and the closure element is relatively compliant when the smart fluid is not magnetized and access to the opening is less inhibited.   
     
     
         40 . The releasable closure of  claim 39 , wherein the smart fluid is any fluid whose viscosity changes in the presence of an electric field. 
     
     
         41 . The releasable closure of  claim 39 , wherein the smart fluid is any fluid whose viscosity changes in the presence of a magnetic field. 
     
     
         42 . The releasable closure of  claim 39 , wherein the overlying material comprises a flap that covers the opening. 
     
     
         43 . The releasable closure of  claim 42 , wherein the closure element is coupled to the substrate material and routed down the flap. 
     
     
         44 . The releasable closure of  claim 39 , wherein the smart fluid is any fluid of the group of electrorheological fluid, magnetorheological fluid, and ferrofluid. 
     
     
         45 . The releasable closure of  claim 39 , wherein the overlying material comprises a tongue, wherein the closure element is affixed to the overlying material along a length of the tongue. 
     
     
         46 . The releasable closure of  claim 45 , further comprising a strap, wherein the tongue is configured to fit beneath the strap. 
     
     
         47 . The releasable closure of  claim 45 , further comprising a slot, wherein the tongue is configured to fit into the slot. 
     
     
         48 . The releasable closure of  claim 46 , wherein the tongue is inhibited from movement, flexing, or disengagement when the closure element is relatively rigid. 
     
     
         49 . The releasable closure of  claim 45 , wherein the substrate comprises an upper of an item of footwear and the tongue is associated with an opening of the upper. 
     
     
         50 . The releasable closure of  claim 39 , further comprising a permanent moveable magnet configured to move between a first position and a second position, wherein when the magnet is in the first position, the smart fluid in the closure element is magnetized, and when the magnet is in the second position, the smart fluid in the closure element is not magnetized. 
     
     
         51 . The releasable closure of  claim 39 , wherein the substrate material is a fabric or a synthetic fabric. 
     
     
         52 . A releasable closure for inhibiting access to an opening, comprising:
 a. a pocket attached to a substrate material and defining an opening at a top of the pocket; and   b. a closure element comprising a structure having a smart fluid therein positioned at a perimeter at the top of the pocket, wherein the closure element is relatively rigid when the smart fluid is magnetized and access to the opening is more inhibited, and the closure element is relatively compliant when the smart fluid is not magnetized and access to the opening is less inhibited.   
     
     
         53 . The releasable closure of  claim 52 , further comprising a permanent moveable magnet configured to move between a first position and a second position, wherein when the magnet is in the first position, the smart fluid in the closure element is magnetized, and when the magnet is in the second position, the smart fluid in the closure element is not magnetized. 
     
     
         54 . A selectable stay, comprising:
 a. a flexible substrate material; and   b. a closure element comprising a structure having a smart fluid therein affixed to a length of the substrate material, wherein the closure element is relatively rigid when the smart fluid is magnetized and the length of the substrate material is relatively rigid, and the closure element is relatively compliant when the smart fluid is not magnetized and the length of the substrate material is less rigid.   
     
     
         55 . The releasable closure of  claim 53 , wherein the flexible substrate material comprises a bag, and wherein the closure element is configured to hold the bag open when magnetized. 
     
     
         56 . The selectable stay of  claim 53 , wherein the flexible substrate material comprises a strap of a backpack, and wherein the closure element is configured to hold the strap away from the backpack when magnetized.