Electrically releasable hook and loop fastener
First Claim
1. An electrically releasable hook and loop fastener assembly (10) comprising:
- a loop fastener half-portion (12) having a loop fastener base (16) with a plurality of loop elements (18) extending therefrom;
a hook fastener half-portion (14) having a hook fastener base (20) with a plurality of hook elements (21) extending therefrom;
said hook elements having a fixed end (22) mounted to said hook fastener base and a free end (23), remote from said fixed end, defining a hook shape (24);
said hook elements being dimensioned to mechanically engage said loop elements when said loop fastener half-portion and said hook fastener half portion are pressed into contact with each other;
said hook elements comprising a first length of flexible material (28) and a second length of flexible, electrically responsive and electrically conductive shape-memory material (27) of the type that changes from a first configuration to a second configuration in response to electrical current flow therethrough;
means (32, 33) associated with at least said hook fastener half portion for applying an electrical potential difference between said fixed end and said free end of said hook elements; and
, said length of shape-memory material being positioned to substantially straighten said hook shape in response to change in shape of said shape memory material upon application of an electrical potential difference between the ends thereof.
1 Assignment
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Accused Products
Abstract
An electrically releasable form of hook and loop fastener (10) allows one half of the fastener to release from the other half without applying direct physical force to either half. The hook elements (21) of the fastener are formed of a shape-memory alloy material (27) such as commercially available Ninitol. Release of the hook half (14) of the fastener from the loop half (12) is accomplished by passing an electrical current through the shape-memory alloy material to straighten the hooks (21) so that they release their engagement with the loops (18). The flow of electricity through the hook half energizes the Ninitol material (27) to change its shape, either expanding or contracting in length; the change in shape is made to act against another length of material (28) that remains fixed in length or changes shape in an opposite direction so as to cause the hook shape to straighten toward a rod shape. Upon termination of the flow of electrical energy, the hooks return (21) to their hook shape, ready for re-engagement with the loops (18) upon conventional mating of the two halves of the fastener. Release and re-engagement can be repeated, substantially indefinitely.
10 Citations
12 Claims
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1. An electrically releasable hook and loop fastener assembly (10) comprising:
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a loop fastener half-portion (12) having a loop fastener base (16) with a plurality of loop elements (18) extending therefrom;
a hook fastener half-portion (14) having a hook fastener base (20) with a plurality of hook elements (21) extending therefrom;
said hook elements having a fixed end (22) mounted to said hook fastener base and a free end (23), remote from said fixed end, defining a hook shape (24);
said hook elements being dimensioned to mechanically engage said loop elements when said loop fastener half-portion and said hook fastener half portion are pressed into contact with each other;
said hook elements comprising a first length of flexible material (28) and a second length of flexible, electrically responsive and electrically conductive shape-memory material (27) of the type that changes from a first configuration to a second configuration in response to electrical current flow therethrough;
means (32, 33) associated with at least said hook fastener half portion for applying an electrical potential difference between said fixed end and said free end of said hook elements; and
,said length of shape-memory material being positioned to substantially straighten said hook shape in response to change in shape of said shape memory material upon application of an electrical potential difference between the ends thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for electrically releasing hook and loop fastener halves from engagement with each other, said system comprising:
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a loop fastener half-portion (12) having a loop fastener base (16) with a plurality of loop elements (18) extending therefrom;
a hook fastener half-portion (14) having a hook fastener base (20) with a plurality of hook elements (21) extending therefrom;
said hook elements having a fixed end (22) mounted to said hook fastener base and a free end (23), remote from said fixed end, defining a hook shape (24);
said hook elements being dimensioned to mechanically engage said loop elements when said loop fastener half-portion and said hook fastener half portion are pressed into contact with each other;
said hook elements comprising a first length of flexible material (28) and a second length of flexible, electrically responsive and electrically conductive shape-memory material (27) of the type that changes from a first configuration to a second configuration in response to electrical current flow therethrough;
said length of shape-memory material being positioned to substantially straighten said hook shape in response to change in shape of said shape memory material upon application of an electrical potential difference between the ends thereof;
electrical on-off control switch means and a source of electrical energy connected in series with each other and with said first length of shape memory material to form an electrical path through said first length of material when said switch is on and to interrupt said electrical path when said switch is off; and
,means (32, 33) associated with at least said hook fastener half portion for applying an electrical potential difference between said fixed end and said free end of said hook elements.
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Specification