HK1241554B - Magnetic closures - Google Patents

Description

Magnetic closure

Related applications

This application claims the benefit of and priority to U.S. Provisional Application Serial No. 62/094,926, filed December 19, 2014, the contents of which are hereby incorporated by reference for all purposes as if fully set forth herein.

background

The present subject matter generally relates to closures for closing openings in objects or creating connections between parts of an object. The closures are magnetic and are intended to be suitable for use as replacements for zippers and other such closures. For example, the closures of the present invention are suitable for use in clothing and other textile-based objects, as well as footwear applications.

Magnets attract ferromagnetic materials, and magnets attract magnets when opposite poles align. Magnetic fields can be permanent or selective. That is, a magnetic field can be selectively established in an object by an electric current, or induced in certain materials (such as smart fluids) that can be magnetized in the presence of an applied magnetic field.

All moving charged particles, such as electric current, generate a magnetic field. Current flowing in a wire creates magnetic field lines in concentric circles around the length of the wire. Current flowing in two adjacent wires creates a magnetic field, which generates a magnetic force that can either attract the wires together or repel them, depending on the relative directions of the currents.

One class of fluids, referred to herein as "smart" fluids, has properties that can change when subjected to an external electromagnetic force. Examples include magnetorheological (MR) fluids, which change rheological properties in response to an applied magnetic field; ferromagnetic fluids, which become strongly magnetized in the presence of a magnetic field; and electrorheological (ER) fluids, which exhibit a change in fluid viscosity in response to an electric field.

MR fluids are suspensions of micron-sized, magnetically polarizable particles in oil or other liquids. When an MR fluid is exposed to a magnetic field, the normally randomly oriented particles within the fluid form chains of particles in the direction of the magnetic field lines. This alignment increases the fluid's apparent viscosity, and magnetization occurs along the chains of aligned particles. MR elastomers are suspensions of micron-sized, magnetically polarizable particles in a thermosetting elastomeric polymer or rubber. The stiffness of the elastomeric structure can be altered by varying the strength of the applied magnetic field. When exposed to a magnetic field, MR fluids and elastomers typically change viscosity within only milliseconds. Ceasing exposure of the MR fluid or elastomer to the magnetic field reverses the process: the fluid loses its magnetism and returns to a lower viscosity state, and the elastomer returns to its lower modulus state. MR fluids enclosed in structural elements are disclosed in U.S. Patent No. 5,547,049.

Ferrofluids are stable suspensions of magnetic particles in a liquid carrier. These particles typically have an average size of about 10 nm and are coated with a surfactant that prevents particle agglomeration even when a strong magnetic field is applied. Various magnetic solids, surfactants, and carriers are known and available and can be used to adjust the properties of ferrofluids according to the intended application.

Ferrofluids generally behave the same regardless of their composition. In the absence of a magnetic field, the magnetic moments of the particles in a ferrofluid are randomly distributed, and the fluid has no net magnetization. When a magnetic field is applied to the ferrofluid, the magnetic moments of the particles are oriented along the field lines, and the ferrofluid is magnetized. Ferrofluids generally respond almost immediately to changes in the applied magnetic field, and when the applied field is removed, these magnetic moments quickly randomize again. The retention force of a ferrofluid can be adjusted by changing the composition of the fluid or by changing the magnetic field that causes the magnetization.

Electrorheological (ER) fluids are dispersions that can rapidly and reversibly change their apparent viscosity in the presence of an applied electric field. ER fluids are dispersions of finely divided solids (<50 microns) in a hydrophobic, non-conductive oil that have the ability to change their rheological properties, even to the point of becoming a solid, when exposed to a sufficiently strong electric field. When the field is removed, the fluid returns to its normal liquid state. The current passed through the ER fluid can be very low and still achieve the desired state change.

"Printed electronics" refers to printing methods for creating electrical devices on various substrates. Conventional printing equipment and processes, such as screen printing, flexographic printing, gravure printing, offset printing, and inkjet printing, can be used to define electrical patterns on materials. Electrically operated electronic inks are deposited on substrates to create active or passive devices, such as conductors, transistors, and resistors.

One type of textile that can include electronic circuitry is electronic textiles or smart fabrics, which have digital components embedded in them. Electronic textiles include textiles with classical electronics (such as conductors, integrated circuits, LEDs, and batteries embedded in clothing) and textiles with electronics integrated directly into the textile substrate. This can include passive electronic devices such as conductors and resistors, or active components such as transistors, diodes, and solar cells.

Another area where conductors and circuits can be integrated into textiles is in "fibertronics," which uses conductive and semiconducting materials in the manufacture of woven materials. Commercial fibers, such as metal fibers, can be woven or sewn into clothing or other textile items. Organic electronics may be suitable because they can be conductive, semiconducting, and designed into inks and plastics.

Advances in this field are ongoing, and future textiles with electromagnetic properties may be suitable for implementing the inventive concepts disclosed herein.

Closures join things together, and as used herein, a closure refers to a device that connects one object to another object or one part of an object to another part of the same object. Known examples of releasable closures include zippers, buttons, Velcro, ties, latches, magnets, and snaps. Examples of non-releasable closures (i.e., closures intended to be permanent) include nails, screws, and most adhesives.

Releasable closures are common in clothing, footwear, camping equipment (such as tents, sleeping bags, and backpacks), sporting equipment (such as pads, helmets, and safety gear), upholstered items (such as chairs and sofas), and many other applications in all possible fields. Considerations when selecting a releasable closure for an application include its weight, damage resistance, resistance to environmental factors (water, dust, wind, etc.), holding strength, flexibility, aesthetics, ease of use, profile (e.g., thinness), and reliability.

Magnetic closure systems based on zipper-like interlaced magnetic elements are known. U.S. Patent No. 6,983,517, entitled "Releasable Closure System," discloses the use of MR fluid in the headers of the interlaced elements. The headers on the interlaced elements may include MR fluid that can be magnetically opened or closed to change their configuration so that they engage with complementary headers on opposing interlaced elements.

Unfortunately, closure systems based on interlaced elements have significant drawbacks. Such systems require a sliding closure, complicating manufacture and use. Interlaced elements are also prone to failure. If a single element fails, the entire closure fails. They are also difficult or expensive to design for weather resistance, as each element presents an ingress point for moisture or air, due to imperfect seals in conventional designs.

Thus, the releasable closure industry could benefit from a releasable closure that includes properties not found in prior art devices and that provides reliability, ease of use, resistance to environmental elements, and good holding strength.

There also exists a need for garment components that are more securely and aesthetically pleasingly coupled together. And there is a need for easily operable devices for coupling garments and other objects and for opening or closing common openings of such objects.

The inventive subject matter disclosed herein, in its various possible embodiments and applications, addresses the foregoing needs and other needs and overcomes the shortcomings of the prior art.

Overview

The following is a brief description of some of the various inventive lines underlying the present invention. The appended claims, as originally filed in this document or subsequently amended, are hereby incorporated into this summary as if directly written. The following is not intended to be an exhaustive list of embodiments and features of the present invention. Those skilled in the art will be able to understand other embodiments and features from the following detailed description in conjunction with the accompanying drawings.

In some embodiments, the present subject matter relates to a releasable closure having a first structure that encapsulates a magnetic composition based on magnetic particles, such as a smart fluid, which is a fluid in the group of electrorheological fluids, magnetorheological fluids, ferromagnetic fluids, or the first structure is formed of a printable composition with dispersed magnetic particles. The first structure is magnetically attracted to an opposing second structure and thereby can be bonded to the opposing second structure, and the first structure and the second structure form a releasable closure. The second structure can be a magnetic structure or a magnetizable structure like the first structure. Alternatively, it can be made of a ferromagnetic material that is attracted to a magnet but is not itself a magnet. As used herein, a "mateable element" can refer to any structure that is magnetically attracted to a first structure and can be bonded to the first structure.

In certain of its various possible embodiments, the present subject matter is generally directed to a releasable closure system comprising: two structures having hollow portions, each hollow portion enclosing a smart fluid; and two switchable electromagnetic field sources, wherein the switches are operable to induce an electromagnetic field in the smart fluid, thereby magnetizing the smart fluid and, when properly arranged, causing the structures to attract each other and thereby be secured.

In another embodiment, the hollow structures containing the smart fluid fit loosely into a coupled state when no (or very low) electromagnetic field is present, and then become securely coupled when an electromagnetic field is present that causes the smart fluid to change state (from a relatively low viscosity fluid to a relatively high viscosity fluid), thereby substantially stiffening the hollow structures so that they are mechanically coupled.

In another embodiment of a releasable closure employing the concepts of the present invention, elongated conductors are positioned along opposing sides of an opening, and current is passed through the conductors, generating a magnetic field around the conductors. When current is passed through the conductors in the same direction, the resulting magnetic field attracts the conductors, drawing them together. If the sides of the opening are allowed to move, the resulting magnetic force secures the sides together.

The elongated conductors may be printed electronics, e-textiles or e-fiber materials embedded in fabrics or other textiles.

The subject matter of the present invention may be implemented as releasable closures for apparel, footwear, equipment, upholstered items including but not limited to jackets, sleeping bags, tent flaps, backpack openings, bags, flaps, suitcases and bags, footwear, furniture, cushions, and many other applications.

When used with footwear, the need for lacing can be eliminated, and the footwear is streamlined and more comfortable. In one example, a releasable closure with the present invention's concepts would be located between the tongue and the side of the upper (where the two overlap). In another embodiment, the smart fluid would be enclosed in a hollow, strap-like structure (similar in size and dimensions but smaller and more durable, and less susceptible to degradation by dirt or other contaminants). When the straps overlap and are subjected to an electromagnetic field, they will be magnetized and tightened.

In another embodiment, small diameter tubes can be woven into the fabric in a predetermined pattern, where the tubes encapsulate the smart fluid and a nearby switch induces an electromagnetic field, thereby magnetizing the tubes. Other sheets of the fabric can include similar narrow diameter tubes that are similarly magnetized and arranged to attract each other, or sections of the fabric can include braided metal wires that are attracted to the magnetic field in the woven tubes.

These and other embodiments are described in greater detail in the following detailed description and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings illustrate embodiments according to the inventive subject matter, unless stated otherwise to illustrate prior art.

Figure 1A shows a schematic plan view of a first representative embodiment of a releasable closure. Figure 1B shows an enlarged plan view of a portion of the first representative embodiment shown in Figure 1A. Figure 1C shows a cross-sectional view of the first embodiment with the sides of the system secured.

FIG2 illustrates a schematic plan view of a second representative embodiment of a switch assembly.

FIG3 shows a schematic plan view of a second representative embodiment of a releasable closure.

FIG4A shows a schematic diagram of a tubular element according to a representative embodiment, and FIG4B shows a cross-section of the tubular element.

FIG. 5A shows a schematic diagram of a representative embodiment of a hollow element, and FIG. 5B , 5C and 5D show cross-sections of three embodiments of the hollow element.

Figure 6A shows a schematic plan view of one embodiment of a representative embodiment of a releasable closure. Figure 6B shows a cross-sectional view of the embodiment taken along line 6-6, and Figure 6C shows a side view of the embodiment being fastened.

FIG. 7A shows a schematic plan view of a representative embodiment of a releasable closure, and FIG. 7B shows a detail of the embodiment of FIG. 7A .

8A shows a schematic plan view of another representative embodiment of a releasable closure with the halves of the closure system separated, and FIG. 8B shows a detail of the embodiment of FIG. 8A with the opposing halves of the closure joined.

9 shows a schematic diagram of a bag attached to a base material and having an embodiment for structurally controlling access to the bag.

10 shows a schematic diagram of a bag flap attached to a base material and having an embodiment for structurally controlling access to the bag.

FIG. 11 shows a schematic diagram of a tab engaged with a retaining strip attached to a base material.

Detailed description

Representative embodiments according to the present subject matter are shown in Figures 1-8, where identical or substantially similar features share the same reference numerals.

The present subject matter generally relates to releasable closures having a first structure that encapsulates a magnetic composition based on magnetic particles, such as a smart fluid, which is a fluid from the group consisting of electrorheological fluids, magnetorheological fluids, and ferrofluids, or a printable composition having dispersed magnetic particles. The first structure is magnetically attracted to, and thereby bondable to, an opposing second structure, and the first and second structures form a releasable closure.

FIG1 shows a representative example of a releasable closure 10 as part of a closure system 12. The closure 10 includes a left plate 14 and a right plate 16 that support a first tubular element 18 and a second tubular element 20, respectively. Tubular element 18 is mounted to the front face of plate 14, as seen in FIG1A , and is therefore shown in dashed lines. The system also includes a first switch 22 and a second switch 24, shown at the lower ends of the respective tubular elements. Elements 18 and 20 can be filled with or formed from a magnetic or magnetizable material. They can be a unitary construction extending along the entire length of an opening to be closed or an edge to be engaged with another object. Alternatively, they can be part of a series of tubes spaced along the opening or along the edge and collectively forming a closure or system that engages objects. For example, the single tube shown in FIG1 can be broken down into multiple tubes spaced along the edges of plates 14 and 16. The multiple tubes can be connected by thinner connecting tubes to conduct magnetic fields between the multiple tubes. The elements 18, 20 may also have spaced-apart walls extending through the longitudinal cross-section, creating a series of independent chambers for the MR fluid along the length of the element. The independent chambers may have any desired spacing based on wall thickness and/or spacing. The closed system may also be based on other geometric forms that may be staggered when magnetizing the smart fluids in opposing housings or containers.

The left and right panels 14, 16 can be fabric, leather, polymers (e.g., plastic), or other materials, or can be any other removable parts that need to be fastened together. For example, the left and right panels can be the sides of a shirt or jacket that need to be fastened together when donning and released for undressing. Alternatively, the panels can be the lateral or medial sides and tongue of a shoe, or part of a sleeping bag. The releasable closures according to the present invention can be used to fasten any suitable removable part.

The tubular elements 18, 20 may be flexible polymer tubes or tubes made of waterproof fabric or other material that will safely contain the fluid 26 (fluid 26 is shown in the cross-sectional view of FIG1C within the central cavity of the tubular element). The central cavity need not extend the length of the tube and may extend only partially along its length.

Elements 18 and 20 may be referred to as "tubular" elements; however, the cross-sectional shape need not be circular and may instead be oval, triangular, rectilinear, or other suitable shapes. Asymmetric shapes may provide advantages in certain configurations. Examples of asymmetric shapes are teardrop shapes or cross-sections having a wavy shape.

Oval cross-section elements will mean that element 18 and element 20 will be relatively flat elements (relative to circular cross-section elements of the same volume). Overlapping them will increase the contact area between the elements, thereby affecting the closing force. The width and thickness of elements 18, 20 can be varied (allowing the amount of fluid 26 to be controlled) to control the amount and strength of the attractive force between the sides. Combinations of elements with different cross-sections can also be used, for example, element 18 can be a flat element with an oval cross-section, and element 20 can be a tube with a circular cross-section, or alternatively, element 18 can have a circular cross-section and element 20 can have a wavy cross-section that supports element 18.

The elements 18, 20 can be attached directly or indirectly to the plates 14, 16 or be integral with the plates 14, 16. For example, the present subject matter contemplates that the tubes 18, 20 can be indirectly attached to the plates using an intermediate structure. For example, the tubes 18, 20 can be provided on a belt (e.g., a fabric strip), such as the kind used to support conventional zipper teeth. The belt with the tubes 18, 20 can be sewn to the edge of an opening for a garment or other object. Thus, the present subject matter contemplates a stand-alone construction comprising a magnetic closure (e.g., a tube 18, 20 filled with a smart fluid) and a supporting substrate such as a belt. It is also contemplated that the tubular element can be formed as part of a monolithic structure with the plate. For example, the entire plate and tube can be printed in a 3D printing process or formed in a molding process.

Although tubes 18 and 20 are shown as straight cylindrical tubes, they can have other configurations. For example, as noted above, they can have non-circular cross-sections, and their cross-sectional dimensions and profiles can vary along their lengths. They can have shapes that provide a larger surface area than a cylinder to facilitate male-female engagement. For example, the opposing sides can have wavy profiles, with the peaks of one section on one tube complementing the valleys on the opposing section on the other tube. The operation of the closure is improved when tubes 18 and 20 do not have non-matching shapes or arrangements; for example, if one tube is straight and arranged vertically and the other tube is wavy and arranged away from the vertical, the degree of closure may be reduced. Therefore, matchable shapes and arrangements of tubes 18 and 20 are preferred.

Fluid 26 is a smart fluid, which in this context means a fluid whose properties change in the presence of a magnetic field or an electromagnetic field. Since all electric currents induce magnetic fields and vice versa, references to electromagnetic fields in this context refer to fields that are primarily electric, primarily magnetic, or any combination of electric and magnetic fields.

Smart fluids include ferrofluids, which are liquids that become magnetized in the presence of a magnetic field. Ferrofluids generally do not remain magnetized in the absence of an externally applied electromagnetic field.

Smart fluids include magnetorheological (MR) fluids, which, when subjected to an electromagnetic field, increase their apparent viscosity significantly, to the point of becoming a viscoelastic solid. The main difference between ferrofluids and MR fluids is the size of the suspended particles.

Smart fluids also include electrorheological (ER) fluids, which are suspensions of very fine, non-conductive particles (up to 50 μm or so) in an electrically insulating fluid. The apparent viscosity of an ER fluid changes reversibly in response to an electromagnetic field, typically on the order of, for example, 100 K. A typical ER fluid can change from a relatively low-viscosity liquid to a relatively high-viscosity gel, and back from a relatively high-viscosity gel to a relatively low-viscosity liquid, with a response time of a few milliseconds.

FIG1B shows an enlarged view of switch 24 (which is also a representative of switch 22). In this embodiment, switch 24 is a permanent magnet 25 mounted on a rotating seat 28. An optional retainer, such as a retaining magnet 30, is shown in dotted lines to indicate that it is mounted behind plate 16. Arrow 32 shows the movement of switch 24 from the actuated position (on the left side of the schematic diagram) to the non-actuated position (to the right). In the non-actuated position, retaining magnet 30 holds the switch and prevents it from being unintentionally moved to the actuated position. The retainer does not have to be a magnet, but can be another system that holds the switch in the off position. For example, the switch and retainer can be constructed as mutually engaging parts, such as snap fasteners.

The magnet 30 or other retaining system is selected to have sufficient magnetic strength to retain the switch in the unactuated position through the intended use of the closure system.

When switch 24 is moved to the actuated position, as shown in FIG1B , permanent magnet 25 is positioned adjacent to second tubular element 20, and smart fluid 26 within the tubular element enters the permanent magnet's magnetic field, causing a phase change in which the smart fluid becomes magnetized. As shown in FIG1B , permanent magnet 25 is oriented with its north pole facing upward and adjacent to the tubular element, forming a south pole at the point in the smart fluid column closest to the permanent magnet. When magnetized, the opposite end of the smart fluid column will therefore become a north pole.

On the opposite left plate 14, switch 22 has a similar structure and components to switch 24, but its permanent magnet 27 is arranged with its south pole facing upward and closest to the first element 18, thereby magnetizing the smart fluid column in the first element with its north pole close to the switch 22 and its south pole located at the opposite end.

When switches 22 and 24 are positioned in their actuated positions, closest to respective elements 18 and 20, the columns of smart fluid in the tubular elements become magnetic poles, with their poles arranged opposite each other, i.e., the north pole of the smart fluid in one element is opposite the south pole of the smart fluid in the other element, and the columns of smart fluid are now magnetically attracted to each other and secured, as shown in FIG. 1C , thereby coupling the left and right plates 14 , 16 together.

When the switches 22, 24 are moved away from their actuated positions, the magnetic fields of the permanent magnets 25, 27 move away from the columns of the smart fluid and the smart fluid loses its magnetic properties, loosening the system and allowing the plates to be easily decoupled.

The strength of the magnetic attraction force between the smart fluid columns in the first and second tubular elements can be controlled by the strength of the permanent magnets 25, 27, the amount and type of smart fluid in the tubular elements, and the structure of the tubular elements (e.g., thinner walls will allow for greater proximity and, therefore, a stronger magnetic coupling). The strength of the magnetic attraction force can be selected depending on the application of the closure system; for example, a shoe may require a greater closure retention strength than, perhaps, opening a wallet.

Figure 2 shows an embodiment where the switch 24a mounts the permanent magnet 25 in a slider mechanism 34 so that the magnet 25 can slide from left to right to control whether the smart fluid is magnetically actuated. Alternatively, the slider mechanism can move the magnet up and down.

As an alternative to permanent magnets 25, 27, electromagnets can be used. A battery or other power source can be located, for example, on the corresponding plates 14, 16 to actuate the electromagnets, thereby inducing a magnetic field in the corresponding smart fluid column. When using electromagnets, there is no need to physically move the electromagnets toward or away from the tubular element. Instead, the electromagnets can be fixedly attached to the corresponding plates near the tubular element. The strength of the electromagnetic field will affect the holding strength of the closure.

It should be understood that the actuating magnets, whether permanent or electromagnets, can be positioned at either end of the tubular element. Furthermore, as long as the opposing smart fluids are positioned relative to each other, either plate 14 or 16 can orient the north pole of the smart fluid upward or downward. Permanent magnets can also be positioned intermediately along the length of elements 18 and 20. Furthermore, elements 18 and 20 can have doglegs at either end, with the permanent magnets positioned adjacent to the ends of the doglegs to prevent one magnetic switch from interfering with the magnetic field of another. Magnetic insulating materials can also be used to control potential crosstalk between the switches.

Additionally, an embodiment may employ one tubular element with a smart fluid and position ferromagnetic material on opposing plates, wherein by magnetizing the smart fluid in the tubular element, the tubular element thereby becomes attracted to the ferromagnetic material and secures thereto.

Fig. 3 shows an embodiment, wherein the first plate 310 has a tubular element 314 with protrusions 318a-318f (not shown in all figures), and the second plate 312 has a tubular element 316 with protrusions 320a-320f (not shown in all figures). Tubular element 314 and tubular element 316 are in fluid communication with their corresponding protrusions 318a-f and protrusions 320a-f, and corresponding protrusions 318a-f and protrusions 320a-f magnetically attract each other. Smart fluid is encapsulated in each tubular element. Switches 322, 324 are located near the tubular element and can be moved from an actuated position (switch 322 is shown in the actuated position) and a non-actuated position (switch 324 is shown in the non-actuated position). In the actuated position, the permanent magnets associated with the switches magnetize the smart fluid in the corresponding tubular elements, and as described above, the magnets are arranged to magnetize the smart fluid so that their respective poles are facing each other and the tubular elements are magnetically attracted to each other and secured. Moving the switches to the non-actuated position demagnetizes the smart fluid and releases the system. An advantage of this system is that it orients the protrusions 318a-f and protrusions 320a-f transversely to the edges of plates 310 and 312, making the plates more flexible when the closure system is actuated. This type of closure system is advantageous when used for outdoor sportswear because the user can participate in various sports that require flexibility. (As noted above, when magnetized, the smart fluid can become more viscous, thereby hardening.) In addition, the cross-sections of elements 314 and 316 can be thinner than those of protrusions 318a-f and protrusions 320a-f to further promote flexibility.

Fig. 4A and Fig. 4B show an embodiment of the exemplary tubular element 410,412 of the tubular element 18,20 and tubular element 314,316 described above.The tubular element or other housing element can be any material that can hold liquid and does not make a lot of liquid flow out from the housing.Common example is polymer tube.Each tubular element encapsulates the column of smart fluid 414,416, as represented in the cross-sectional view in Fig. 4B.The tubular element has a tubular wall thickness, which will affect the rigidity of the tubular element and the proximity that the column of smart fluid can enter, and therefore affects the strength of the closure using these elements. The magnetic attraction of two magnets and the closure holding strength therefore are partly determined by their proximity.The tubular element can be located in a fabric sleeve (not shown) so that it is aesthetically attractive and/or convenient to be attached to a plate, wherein the tubular element can be fastened to a plate.The tubular element in Fig. 4A and Fig. 4B is shown as having a circular cross section, but as represented above, other embodiments can have a non-circular cross section, including cross sections of square, oval, star, triangle, etc.

5A and 5B illustrate a hollow member 510 and a hollow receiving member 512 of the receiving member 510. FIG5B illustrates the hollow member 510 as a tubular structure sized to fit within the receiving member 512. FIG5B illustrates the hollow member 510 as a tubular structure sized to fit within the receiving member 512.

As noted above, a property that may be affected when an applied electromagnetic field is applied to a smart fluid is an increase in the viscosity of the smart fluid, thereby stiffening the smart fluid and the structure surrounding the fluid. The embodiments of Figures 5a and 5b utilize this stiffening to produce mechanical fastening of the corresponding hollow elements. In Figure 5b, the elements can be easily or loosely press-fit together, but in the presence of electromagnetic forces, the stiffening of the smart fluid causes the receiving element to more firmly clamp the smaller element or causes the smaller element to resist deformation that would allow it to easily move out of the receiving element. In embodiments where both element 510 and element 512 contain smart fluids and these fluids are magnetized by opposing magnetic poles, the elements are coupled by magnetic attraction and mechanical fastening. In the case where only one element (e.g., receiving element 512) contains the smart fluid, the elements will be fastened only by mechanical fastening.

Fig. 6A-Fig. 6C show an embodiment in which hollow element 610 and hollow element 612 are shown as having an elliptical cross-section, which is conducive to stacking the elements when the elements are fastened together. Hollow element 610 and hollow element 612 encapsulate smart fluid and are actuated and fastened in the manner described above. Alternatively, element 610 or element 612 can encapsulate smart fluid, and the other element can be a magnetizable material such as ferromagnetic material. In all cases of ferromagnetic material, these materials can be metal fibers, yarns or printed films of different thicknesses and widths, and can be materials attracted by magnetic potential, some rare earth materials, such as neodymium. And Fig. 6 C shows a plate between element 610 and element 612, and the plate can be arranged so that the elements are in direct, stacked contact.

As shown in Figures 9 and 10, the increase in viscosity may be employed for its structural benefits and its use as a closure mechanism.

FIG9 shows a schematic diagram of a container, such as a bag 910, attached to a base material 912, such as a fabric or synthetic fabric. The top of the bag defines an opening 916. A closure element 918 having a structure that surrounds the smart fluid can be positioned along the perimeter of the top of the bag. When the smart fluid is not magnetized, the bag opening is flexible and the contents of the bag are easily accessible. When a permanent magnet, such as magnet 920, is moved near the closure element 918, the smart fluid is magnetized, and the element 918 becomes relatively rigid and restricts access to the pocket by limiting the expansion or enlargement of the opening.

10 , a closure element 1010 can be attached to a base material 1012 and routed down a flap (e.g., a bag flap 1014 covering a container such as a bag opening 1016). When the smart fluid enclosed in the closure element 1010 is not magnetized, the flap is flexible and can be bent to enter the bag opening below, but when the smart fluid is magnetized by the movable permanent magnet 1018, the closure element 1010 becomes relatively rigid and thereby holds the flap 1014 in place, inhibiting entry into the bag.

Closure elements, such as element 918 and element 1010, can also be shaped as optional stays. For example, when the smart fluid is magnetized, the stays can be used to keep the bag open, or to keep the shoulder straps of a backpack outward to make it easier to put on the backpack.

Another example, as shown in Figure 11, can include a fabric tongue 1110. The tongue is movably associated with a base 1111. The tongue can be used to cover or fill an opening in the base (not shown). The tongue has a fixed or integrated closure element 1112 along its length. The tongue can optionally fit into a slot or under a strip 1114. The closure element 1112 encapsulates the smart fluid. When the smart fluid is not magnetized, the tongue with element 1112 is flexible and easily movable relative to the base. If the optional slot or strip 1114 is used, the tongue can easily engage into the slot or under the strip 1114 when not magnetized. However, when the smart fluid is magnetized by the magnet 1118, the closure element 1112 becomes relatively rigid and prevents the tongue from moving, flexing, or separating. Base 1111 may represent an upper of an article of footwear, and tongue 1114 may be a tongue associated with an opening in the upper, as in standard footwear construction.

The description of utilizing viscosity changes for their structural benefits described with reference to exemplary elements 918, 1010, and 1112 is not intended to limit such use of structural benefits to these configurations, and the described embodiments and other embodiments may employ elements described above having other cross-sections and configurations.

FIG7A shows an embodiment in which an attractive magnetic field is generated by electric current. In FIG7A , an elongated conductor 710 is arranged on the side of an opening 712 on plates 714 and 716 along with a power source 718 and a switch 720. The switch 720 opens and closes a circuit through the corresponding conductor, power source, and wire 722. When the switch is “open,” i.e., positioned to open the circuit, no current flows through the conductor. When the switch is “closed,” the circuit is closed, and current flows from the corresponding power source through the conductor. The current in the conductor induces a magnetic field, as shown in the detailed diagram in FIG7B , in which the current i induces a magnetic field B that generates a magnetic force F that attracts the conductor 710 and connects the plates 714 and 716 together. Opening the switch opens the circuit, and the magnetic force drops to zero. Thus, controlling the current in the switch and the conductors produces a releasable closure.

Power supply 718 can be any suitable electrical storage device, such as a battery. In embodiments where panels 714 and 716 are parts of the same article, a single power supply can be used instead of the separate power supplies shown in FIG. 7A . Furthermore, an electrical generator, such as a photovoltaic cell, can be included to generate electrical energy for the power supply. Furthermore, additional circuit elements, such as resistors, diodes, or potentiometers, may be required to provide additional control for the circuit or for safety reasons.

The conductors 710 and the wires 722 can be wire conductors attached to a board or a printed circuit that is applied to the board by processes such as screen printing, flexographic printing, gravure printing, offset printing, inkjet and 3D printing (hereinafter, such technology or its products may be referred to as "printed", "printed" or other variations of the word "printed"). Similarly, the power supply can be printed electronics or available battery technology. Printed electronics technology can also provide resistors and other electronic devices. Alternatively, the conductors, switches, power supplies and other circuit elements can be electronic fiber materials or electronic textiles. This embodiment also includes the use of an electromagnet on one side and a magnetically attractive ferromagnetic material on the opposite closure side. To allow for greater flexibility of the fabric and closure, these printed circuits can be arranged in, for example, a ladder shape or any nonlinear pattern, as long as each printed layer is connected to the current of the same wire (printed or fiber-based). This concept was previously described for tubular arrays that enclose a fluid.

In addition to printed conductors, the subject matter of the present invention also relates to printed permanent magnets arranged as interlaced elements. Figures 8A-8B show one possible example. The printed magnets shown as interlaced in Figures 8A-8B can be prepared using inks, pastes, coatings, sprays, deposits (e.g., chemical vapor deposition, plasma deposition), etc. formed from materials having magnetic particles. Examples of such materials, printing techniques, magnetic particle compositions, and related structures are known and disclosed, for example, in US5682670 and US7229746, the entire contents of which are incorporated herein by reference for all purposes.

Referring to FIG8A , a support substrate 2 (having a predetermined pattern of printed magnet segments 3) has a complementary support substrate 4 (having magnet segments 5 printed thereon in a predetermined pattern) positioned above it. The support substrate 2 can be attached directly or indirectly to the edge of a closable opening. That is, the support substrate can be an elongated strip of material that is directly sewn, glued, fused, etc. to the bondable edge of a garment or other closable object. Alternatively, it can be first attached to another structure, such as a zipper tape, which is then directly attached to the bondable edge of the object.

In other advantageous embodiments, it is not necessary to form a support base separate from the closable object, thereby reducing manufacturing steps and saving material. Instead, the interlaced magnetic elements are formed directly on the bondable edge of the closable object, thereby eliminating the need for any separate support base and strap.

8A , the printed magnet segments 5 on the support substrate 4 are magnetized so that the north pole of the magnet faces downwards and the south pole of the magnet faces upwards. Thus, the printed pattern on the support substrate 4 is complementary to the printed pattern on the support substrate 2 .

Figure 8B shows the staggering of magnets on support substrates 2 and 4. It will be apparent that in the finished support substrate, such as a belt or garment edge, segments 3 alternate with segments 5 along the length of the support substrate.

Suitable magnetic print media include magnetic particles dispersed in liquids, pastes, and powders. The carrier for the particles can be organic or inorganic, including, for example, fusible polymers, epoxy resins, and ceramic powders.

As noted, releasable closures can be used in many items, from everyday items to professional tools. Releasable closures employing the inventive concepts disclosed herein can similarly be used in a wide variety of products. As a closure system for sleeping bags, the releasable closures disclosed herein may be superior to zippers because they do not trap loose fabric around them. As closures for footwear, the releasable closures disclosed herein may be more comfortable and easier to operate than laces. As closures for backpack openings, the releasable closures disclosed herein may be more reliable and secure than zippers when wet or dirty. Many additional advantages will be apparent to those skilled in the art.

The figures that form part of this specification do not represent specific proportions or relative sizes. All figures are representative only and do not depict actual items or products. Peripheral aspects of the embodiments may not be depicted in the following circumstances, that is, in the case where they are not closely related to the description of the embodiments, or in the case where such description would obscure the description of multiple aspects of the specification.

As used herein, "and/or" means "and" or "or" as well as "and" and "or".

Any and all patent and non-patent literature cited herein are incorporated by reference in their entirety for all purposes.

The principles described above for any particular example can be combined with the principles described for any one or more of the other examples. Therefore, this detailed description should not be interpreted in a limiting sense, and following the review of this disclosure, it will be understood by those skilled in the art that various systems can be designed using the various concepts described herein. In addition, it will be understood by those skilled in the art that the exemplary embodiments disclosed herein can be used in various configurations without departing from the disclosed principles.

The previous description of the embodiments is provided to enable any person skilled in the art to make or use the disclosed innovation. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but rather to be consistent with the full scope consistent with the language of the claims. In the claims, reference to elements in the singular, such as by use of the article "a" or "an", is not intended to mean "only one", unless specifically stated otherwise, but rather to mean "one or more".

All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the features described and claimed herein. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a "means-plus-function" claim under U.S. patent law unless the element is expressly recited using the phrase "means for" or "step for."

The inventors reserve all rights to the subject matter disclosed herein, including the right to assert all content within the scope and spirit of the following claims and any additional inventive subject matter not disclosed at this time.

Claims (23)

1. A releasable closure for connecting a first portion to a second portion along a predetermined length thereof, said releasable closure comprising: a. A first element, which is coupled to the first portion and encapsulates the smart fluid, and extends along the predetermined length; b. A mating element that is connected to the second portion and extends along the predetermined length; and c. A first switch for selectively inducing an electromagnetic field in the smart fluid, thereby altering the state of the fluid and causing the first element to be uniformly connected to the mating element along the predetermined length. 2. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose properties change in the presence of an electric field. 3. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose properties change in the presence of a magnetic field. 4. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose viscosity changes in the presence of an electric field. 5. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose viscosity changes in the presence of a magnetic field. 6. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose magnetism changes in the presence of an electric field. 7. The releasable closure according to claim 1, wherein the smart fluid is any fluid whose magnetism changes in the presence of a magnetic field. 8. The releasable closure according to claim 1, wherein the smart fluid is any fluid from the group consisting of electrorheological fluids, magnetorheological fluids, and ferromagnetic fluids. 9. The releasable closure of claim 1, wherein the mating element encapsulates a smart fluid, and the releasable closure further comprises a second switch for inducing an electric or magnetic field in the smart fluid within the mating element. 10. The releasable closure of claim 9, wherein the first switch and the second switch are actuable to generate a magnetic field in the vicinity of the first element and the mating element, thereby magnetizing the smart fluid in the first element and the mating element, and the first element, the mating element, the first switch, and the second switch are arranged such that the magnetic poles of the magnetized smart fluid in the first element and the mating element are opposite. 11. The releasable closure according to claim 1, wherein the first switch causes the first element to be magnetized, and the mating element is a material attracted by a magnet. 12. The releasable closure of claim 1, wherein the first portion is fabric and the first element is tubular. 13. The releasable closure according to claim 1, wherein the mating element is shaped to receive the first element when the first element and the mating element are relatively flexible, and to fasten to the first element when the first element is relatively rigid due to a change in state caused by actuation of the first switch. 14. The releasable closure according to claim 1, wherein the first element is shaped to receive the mating element when the first element and the mating element are relatively flexible, and to fasten to the mating element when the first element is relatively rigid due to a change in state caused by actuation of the first switch. 15. The releasable closure according to claim 1, wherein the first switch comprises a permanent magnet. 16. The releasable closure according to claim 1, wherein the first switch includes an electromagnet. 17. The releasable closure of claim 1 further includes a power source, wherein the first element is a conductor, and the first switch closes the circuit, thereby allowing current to be conducted through the conductor to generate a magnetic force, and the mating element is a ferromagnetic material attracted by the magnetic force. 18. The releasable closure of claim 1, wherein the first element includes an internal cavity, and the releasable closure further includes a smart fluid located in the cavity, and the first switch generates a magnetic field that magnetizes the smart fluid, thereby generating a magnetic force that attracts the first element and the mating element together. 19. The releasable closure of claim 1, wherein the first portion and the second portion comprise multiple segments of clothing, footwear, or equipment. 20. A releasable closure having a predetermined length, comprising: a. A first structure having a cavity, the first structure having a length at least as long as the predetermined length; b. A second structure having a cavity, the second structure having a length at least as long as the predetermined length; c. A smart fluid located in the corresponding cavities of the first structure and the second structure, the smart fluid being a type of fluid whose properties can be altered by applying an electric field or a magnetic field; d. A first switch, located near the first structure; e. A second switch, located near the second structure; f. And wherein actuation of the first switch magnetizes the smart fluid in the first structure, and actuation of the second switch magnetizes the smart fluid in the second structure, such that the first structure and the second structure are magnetically attracted together along the predetermined length. 21. The releasable closure of claim 20, wherein the first structure and the second structure are tubular, and the smart fluid fills the cavity therein. 22. The releasable closure of claim 20, wherein the smart fluid is any fluid from the group consisting of electrorheological fluids, magnetorheological fluids, and ferromagnetic fluids. 23. The releasable closure of claim 20, wherein the first structure receives at least a portion of the second structure, and actuation of the first switch further increases the viscosity of the smart fluid in the first structure, thereby mechanically securing the first structure to the second structure.