PATENT DOCUMENT

Publication Number: US-9154866-B2
Application Number: US-63750909-A
Country: US
Kind Code: B2

Title: Fiber-based electronic device structures

Abstract:
Fibers may be intertwined to form structures for electronic devices and other parts. Fibers may be intertwined using computer-controlled braiding, weaving, and knitting equipment. Binder materials may be selectively incorporated into the intertwined fibers. By controlling the properties of the intertwined fibers and the patterns of incorporated binder, structures can be formed that include antenna windows, sound-transparent and sound-blocking structures, structures that have integral rigid and flexible portions, and tubes with seamless forked portions. Fiber-based structures such as these may be used to form cables and other parts of headphones or other electronic device accessories, housings for electronic devices such as housings for portable computers, and other structures.

Claims:
What is claimed is: 
     
       1. An electronic device housing comprising:
 intertwined fibers including a first type of fiber having a first property and a second type of fiber having a second property; and 
 a binder that binds the intertwined fibers together into a seamless housing structure including at least a planar section and a non-planar section forming one or more compound curves; wherein 
 one of the planar and non-planar sections includes the first and second types of fibers in spatial variation with a higher concentration of the second type of fiber than the first type of fiber; and 
 another of the planar and non-planar sections contains said first and second types of fibers in spatial variation with a higher concentration of said first type of fiber than the second type of fiber. 
 
     
     
       2. The electronic device housing defined in  claim 1 , wherein the one or more compound curves forms a corner. 
     
     
       3. The electronic device housing defined in  claim 1 , further comprising:
 an inner support structure that is covered by the seamless non-planar housing structure. 
 
     
     
       4. The electronic device housing defined in  claim 3  wherein the inner support structure comprises a planar sheet of fiber. 
     
     
       5. The electronic device housing defined in  claim 1  wherein the intertwined fibers comprise interwoven fibers. 
     
     
       6. The electronic device housing defined in  claim 1  further comprising a hinge formed from intertwined fibers and attached to the housing. 
     
     
       7. The electronic device housing defined in  claim 1 , wherein the second type of fibers comprise plastic fibers. 
     
     
       8. The electronic device housing defined in  claim 1 , wherein the first type of fibers comprise conductive fibers. 
     
     
       9. The electronic device housing defined in  claim 1 ; wherein
 the first type of fibers comprise conductive fibers and form a conductive portion of the housing that blocks radio-frequency signals; and 
 the second type of fibers comprise dielectric fibers that form a window portion of the housing that is transparent to radio-frequency signals. 
 
     
     
       10. The electronic device housing defined in  claim 1 , wherein the electronic device housing comprises a computer housing. 
     
     
       11. An electronic device comprising:
 a housing formed from:
 intertwined fibers, comprising:
 a first type of fiber transparent to radio-frequency signals; 
 a second type of fiber that blocks radio-frequency signals; and 
 
 a binder that binds together the intertwined fibers; 
 
 an antenna within the housing; wherein 
 the housing defines a first region, a second region adjacent the first region, and a third region adjacent the second region; 
 the first region is formed primarily from the first type of fiber and is transparent to radio-frequency signals; 
 the second region is formed from a spatially varying concentration of the first and second fibers; 
 the third region is formed primarily from the second type of fiber and blocks radio-frequency signals; and 
 the antenna is disposed to emit signals through the first region. 
 
     
     
       12. The electronic device of  claim 11 , wherein the first, second and third regions are integrally and unitarily formed with one another. 
     
     
       13. The electronic device defined in  claim 12 , wherein the second portion of the housing is seamless and non-planar. 
     
     
       14. The electronic device defined in  claim 13 , wherein the second portion of the housing forms at least one curved corner. 
     
     
       15. The electronic device defined in  claim 12 , wherein the fibers comprise interwoven fibers. 
     
     
       16. The electronic device defined in  claim 12 , wherein the second type of fibers comprise nylon fibers. 
     
     
       17. The electronic device of  claim 12 , wherein the first, second and third regions are formed as a continuous surface as a single element. 
     
     
       18. The electronic device of  claim 12 , wherein the first, second and third regions are woven together.

Description:
This application claims the benefit of provisional patent application No. 61/185,934, filed Jun. 10, 2009, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This invention relates to structures formed from fibers, and more particularly, to ways in which to form structures for electronic devices from fibers. 
     Modern weaving, braiding, and knitting equipment can be used to create structures that would be difficult or impossible to implement using other fabrication technologies. For example, woven carbon fiber sheets may be used to form housing structures for electronic devices that are lighter and stronger than housing structures formed from other materials. Flexible cable sheaths may be formed using fiber braiding tools. Many medical devices are formed from fibers. For example, bifurcated vascular grafts and other cardiovascular devices may be formed from fibers. 
     SUMMARY 
     Fiber-based structures may be used in forming structures for electronic devices. For example, intertwined fibers may be used in forming housings for electronic devices. The housings may have seamless compound curves. Features such as hooks and pockets may be formed as integral parts of fiber-based structures. These fiber-based structures may, if desired, include structures such as fiber-based cases for carrying an electronic device. Intertwined fibers may also be used to form sheaths for cables, parts of accessories such as headsets, and other structures. 
     Fiber intertwining equipment such as tools for weaving, braiding, and knitting may be used to intertwine fibers. The fibers that are intertwined with this equipment may include polymer fibers, metal fibers, insulator-coated metal fibers, glass fibers, or other suitable fibers. Once intertwined, a binder such as epoxy or other suitable matrix may be incorporated into the intertwined structure and cured. 
     Parameters that may be varied during the fabrication process include the number of fibers that are incorporated into a particular region of the structure, the spacing between fibers, fiber type, binder type, binder location, etc. By selectively varying these factors, structures can be formed in which different regions of the structures have different flexibilities, different densities (e.g., to adjust audio transparency, moisture penetration, etc.), different conductivities, etc. Shapes that may be formed using the intertwining equipment include forking structures (e.g., bifurcated structures), tubular structures of variable diameter, structures that have potentially complex compound curves, etc. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of illustrative fabrication equipment that may be used to fabricate structures with intertwined fibers in accordance with an embodiment of the present invention. 
         FIG. 2  is a graph showing how parameters such as intertwining parameters and binder incorporation parameters may be varied as a function of position within a structure when fabricating the structure in accordance with an embodiment of the present invention. 
         FIG. 3  is a side view of an illustrative structure showing how the number of fibers per unit area may be varied as a function of position in accordance with an embodiment of the present invention. 
         FIG. 4  is a side view of an illustrative structure showing how the type of fiber that is used may be varied as a function of position in accordance with an embodiment of the present invention. 
         FIGS. 5 ,  6 , and  7  are side views of illustrative binder incorporation patterns that may be used when forming structures in accordance with an embodiment of the present invention. 
         FIG. 8  is a view of an illustrative tubular structure with a diameter that has been varied during a fiber intertwining process in accordance with an embodiment of the present invention. 
         FIG. 9  is a perspective view of an illustrative electronic device having housing with compound curves that have been formed by intertwining fibers in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional side view of an illustrative electronic device having compound housing curves that have been formed by intertwining fibers and that contains electronic components and a display screen in accordance with an embodiment of the present invention. 
         FIG. 11  is a rear view of an electronic device of the type shown in  FIG. 10  in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional side view of an illustrative structure having a layer of intertwined fibers that have been used to form a cosmetic cover layer and a fiber sheet that has been used to implement a structural support member in accordance with an embodiment of the present invention. 
         FIG. 13  is a top view of an illustrative fiber sheet of the type shown in  FIG. 12  showing portions where material may be removed to help the fiber sheet accommodate a compound curve shape in accordance with an embodiment of the present invention. 
         FIG. 14  is a cross-sectional side view of an illustrative structure in which an inner support structure such as a solid support or a skeletal frame has been covered with a layer of fiber that has been intertwined to accommodate a compound curve shape in accordance with an embodiment of the present invention. 
         FIG. 15  is a perspective view of an illustrative electronic device that may be formed using intertwined fiber in accordance with an embodiment of the present invention. 
         FIG. 16  is a perspective view of a forked (bifurcated) tubular structure formed with intertwining equipment in accordance with an embodiment of the present invention. 
         FIG. 17  is a cross-sectional view of a tubular structure such as a cable for an electronic device in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross-sectional side view of illustrative resin transfer mold equipment that may be used to selectively incorporate binder into intertwined fibers in accordance with an embodiment of the present invention. 
         FIG. 19  is a top view of illustrative manufacturing equipment that may be used to incorporate binder into a tubular structure in accordance with an embodiment of the present invention. 
         FIG. 20  is a view showing how a headset cables may be formed by cutting lengths of tube from a continuous tube of intertwined fiber having bifurcated sections in accordance with an embodiment of the present invention. 
         FIG. 21  is a cross-sectional view of an illustrative switch formed from intertwined conductive fibers in accordance with an embodiment of the present invention. 
         FIG. 22  is a perspective view of a tube of intertwined fibers having a conductive electrode portion for use in a switch or other structure in accordance with the present invention. 
         FIG. 23  is a cross-sectional view of an illustrative switch formed from a fiber tube with multiple branches with conductive fibers and insulating branch separator members in accordance with the present invention. 
         FIG. 24  is a side view of an illustrative fiber earbud structure having portions that are more dense and that pass relatively small amounts of sound and having portions that are less dense and that pass relatively large amounts of sound in accordance with an embodiment of the present invention. 
         FIG. 25  is a side view of an illustrative audio connector such as a 3.5 mm audio plug showing how different parts of an associated sheath tube may be provided with different amounts of rigidity in accordance with an embodiment of the present invention. 
         FIG. 26  is a cross-sectional side view of an illustrative audio plug and associated cable sheath that may be formed of intertwined fibers in accordance with an embodiment of the present invention. 
         FIG. 27  is a side view of an illustrative audio plug having a fiber cable into which binder has been selectively incorporated to adjust cable flexibility along the length of the cable in accordance with an embodiment of the present invention. 
         FIG. 28  is a perspective view of an audio plug and fiber cable showing how binder may be incorporated into the cable in a pattern that is not radially symmetric to gradually adjust cable flexibility in accordance with an embodiment of the present invention. 
         FIG. 29  is a perspective view of an illustrative complex structure of the type that may be formed in an electronic device structure using fiber intertwining and binder incorporation equipment in accordance with an embodiment of the present invention. 
         FIG. 30  is a perspective view of a fiber-based structure such as a computer housing or a protective detachable case for an electronic device that may be provided with a flexible hinge portion and rigid upper and lower planar portions in accordance with an embodiment of the present invention. 
         FIG. 31  shows how a fiber-based structure may be provided with a flexible pocket portion and a rigid planar portion in accordance with an embodiment of the present invention. 
         FIG. 32  is a perspective view of an illustrative electronic device having a housing formed of fibers with different properties in different regions to form a radio-frequency (RF) antenna window in accordance with an embodiment of the present invention. 
         FIG. 33  is a cross-sectional side view of an illustrative electronic device of the type shown in  FIG. 32  showing how an antenna and transceiver circuitry may be mounted within the device in accordance with an embodiment of the present invention. 
         FIG. 34  is a flow chart of illustrative steps involved in forming fiber-based structures with selectively incorporated binder in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     A schematic diagram of illustrative fabrication equipment that may be used to fabricate structures with intertwined fibers in accordance with an embodiment of the present invention is shown in  FIG. 1 . Fabrication equipment may be used to form fiber-based structures for any suitable device. Examples in which fabrication equipment  10  is used to form parts of electronic devices such as electronic device housings, cable sheaths for headsets, electrical connectors, and other electrical equipment are sometimes described herein as an example. In general, however, fabrication equipment  10  may be used to form any suitable parts (e.g., parts for medical application, for industrial equipment, for mechanical structures with no electrical components, etc.). 
     As shown in  FIG. 1 , fabrication equipment  10  may be provided with fibers from fiber sources  12 . Fiber sources  12  may provide fibers of any suitable type. Examples of fibers include metal fibers (e.g., strands of steel or copper), glass fibers (e.g., fiber-optic fibers that can internally convey light through total internal reflection), plastic fibers, etc. Some fibers may exhibit high strength (e.g., polymers such as aramid fibers). Other fibers such as nylon may offer good abrasion resistance (e.g., by exhibiting high performance on a Tabor test). Yet other fibers may be highly flexible (e.g., to stretch without exhibiting plastic deformation). The fibers provided by sources  12  may be magnetic fibers, conducting fibers, insulating fibers, or fibers with other material properties. 
     Fibers may be relatively thin (e.g., less than 20 microns or less than 5 microns in diameter—i.e., carbon nanotubes or carbon fiber) or may be thicker (e.g., metal wire). The fibers provided by sources  12  may be formed from twisted bundles of smaller fibers (sometimes referred to as filaments) or may be provided from sources  12  as unitary fibers of a single untwisted material. Regardless of their individual makeup (i.e. whether thick, thin, or twisted or otherwise formed from smaller fibers), the strands of material from fiber sources  12  are referred to herein as fibers. The fiber from sources  12  may also sometimes be referred to as cords, threads, ropes, yarns, filaments, strings, twines, etc. 
     Intertwining tool(s)  14  may be based on any suitable fiber intertwining technology. For example, intertwining equipment  14  may include computer-controlled weaving tools, computer-controlled braiding tools (e.g., for forming tubular structures), and/or computer-controlled knitting equipment (e.g., three-dimensional knitting tools capable of producing intertwining fiber structures with bifurcations, compound curves, and other such complex shapes). These tools are sometimes referred to collectively herein as intertwining tool(s)  14 . 
     Tools  14  form intertwined fiber structures. Matrix incorporation tools(s)  16  may be used to incorporate binder material into the intertwined fiber (e.g., to provide these structures with rigidity or other suitable properties). The binder, which is sometimes referred to as a matrix, may be formed from epoxy or other suitable materials. These materials may sometimes be categorized as thermoset materials (e.g., materials such as epoxy that are formed from a resin that cannot be reflowed upon reheating) and thermoplastics (e.g., materials such as acrylonitrile butadiene styrene, polycarbonate, and ABS/PC blends that are reheatable). Both thermoset materials and thermoplastics and combinations of thermoset materials and thermoplastic materials may be used as binders if desired. 
     Tools  16  may include molds, spraying equipment, and other suitable equipment for incorporating binder into portions of the intertwined fibers produced by intertwining equipment  14 . Tools  16  may, if desired, include computer-controlled equipment and/or manually operated equipment that can selectively incorporate binder into different portions of a workpiece in different amounts. For example, when it is desired to stiffen a fiber structure, more resin can be incorporated into the intertwined fiber, whereas less resin can be incorporated into the intertwined fiber when a flexible structure is being formed. Different portions of the same structure can be formed with different flexibilities in this way. Following curing (e.g., using heat or ultraviolet light, the binder will stiffen and harden). The resulting structure (called finished part  20  in  FIG. 1 ) can be used in a computer structure, a structure for other electrical equipment, etc. 
     A graph showing how parameters such as intertwining parameters and binder incorporation parameters may be varied as a function of position within a structure when fabricating the structure is shown in  FIG. 2 . The horizontal axis in the graph of  FIG. 2  represents position within a fiber-based structure (e.g., length along a cable or lateral distance across a planar surface). The vertical axis represents the magnitude of the parameter that is being varied. As the lines of the graph of  FIG. 2  indicate, parameters can be varied smoothly and continuously, discretely, in an increasing fashion, decreasing, periodically, etc. Examples of parameters that can be varied according to the lines of the graph of  FIG. 2  include the number of fibers in a given area, the size of the individual fibers, the spacing between adjacent fibers (porosity or fiber density), the type of filaments being used (e.g., the amount which a fiber or collection of fibers is insulating, abrasion-resistant, conducting, strong, magnetic, etc.), and the amount and/or type of binder being incorporated. 
       FIG. 3  is a side view of an illustrative structure such as a tube or planar patch of intertwined fiber showing how the number of fibers per unit area may be varied as a function of position. In region  22  there are more fibers per unit area than in region  24 . The portion of the structure in region  24  will tend to be weaker, more porous and therefore transparent to moisture and sound, lighter, and more flexible than the portion of the structure in region  22 . 
     As shown in  FIG. 4 , structure  26  may have two or more different types of fibers such as fibers  28  and fibers  30 . These fibers may have different properties. In the  FIG. 4  example, there are more of fibers  28  in region  32  than fibers  30 . In region  34 , however, fibers  30  are more prevalent than fibers  28 . This type of spatial variation of fiber type allows the properties of structure  26  to be spatially adjusted during fabrication with equipment  10 . 
       FIGS. 5 ,  6 , and  7  are examples of structures in which binder has been incorporated in different patterns. In structure  36  of  FIG. 5 , intertwined fiber portions  38  may be formed without binder, whereas portions  40  may include binder. Structure  36  may be a fiber tube or a planar fiber-based structure (as examples). In structure  42  of  FIG. 6 , there is only a single relatively large portion of binder (region  44 ), while regions  46  are free of binder. In structure  48  of  FIG. 7 , regions  50  are binder-free, whereas regions  52  incorporate binder in different patterns. 
     Equipment  10  can be used to form fiber-based structures of various shapes (e.g., tubes, planar members such as housing surfaces, spheres or parts of spheres, shapes with compound curves, cylinders or partial cylinders, cubes, tubes with bifurcations or regions of three-or more forked branches, combinations of these shapes, etc.).  FIG. 8  shows how equipment  10  can form a tube or other structure  58  with a diameter D that is narrower in some regions (e.g., regions  54 ) than in other regions (e.g., region  56 ). 
     A perspective view of an illustrative electronic device having a housing with compound curves is shown in  FIG. 9 . As shown in  FIG. 9 , device  60  may have a housing or other structure that has a planar rear surface portion such as portion  64 . Device  60  may also have four corner portions  62 . Each corner portion  62  has compound curves. These curves may be difficult or impossible to form from conventional woven-fiber sheets. 
     With equipment  10  of  FIG. 1 , three-dimensional (3D) knitting equipment or other intertwining tools  14  can be used to form a fiber-based structure (e.g., a housing or covering) that conforms to both the planar rear surface  64  and compound curve corners  62  of structure  60 . 
     A cross-sectional side view of device  60  of  FIG. 9  taken along line  66  of  FIG. 9  and viewed in direction  68  is shown in  FIG. 10 . As shown in  FIG. 10 , device  10  may have curved sidewalls  70 , a display or other front-mounted component  74 , and internal electronic devices  72  (e.g., processor and memory circuitry). A rear view of device  60  is shown in  FIG. 11 , illustrating part of the curved shapes of corners  62  that can be covered smoothly without wrinkles or seams using the knit fiber produced by equipment  10 . 
     The ability of equipment  10  to produce thin layers of intertwined fiber that conform to complex non-planar shapes can be used to create a cosmetic cover layer with compound curves. As shown in  FIG. 12 , device housing  80  may have an inner layer  78  that is formed from a planar sheet of fiber with cut-away portions to accommodate compound curve housing shapes (e.g., corners  62  of  FIG. 9 ). Layer  76  may be a conformal cosmetic cover layer formed using equipment  76 . Layers  76  and/or layer  78  may be impregnated with binder using a matrix incorporation tool. 
       FIG. 13  is a top view of a planar layer such as layer  78  that has removed portions  82  to accommodate compound curve shapes (e.g., housing corners). This process leaves unsightly seams that are hidden by cosmetic layer  76  ( FIG. 12 ). 
       FIG. 14  is a cross-sectional side view of device  80  showing how layer  76  may conformally cover an inner support structure (i.e., structure  84 ) and how device  80  may have a display module or other component  86  mounted to its front surface. Structure  84  may be solid, may be hollow (e.g., as in a frame or skeletal support), may include components, etc. 
     An example of an electronic device that may be formed from intertwined fiber structures is a pair of audio headphones. An illustrative headset is shown in  FIG. 15 . As shown in  FIG. 15 , headset  88  may include a main cable portion  92 . Cable  92  may be formed from intertwined fibers and may have portions formed from different types and amounts of fibers and different patterns and amounts of binder (as examples). Earbuds  90  may be mounted at the ends of the right and left branches of cable  92 . In region  94 , cable  92  may have a bifurcation (forked region). Feature  96  may be an enclosure for a switch, microphone, etc. The end of cable  92  may be terminated by audio connector (plug)  98 . 
       FIG. 16  shows how intertwining tool  14  may, if desired, form Y-junction  94  of cable  92  without visible seams. A cross-sectional view of cable  92  is shown in  FIG. 17 . As shown in  FIG. 17 , cable  92  may have a tubular sheath such as sheath  100  that surrounds one, two, or more than two wires. In the  FIG. 17  example, there are two conductive wire bundles within sheath  100 . Wire bundle  102  may be formed from a first set of metal fibers and wire bundle  104  may be formed from a second set of wire bundles. The individual wires in bundles  102  and  104  may be coated with a thin layer of insulator (if desired). Sheath  100  may be formed from a fiber with sufficient strength to resist damage during use by a user and sufficient flexibility to allow cable  92  to flex. If desired, regions such a Y-junction region  94  and portions of device  88  near earbuds  90  and plug  98  may be provided with stronger fibers and more binder to strengthen these regions. 
     Structure  96  may also be strengthened in this way. As an example, structure  96  may be impregnated with binder, whereas most of the rest of cable  92  may be left binder-free.  FIG. 18  shows how a resin transfer molding tool such as tool  106  may be used to selectively incorporate binder  110  into region  96  of cable  92  (e.g., by introducing binder  110  into the interior of tool  106  through opening  108 ). 
     As shown in  FIG. 19 , cable  92  may be rotated in direction  124  about longitudinal axis  126  while binder  110  is being sprayed onto cable  92  from spraying tool  114 . Binder  110  may be cured using ultraviolet light  122  from ultraviolet light source  120 . Shield  116  may prevent binder  110  from striking source  120  and may prevent light  122  from curing binder  110  at the exit of nozzle  128 . 
     Equipment  10  may produce cable  92  using a continuous process. As shown in  FIG. 20 , equipment  10  may produce a cable shape that periodically forks to form two separate branches and then fuses so that the two branches form a single tubular structure. With this type of arrangement, post processing tools  18  of  FIG. 1  may be used to cut cable  92  along cut lines  130 . 
     As shown in  FIG. 21 , cable  92  may be provided with conductive fibers such as fibers  132  and  134 . This type of configuration may be produced when it is desired to form a switch in structure  94 . As shown in  FIG. 21 , conductive fibers  132  and conductive fibers  134  in structure  96  may be separated by gap region  136 . Region  136  may be filled with air (as an example). When a user squeezes outer edges inwardly in directions  140 , opposing inner portions  142  of conductors  132  and  134  can meet, thereby closing the switch. 
     Conductive fibers on sheath  92  may be used to form a capacitor electrode (e.g., as part of a switch based on a capacitive sensor). This type of configuration is illustrated by conductive fiber band  144  on cable  92  in  FIG. 22 . 
     In the example of  FIG. 23 , switch  96  has been formed from opposing metal conductor portions  132  and  134  (each of which may be connected to a respective cable wire such as wires formed from wire bundles  102  and  104 ). Cable  92  may have two branches that rejoin each other on either end of switch structure  96 . In the center of structure  96 , outward biasing members  146  (e.g., air filled balloons or spring-filled members) may be used to bias switch contacts  132  and  134  away from each other in outward directions  148  so that switch  96  is off when not compressed inwardly by a user. 
     A side view of an illustrative fiber-based earbud and associated cable is shown in  FIG. 24 . As shown in  FIG. 24 , earbud  90  may have regions  150  and  152 . Region  150  may be more porous than region  152  and may be more (or less) flexible than region  152 . The increased porosity of region  150  may make region  150  transparent to audio, so that sound from internal speaker drivers may pass through regions  150  unimpeded. Regions  150  may have fewer and less densely intertwined fibers than region  152  and may incorporate less binder than region  152  or no binder. It may be desirable to make region  152  less porous (e.g., to block sound, to increase rigidity or durability, etc.). Accordingly, more binder may be incorporated into region  152  than in region  150  and/or fibers may be more densely intertwined. In addition to increasing the fiber density and/or binder quantity in region  152 , different (e.g., denser, thicker, etc.) fibers may be used in region  152 . Cable  92  in region  154  may be formed of flexible fibers (e.g., with little or no binder). If desired, some of cable  92  near region  152  may be provided with stronger fibers, more fibers, more binder for rigidity and strength, etc. 
     As shown in  FIG. 25 , audio plug  98  (or other electrical connectors) may be provided with a flexible cable portion  92  and a rigid inner strain relief structure  158 . Metal plug structure  160  may be connected to wires within cable  92 . In region  156 , binder may be incorporated into the fibers of cable  92  to increase strength and rigidity. If desired, cable  92  may also be provided with an increased number of strong fibers in region  156  and/or may be provided with a higher fiber density to further increase strength. These types of structural features may be used for any suitable electrical connector. The use of an audio connector in  FIG. 25  is merely an example. 
       FIG. 26  shows how cable  92  may form a conformal sheath over support (strain-relief) structure  158  and wires  102  and  104 . 
     The flexibility of cable  92  can be adjusted along its length by selectively incorporating binder in appropriate areas. This type of arrangement is shown in  FIG. 27 . In the example of  FIG. 27 , connector  98  may have a metal multi-contact portion such as portion  160  (e.g., a three-contact or four-contact audio plug). Region  162  of connector  98  may be completely filled with binder. Only some portions (e.g., rings  168 ) of region  164  are provided  15  with binder (in this example), so cable  92  will be more flexible in region  164  than in region  162 . In region  170 , there is no binder in the fibers of cable  92 , so cable  92  has maximum flexibility in region  170 . 
     Another suitable arrangement for connector  98  is shown in  FIG. 28 . In the example of  FIG. 28 , cable  92  has no binder in region  178  and is therefore flexible in this region. In region  176 , a non-radially symmetric pattern of binder  172  is used to provide a decreased flexibility. Region  174  has more binder than region  172  and is therefore rigid and structurally strong. This type of configuration allows the binder pattern in region  176  to serve as a moderate-flex interface between rigid region  174  and flexible region  178 . 
       FIG. 29  shows how equipment  10  may be used to form complex shapes for part  20  such as hook  180  with hole  182 . The fiber in hook  180  may be formed of stronger material than the fiber elsewhere in the structure. Part  20  may be formed as an integral portion of an electronic device housing (as an example) 
     As shown in  FIG. 30 , equipment  10  may form structures such as structure  184  that have rigid planar portions such as rigid planar portions  186  and  188  and flexible hinge portions such as flexible hinge  190 . This type of arrangement may be provided by incorporating binder into portions  186  and  188 , but not into hinge  190 . Structure  184  may be used for a portable computer housing, a folio-style case for a detachable electronic device such as a media player or cellular telephone, etc. 
     As shown in  FIG. 31 , a fiber-based case or other fiber-based structure  192  may be formed from a rigid binder-filled planer portion  194  and a flexible binder-free portion  196 . Portion  196  may serve as a flexible pocket that holds a cellular telephone or music player. Portion  194  may be provided with a matching front face if desired. 
     Some parts that are formed from fiber-based structures may be used for electronic device housings or other applications in which at least a portion of the structure is adjacent to an antenna. In situations such as these, it may be desirable to incorporate one or more antenna windows into the part. For example, in an electronic device housing that is formed from conductive fibers, an antenna window that is transparent to radio-frequency antenna signals can be formed over an antenna within the electronic device housing. The antenna window  30  can be formed by incorporating a solid dielectric window in the housing and by attaching the conductive fibers to the solid window (e.g., using epoxy or other adhesive). Antenna window structures can also be formed by using equipment  10  to form an integral fiber-based antenna window structure within part of the electronic device housing. The antenna window structure may be formed from a fiber that contains primarily polymer, glass, or other dielectric. Because this material is nonconducting, the antenna window structure will be able to pass radio-frequency signals without interference from the fibers in the window. 
     An illustrative fiber-based structure with an antenna window is shown in  FIG. 32 . Structure  200  of  FIG. 32  may be, for example, a housing for an electronic device such as a media player, cellular telephone, portable computer, or other electronic device. Structure  200  may be formed using equipment  10 . For example, structure  200  may include corner portions that have compound shapes that have been created using intertwining tool  14  (e.g., 3D knitting equipment). In regions  198 , housing walls can be formed from insulating or conductive materials or combinations of insulating and conductive materials (e.g., carbon fibers, polymers, steel filaments, etc.). The materials in regions  198  may include conductors (nondielectrics) and may therefore block radio-frequency wireless signals. Equipment  10  can use dielectric fiber when forming the intertwined fibers of antenna window  202 , thereby ensuring that the material in window  202  will be transparent to antenna signals. 
     A cross-sectional side view of structure  200  of  FIG. 32  taken along line  201  is shown in  FIG. 33 . As shown in  FIG. 33 , structure  200  may have housing walls  198  that are formed from intertwined fibers and associated binder. In region  202 , an antenna window is formed by using dielectric fibers and binder that are transparent to wireless radio-frequency signals. This allows radio-frequency signals  212  to pass through window  202  during wireless transmission and reception operations with antenna  206 . Antenna  206 , which may be a single band antenna or a multi-band antenna and which may include one or more individual antenna structures, may be coupled to radio-frequency transceiver circuitry  210  on printed circuit board  204  using transmission line path  208 . 
     Illustrative steps involved in forming fiber-based structures using equipment  10  of  FIG. 1  are shown in  FIG. 34 . At step  214 , equipment  10  may be provided with one or more different sources of fibers (e.g., fiber sources  12  of  FIG. 1 ). Fibers may be used that provide suitable amounts of strength, stretchability, flexibility, abrasion resistance, insulation, conductivity, color, weight, magnetism, etc. Some of the fibers may be formed from metals such as ferrous metals. Other fibers may be formed from polymers or glasses. There may be one, two, three, or more than three different types of fiber sources available to a given intertwining tool  14 . Each fiber may have a different property and may be incorporated into a workpiece in an accurately controlled percentage. This allows tools  14  to form structures that have portions with different properties. 
     At step  216 , tools  14  may be used to form fiber-based structures of appropriate shapes and sizes. Different types of tools may be used for different types of operations. For example, a computer-controlled braiding machine may be used to form a continuous or semi-continuous fiber-based tube for a headset cable sheath, a weaving tool may be used to form housing sidewalls for a portable computer with an integral antenna window or a flexible hinge portion, and a 3D knitting tool may be used to form housing shapes with compound curves for a cosmetic or structural housing surface. These tools may each be used to form separate parts that are assembled together by hand or by automated assembly tools or may be used to form unitary structures that are complete without the addition of further fiber-based parts. 
     During the operations of step  218 , matrix incorporation equipment  16  may be used to selectively incorporate binder into the intertwined fibers that were produced during the operations of step  214 . Binder may be incorporated in patterns that provide controlled amounts of flexibility. For example, binder patterns may include rings of the same shape or different shapes (e.g., rings of varying width of other patterns that provide a smooth transition in the amount flexibility at various points along the length of a tube or other elongated structure). Binder patterns may also include solid regions (e.g., for forming rigid planar structures such as housing walls for a portable computer, handheld electronic device, or other structure). Other regions of a structure may be provided with little or no binder (e.g., in a hinge structure, cable, or pocket where maximum flexibility is desired or in an earbud speaker port or computer housing speaker port where audio transparency is desired). 
     After incorporating desired patterns of binder into the intertwined fiber structures, additional processing steps may be performed during the operations of step  220 . These operations may include, for example, assembling a headset by cutting headset parts from a continuous stream of parts, adding a cosmetic cover to a structural housing member, using adhesive or other fasteners to connect separate fiber-based structures to each other or to parts that do not include fibers, etc. 
     If desired, the steps of  FIG. 34  may be repeated and/or performed in different orders. For example, it may be desirable to assemble two or more intertwined fiber parts before matrix incorporation operations are performed at step  218 . It may also be desirable to build up complex structures by using a series of incremental operations. During each such incremental step, a layer of fiber-based material may be added to a workpiece and additional binder may be incorporated and cured. An incremental approach such as this may be used for part of a fiber-based structure while other parts of the structure are formed using a single intertwining operation and a single binder incorporation operation (as examples) 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20091214
Publication Date: 20151006
Grant Date: 20151006
Priority Date: 20090610
Inventors: BIBL DAVID
ROHRBACH MATTHEW
RUSSELL-CLARKE PETER
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R5/033", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1041", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R5/033", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 43305987