PATENT DOCUMENT

Publication Number: US-8467560-B2
Application Number: US-89231510-A
Country: US
Kind Code: B2

Title: Cables with intertwined strain relief and bifurcation structures

Abstract:
An electrical device such as a headset may have a cable. Wires in the cable may be used to connect speakers in the headset to a connector such as an audio jack. The cable may have a tubular intertwined cable cover that covers the wires. Computer-controlled servo motors in fiber intertwining equipment may be adjusted in real time so that intertwined attributes such as intertwining density and intertwining tension are varied as a function of length along the intertwined cable cover. The fiber intertwining equipment may make these variations to locally increase the strength of the intertwined cable cover and the cable in the vicinity of a bifurcation in the cable and in the vicinity of the portion of the cable that terminates at the audio jack.

Claims:
What is claimed is: 
     
       1. Headphones, comprising:
 a plurality of speakers; 
 an electrical connector comprising a plurality of terminals; 
 a plurality of wires that electrically connect the plurality of speakers to the plurality of terminals; and 
 an intertwined fiber cable cover that covers the plurality of wires, wherein a first segment of the intertwined fiber cable cover comprises a bifurcation, and wherein an intertwined attribute of the intertwined fiber cable cover at the first segment is different than at a second segment of the intertwined fiber cable cover. 
 
     
     
       2. The headphones defined in  claim 1  wherein the intertwined attribute comprises intertwining tension, and wherein the first segment is locally strengthened by an increased intertwining tension relative to the second segment. 
     
     
       3. The headphones defined in  claim 1  wherein the intertwined attribute comprises intertwining density, and wherein the first segment is locally strengthened by an increased intertwining density relative to the second segment. 
     
     
       4. The headphones defined in  claim 1  further comprising an integral strain relief structure formed from a portion of the intertwined fiber cable cover proximate the electrical connector. 
     
     
       5. The headphones defined in  claim 1 , wherein the electrical connector comprises an audio jack, and wherein the plurality of terminals comprises a plurality of contacts in the audio jack. 
     
     
       6. The headphones defined in  claim 5  wherein the audio jack comprises a plastic shell at which an end of the intertwined fiber cable cover is terminated, and wherein the headphones further comprise a tapered strain relief member comprising a first portion that is mounted within a portion of the intertwined fiber cable cover and a second portion that is mounted within a portion of the plastic shell. 
     
     
       7. The headphones defined in  claim 6 , wherein the tapered strain relief member comprises an elongated shape that extends along a longitudinal axis of the intertwined fiber cable cover. 
     
     
       8. The headphones defined in  claim 7 , wherein the tapered strain relief member comprises stiffness that gradually changes along the longitudinal axis. 
     
     
       9. The headphones defined in  claim 4 , wherein the portion of the intertwined fiber cable cover comprises a locally increased intertwining density. 
     
     
       10. The headphones defined in  claim 4 , wherein the portion of the intertwined fiber cable cover comprises a locally increased intertwining tension. 
     
     
       11. Apparatus, comprising:
 an electrical connector comprising a plurality of terminals; 
 a plurality of wires, wherein each wire of the plurality of wires is connected to a respective one of the plurality of terminals; and 
 a tubular intertwined fiber cable cover that covers the plurality of wires, wherein the tubular intertwined fiber cable cover comprises a first portion that comprises a bifurcation, a second portion that terminates at the electrical connector, and a third portion that is separate from each of the first portion and the second portion, and wherein the tubular intertwined fiber cable cover comprises a plurality of intertwined fibers that exhibits a local increase in at least a selected one of: intertwining tension at the first portion and at the second portion relative to the third portion and intertwining density at the first portion and at the second portion relative to the third portion. 
 
     
     
       12. The apparatus defined in  claim 11  further comprising a plurality of speakers coupled to the plurality of wires. 
     
     
       13. The apparatus defined in  claim 12  further comprising:
 an elongated strain relief member; and 
 a shell in which the electrical connector and at least a part of the elongated strain relief member are mounted. 
 
     
     
       14. The headphones defined in  claim 1 , wherein the difference of the intertwined attribute:
 provides a local strengthening of the first segment; and 
 prevents unraveling of fibers in the intertwined fiber cable cover at the bifurcation.

Description:
BACKGROUND 
     This invention relates to structures formed from intertwined fibers, and more particularly, to ways in which to form structures for electronic devices from intertwined fibers. 
     Electronic devices such as music players often use headsets. Some headsets are formed from wires that are contained within a cable formed from braided fibers. Seams may be present at a bifurcation where the headset cable splits into left and right branches. The end of the cable may be terminated with an audio jack. To help prevent damage to the cable in the vicinity of the audio jack, a plastic strain relief structure is typically formed over the cable. 
     Headsets with cables such as these may be unsightly due to the presence of undesired seams and strain relief features. Moreover, if care is not taken, the fibers of the cable may be prone to unraveling in the vicinity of the bifurcation. 
     It would therefore be desirable to be able to provide improved cable structures such as improved intertwined cables with bifurcations and strain relief structures for devices such as headsets. 
     SUMMARY 
     Accessories such as audio headsets may include cabling. A cable for an audio headset may contain wires. The wires in a headset may be electrically connected between headset components such as speakers, buttons, and an audio jack or other connector. 
     To provide the cable in a headset or other device with an attractive and durable finish, the cable may be covered with an intertwined cable cover (e.g., a braided or woven cable cover). Fibers in the intertwined cable cover may be formed from polymers or other suitable materials. 
     Fibers may be intertwined to form the intertwined cable cover using computer-controlled intertwining equipment (e.g., braiding or weaving equipment). The intertwining equipment may include servo motors that can be controlled in real time to adjust interweaving formation parameters such as intertwining density and intertwining tension (e.g., braid density and braid tension or weave density and weave tension). The intertwining density and intertwining tension of an intertwined cable cover may affect the attributes of the intertwined cable cover. For example, segments of an intertwined cable cover that are formed with an elevated intertwining tension and an elevated intertwining density may be stiffer and more durable than segments of the intertwined cable cover that are formed with reduced intertwining tension and intertwining density. 
     To accommodate left and right speakers, the cable in the headset may have a bifurcation. Below the bifurcation, the wires may be covered in a single segment of intertwined cable cover. Above the bifurcation, the cable cover can split into left and right portions. The bifurcation can be formed seamlessly using the intertwining equipment. To reduce the susceptibility of the intertwined cable cover to unraveling fibers in the vicinity of the bifurcation, one or more intertwined attributes such as intertwining density and intertwining tension may be locally increased in a segment of the cable that includes the bifurcation. 
     There is a potential for strain to damage the cable in the vicinity of the segment of cable that terminates at the audio jack. This segment of cable may also be locally increased in strength. In particular, the intertwining equipment may locally increase intertwining tension and intertwining density to form an integral strain relief structure in the cable cover at the audio jack. The audio jack may also be provided with an internal tapered strain relief member. 
     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 perspective view of an illustrative accessory such as a headset that has been formed from intertwined fibers in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross-sectional view of a cable in accordance with an embodiment of the present invention. 
         FIG. 3  is a schematic diagram of illustrative equipment that may be used in forming cables and associated devices in accordance with an embodiment of the present invention. 
         FIG. 4  is a side view of a conventional cable strain relief structure. 
         FIG. 5  is a side view of a conventional strain relief structure in an intertwined cable. 
         FIG. 6  is a side view of a cable with a strain relief structure in accordance with an embodiment of the present invention. 
         FIG. 7  is a graph showing how intertwined attributes may be varied as a function of length along a cable in the vicinity of a cable strain relief region by varying fiber tension and/or pull speed during intertwining operations in accordance with an embodiment of the present invention. 
         FIG. 8  is a side view of a portion of a cable with a seamless intertwined bifurcation in accordance with an embodiment of the present invention. 
         FIG. 9  is a graph showing how intertwined attributes may be varied as a function of length along a cable segment in the vicinity of a bifurcation of the type shown in  FIG. 8  in accordance with an embodiment of the present invention. 
         FIG. 10  is a side view of an intertwined cable with an inner strain relief member in accordance with an embodiment of the present invention. 
         FIG. 11  is a perspective view of an illustrative strain relief member of the type that may be used in an intertwined cable such as the intertwined cable of  FIG. 10  in accordance with an embodiment of the present invention. 
         FIG. 12  is a flow chart of illustrative steps involved in forming structures based on intertwined fibers using equipment of the type shown in  FIG. 3  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Cables may be used in headphones, patch cords, power cords, or other equipment they conveys electrical signals. As an example, cables are sometimes described herein in the context of accessories such as headsets. This is, however, merely illustrative. Any suitable apparatus may be provided with a cable if desired. 
     The inner portions of a cable may contain wires for carrying power and data signals and an optional strengthening cord. Electromagnetic shielding (e.g., a metal braid, interwoven metal, and/or wrapped metal foil), a plastic sheath, and other layers may be used to cover the wires and strengthening cord. To provide the cable with an attractive and durable outer layer, the cable may be covered with intertwined fibers. The intertwined fibers of the outer layer may be formed by an intertwining tool such as an intertwining tool. The outer layer may have a tubular shape and may sometimes be referred to as an intertwined fiber cable cover or tubular intertwined fiber cable cover. 
     An illustrative device that may include cabling with an intertwined cable cover is the headset shown in  FIG. 1 . As shown in  FIG. 1 , 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 and coatings (as examples). Speakers  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 a connector such as audio jack  98 . 
     A cross-sectional view of cable  92  is shown in  FIG. 2 . As shown in  FIG. 2 , cable  92  may include fibers  102  that have been intertwined to form a cable cover such as cover  100 . Cover  100  may be formed from an elongated tube (sheath) of fibers  102  that are intertwined using an intertwining tool (as an example). 
     Cover  100  may enclose fibers such as fibers  106 . Fibers  106  may include wires  104  for conducting electrical signals. Wires  104  may be used to carry power, digital signals, analog signals, etc. Wires  104  may include conductors  110  such as stranded conductors or solid conductors. Wire insulation  112  may be provided by dielectric coatings (e.g., polymer coatings). Fibers  106  may also include one or more strengthening cords such as optional cord  108  (e.g., a cord formed from polymer fibers such as aramid fibers). 
     Fibers  106  may optionally be covered with one or more layers such as layer  114 . Layer  114  may include one or more layers of electromagnetic shielding structures (e.g., intertwined or wrapped foil conductive sheaths that surround bundles of wires within jacket  100 ) and/or plastic sheath layers (e.g., an inner jacket for cable  92 ). 
     Cable  92  may include any suitable number of wires  104  (e.g., one or more). For example, cable  92  may include two wires  104  (e.g., a positive wire and a negative wire). Cable  92  may also include three wires  104 , four wires  104 , five wires  104 , six wires  104 , or more than six wires  104 . Arrangements with more wires  104  may be used to handle additional audio channels (e.g., left and right speaker channels, surround sound channels, etc.). Arrangements with more wires  104  may also be able to use two or more wires  104  for conveying power (e.g., by forming a power path that is not used to handle any data signals or that handles only a minimal number of data signals). The incorporation of additional wires  104  within cable  92  may also allow cable  92  to handle control signals (e.g., by providing a signal path for conveying signals from a controller in region  96  of headset  88  of  FIG. 1  to connector  98 ). 
     Cover  100  may include intertwined fibers  102 . Binder materials (sometimes referred to as matrix materials) such as epoxy or other binders that fill interstitial spaces between intertwined fibers, coatings, or other suitable materials may, if desired, be incorporated into some or all of cover  100 . 
     Cover  100  may be formed from one or more layers of fibers  102 . As shown in the illustrative cross-sectional view of  FIG. 2 , cover  100  may be formed from a single layer of intertwined fibers  102  (as an example). 
     Fibers  102  may be formed from any suitable materials. Examples of fibers  102  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). Fibers may have different magnetic properties, different thermal properties, different melting points, different dielectric constants, different conductivities, different colors, etc. 
     The fibers of cable  92  including cable cover fibers  102  and interior fibers  106  (e.g., wires  104  and strengthening cord  108 ) may be formed from metal, dielectric, or other suitable materials. The fibers of cable  92  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 of cable  92  may be formed from twisted bundles of smaller fibers (sometimes referred to as filaments) or may be formed 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 that make up the wires, strengthening cords, and fibers in cover  100  are referred to herein as fibers. In some contexts, the fibers of cable  92  may also be referred to as cords, threads, ropes, yarns, filaments, strings, twines, etc. 
     Fabrication equipment of the type that may be used to form headset  88  is shown in  FIG. 3 . As shown in  FIG. 3 , 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 with or without insulating coatings such as sheaths of plastic), glass fibers (e.g., fiber-optic fibers that can internally convey light through total internal reflection), plastic fibers, etc. 
     Intertwining tool(s)  14  may be based on any suitable fiber intertwining technology. For example, intertwining equipment  14  may include computer-controlled intertwining tools. Equipment  14  may be used to form tubular interwoven structures such as cover  100  surrounding fibers  106  (e.g., around wires  104  and one or more strengthening cords  108 ). Seamless bifurcations (see, e.g., bifurcation  94  of  FIG. 1 ) may be formed in a tubular cable cover shape using equipment  14 . In this type of configuration, some of wires  104  will follow the left-hand branch of cable  92  and some of the wires will follow the right-hand branch of cable  92  above bifurcation  94 . Between bifurcation  94  and connector  98 , all of fibers  106  may be surrounded by a single tubular intertwined cable cover structure formed from fibers  102 . Tool  14  may form the portion of the cover that lies between connector  98  and bifurcation  94  from 32 of fibers  102  (as an example). Above bifurcation  94 , 16 of the 32 fibers  102  may be intertwined to form the intertwined cable cover for the left-hand branch of cable  92  and 16 of the 32 fibers  102  may be intertwined to form the intertwined cable cover for the right-hand branch of cable  92 . 
     Different portions of cable  92  may be subject to different forces. For example, the fibers in the region of bifurcation  94  ( FIG. 1 ) may be susceptible to unraveling (e.g., when pulled apart as with a chicken bone). Cable  92  may also be susceptible to wear in the vicinity of connector  98 . 
     To address these concerns, tools  14  may include computer-controlled servo motors that are used to adjust the tension of fibers  102  (i.e., intertwining tension) and the speed with which cable  92  is passed through the intertwining tool (which controls intertwining density and fiber-to-fiber pitch). By adjusting intertwined formation attributes such as fiber tension and intertwining density (pitch) in real time during the intertwining process, the physical attributes of the intertwined structures (i.e., the closeness of the weave braid, or other intertwining and therefore the flexibility and durability of the intertwined structures) may be varied as a function of position along the longitudinal axis (length) of cable  92 . In portions of cable  92  that are subject to potential wear such as bifurcation  94 , the intertwined structures may be formed in a stiffer and more durable configuration (e.g., by using a higher intertwining density, by intertwining together fibers using a higher fiber tension, and/or by increasing stiffness by locally increasing the number of layers of fiber  102  in the intertwined structures). A strain relief structure may be formed in this way at connector  98  if desired. 
     After intertwining fibers  102  to form cable cover  100  using tools  14 , tools  16  may be used to process cable  92 . Tools  16  may include tools such as molds, spraying equipment, and other suitable equipment for incorporating binder into portions of the intertwined fibers produced by intertwining equipment  14 . Tools  16  may also include dipping tools for forming coatings, heating tools for applying heat to cable  92  (e.g., to melt, dry, or cure a binder, to melt fibers in cable cover  100  or elsewhere in cable  92 , etc.). An ultraviolet (UV) lamp may be included in tools  16  for UV curing operations. A cutting tool may include blades or other cutting equipment for dividing cover  100  and fibers  106  into desired lengths for forming cable  92  for accessory  88 . The tools of equipment  16  may be controlled by computers or other suitable control equipment. If desired, additional tools may be included in system  10 . The examples of  FIG. 3  are merely illustrative. 
     Equipment in system  10  such as intertwining tool  14  and equipment  16  may be used to form finished parts such as finished part  26  (e.g., cable  92  for headset  88  of  FIG. 1 ) or other structures from fibers provided from fiber sources  12 . 
     Conventional cables often have unsightly and bulky strain relief structures. Conventional cables with strain relief structures are shown in  FIGS. 4 and 5 . 
     A conventional cable without a fiber cover is shown in  FIG. 4 . As shown in  FIG. 4 , cable  200  may have a plastic-coated cable portion  202  that is terminated to electrical connector  208  using elastomeric strain relief structure  204  and plastic connector shell  206 . Structures such as structure  204  may help prevent cable  200  from being damaged when cable  202  is flexed during use, but may be undesirably bulky and unsightly. 
     A conventional cable with an intertwined cover is shown in  FIG. 5 . As shown in  FIG. 5 , intertwined-structure-covered cable portion  212  of cable  210  may be attached to plastic connector shell  216  and electrical connector  218  using elastomeric strain relief structure  214 . As with structures such as structure  204  of  FIG. 4 , structure  214  of  FIG. 5  may help prevent cable  210  from being damaged when cable  210  is flexed during use, but may be undesirably bulky and unsightly. Bulky elastomeric covers of the type that are sometimes placed over the bifurcations in conventional fiber-covered cables to prevent the fibers of the cable cover from unraveling may also be undesirably bulky and unsightly. 
     As shown in  FIG. 6 , cable  92  (see, e.g.,  FIG. 1 ) may have a fiber-covered portion  92 T that is terminated to electrical connector member  98 P (e.g., an audio jack or other multi-terminal electrical connector member in connector  98 ) using optional connector shell  98 S (e.g., a plastic or metal shell or a shell formed from one or more pieces of other materials) and the fibers  102  of cable portion  92 T. 
     Cable  92  has longitudinal axis  92 A. Distance along the longitudinal dimension (length) of cable  92  may be represented by distance X. The distance X may be measured in direction  220  starting at origin ORG. Origin ORG may be longitudinally aligned with top surface of shell  98 S, may be longitudinally aligned with an internal portion of connector (e.g., a position within connector shell  98 S such as position  98 TP as shown in  FIG. 6 ), or may be longitudinally aligned with the bottom edge of shell  98 S (as examples). 
     To form an integral strain relief structure within cable  92  without adding unsightly strain relief structures such as structures  204  and  214  of  FIGS. 4 and 5 , tools  14  ( FIG. 3 ) may alter intertwined formation attributes and therefore the physical attributes of the resulting intertwined structure formed from fibers  102  as a function of X. 
     Consider, as an example, the graph of  FIG. 7 . As shown in  FIG. 7 , intertwining attributes such as fiber tension, intertwining density, and other aspects of the intertwining may be varied by tools  14  so that these attributes are different near origin ORG than they are farther away from origin ORG. Illustrative intertwined attribute profile BA 1  shows how intertwined attributes such as fiber tension may be reduced in a stepwise fashion at increasing values of X. Intertwined attribute profile BA 2  shows how intertwined attributes such as fiber tension may be reduced more gradually. Intertwined attributes such as intertwining density may likewise be adjusted in step-wise and/or continuous fashions. With one illustrative arrangement, intertwining density and/or fiber tension is greatest in a segment of cable  92  near jack  98  (i.e., near X=ORG) and is reduced as a function of length along cable  92  away from ORG. This will tend to make the intertwining of cover  100  strongest and most resistant to wear immediately in the vicinity of connector  98  and will form an integral strain relief structure for cable  92  without the need to add an unsightly extra strain relief member to cable  92 . 
     The quality of cable cover  100  may also be adjusted in the vicinity of bifurcation  94  in cable  92 . As shown in  FIG. 8 , the length along cable  92  may be measured by dimension Y in the vicinity of cable bifurcation  94 . As shown by illustrative intertwined attribute profile BA 3  in  FIG. 9 , intertwined attributes such as fiber tension, intertwining density, and other intertwining parameters may be varied as a function of dimension Y. For example, intertwining tension and/or intertwining density may be increased locally in the vicinity of bifurcation  94  to ensure that cable  92  is sufficiently strong to resist wear in the vicinity of bifurcation  94 . The distance L over which there is a local strengthening of cable cover  100  of cable  92  may be, for example, 2-10 mm, 2-20 mm, 5-30 mm, more than 4 mm, less than 50 mm, or other suitable length (e.g., a segment length sufficient to extend over bifurcation region  94  while providing a smooth transition to the segments of cable  94  that have not been strengthened). 
     As shown in  FIG. 10 , an internal strain relief member such as internal strain relief member SR may be provided within cable  92  in the vicinity of connector  98 . Strain relief member SR may be formed from a material such as plastic, metal, or a fiber composite. Wires such as wires  104  may run along the interior of cable  92  and may be connected to connecter terminals  98 TM (e.g., audio jack contacts) within electrical connector portion  98 P of connector  98  (e.g., an audio jack). Strain relief member SR may have an elongated shape that is extends along longitudinal axis  92 A of cable  92 A and connector  98 . Strain relief member SR may have a first end such as end  300  that is mounted within connector shell  98 S. (e.g., using plastic, epoxy, or other suitable fillers, metal attachment structures, etc.), and may have a second end such as end  302  that is mounted within the core of cable section  92 T of cable  92 . 
     Strain relief member SR may be cylindrical, rectangular, or may have other shapes. If desired, strain relief member SR may have a stiffness that tapers off as a function of distance X, so that the amount of stiffening that is provided to cable  92  is gradually reduced as distance from connector  98  increases. This provides a smooth transition between the reinforced portion of cable  92  near connector  98  and the flexible unreinforced portion of cable  92  along its main length. The gradual reduction in stiffness of member SR may be implemented using different materials at different distances X, using different amounts of materials in member SR as a function of X, using different shapes or sizes for the cross-section of member SR as a function of X, etc. 
     A perspective view of an illustrative conical shape that may be used for strain relief member SR is shown in  FIG. 11 . When cable  92  is flexed in the vicinity of connector  98 , strain relief member SR will tend to bend in direction  304  towards position  306  at narrow end  302 , whereas wide end  300  will tend to remain fixed within shell structure  98 S ( FIG. 10 ). 
     Illustrative steps involved in using computer-controlled intertwining equipment such as tools  14  of  FIG. 3  to form integral strain relief structures and bifurcation structures in accessory  88  are shown in  FIG. 12 . 
     At step  308 , fibers such as fibers  106  for the interior of cable  92  and fibers such as fibers  102  for intertwined cable cover  100  may be loaded into fiber sources  12 . 
     At step  310 , tool  14  may be used to form cover  100  around fibers  106 , as shown in  FIG. 2 . Fibers  106  may include metal wires (e.g., insulated or bare wires  104  of stranded and/or solid copper) and one or more strengthening cords such as cord  108  of  FIG. 2 . Cable components such as shielding layers, plastic sheaths, and other layers (shown as layer  114  in  FIG. 2 ) may be formed around fibers  106  (e.g., before feeding fibers  106  into the intertwining tool). 
     Tool  14  may braid, weave, or otherwise intertwine fibers  102  around fibers  106  and layer  114 . In doing so, computer controlled servo motors may be used to control intertwining tension (e.g., by increasing or decreasing tension on each individual fiber that is being fed from a respective bobbin in the intertwining tool to the intertwined structure as the bobbin passes along a predefined track path), fiber density (e.g., by increasing or decreasing the speed with which the cable passes through the intertwining tool), or other intertwined formation attributes. 
     These intertwined formation attributes affect the physical attributes of the resultant intertwined cable cover  100  such as the strength of the cable cover  100 , the closeness of the individual fibers to each other (e.g., the tightness of the weave, braid, or other intertwining in cover  100 ), the fiber density in the cover, the stiffness of the cable, the resistance of the cable cover to wear, etc. By controlling equipment  14  during intertwining, these physical attributes may be adjusted in real time to provide certain sections of cable  94  with localized strength. In particular, integral strain relief structures may be formed in the portions of cable  92  that are connected to connector (e.g., by increasing the intertwining tension and/or intertwining density and thereby stiffening and strengthening the cable cover and cable to form a strain relief structure for connector  98 ), strengthening structures may be formed to locally adjust the attributes of cable  94  in the vicinity of bifurcation  94  relative to the other portions of cable  94  (e.g., by increasing the intertwining tension and/or intertwining density and thereby stiffening and strengthening the cable cover and cable in a 3 mm to 5 cm segment of the cable cover that surrounds bifurcation  94  to form a strengthening structure for bifurcation  94  that helps prevent fiber unraveling), etc. 
     During the operations of step  312 , the process of forming cable  92  and headset  88  (or other suitable device) may be completed using tools  16 . During these steps, tool  18  may incorporate binder into the fibers of cable cover  100 , cable cover  100  may be coated with liquid, heat may be applied, a cutting tool may divide cable  94  into sections, internal strain relief members such as member SR of  FIG. 10  may be incorporated into cable  92  while connecting connector  98 P, shell  98 S, and cable section  92 T, components such as speakers for ear buds  90 , buttons in controller  96 , and contacts in connector  98 P may be connected to wires  104 , etc. 
     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: 20100928
Publication Date: 20130618
Grant Date: 20130618
Priority Date: 20100928
Inventors: WEBER DOUGLAS
AASE JONATHAN S.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01B13/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1033", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01B13/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "D07B1/16", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 45870696