PATENT DOCUMENT

Publication Number: US-9071009-B2
Application Number: US-201113246048-A
Country: US
Kind Code: B2

Title: Strain relief members for cables and methods for making the same

Abstract:
Aesthetically pleasing strain-relief members for cables and methods for making the same are disclosed. The strain-relief members are constructed to have one or more tuning members that provide selective strain relief for the cable. Each tuning member can vary the wall thickness of the strain relief member, and depending on several factors such as how many tuning members are present, their shape, and their positions within the strain-relief member, the strain-relief member can be specifically tailored to meet desired strain relief characteristics.

Claims:
What is claimed is: 
     
       1. A cable strain-relief member comprising:
 a housing engagement member; and 
 a strain-relief part that extends away from the housing engagement member, the strain-relief part comprising:
 an outer surface that defines an outer dimension of the strain-relief part, wherein the outer surface comprises a smooth and continuous shape; 
 a cable receiving passage extending from a first end of the strain-relief part that is away from the housing engagement member to a second end of the strain-relief part that is proximate to the housing engagement member; and 
 an inner wall defining dimensions of the cable receiving passage, the inner wall comprising at least one tuning member that defines a flex characteristic of the strain-relief part, wherein:
 the at least one tuning member comprises a plurality of tuning members; 
 the plurality of tuning members comprises:
 a first tuning member proximate the first end of the strain-relief part; 
 a second tuning member proximate the second end of the strain-relief part; and 
 a third tuning member between the first tuning member and the second tuning member; 
 
 at least one of the width and the depth of the third tuning member is greater than at least one of the width and the depth of the second tuning member; and 
 at least one of the width and the depth of the first tuning member is greater than at least one of the width and the depth of the third tuning member. 
 
 
 
     
     
       2. The strain-relief member of  claim 1 , wherein the housing engagement member and strain-relief part comprise an integrated structure. 
     
     
       3. The strain-relief member of  claim 1 , wherein the outer surface resembles a cylindrical body. 
     
     
       4. The strain-relief member of  claim 1 , wherein the at least one tuning member is operative to selectively provide strain relief for the portion of the strain-relief part at which the at least one tuning member resides. 
     
     
       5. The strain-relief member of  claim 1 , wherein each of the tuning members has different dimensions. 
     
     
       6. The strain-relief member of  claim 1 , wherein the tuning members are positioned and dimensioned to provide more strain relief at the first end than at the second end. 
     
     
       7. The strain-relief member of  claim 1 , wherein the at least one tuning member comprises at least one of a ring shape and a doughnut shape. 
     
     
       8. The strain-relief member of  claim 1 , wherein the at least one tuning member comprises a taper region, a neck region and a non-taper region. 
     
     
       9. The strain-relief member of  claim 1 , wherein the strain-relief member is constructed from silicone. 
     
     
       10. The strain-relief member of  claim 1 , wherein the smooth and continuous shape comprises an uninterrupted cylindrical shape. 
     
     
       11. A method for making a cable assembly, the method comprising:
 providing the cable strain-relief member of  claim 1 ; 
 coupling a cable to a plug; 
 sliding the cable through the cable receiving passage of the cable strain-relief member; and 
 inserting the plug, the cable, and the housing engagement member of the cable strain-relief member into a connector housing; and 
 securing the plug, the cable, and the housing engagement member of the cable strain-relief member in the connector housing. 
 
     
     
       12. The strain-relief member of  claim 1 , wherein a predetermined amount of space exists between each of the tuning members along the length of the strain-relief part between the first end of the strain-relief part and the second end of the strain-relief part. 
     
     
       13. The strain-relief member of  claim 12 , wherein the predetermined amount of space between each tuning member is the same. 
     
     
       14. The strain-relief member of  claim 12 , wherein the predetermined amount of space between each tuning member is different. 
     
     
       15. A cable assembly comprising:
 a plug; 
 a connector housing coupled to the plug; the strain-relief member of  claim 1 , wherein the housing engagement member of the strain-relief member is coupled to the connector housing; and 
 a cable coupled to the connector housing, the strain-relief member, and the plug, wherein the cable passes through the cable receiving passage of the of the strain-relief member. 
 
     
     
       16. The cable assembly of  claim 15 , wherein the strain-relief member provides selective strain relief to the cable. 
     
     
       17. The cable assembly of  claim 15 , wherein the housing engagement member of the strain-relief member is coupled to the connector housing with an adhesive. 
     
     
       18. The cable assembly of  claim 15 , wherein the housing engagement member of the strain-relief member is encased inside the connector housing. 
     
     
       19. The cable assembly of  claim 15 , wherein the strain-relief part of the strain-relief member and the connector housing comprises an opening, and wherein the strain-relief part of the strain-relief member extends away from the connector housing through the opening. 
     
     
       20. A method for making the strain-relief part of the cable strain-relief member of  claim 1 , the method comprising:
 providing a mold that forms the outer dimension of the strain-relief part; 
 securing a removable rod within the mold during a molding step, the rod shaped to ensure the cable receiving passage of the strain-relief part of the cable strain-relief member is formed; 
 molding the strain-relief part of the cable strain-relief member using the mold and the removable rod; and 
 removing the removable rod to yield the strain-relief part of the cable strain-relief member. 
 
     
     
       21. The method of  claim 20 , wherein the molding the strain-relief part of the cable strain-relief member comprises compression molding the strain-relief part. 
     
     
       22. The method of  claim 20 , wherein the molding the strain-relief part of the cable strain-relief member comprises injection molding the strain-relief part. 
     
     
       23. A cable strain-relief part comprising:
 a wall, wherein:
 an outer wall surface of the wall comprises a smooth and continuous shape; 
 an inner wall surface of the wall defines a cable receiving passage extending along a length of the wall from a first end of the wall to a second end of the wall; and 
 the inner wall surface comprises at least three tuning members that vary a flex characteristic of the strain-relief part along the length of the wall, wherein the amount of space between a first set of adjacent tuning members of the at least three tuning members is different than the amount of space between a second set of adjacent tuning members of the at least three tuning members. 
 
 
     
     
       24. The cable strain-relief part of  claim 23 , wherein a first tuning member of the at least three tuning members has different dimensions than a second tuning member of the at least three tuning members. 
     
     
       25. A method for making a cable assembly, the method comprising:
 providing the cable strain-relief part of  claim 23 ; 
 coupling a cable to a plug; 
 sliding the cable through the cable receiving passage of the cable strain-relief part; and 
 inserting the plug, the cable, and a portion of the cable strain-relief part into a connector housing; and 
 securing the plug, the cable, and the portion of the cable strain-relief part in the connector housing. 
 
     
     
       26. A cable assembly comprising:
 a plug; 
 a connector housing coupled to the plug; 
 the cable strain-relief part of  claim 23  coupled to the connector housing; and 
 a cable coupled to the connector housing, the cable strain-relief part, and the plug, wherein the cable passes through the cable receiving passage of the of the cable strain-relief part. 
 
     
     
       27. The cable assembly of  claim 26 , wherein the cable strain-relief part provides selective strain relief to the cable. 
     
     
       28. The cable assembly of  claim 26 , wherein the cable strain-relief part is coupled to the connector housing with an adhesive. 
     
     
       29. The cable assembly of  claim 26 , wherein a portion of the cable strain-relief part is encased inside the connector housing. 
     
     
       30. The cable assembly of  claim 26 , wherein the connector housing comprises an opening, and wherein another portion of the cable strain-relief part extends away from the connector housing through the opening. 
     
     
       31. A method for making the cable strain-relief part of  claim 23 , the method comprising:
 providing a mold that forms the outer wall surface of the cable strain-relief part; 
 securing a removable rod within the mold during a molding step, the rod shaped to ensure the cable receiving passage of the cable strain-relief part is formed; 
 molding the cable strain-relief part using the mold and the removable rod; and 
 removing the removable rod to yield the cable strain-relief part. 
 
     
     
       32. The method of  claim 31 , wherein the molding the cable strain-relief part comprises compression molding the cable strain-relief part. 
     
     
       33. The method of  claim 31 , wherein the molding the cable strain-relief part comprises injection molding the cable strain-relief part. 
     
     
       34. A cable strain-relief comprising:
 a wall extending between a first wall end and a second wall end, the wall comprising:
 an outer wall surface that comprises an uninterrupted cylindrical shape; and 
 an inner wall surface that defines a cable receiving passage, wherein the inner wall surface comprises at least three tuning members that change a flex characteristic of the cable strain-relief along the length of the wall, and wherein at least one of the following is true: 
 the amount of space between a first set of adjacent tuning members of the at least three tuning members is different than the amount of space between a second set of adjacent tuning members of the at least three tuning members; and 
 a first tuning member of the at least three tuning members has different dimensions than a second tuning member of the at least three tuning members. 
 
 
     
     
       35. The cable strain-relief of  claim 34 , wherein:
 the concentration of the at least three tuning members is more concentrated near the first wall end than the second wall end. 
 
     
     
       36. A method for making a cable assembly, the method comprising:
 providing the cable strain-relief of  claim 34 ; 
 coupling a cable to a plug; 
 sliding the cable through the cable receiving passage of the cable strain-relief; and 
 inserting the plug, the cable, and a portion of the cable strain-relief into a connector housing; and 
 securing the plug, the cable, and the portion of the cable strain-relief in the connector housing. 
 
     
     
       37. A cable assembly comprising:
 a plug; 
 a connector housing coupled to the plug; 
 the cable strain-relief of  claim 34  coupled to the connector housing; and 
 a cable coupled to the connector housing, the cable strain-relief, and the plug, wherein the cable passes through the cable receiving passage of the of the cable strain-relief. 
 
     
     
       38. The cable assembly of  claim 37 , wherein the cable strain-relief provides selective strain relief to the cable. 
     
     
       39. The cable assembly of  claim 37 , wherein the cable strain-relief is coupled to the connector housing with an adhesive. 
     
     
       40. The cable assembly of  claim 37 , wherein a portion of the cable strain-relief is encased inside the connector housing. 
     
     
       41. The cable assembly of  claim 37 , wherein the connector housing comprises an opening, and wherein another portion of the cable strain-relief extends away from the connector housing through the opening. 
     
     
       42. A method for making the cable strain-relief of  claim 34 , the method comprising:
 providing a mold that forms the outer wall surface of the cable strain-relief; 
 securing a removable rod within the mold during a molding step, the rod shaped to ensure the cable receiving passage of the cable strain-relief is formed; 
 molding the cable strain-relief using the mold and the removable rod; and 
 removing the removable rod to yield the cable strain-relief. 
 
     
     
       43. The method of  claim 42 , wherein the molding the cable strain-relief comprises compression molding the cable strain-relief. 
     
     
       44. The method of  claim 42 , wherein the molding the cable strain-relief comprises injection molding the cable strain-relief.

Description:
This application claims the benefit of U.S. Provisional Patent Application No. 61/450,591, filed Mar. 8, 2011, which is incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Cables are commonly used with electronic devices such as computers, cellphones, and portable media devices. When cables are subject to repeated physical manipulations that exert bend and strain forces on the cable, the cable can eventually break or tear. Smaller diameter cables and cables used in connection with portable electronic devices are generally more susceptible to breakage because they are more frequently handled by being bent, pulled, tangled, or wrapped. Cable manufacturers have conventionally used strain-relief mechanisms to ease the stress burden on cables. However, many of these conventional strain-relief mechanisms are ineffective or are not aesthetically pleasing. 
     SUMMARY 
     Aesthetically pleasing strain-relief members for cables and methods for making the same are disclosed. The strain-relief members are constructed to have one or more tuning members that provide selective strain relief for the cable. Each tuning member can vary the wall thickness of the strain relief member, and depending on several factors such as how many tuning members are present, their shape, and their positions within the strain-relief member, the strain-relief member can be specifically tailored to meet desired strain relief characteristics. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and advantages of the invention will become more apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIG. 1  is a perspective view of an illustrative cable assembly with strain relief according to an embodiment of the invention; 
         FIG. 2  is a cross-sectional view of a conventional strain-relief member; 
         FIGS. 3A-B  show cross-sectional views of different illustrative strain-relief members according to embodiments of the invention; 
         FIG. 4  is a cross-sectional top view of another strain-relief member according to an embodiment of the invention; 
         FIG. 5  is a cross-sectional top view of yet another strain-relief member according to an embodiment of the invention; 
         FIG. 6  is an illustrative flow chart for manufacturing a strain-relief member according to an embodiment of the invention; and 
         FIG. 7  is a flow chart of a method for manufacturing a cable assembly with a strain-relief member according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
       FIG. 1  is a perspective view of an illustrative cable assembly  100  according to an embodiment of the invention. Cable assembly  100  can include strain-relief member  110 , cable  120 , connector housing  130  and plug  132 . In some embodiments, such as the one shown, a portion of member  110  can be integrated within housing  130 . This portion (not shown) is referred to herein as a housing engagement member—see, for example,  FIGS. 3A-B  for illustrations of housing engagement member  312 . This portion can be secured within housing  130  with an adhesive, thermal bond, or one or more mechanical clips. 
     In another embodiment, the housing engagement member of strain-relief member  110  may be coupled to the outer surface of the connector housing  130 . Any suitable method for securing strain-relief member  110  may be employed. For example, strain-relief member  110  can be directly coupled to the outer surface of connector housing  130  with an adhesive or thermal bonding. 
     The strain-relief part of member  110 , which is the portion shown extending through opening  134  away from housing  130 , engages cable  120 , which passes through member  110  into housing  130 . The portion of cable  120  that engages strain-relief member  110  is provided with strain relief. Embodiments according to this invention provide strain relief tuned specifically to the type of cable  120  being used in cable assembly  100 . For example, some cables may be better suited to have enhanced strain relief in the region of member  110  that abuts housing  130 , whereas other cables may be better suited to have reduced strain relief in that same region. As another example, strain relief may be selectively tuned along the length of strain-relief member  110  based on, for example, the type of cable for which it is providing strain relief. 
     Strain-relief member  110  may be constructed from silicone, thermoplastic elastomer (“TPE”), polyurethane, or other suitable material. In addition, strain-relief member  110  is constructed to have an aesthetically pleasing outer shell that has a smooth and continuous shape. As shown, the outer shell has a smooth and uninterrupted cylindrical shape. In contrast, and by way of example, a non-smooth and discontinuous outer shell could have corrugations, ridges, or cutouts. 
     Connector housing  130  may provide protection for physical and electrical connections between cable  120  and plug  132  (e.g., solder connections). Connector housing  130  may be constructed from a resilient material (e.g., plastic or metal). Plug  132  may be any type of electrical connector (e.g., RCA, DVI, HDMI, HDCP, VGA, display port, USB, Mini USB, Micro USB, a power connector, a magnetic connector, a 30-pin connector, or any other standard or proprietary interface) operable to couple a cable (e.g., cable  120 ) to an electronic device. 
       FIG. 2  is a cross-sectional perspective view of conventional strain-relief member  210 . Strain-relief member  210  can include housing engagement member  212 , strain-relief part  214 , and wall  217 , which has inner surface  216  and outer surface  218 . Cable receiving passage  211  is operable to receive a cable (e.g., cable  120  of  FIG. 1 ) and includes first end  213  and second end  215 . The thickness of wall  217  is substantially constant along the length of part  214 . The design of strain-relief member  210  results in uniform flex characteristics throughout, leading to the creation of a relatively high-stress point for any cable contained within cable receiving passage  211  at second end  215 . 
       FIG. 3A  is a cross-sectional perspective view of illustrative strain-relief member  301  according to an embodiment of the invention. Strain-relief member  301  includes housing engagement member  312 , strain-relief part  314 , and wall  317 , which has inner surface  316  and outer surface  318 . Cable receiving passage  311  is operable to receive a cable (e.g., cable  120  of  FIG. 1 ) and includes first end  313  and second end  315 . Strain-relief member  301  also includes one or more tuning members  350 , each of which changes the contours/dimensions of inner surface  316  and the corresponding thickness of wall  317 , thereby resulting in variable wall thickness along the length of part  314 . 
     Tuning members  350  provide tunable flex and/or strain relief characteristics for strain-relief part  314 . Any suitable number of factors can be employed to tune strain-relief part  314 . For example, the number of tuning members  350  used in part  314  and the spacing between tuning members  350  can contribute to the tuning of part  314 . In addition, the shape and size of each tuning member  314  can be constructed to achieve desired flex characteristics. For example, a tuning member can have a ring or doughnut shape in which the depth, width, and taper angle can be varied. As shown in  FIG. 3A , a series of ring or doughnut shaped tuning members  350  provides a corrugated or undulating, accordion like cable receiving passage  311 . As another example (not shown), the tuning members can have a shape that is more angular in nature than a ring or doughnut shape. For example, a trapezoidal or triangular shape may be used. 
     Flexibility increases with decreased wall thickness and decreases with increased wall thickness. Using this generalization as a design roadmap, it can be appreciated that strain-relief member  301  is tuned to be more flexible near end  315  than at end  313 . The concentration of tuning members  350  are more concentrated near end  315 , and as a result of this concentration, the thickness of wall  317  is thinner near end  315  than at end  313 . This is illustrated more clearly in  FIG. 3B , which shows a cross-sectional top view of strain-relief member  301 . 
     Tuning members  350  are now specifically identified as tuning members  352 ,  354 ,  356  and  358 . Strain-relief member  301  is designed to provide stiff support for a cable at end  313  (e.g., the portion of member  301  where a cable interfaces with a connector housing. Members  352 ,  354 ,  356 , and  358  gradually increase in width and depth from tuning member  352  to tuning member  358 , thereby allowing for increasingly more cable flex along the length of strain-relief part  314  as the cable approaches second end  315 . With strain-relief member  301  tuned in this manner, the strain on the cable near second end  315  is substantially mitigated. 
     Depending on the dimensions and shape of tuning members used in a strain-relief member, all or a portion of the inner surface of wall  317  is in contact with the cable (not shown) in cable receiving passage  311 . In some embodiments, the portions of wall  317  that do not have tuning members may fit flush against the cable. For example, the portion of cable receiving passage  311  at second end  315  may form a tight interference fit with the cable. The cable may be free floated within cable receiving passage  311  (i.e., not physically bonded to the inner surface of wall  317 ). In other embodiments, the cable can be bonded (by a thermal bond or an adhesive) to at least a portion of the inner surface of wall  317 . 
       FIG. 4  is a cross-sectional top view of strain-relief member  401  according to an embodiment of the invention. Strain-relief member  401  has many of the same attributes of strain-relief member  301 , and therefore similar features are similarly labeled, except instead of “3XX,” the features are now labeled “4XX.” Member  401  includes cable receiving passage  411  and wall  417 , which has outer surface  418  and inner surface  416 . Strain-relief member  401  differs from strain-relief member  301  in that strain-relief part  414  has a shorter a length. In addition, tuning members  452 ,  454  and  456  are designed so member  401  has more flex near end  413  than at end  415 . 
       FIG. 5  is a cross-sectional top view of strain-relief member  501  according to an embodiment of the invention. Strain-relief member  501  includes lone tuning member  552 . Tuning member  552  can include tapered portion  553  and necked portion  554 , which provides a step change in wall thickness of wall  517 , and non-tapered portion  555 . Tapered portion  553  can gradually decrease wall thickness from first end  513  as it extends towards necked portion  554 . At necked portion  554 , the wall thickness changes to accommodate the wall thickness of non-tapered portion  555 . If desired, non-tapered portion  555  can be designed to taper. 
       FIG. 6  is an illustrative flow chart for manufacturing a strain-relief member according to an embodiment of the invention. Beginning at step  610 , a mold is provided that forms the external dimensions of a strain-relief member. For example, the mold can form the outer dimensions of the housing engagement member and strain relief part. At step  620 , a removable rod is positioned within the mold and held in place during a molding step. The rod is shaped to ensure the cable receiving passage (e.g., passage  311  of  FIG. 3A ) with one or more appropriately sized and shaped tuning members is formed. 
     At step  630 , the stress-relief member is molded using the mold and removable rod. In one embodiment, a compression mold may be used to mold the stress-relief member. Compression molds may be made using any number of different techniques. In one approach, silicon sheets can be molded around the rod. In another approach, a combination of urethane sheets and foam can form the stress-relief member. In another embodiment, an injection mold process may be used to mold the stress-relief member. At step  640 , the removable rod is removed to yield a strain-relief member having one or more tuning members according to an embodiment of the invention. 
       FIG. 7  is an illustrative flow chart for manufacturing a cable assembly having a strain-relief member according to an embodiment of the invention. At step  710 , a strain-relief member (e.g., strain-relief member  110  of  FIG. 1 ) is provided. Next, at step  720 , a cable (e.g., cable  120 ) can be electrically coupled to a plug (e.g., plug  132 ). Electrical coupling between the cable and plug can include, for example, solder connections between individual wires in the cable and electrically conductive contacts on the plug. 
     At step  730 , the cable is slid through a cable receiving passage (e.g., cable receiving passage  311  of  FIG. 3 ) of the strain-relief member. The strain-relief member may be oriented such that the strain-relief part will pass through an opening of a connector housing when inserted into the connector housing. At step  740 , the plug, cable, and strain relief member are inserted into a connector housing and permanently attached thereto. A housing engagement member of the strain-relief member may be secured to the connector housing any suitable method. 
     It is understood that the various features, elements, or processes of the foregoing figures and description are interchangeable or combinable to realize or practice the invention described herein. Those skilled in the art will appreciate that the invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation, and the invention is limited only by the claims, which follow.

Metadata:
Filing Date: 20110927
Publication Date: 20150630
Grant Date: 20150630
Priority Date: 20110308
Inventors: ARDISANA JOHN B.
SIHAAN EDWARD
JOL ERIC
Assignee: APPLE INC
CPC Classifications: [{"code": "H01R13/562", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49174", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/5845", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/5812", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/562", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49174", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R13/5812", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/5845", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 46795978