Abstract:
An exemplary cable connector plug includes a first contact, a second contact and a first insulator portion. The first contact and the second contact are insulated from each other by the first insulator portion. The second contact includes an annular contact portion, the annular contact portion surrounding the first insulator. The annular contact portion includes an anti-rotation member defined at an inner side thereof, and the insulator portion is engaged with the anti-rotation member such that the annular contact portion cannot rotate relative to the first insulator portion. The anti-rotation member of the present cable connector plug prevent or avoid the occurrence of displacement as between adjacent contacts of the cable connector plug.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related to two co-pending U.S. patent applications, application serial no. [to be advised] (Docket No. US13427), entitled “CABLE CONNECTOR PLUG HAVING CONTACT WITH CURVED EXTENSION PORTION”, wherein the inventor is Wu-Kuang Chen et al, and application serial no. [to be advised] (Docket No. US13428), entitled “CABLE CONNECTOR PLUG HAVING CONTACT WITH HOOKING PORTION”, wherein the inventor is Wu-Kuang Chen et al. Such applications have the same assignee as the present application and have been concurrently filed herewith. The disclosures of the above identified applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to electrical connector plugs, and more particularly to a cable connector plug used in a connector for transmitting audio signals or other signals. 
         [0004]    2. Discussion of the Related Art 
         [0005]      FIG. 5  is a side cross-sectional view of a conventional cable connector plug  10 . The cable connector plug  10  includes a first contact  11 , a second contact  12 , a third contact  13 , a fourth contact  14 , and a plurality of insulators  15  between the contacts  11 ,  12 ,  13 ,  14 . The contacts  11 ,  12 ,  13 ,  14  are electrical conductors, and are insulated from each other by the insulators  15 . 
         [0006]    The first contact  11  includes a contact portion  110 , an extension portion  111  extending rearwardly from the contact portion  110  along an axis of the cable connector plug  10 , and a rear portion  112  extending rearwardly from the extension portion  111 . The second and third contacts  12 ,  13  respectively include an annular contact portion  120 ,  130 , a cylindrical extension portion  121 ,  131  extending rearwardly from the contact portion  120 ,  130 , and a rear portion  122 ,  132  extending from the extension portion  121 ,  131 . The fourth contact  14  includes a cylindrical contact portion  140 , an annular extension portion  141  extending rearwardly from the contact portion  140 , and a rear portion  142  extending from the extension portion  141 . The extension portions  111 ,  121 ,  131 ,  141  of the first, second, third, and fourth contacts  11 ,  12 ,  13 ,  14  are coaxially arranged in that order from an inside to an outside of the cable connector plug  10 . Accordingly, diameters of the extension portions  111 ,  121 ,  131 ,  141  increase in that sequence. The contact portions  110 ,  120 ,  130 ,  140  of the contacts  11 ,  12 ,  13 ,  14  are insulated from each other by a plurality of annular insulating ring portions (not labeled) of the insulators  15 . The extension portions  111 ,  121 ,  131 ,  141  of the contacts  11 ,  12 ,  13 ,  14  are insulated from each other by a plurality of cylindrical portions (not labeled) of the insulators  15 . 
         [0007]    The rear portion  112  of the first contact  11  extends rearwardly beyond the insulators  15  for soldering with a first wire (not shown) of a cable (not shown). A rearmost part of the rear portion  122  of the second contact  12  is exposed for soldering with a second wire (not shown) of the cable. The other part of the rear portion  122  of the second contact  12  is embedded between the corresponding insulators  15 . A rearmost part of the rear portion  132  of the third contact  13  is exposed for soldering with a third wire (not shown) of the cable. The other part of the rear portion  132  of the third contact  13  is embedded between the corresponding insulators  15 . The rear portion  142  of the fourth contact  14  extends perpendicularly outward from the insulator  15  that is between the third and fourth contacts  13 ,  14 , and is for soldering with a fourth wire (not shown) of the cable. 
         [0008]    Generally, surfaces of the second contact  12  are smooth surfaces. When the cable connector plug  10  is inserted into a mating socket of a housing of a complementary connector and rotated relative to the housing, the second contact  12  may easily slide and/or rotate relative to the first contact  11 . When this happens, a binding strength as between the first and second contacts  11 ,  12  is reduced. Thus the cable connector plug  10  is liable to loosen and malfunction or even break apart. 
         [0009]    What is needed, therefore, is a new cable connector plug which can overcome the above-described shortcomings. 
       SUMMARY 
       [0010]    A cable connector plug according to a preferred embodiment includes a first contact, a second contact and a first insulator portion. The first contact and the second contact are insulated from each other by the first insulator portion. The second contact includes an annular contact portion, the annular contact portion surrounding the first insulator. The annular contact portion includes a first anti-rotation member defined at an inner side thereof, and the insulator portion is engaged with the first anti-rotation member such that the annular contact portion cannot rotate relative to the first insulator portion. 
         [0011]    Other novel features and advantages will become more apparent from the following detailed description of various embodiments, when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present cable connector plug. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, and all the views are schematic. 
           [0013]      FIG. 1  is an isometric view of a cable connector plug according to a first preferred embodiment of the present invention, the cable connector plug including a first contact, a second contact, a third contact, and a fourth contact. 
           [0014]      FIG. 2  is a side, cross-sectional view of the cable connector plug of  FIG. 1 , taken along line  11 - 11  thereof. 
           [0015]      FIG. 3  is a side, cross-sectional view of the second contact of the cable connector plug shown in  FIG. 2 . 
           [0016]      FIG. 4  is a side, cross-sectional view of a cable connector plug according to a second preferred embodiment of the present invention. 
           [0017]      FIG. 5  is a side, cross-sectional view of a conventional cable connector plug. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Reference will now be made to the drawings to describe preferred embodiments of the present cable connector plug, in detail. 
         [0019]    Referring to  FIGS. 1 and 2 , a cable connector plug  20  according to a first preferred embodiment of the present invention is shown. The cable connector plug  20  includes a first contact  21 , a second contact  22 , a third contact  23 , a fourth contact  24 , and a plurality of insulators  25 . The contacts  21 ,  22 ,  23 ,  24  are made of metallic material, and are insulated from each other by the insulators  25 . The first contact  21  includes a contact portion  210 , an extension portion  211  extending rearwardly from the contact portion  210  along an axis of the cable connector plug  20 , and a rear portion  212  extending rearwardly from the extension portion  211 . 
         [0020]    The second and third contacts  22 ,  23  respectively include an annular contact portion  220 ,  230 , a cylindrical extension portion  221 ,  231  extending rearwardly from the contact portion  220 ,  230 , and a rear portion  222 ,  232  extending rearwardly from the extension portion  221 ,  231 . The fourth contact  24  includes a cylindrical contact portion  240 , an annular extension portion  241  extending rearwardly from the contact portion  240 , and a rear portion  242  extending from the extension portion  241 . The extension portions  211 ,  221 ,  231 ,  241  of the first, second, third, and fourth contacts  21 ,  22 ,  23 ,  24  are coaxially arranged in that order from an inside to an outside of the cable connector plug  20 . Accordingly, diameters of the extension portions  211 ,  221 ,  231 ,  241  increase in that sequence. The contact portions  210 ,  220 ,  230 ,  240  of the contacts  21 ,  22 ,  23 ,  24  are insulated from each other by a plurality of ring portions (not labeled) of the insulators  25 . The extension portions  211 ,  221 ,  231 ,  241  of the contacts  21 ,  22 ,  23 ,  24  are insulated from each other by a plurality of cylindrical portions (not labeled) of the insulators  25 . 
         [0021]    The rear portion  212  of the first contact  21  extends rearwardly beyond the insulators  25  for soldering with a first wire (not shown) of a cable (not shown). A rearmost part of the rear portion  222  of the second contact  22  is exposed for soldering with a second wire (not shown) of the cable. The other part of the rear portion  222  of the second contact  22  is embedded between the corresponding insulators  25 . A rearmost part of the rear portion  232  of the third contact  23  is exposed for soldering with a third wire (not shown) of the cable. The other portion of the rear portion  232  of the third contact  23  is embedded between the corresponding insulators  25 . The rear portion  242  of the fourth contact  24  extends perpendicularly outward from the insulator  25  that is between the third and fourth contacts  23 ,  24 , and is for soldering with a fourth wire (not shown) of the cable. 
         [0022]    The cable connector plug  20  can be manufactured by way of insert molding. In a typical process, firstly, the contacts  21 ,  22 ,  23 ,  24  are manufactured by a machining method. Secondly, the cable connector plug  20  is integrally assembled by an insert molding method. In particular, the contacts  21 ,  22 ,  23 ,  24  are coaxially aligned in a mold. Molten insulating material is injected into the mold and fills spaces between the contacts  21 ,  22 ,  23 ,  24 . The cooled insulating material forms the insulators  25  of the cable connector plug  20 . 
         [0023]    Referring to  FIGS. 2 and 3 , the contact portion  220  of the second contact  22  has an inner surface  223 . The inner surface  223  is in immediate contact with the insulator  25  that substantially surrounds the first contact  21 . A first anti-rotation member  225  is defined at the inner surface  223 . The first anti-rotation member  225  is configured to lockingly engage with the insulator  25 . For example, the first anti-rotation member  225  can include a plurality of depressions or one or more grooves, which are defined at the inner surface  223 . The depressions can be contiguous elongated depressions or discrete depressions. In this embodiment, the first anti-rotation member  225  includes a screw thread groove. Correspondingly, the insulator  25  has a screw thread that matches the screw thread groove. Thereby, a mechanical bonding strength between the insulator  25  and the second contact  22  is increased. Accordingly, when the cable connector plug  20  is inserted into a mating socket of a housing of a complementary connector and rotated relative to the housing, displacement as between the second contact  22  and the first contact  21  is avoided. 
         [0024]    Referring to  FIG. 2 , similarly, the extension portion  242  of the fourth contact  24  has an inner surface  243 . The inner surface  243  is in immediate contact with the insulator  25  that substantially surrounds the third contact  23 . A second anti-rotation member  245  is defined at the inner surface  243 . The second anti-rotation member  245  is configured to lockingly engage with the insulator  25 . For example, the second anti-rotation member  245  can include a plurality of depressions or one or more grooves, which are defined at the inner surface  243 . The depressions can be contiguous elongated depressions or discrete depressions. In this embodiment, the second anti-rotation member  245  includes a screw thread groove. Correspondingly, the insulator  25  has a screw thread that matches the screw thread groove. Thereby, a mechanical bonding strength between the insulator  25  and the fourth contact  24  is increased. Accordingly, when the cable connector plug  20  is inserted into the mating socket of the housing of the complementary connector and rotated relative to the housing, displacement as between the fourth contact  24  and the first contact  21  is avoided. 
         [0025]    The contacts  21 ,  22 ,  23 ,  24  are made of metallic material having good electrical conductive capability, such as copper, aluminum, and so on. In order to ensure good electrical contact and attain an aesthetically pleasing surface, an anticorrosion coating can be formed on an outer surface of each of the contacts  21 ,  22 ,  23 ,  24 . The anticorrosion coating is preferably made of nickel. The insulators  25  are preferably made of polyamide resin. 
         [0026]    Referring to  FIG. 4 , a cable connector plug  30  in accordance with a second preferred embodiment of the present invention is shown. The cable connector plug  30  is similar in principle to the cable connector plug  20  of the first embodiment, except that the cable connector plug  30  includes a second contact  32  having one or more first anti-rotation members  325 . The first anti-rotation member(s)  325  is/are configured to lockingly engage with a corresponding one of insulators  35 . For example, the first anti-rotation member(s)  325  can include a plurality of protrusions or one or more beads. The protrusions can be contiguous elongated protrusions or discrete protrusions. In this embodiment, the first anti-rotation member  325  is a screw thread provided on an inner surface of a contact portion of the second contact  32 . The insulator  35  is in immediate contact with the screw thread, so that a bonding strength between the insulator  35  and the second contact  32  is increased. Accordingly, when the cable connector plug  30  is inserted into a mating socket of a housing of a complementary connector and rotated relative to the housing, displacement as between the second contact  32  and a first contact (not labeled) is avoided. 
         [0027]    In an alternative embodiment of the cable connector plug  20 , the second anti-rotation member  245  can instead include a plurality of protrusions or one or more beads or a screw thread formed at the inner surface  243  of the extension portion  241  of the fourth contact  24 . The protrusions can be contiguous elongated protrusions or discrete protrusions. The second anti-rotation member is configured to lockingly engage with the corresponding insulator  25 . 
         [0028]    In another alternative embodiment of the cable connector plug  20 , the first anti-rotation member  225  can be omitted. That is, the cable connector plug  20  only has a single anti-rotation member, which is the anti-rotation member  245  at the inner surface  243  of the extension portion  241  of the fourth contact  24 . 
         [0029]    In a further alternative embodiment of the cable connector plug  20 , the second anti-rotation member  245  can instead be provided at an inner surface of the cylindrical portion  240  of the fourth contact  24 . This second anti-rotation member is configured to lockingly engage with the corresponding insulator  25 . 
         [0030]    It is should be noted that the above-described anti-rotation members of the cable connector plugs are not limited to the configurations provided. Each anti-rotation member can instead include any of various other suitable structures not described herein. For example, one or more non-planar structures can be formed on the inner surface of at least one of the second, the third, and the fourth contacts, whereby each of the anti-rotation members prevents or avoids the occurrence of displacement as between adjacent contacts of the cable connector plug. In other alternative embodiments, any two or all three of the insulators  25  of the cable connector plug  20  can be joined to each other at rear ends thereof, and any two or all three of the insulators  35  of the cable connector plug  30  can be joined to each other at rear ends thereof. 
         [0031]    It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.