Abstract:
The invention provides a coaxial cable connector having a step up pin that engages the center conductor of a coax cable to increase the diameter of the center conductor to thereby make it more manageable. The pin is stored with the connector until the pin and connector are affixed to a coax cable.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation-In-Part of U.S. Utility patent application Ser. No. 11/520,346 filed Sep. 13, 2006, the disclosure of which is herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to coaxial cable connectors that engage the center conductor and the outer conductor of an end of a coaxial cable. 
       BACKGROUND OF THE INVENTION 
       [0003]    A coax cable connector is generally used to provide a simple connection to an externally threaded coax receptacle or jack. The connector contacts the outer conductor of the cable in order to conduct the outer conductor signal to the jack. The center conductor of the cable passes through the center of the connector to engage the center hole of the jack. A dielectric portion between the components of the connector that contact the center conductor and the outer conductor isolates the signals. In some cases, such as with miniature coaxial cable, the center conductor is too small to engage the center hole of the jack fully for good conduction of the center conductor signal. A step up pin may be applied to the end of the center conductor to increase the diameter of the center conductor; however, step up pins are conventionally difficult to manage, are easily lost, and may be difficult to apply to the center conductor. Further, step up pins tend to be easily damaged during handling. In some cases, the pin might be a fixed part of the connector. It is difficult to line up the center conductor of the coax cable with the pin in this case because the user cannot see the opening of the axial bore of the pin. 
         [0004]    A number of U.S. patents are directed to coax cable connectors including U. S. Pat. No. 4,613,199 issued to McGeary. McGeary teaches a coaxial cable connector having a captive inner pin contact. The connector includes a tubular main body that is crimped over the cable braid of a coaxial cable. A crimp ring is provided inside the rear end of the tubular main body and secures the cable braid of the coaxial cable against a ferrule which is inserted between the cable braid and the cable dielectric prior to crimping. A cylindrical contact insulator is secured inside the front end of the tubular main body, separates the inner pin contact from the front end of the tubular main body, and secures the inner pin contact in combination with the insulator ring and ferrule. Threads are provided on the inside surface of the ferrule to hold the ferrule in position during crimping, to help provide positive contact to the tubular main body, and to captivate the insulator ring and inner pin contact. McGeary does not teach how the pin might be stored prior to assembly of the connector onto a cable. Nor does McGeary teach a step up pin having tabs or spring fingers for engaging the connector or the center conductor. 
         [0005]    U.S. Pat. No. 6,863,565 issued to Kogan, et al. teaches a connector for receiving a mating plug, forming a constant impedance connection. The center conductor of the first plug is supported with a cap attached over a portion of the center conductor that extends beyond the outer conductor portion of the same plug. The mating plug has an outer conductor that projects beyond the inner conductor, and is made to receive the connector or first plug portions. Kogan thus teaches a pin having a larger diameter than the center conductor and supporting the center conductor. Kogan does not discuss securing the pin to the connector prior to assembly in a way that prevents the pin from being lost and that aids assembly of the pin onto the center conductor. Kogan further does not teach a step up pin with an enlarged cable guide portion or spring fingers and tabs for engaging the center conductor or the connector. 
         [0006]    U.S. Pat. No. 4,981,445 issued to Bacher, et al. teaches a unitary three-vane support bead with a central conductor having an axial blind bore in each end. The smaller diameter end engages a center conductor of a coax cable. The central conductor is formed in place in the connector. Bacher does not teach a method of securing the pin to the connector prior to assembly in a way that prevents the pin from being lost and that aids assembly of the pin onto the center conductor. 
         [0007]    U.S. Pat. No. 4,672,342 issued to Gartzke teaches a coaxial cable connector assembly for connecting coaxial cables of different diameters, the assembly including a center conductor with a large diameter end and a small diameter end. Each end includes spring fingers for engaging the center conductor of a coaxial cable. Gartzke does not discuss securing the pin to the connector prior to assembly in a way that prevents the pin from being lost and that aids assembly of the pin onto the center conductor. 
         [0008]    Therefore, a coaxial cable connector that provides storage and protection for a step up pin, and that provides a simple way to apply the step up pin to the center conductor is desired. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention comprises, in one form, a step up pin for increasing the diameter of a coaxial cable&#39;s center conductor. In certain embodiments, the step up pin is used in conjunction with a coaxial cable connector. The step up pin includes a blind bore sized for a tight fit with the center conductor to provide good conduction between the center conductor and the pin. The pin further includes an enlarged cable guide. The pin is stored with the connector until the pin and connector are affixed to a coax cable. 
         [0010]    More particularly, the invention includes a coaxial cable connector that comprises a connector body having a collar with a nut body engaging one end of the collar; a non-conducting pin guide situated within the connector body proximate to the junction between the nut body and the collar; and a step up pin comprising a pin body and a cable guide. The pin guide defines a through bore, and the step up pin is removably engaged with the through bore of the pin guide with the cable guide situated within the nut body and with the step up pin directed toward the opposing end of the collar. 
         [0011]    In another form, the invention includes a coaxial cable connector that comprises a connector body defining an axial bore for engaging a coaxial cable; a compressor ring defining a sidewall bore with an enlarged recessed portion, the compressor ring operatively attached to the connector body; and a step up pin having a cable guide and defining a blind bore for engaging a center conductor of a coaxial cable. The step up pin is removably engaged to the sidewall bore with the cable guide situated at least partially within the recessed portion prior to the coaxial cable being inserted into the axial bore of the connector. 
         [0012]    The invention allows the pin to be stored with the connector so that the pin is not easily dropped or lost and such that the pin is easily attached to even small diameter center conductors. Further, because the pin is not fixed within the body of the connector with the opening of the pin hidden within the connector, the user can easily see the opening of the pin for lining up the center conductor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention is disclosed with reference to the accompanying drawings, wherein: 
           [0014]      FIG. 1  is an isometric view of a coax cable connector according to the present invention; 
           [0015]      FIG. 2  is a cross-sectional view of the coax cable connector of  FIG. 1 ; 
           [0016]      FIGS. 3A-3B  are views of the step up pin according to the present invention; 
           [0017]      FIG. 4A  is an isometric view of the compression ring and step up pin of  FIG. 1 ; 
           [0018]      FIG. 4B  is an end view of the compression ring and step up pin of  FIG. 4A ; 
           [0019]      FIGS. 5A-5E  are various views of the application of the step up pin and the coax cable connector of  FIG. 1  onto a coax cable; 
           [0020]      FIG. 6A  is an isometric view of the compression ring and step up pin of a second embodiment of the coax cable connector of the present invention; 
           [0021]      FIG. 6B  is an end view of the compression ring and step up pin of  FIG. 6A ; 
           [0022]      FIG. 7A  is an isometric view of the compression ring and step up pin of a third embodiment of the coax cable connector of the present invention; 
           [0023]      FIG. 7B  is an end view of the compression ring and step up pin of  FIG. 7A ; 
           [0024]      FIG. 8A  is an isometric view of a particular embodiment of the coax cable connector with the step up pin stored in engagement with the pin guide; 
           [0025]      FIG. 8B  is a cross-sectional side view of the coax cable connector of  FIG. 8A ; 
           [0026]      FIGS. 9A-9F  are various views of the application of the step up pin and the coax cable connector of  FIG. 8A  onto a coax cable; and 
           [0027]      FIGS. 10A-10C  are views of a particular embodiment of the coax cable connector with the step up pin stored in engagement with a countersunk sidewall bore in the compression ring. 
       
    
    
       [0028]    Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate several embodiments of the invention but should not be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION 
       [0029]      FIG. 1  shows the coax cable connector of the present invention. The connector  10  includes a connector body  12  and a step up pin  14 . The connector body  12  includes a nut body  20 , a collar  22 , a compression ring  24 , and an inner post  26  (see  FIG. 2 ). The nut body  20  includes internal threads for connection to an externally threaded coax jack (not shown). The nut body  20  contacts the inner post  26  for electrical connection and engages the collar  22  via an o-ring  27 . The collar  22  is knurled or otherwise textured to provide an improved grip on the collar. In its pre-use or storage position, the compression ring  24  is clipped into the end of the collar  22  as shown in  FIG. 2 . The inner post  26  includes a pin guide  28  and a shaft  30  with barbs for engaging the coax cable&#39;s dielectric sleeve. 
         [0030]    The step up pin  14 , which may be used in conjunction with the connector  10  or with any application requiring the increased diameter of the center conductor, includes a pin body  32  and a cable guide  34 . The pin body  32 , best shown in  FIGS. 2 and 3A , includes an axial bore  35  sized for a snug fit with the center conductor of a coax cable. Spring fingers  36  may be included to secure the center conductor within the bore and to improve the conduction between the center conductor and the step up pin  14 . The spring fingers  36  project into the pin body  32  and are directed away from the bore opening. As shown, the axial bore  35  is a blind bore with an open end  37 . Tabs  38  project outward from the pin body  32 , toward the opening of the bore. The cable guide  34  is either integrally formed with the pin body  32  or affixed thereto, such as by an interference fit or an adhesive. The cable guide  34  is complementarily contoured to fit into the slope of the pin guide  28 . The outward bias of the tabs  38  assists in retaining the step up pin  14  within the pin guide  28 . The step up pin  14  is applied to a coax cable  40  as shown in  FIGS. 3A and 3B . 
         [0031]    As shown in  FIGS. 4A and 4B , a sidewall bore  39  is either machined or molded into the compression ring  24  for the storage of the step up pin  14  prior to assembly. The sidewall bore  39  is configured for a snug fit with the pin body  32  to prevent the pin  14  from being separated from the connector body  12 . Also, the outward bias of the tabs  38  resists separation of the step up pin  14  and the sidewall bore  39 . 
         [0032]    The connector  10  is assembled onto a coax cable as shown in  FIGS. 5A-5E . With reference to  FIG. 5A , the coax cable  40  is of a known type comprising an electrical central conductor  42 , a dielectric sleeve  44 , an outer conductor  46 , and a jacket  48 . The outer conductor  46  may comprise a sheath of fine braided metallic strands, a metallic foil, or multiple layer combinations of either or both. The cable  40  is prepared as usual, such as by exposing about 0.25-in of the center conductor  42  and about 0.25-in of the dielectric sleeve  44  and outer conductor  46  above that. The outer conductor  46  is folded back over the jacket  48 . The user inserts the center conductor  42  into the axial bore of the pin body  32  as shown in  FIG. 5B . The user then withdraws the cable  40  with the step up pin  14  from the sidewall bore  39  of the compression ring  24  and inserts the cable  40  and step up pin  14  into the axial bore of the compression ring  24  as shown in  FIG. 5C . 
         [0033]    The step up pin  14  and the dielectric sleeve  44  are inserted into the axial bore of the inner post  26  such that the shaft  30  is forced in between the dielectric sleeve  44  and the outer conductor  46  as shown in  FIG. 5D . The user continues to direct the cable  40  into the connector body  12  until the cable guide  34  engages the pin guide  28  as shown in  FIG. 5E . A compression tool (not shown) forces the compression ring  24  into the collar  22  such that the compression ring  24  compresses the jacket  48  and the outer conductor  46  against the shaft  30  to secure the cable  40  within the connector  10  and to provide good conduction between the outer conductor  46  and the inner post  26 . 
         [0034]    In uses the connector  10  is attached to a coaxial cable jack (not shown) by inserting the step up pin  14  into an axial bore of the jack and threading the internal threads of the nut body  20  onto corresponding external threads of the jack. An electrical signal is conducted between the center conductor of the jack and the center conductor  42  via the pin body  32 . An electrical signal is conducted from the threaded outer conductor of the jack to the nut body  20  and the end of the inner post  26 . The inner post  26  conducts the signal to the outer conductor  46 . The non-conducting pin guide  28  isolates the inner conductor signal from the outer conductor signal within the connector  10 . The cable guide  34  may also be non-conducting. 
         [0035]    In an alternative embodiment, the step up pin  14  is stored in a concentric position within the compression ring  24  as shown in  FIGS. 6A and 6B . The step up pin is held within the compression ring  24  by sprue tabs  50 . The cable guide  24  is molded with the compression ring  24  with the sprue tabs  50  being formed therebetween. During assembly, the center conductor engages the bore of the ping body  32  and the cable is pushed into the connector body  12  thereby breaking the sprue tabs  50  and driving the step up in  14  to the pin guide  28 . 
         [0036]    In a further alternative embodiment, the step up pin  14  is stored in engagement with the outer surface of the compression ring  24  as shown in  FIGS. 7A and 7B . The cable guide  34  is molded with the compression ring  24  with sprue tabs  52  formed therebetween. The connector  10  is assembled onto a coax cable by inserting the center conductor into the bore of the pin body  32  and twisting the step up pin  14  to break the sprue tabs  52  and remove the cable guide  34  from the compression ring  24 . The assembly is completed as described above with reference to  FIGS. 5C-5E . 
         [0037]    In a particular embodiment shown in  FIGS. 8A and 8B , the step up pin  14  is stored within the connector body  12  in a press-fit engagement with an axial through bore of the non-conducting pin guide  28 . The step up pin  14  is inserted through the nut body  20  and into the pin guide  28  for storage within the connector body  12 . The cable guide  34  is situated within the nut body  20  and the opening  37  of the blind bore  35  directed towards the opening of the nut body  20 . The step up pin  14  is therefore directed towards the compressor ring end of the connector body  12 . This has the advantage of providing easy access to the open end  37  of the blind bore  35  of the step up pin  14  when assembling the pin on the center conductor. The step up pin  14  is thus conveniently stored within the connector body  12 , which protects the potentially fragile pin from damage during handling. The compression ring  24  does not require a sidewall bore or sprue tabs for retaining the step up pin before assembly. 
         [0038]    The connector  10  is assembled onto the prepared end of a coax cable  40  by inserting the center conductor  42  through the open end  37  of the axial blind bore  35  via the axial bore of the nut body  20  as shown in  FIGS. 9A and 9B . The spring fingers  36  help secure the center conductor  42  within the axial blind bore  35 . The user withdraws the cable and the step up pin from the nut body end of the connector body  12  and turns over the connector body  12  to insert the cable and pin into the compression ring end of the connector body  12  as shown in  FIGS. 9C and 9D . The step up pin  14  and the dielectric sleeve  44  are inserted into the axial bore of the inner post  26  such that the shaft  30  is forced in between the dielectric sleeve  44  and the outer conductor  46  as shown in  FIG. 9E . The user continues to direct the cable  40  into the connector body  12  until the sloped surface  54  of the cable guide  34  engages the complementary sloped recess  56  of the pin guide  28  as shown in  FIG. 9F . A compression tool (not shown) forces the compression ring  24  into the collar  22  such that the compression ring  24  compresses the jacket  48  and the outer conductor  46  against the shaft  30  to secure the cable  40  within the connector  10  and to provide good conduction between the outer conductor  46  and the inner post  26 . 
         [0039]    In a further particular embodiment shown in  FIGS. 10A-10C , the step up pin  14  stored in engagement with a sidewall bore of the compression ring, similarly to that described above in relation to  FIGS. 1 ,  2 ,  4 A, and  4 B. In the embodiment shown in  FIGS. 10A-10C , however, the pin is stored in a countersunk sidewall bore  139  in the compression ring  124 . The sidewall bore  139  includes an enlarged recessed portion  160  that receives the guide  34 , and the bore  139  continues through at least a portion of the opposing side of the compression ring  124  to receive the end of the pin body  32 . Thus, little of the step up pin  14  is exposed outside the compression ring  124  during storage and the pin is protected from damage during handling. 
         [0040]    The connector  10  is assembled onto the prepared end of a coax cable. The user inserts the center conductor  42  into open end  37  of the axial blind bore  35 , withdraws the cable  40  with the step up pin  14  from the sidewall bore  139 , and inserts the cable  40  and step up pin  14  into the axial bore of the compression ring  24  as shown in  FIG. 9D . The step up pin  14  and the dielectric sleeve  44  are inserted into the axial bore of the inner post  26  such that the shaft  30  is forced in between the dielectric sleeve  44  and the outer conductor  46  as shown in  FIG. 9E . The user continues to direct the cable  40  into the connector body  12  until the sloped surface  54  of the cable guide  34  engages the complementary sloped recess  56  of the pin guide  28  as shown in  FIG. 9F . A compression tool (not shown) forces the compression ring  24  into the collar  22  such that the compression ring  24  compresses the jacket  48  and the outer conductor  46  against the shaft  30  to secure the cable  40  within the connector  10  and to provide good conduction between the outer conductor  46  and the inner post  26 . 
         [0041]    It should be particularly noted that the step up pin  14  may have alternative shapes with respect to the cylindrical shape shown. Further, the pin  14  shown in the figures increases the diameter of the center conductor slightly; however, larger increases may be required and are considered within the scope of the invention. 
         [0042]    While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof to adapt to particular situations without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims. 
       PARTS LIST 
       [0043]      10  connector 
         [0044]      12  connector body 
         [0045]      14  step up pin 
         [0046]      20  nut body 
         [0047]      22  collar 
         [0048]      24  compression ring 
         [0049]      26  inner post 
         [0050]      27  o-ring 
         [0051]      28  pin guide 
         [0052]      30  shaft 
         [0053]      32  pin body 
         [0054]      34  cable guide 
         [0055]      35  axial bore of pin body 
         [0056]      36  spring fingers 
         [0057]      37  open end of pin body 
         [0058]      38  tabs 
         [0059]      39  sidewall bore of compression ring 
         [0060]      40  coax cable 
         [0061]      42  central conductor 
         [0062]      44  dielectric sleeve 
         [0063]      46  outer conductor 
         [0064]      48  jacket 
         [0065]      50  sprue tabs 
         [0066]      52  sprue tabs 
         [0067]      54  sloped surface of cable guide 
         [0068]      56  sloped recess of pin guide 
         [0069]      124  alternate compression ring with countersunk sidewall bore 
         [0070]      139  countersunk sidewall bore 
         [0071]      160  recessed portion of the countersunk sidewall bore