Abstract:
A compression-type coaxial cable connector includes a post with at least one helical thread thereon. A typical coaxial cable includes a dielectric layer and a cable braid. The threaded post engages the coaxial cable between the cable braid and the dielectric layer, and can be installed by screwing the threaded post into the coaxial cable end.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to the field of coaxial cable connectors, and more particularly to a coaxial cable connector with a threaded post. 
       BACKGROUND OF THE INVENTION 
       [0002]    Several types of coaxial cable present difficulties when installing cable connectors. For cables with stiff jacketing, such as PE, an installer has to push very hard to force the post of the connector under the braid of the cable. For very small, or so-called mini cable, pushing hard on very thin cable tends to buckle and severely damage it. There are many sizes of these difficult cables in both the 75 ohm and 50 ohm industries. 
         [0003]    U.S. Pat. No. 5,342,218 (McMills et al.) discloses a basic coaxial cable connector with a helical thread on a mandrel-post body. A problem with this connector is that the only interference fits are (1) between the collar and the outside of the coaxial cable, and (2) between the post and the cable sheath. 
         [0004]    U.S. Pat. No. 5,393,244 (Szegda) and U.S. Pat. No. 5,195,906 (Szegda) disclose a tubular body with threads on it which make contact with the outside of the braided metallic mesh. 
         [0005]    U.S. Pat. No. 5,609,501 (McMills et al.) discloses a coaxial cable connector mandrel body which includes a tubular portion with threads on it. This connector suffers from the same problems as the &#39;218 connector mentioned immediately above in that the only interference fits are (1) between the collar and the outside of the coaxial cable, and (2) between the post and the cable sheath. 
         [0006]    U.S. Pat. No. 5,651,698 (Locati et al.) discloses one set of serrations on a ferrule which come into contact with the outside of the outer cable sheath, and another set of serrations on the ferrule which come into contact with the outside of the conductive braid. 
         [0007]    U.S. Pat. No. 3,384,703 (Forney, Jr. et al.), U.S. Pat. No. 3,390,374 (Forney Jr.), U.S. Pat. No. 3,551,882 (O&#39;Keefe), U.S. Pat. No. 3,644,874 (Hitter), U.S. Pat. No. 4,339,166 (Dayton), U.S. Pat. No. 4,755,152 (Elliot et al.), U.S. Pat. No. 4,990,106 (Szegda), U.S. Pat. No. 5,073,129 (Szegda), U.S. Pat. No. 5,083,943 (Tarrant), U.S. Pat. No. 5,127,853 (McMills et al.), U.S. Pat. No. 5,141,451 (Down), U.S. Pat. No. 5,207,602 (McMills et al.), U.S. Pat. No. 5,217,393 (Del Negro et al.), U.S. Pat. No. 5,501,616 (Holliday), U.S. Pat. No. 6,042,422 (Youtsey), and U.S. Pat. No. 6,089,913 (Holliday) disclose a cable connector with at least one serration or ridge on an inner sleeve which enhance the interference fit between the inner sleeve and the outer braided conductor of the coaxial cable. 
         [0008]    U.S. Pat. No. 6,431,911 (Pitschi) discloses a cable connector which has threads on a contact sleeve which makes contact with a coaxial cable between the dielectric layer and the outer sheath. 
         [0009]    U.S. Pat. No. 6,497,587 (Di Mario) discloses a cable connector with threads on the connector which are clamped to the inside of an outer screening conductor by a connector which slides over the outer screening conductor. 
       SUMMARY OF THE INVENTION 
       [0010]    Briefly stated, a coaxial cable connector includes a post with at least one helical thread thereon. A typical coaxial cable includes a dielectric layer and a cable braid. The threaded post engages the coaxial cable between the cable braid and the dielectric layer, and can be installed by screwing the threaded post into the coaxial cable end. 
         [0011]    According to an embodiment of the invention, a coaxial cable connector for connecting to a coaxial cable includes a connector body having a first end and a second end; a fastener interoperating with the first end of the body; a compression ring mounted to the second end of the body; an electrically conductive post having a first end and a second end; at least one helical thread on the first end of the post, wherein the at least one thread assists in moving the post, with a twisting motion, between a braided layer of a coaxial cable and a dielectric layer of the coaxial cable; and a mandrel portion adjacent the second end of the post. 
         [0012]    According to an embodiment of the invention, a method of manufacturing a cable connector includes the steps of forming a connector body having a first end and a second end; forming a one-piece post and mandrel combination from an electrically conductive material, wherein the post includes a first end and a second end; forming at least one helical thread on a portion of the post; inserting the post into the body; forming or attaching a fastener on or adjacent to and interoperating with the first end of the body; and mounting a compression ring to the second end of the body. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  shows a threaded post according to an embodiment of the present invention. 
           [0014]      FIG. 2  shows an F-mini coaxial cable connector incorporating a threaded post according to an embodiment of the present invention. 
           [0015]      FIG. 3  shows a cross-section of the F-mini coaxial cable connector of  FIG. 2 . 
           [0016]      FIG. 4  shows an exploded view of the F-mini coaxial cable connector of  FIG. 2 . 
           [0017]      FIG. 5  shows the threaded post used in the F-mini coaxial cable connector of  FIG. 2 . 
           [0018]      FIG. 6  shows a sectional view of a BNC compression drop connector incorporating a threaded post according to an embodiment of the present invention. 
           [0019]      FIG. 7  shows an exploded view of the BNC compression drop connector of  FIG. 6 . 
           [0020]      FIG. 8  shows a sectional view of a mini RCA drop connector assembly incorporating a threaded post according to an embodiment of the present invention. 
           [0021]      FIG. 9  shows an exploded view of the mini RCA drop connector assembly of  FIG. 8 . 
           [0022]      FIG. 10  shows a threaded post according to an embodiment of the present invention. 
           [0023]      FIG. 11  shows an N-male 50 ohm connector assembly incorporating a threaded post according to an embodiment of the present invention. 
           [0024]      FIG. 12  shows a cross-section view of the N-male 50 ohm connector assembly of  FIG. 11 . 
           [0025]      FIG. 13  shows an exploded view of the N-male 50 ohm connector assembly of  FIG. 11 . 
           [0026]      FIG. 14  shows an N-female 50 ohm connector assembly incorporating a threaded post according to an embodiment of the present invention. 
           [0027]      FIG. 15  shows a cross-section view of the N-female 50 ohm connector assembly of  FIG. 14 . 
           [0028]      FIG. 16  shows an exploded view of the N-female 50 ohm connector assembly of  FIG. 14 . 
           [0029]      FIG. 17  shows an F compression connector assembly incorporating a threaded post according to an embodiment of the present invention. 
           [0030]      FIG. 18  shows a cross-section view of the F compression connector assembly of  FIG. 17 . 
           [0031]      FIG. 19  shows an exploded view of the F compression connector assembly of  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    Referring to  FIG. 1 , a threaded post  10  is shown which includes a post  12  as is known within the coaxial cable connector industry, but with a helical thread  14  defined thereon. Thread  14  is intended to engage a coaxial cable between the metal foil jacket and metal ground braid of the cable. In practice, threaded post  10  is inserted into the coaxial cable with a twisting motion so that end  16  gradually engages the metal foil instead of the conventional method of pushing very hard to force an unthreaded post under the braid. For very small cable, the so called “mini” cable, using thread  14  to drive a cable connector onto the coaxial cable is very important because pushing hard on mini cable tends to buckle the mini cable and severely damage it. 
         [0033]    There are many sizes of cables in both the 75 ohm and 50 ohm cable industries. The precise combination of pitch and thread height is determined experimentally in order to optimally balance between driving the post effectively while not cutting the metal braid. Determining the pitch and thread height does not require undue experimentation from one of ordinary skill in the art to achieve. A variety of threads such as multiple, segmented, triangular, buttress, square, and so forth are possible embodiments of the invention. 
         [0034]    Referring to  FIGS. 2-5 , an F-mini coaxial cable connector  20  is shown which incorporates a threaded post  26 , preferably made of brass, although any electrically conductive material would be suitable. The thread is a helical thread that preferably has a pitch of 125. Threaded post  26  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  26  is mounted inside a body  22 , which body  22  has a fastener  24  on one end, which interoperates with the mandrel portion of threaded post  26 , and a compression ring  30  on another end which interoperates with body  22 . For purposes of this application, “fastener” includes a coupling nut, push and twist connection, or simply threads on a coaxial cable connector, as is the case with female threads on a female connector. An insulator  28  is preferably shaped to guide and retain a center conductor (not shown) of a coaxial cable (not shown). A contact pin  32  is preferably stored in compression ring  30  to be used by the installer to fit over the center conductor of a mini coaxial cable before inserting the cable into connector  20 . A cable guide  34  holds pin  32  in compression ring  30  so it doesn&#39;t become lost before assembly. 
         [0035]    Referring to  FIGS. 6-7 , a compression-type mini BNC drop connector  40  is shown which incorporates a threaded post  58  preferably made of brass. The thread is a helical thread that preferably has a pitch of 125. Threaded post  58  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  58  is mounted inside a body  42 , which body  42  has a fastener or BNC coupling nut  52  on one end which interoperates with body  42  via a washer  44 , a conductive gasket  46 , a press ring  48 , and a wave spring  50 , and a compression ring  60  on another end which interoperates with body  42 . An insulator  56 , held in place by body  42 , holds a conductive pin  54  centered within body  42 . A collet structure  62  in conductive pin  54  captures a center conductor of a coaxial cable (not shown) when the coaxial cable is attached to connector  40 . 
         [0036]    Referring to  FIGS. 8-9 , a compression-type mini RCA connector  70  is shown which incorporates a threaded post  80  preferably made of brass. The thread is a helical thread that preferably has a pitch of 125. Threaded post  80  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  80  is mounted inside a body  72 , which body  72  includes a fastener or RCA connector portion  84  on one end, and a compression ring  82  on another end which interoperates with body  72 . An insulator  74 , held in place by body  72 , holds a conductive pin  76  centered within body  72 . A collet structure  86  in conductive pin  76  captures a center conductor of a coaxial cable (not shown) when the coaxial cable is attached to connector  72 . An insulator  78  prevents electrical contact between conductive pin  76  and threaded post  80 . 
         [0037]    Referring to  FIGS. 10-13 , a compression-type 50 ohm N-male connector  90  is shown which incorporates a threaded post  100  preferably made of brass. The thread is a helical thread. Threaded post  100  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  100  is mounted inside a body  92 , which body  92  includes a 50 ohm N-male connector portion  110  on one end, and a compression ring  104  on another end which interoperates with body  92 . An insulator  96 , held in place by body  92 , holds a contact  102  centered within body  92  and prevents electrical contact between contact  102  and threaded post  100 . A collet structure  112  in contact  102  captures a center conductor of a coaxial cable (not shown) when the coaxial cable is attached to connector  92 . A clamp  98  is forced by compression ring  104  onto a coaxial cable sheath (not shown) when compression ring  104  is in the compressed position. A fastener  94  is retained on body  92  by a fastener retainer  106  while a gasket  108  protects the connection between connector  90  and a 50 ohm port from the environment. 
         [0038]    Referring to  FIGS. 14-16 , a compression-type 50 ohm N-female cable connector  120  is shown which incorporates a threaded post  130  preferably made of brass. The thread is a helical thread. Threaded post  130  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  130  is mounted inside a body  122 , which body  122  includes a fastener consisting of female threads  140  on one end, and a compression ring  134  on another end which interoperates with body  122 . An insulator  126 , held in place by body  122 , holds a 50 ohm N-female contact  132  centered within body  122  and prevents electrical contact between contact  132  and threaded post  130 . A collet structure  142  in contact  132  captures a center conductor of a coaxial cable (not shown) when the coaxial cable is attached to connector  120 . A clamp  128  is forced by compression ring  134  onto a coaxial cable sheath (not shown) when compression ring  134  is in the compressed position. 
         [0039]    Referring to  FIGS. 17-19 , an F compression coaxial cable connector  150  is shown which incorporates a threaded post  160  preferably made of brass. The thread is a helical thread. Threaded post  160  is preferably a combination of a mandrel and a post as those terms are known in the art. Threaded post  160  is mounted inside a body  152 , which body  152  includes a fastener  154  on one end, which interoperates with a mandrel portion  166  of threaded post  160 , and a compression ring  164  on another end which interoperates with body  152 . An O-ring  162  seals the interface between fastener  154  and body  152  to keep moisture and other environmental influences out of connector  150 . Compression ring  164  clamps onto a coaxial cable sheath (not shown) when compression ring  164  is in the compressed position. 
         [0040]    While the present invention has been described with reference to a particular preferred embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the preferred embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims.