Abstract:
A compression connector for a coaxial cable includes a unitary plastic body with a post connected inside the plastic body and a nut connected to the post. An O-ring seals the connection between the nut and the plastic body. A compression ring is connected to an outside of the plastic body. A reinforcing shield is also connected to the outside of the plastic body. The reinforcing shield serves to reinforce the plastic body when the compression ring is moved to its compressed position, so that softer plastics can be used for the plastic body. The reinforcing shield and compression ring also protect the entire outside of the plastic body from the environment.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from and is a continuation in part of U.S. application Ser. No. 11/180,757 filed on Jul. 13, 2005 now U.S. Pat. No. 7,021,965 and entitled COAXIAL CABLE COMPRESSION CONNECTOR, incorporated by reference herein. 

   FIELD OF THE INVENTION 
   This invention relates generally to the field of coaxial cable connectors, and more particularly to a compression connector with a unitary plastic body having an exterior reinforcing shield. 
   BACKGROUND OF THE INVENTION 
   Coaxial cable is a typical transmission medium used in communications networks, such as a CATV network. The cables which make up the transmission portion of the network are typically of the “hard-line” type, while those used to distribute the signals into residences and businesses are typically “drop” connectors. The principal difference between hard-line and drop cables, apart from the size of the cables, is that hard-line cables include a rigid or semi-rigid outer conductor, typically covered with a weather protective jacket, that effectively prevents radiation leakage and protects the inner conductor and dielectric, while drop connectors include a relatively flexible outer conductor, typically braided, that permits their bending around obstacles between the transition or junction box and the location of the device to which the signal is being carried, i.e., a television, computer, and the like, but that is not as effective at preventing radiation leakage. Hard-line conductors, by contrast, generally span considerable distances along relatively straight paths, thereby virtually eliminating the need for a cable&#39;s flexibility. Due to the differences in size, material composition, and performance characteristics of hard-line and drop connectors, there are different technical considerations involved in the design of the connectors used with these types of cables. 
   In constructing and maintaining a network, such as a CATV network, the transmission cables are often interconnected to electrical equipment that conditions the signal being transmitted. The electrical equipment is typically housed in a box that may be located outside on a pole, or the like, or underground that is accessible through a cover. In either event, the boxes have standard ports to which the transmission cables may be connected. In order to maintain the electrical integrity of the signal, it is critical that the transmission cable be securely interconnected to the port without disrupting the ground connection of the cable. This requires a skilled technician to effect the interconnection. 
   A type of connector usable on cables is the compression type connector, such as is disclosed in U.S. Pat. No. 6,331,123. Compression connectors utilize a compression member that is axially slidable with relation to the connector body for radially displacing connecting and sealing members into engagement with the cable&#39;s outer conductor. A compression tool that slides the compression body into the connector is used by the technician to effect the connection, and due to the physical constraints of the compression member and connector body, it is impossible for the technician to use too much force to effect the interconnection. Thus, compression connectors eliminate the assembly drawbacks associated with threaded, and to some degree, crimp type connectors. 
   SUMMARY OF THE INVENTION 
   Briefly stated, a compression connector for a coaxial cable includes a unitary plastic body with a post connected inside the plastic body and a nut connected to the post. An O-ring seals the connection between the nut and the plastic body. A compression ring is connected to an outside of the plastic body. A reinforcing shield is also connected to the outside of the plastic body. The reinforcing shield serves to reinforce the plastic body when the compression ring is moved to its compressed position, so that softer plastics can be used for the plastic body. The reinforcing shield and compression ring also protect the entire outside of the plastic body from the environment. 
   According to an embodiment of the invention, a compression connector for a coaxial cable includes a unitary plastic body; a post connected inside the plastic body; a nut connected to the post; a compression ring connected to an outside of the plastic body; and a reinforcing shield, separate from the nut, connected to an outside of the plastic body, and wherein the reinforcing shield and compression ring protect the entire outside of the plastic body from the environment when the compression ring is in both a compressed position and an uncompressed position. 
   According to an embodiment of the invention, a method for making a compression connector includes the steps of: (a) forming a first sub-assembly by providing a unitary plastic body and connecting a compression ring to an outside of the plastic body; (b) forming a second sub-assembly by affixing a weather seal between a nut and a retaining ring; (c) connecting a post inside the second sub-assembly until a post flange of the post engages a nut flange of the nut; (d) placing an O-ring onto a capture portion of a reinforcing shield; and (e) connecting the first sub-assembly with the second sub-assembly. 
   According to an embodiment of the invention, a compression connector includes a unitary plastic body; means for connecting a post inside the plastic body; means for connecting a nut to the post; sealing means for sealing a connection between the nut and the plastic body; means for connecting a reinforcing shield to an outside of the plastic body, and means for connecting a compression ring to an outside of the plastic body; wherein the reinforcing shield and compression ring protect the entire outside of the plastic body from the environment when the compression ring is in both a compressed position and an uncompressed position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of a compression connector according to an embodiment of the invention. 
       FIG. 2  shows an exploded view of the components of the compression connector of  FIG. 1 . 
       FIG. 3  shows a front elevation view of the compression connector of  FIG. 1 . 
       FIG. 4A  shows a cross section of an embodiment of the compression connector of the present invention taken along the lines  4 - 4  in  FIG. 3 . 
       FIG. 4B  shows a cross section of an embodiment of the compression connector of the present invention taken along the lines  4 - 4  in  FIG. 3 . 
       FIG. 5  shows a cross-sectional view of a metal shield according to an embodiment of the present invention. 
       FIG. 6  shows an enlarged view of section  6  of  FIG. 5 . 
       FIG. 7  shows a cross-sectional view of a unitary plastic body according to an embodiment of the present invention. 
       FIG. 8  shows an enlarged view of section  8  of  FIG. 7 . 
       FIG. 9  shows a cross-sectional view of a compression connector according to an embodiment of the present invention. 
       FIG. 10  shows a perspective view of a compression connector according to an embodiment of the invention. 
       FIG. 11  shows an exploded view of the components of the compression connector of  FIG. 10 . 
       FIG. 12  shows a partial cutaway perspective view of the compression connector of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1-2 , a coaxial cable compression connector  10  according to an embodiment of the invention is shown. A plastic body  22  is partly covered by a reinforcing shield  18  and partly covered by a compression ring  20 . Compression ring  20  is preferably of metal but optionally is of plastic. A post  14  is disposed inside plastic body  22 . A nut  12 , preferably of metal for its conductive properties but optionally of plastic or composite material, is threaded with a thread  24  to permit connecting connector  10  to an equipment port or other device. An O-ring  16  preferably prevents moisture from entering connector  10  from the interface between nut  12 , post  14 , and plastic body  22 . 
   Referring to  FIGS. 3-8 , additional details of connector  10  are shown. Shield  18  is held in place by shoulders  36  and  42  of plastic body  22 . Plastic body  22  preferably includes a plurality of serrations  26 , which, in conjunction with barbed tip  28  of post  14 , provide a tight fit of the cable (not shown) and help to prevent moisture from entering connector  10  along the surface of the cable. After the end of the cable is prepared for installation, as is known by those skilled in the art of cable installation, the prepared cable end is inserted into end  40  of connector  10 . Post  14  fits between the insulator core of the cable and the braided layer. Because plastic body  22  is of plastic, post  14  is preferably of a conductive material to form part of the electrical ground path from the cable braid to nut  12 . 
   Because plastic body  22  is of plastic, it is susceptible to environmental damage from ultraviolet rays. The plastic is also susceptible to deformation from the forces imparted by compression ring  20  during cable installation, thus limiting the type of plastic used. Shield  18  is preferably metal but could be durable plastic or a composite material. Shield  18  protects plastic body  22  from the environment and also protects plastic body  22  from deformation resulting from compression ring  20 , thus opening up a whole range of available plastic materials for use in making plastic body  22 . 
   Shield  18  preferably includes a beveled edge  30  ( FIG. 6 ) to prevent compression ring  20  from knocking shield  18  out of position while compression ring  20  is moved into position. Beveled edge  30  is preferably angled about 15 degrees from the horizontal. Plastic body  22  includes a beveled edge  38  to assist compression ring  20  in moving over plastic body  22  during assembly. Beveled edge  38  is preferably angled about 15 degrees from the horizontal. During assembly, compression ring  20  is moved over plastic body  22  until a beveled groove  34  in compression ring  20  snaps over a beveled stop  32  on plastic body  22 . 
   Connector  10  is preferably assembled as follows. Shield  18  is snapped over plastic body  22 . Then post  14  is inserted into nut  12 . O-ring  16  is placed onto plastic body  22 . Then the post  14  and nut  12  combination is moved into plastic body  22  until it engages with plastic body  22 . Compression ring  20  is moved onto plastic body  22  until beveled groove  34  in compression ring  20  snaps over beveled stop  32 . During cable installation, the prepared cable end is inserted through compression ring  20  into plastic body  22  so that the end of post  14  is engaged between the cable braid and the cable insulated core. Compression ring  20  is then forced onto plastic body  22  and part of metal shield  18  using a conventional compression tool until compression ring  20  is held tightly in place by the friction fit between the cable, compression ring  20 , shield  18 , plastic body  22 , and post  14 . The installation of connector  10  onto the cable is then complete. 
   In the embodiment of  FIG. 4A , compression ring  20  overlaps shield  18  in the uncompressed position, while in the embodiment of  FIG. 4B , compression ring  20  of compression connector  10 ′ does not overlap shield  18  when in the uncompressed position. When in the compressed position, compression ring  20  overlaps shield  18  whether using the embodiment of  FIG. 4A  or the embodiment of  FIG. 4B . 
   Referring to  FIG. 9 , an embodiment of the invention is shown in which a connector  10 ′ includes a shield  18 ′ which does not include shoulder  36  ( FIGS. 4A-4B ), thus simplifying the manufacturing process. Note that this embodiment still includes a texturing or knurling  44  on body  22  which promotes frictional contact between post  14  and body  22 . 
   Referring to  FIGS. 10-12 , according to an embodiment of the invention, a connector  50  is shown which includes a plastic body  68  partly covered by a reinforcing shield  58  and partly covered by a compression ring  60 . Compression ring  60  is preferably of metal but optionally is of plastic. A post  62  is disposed inside plastic body  68 . A nut  64 , preferably of metal for its conductive properties but optionally of plastic or composite material, is threaded to permit connecting connector  50  to an equipment port or other device. A retaining ring  54 , either of plastic or metal, cooperates with nut  64  to engage a weather seal  52 . Retaining ring  54  preferably includes an integral wrench hex  56  to facilitate wrench tightening when fastening connector  50  onto the equipment port. An O-ring  66  preferably prevents moisture from entering connector  50  from the interface between nut  64 , post  62 , and plastic body  68 . 
   Shield  58  is held in place by an interference fit with body  68 . Plastic body  68  preferably includes a plurality of serrations  76 , which, in conjunction with barbed tip  78  of post  62 , provide a tight fit of the cable (not shown) and help to prevent moisture from entering connector  50  along the surface of the cable. After the end of the cable is prepared for installation, as is known by those skilled in the art of cable installation, the prepared cable end is inserted into end  80  of connector  50 . Post  62  fits between the insulator core of the cable and the braided layer. When body  68  is of plastic, post  62  is preferably of a conductive material to form part of the electrical ground path from the cable braid to nut  64 . 
   Because body  22  is preferably of plastic, it is susceptible to environmental damage from ultraviolet rays. The plastic is also susceptible to deformation from the forces imparted by compression ring  60  during cable installation, thus limiting the type of plastic used. Shield  58  is preferably metal but could be durable plastic or a composite material. Shield  58  protects body  68  from the environment and from deformation resulting from compression ring  60 , thus opening up a whole range of available materials for use in making body  68 . Shield  58  preferably includes a beveled edge as previously described in the earlier embodiments. Shield  58  also includes a snout  72  which includes a capture portion  70 . Capture portion  70  fits under the inside diameter of O-ring  66  during assembly. The structural relationship between retaining ring  54 , nut  64 , post  62 , and shield  58  permits O-ring  66  to have a relatively thick cross section. The interference fit between capture portion  70  and post  62  obviates the need for the knurling  44  ( FIG. 9 ) in body  68 , which instead has a smooth section  74 , which facilitates inserting post  62  into the coaxial cable during installation, as well as removing a manufacturing step. 
   Connector  50  is preferably assembled as follows. Body  68  is press fitted into shield  58  to form a first sub-assembly, while weather seal  52  is affixed between nut  64  and retaining ring  54  to form a second sub-assembly. Then post  62  is inserted into the second sub-assembly until the flange of post  62  engages the flange of nut  64 . O-ring  66  is placed onto capture portion  70  of shield  58 , after which the first sub-assembly is pushed into the second sub-assembly until it stops. 
   During cable installation, the prepared cable end is inserted through compression ring  60  into body  68  so that the end of post  62  is engaged between the cable braid and the cable insulated core. Compression ring  60  is then forced onto body  68  and part of metal shield  58  using a conventional compression tool until compression ring  60  is held tightly in place by the friction fit between the cable, compression ring  60 , shield  58 , body  68 , and post  62 . The installation of connector  50  onto the cable is then complete. 
   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.