Abstract:
A coaxial connector assembly includes a coaxial cable connector and a shield for the connector, the shield including spring fingers adjustably engaging the connector.

Description:
FIELD OF THE INVENTION 
   The invention relates to coaxial cable connector assemblies, particularly to coaxial cable connector assemblies that are mounted on threaded ports. 
   DESCRIPTION OF THE PRIOR ART 
   Coaxial cables are commonly used to transmit high-frequency television and computer signals from signal sources to end-users. 
   The cables include a central conductor for signal transmission and a surrounding grounding braid. Connectors are mounted on the ends of the cables to permit attachment to threaded metal contact ports for forming electrical connections between the braid and the port and the central conductor and a contact in the port. In CATV systems, taps are mounted on distribution cables and coaxial drop cables extend from the taps to individual residences. Connectors on the ends of drop cables are connected to threaded ports on taps on the distribution cable. 
   It is difficult to maintain the security of coaxial cables connectors attached to threaded ports. Unauthorized individuals can remove the connectors from the ports. Signal quality can be degraded by improperly threading connectors on ports or by tampering with coaxial cables properly attached to ports. 
   Conventional security shields prevent tampering with coaxial cable connectors attached to tap ports. These shields are pushed over ports and are held in place by the connectors. A special installation wrench must be used to engage the connector to the port within the shield. 
   Therefore there is a need for a coaxial connector assembly for mounting on a contact port that provides protection against tampering, is easy to install without special tools, and can be installed on ports of different lengths. 
   SUMMARY OF THE INVENTION 
   The present invention is an inexpensive coaxial cable connector assembly that provides protection against tampering, is easy to install, and can be installed on ports of different lengths. 
   The coaxial cable connector assembly includes a cable connector with a nut that is threaded onto a contact port, a shield and boot surrounding the cable. The shield is slid along the cable and over the connector to protect the connection from tampering. The shield latches onto the connector to prevent movement away from the port. An optional boot may be fitted on to the trailing end of the shield. If desired, the nut may include an annular nut seal for forming a seal between the nut and the port. 
   The shield has a cylindrical inner shield member surrounded by a cylindrical outer shield member. The inner shield member includes one or more flexible fingers that latch on one of a number of retention surfaces on the coaxial cable connector to prevent the shield from being removed from the connector. 
   The shield is loosely mounted on the coaxial cable away from the cable connector during threading of the connector onto the port. After the connector has been fully threaded on the port, the shield is moved along the cable, over the connector to latch in place on the connector and against a plate which supports the port. The boot is made of flexible rubber or plastic and is attached to the trailing end of the shield to prevent moisture and other contaminants from entering the shield. For use indoors, the boot may be eliminated. 
   Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying three sheets of drawings illustrating the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cut away view of the coaxial cable connector assembly before it is mounted on a port; 
       FIG. 2  is a plan view of a pre-form for an inner shield member before being rolled into a tubular shape; and 
       FIG. 3  is a cut away view of the coaxial cable connector assembly after it has been mounted on a port. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Coaxial cable connector assembly  10  is mounted on tap assembly  12 . Tap assembly  12  includes a threaded coaxial cable mounting port  14  and a tap plate  16  that supports the port. Port  14  extends perpendicularly away from tap plate  16 . The port includes a central contact for forming an electrical connection with the central conductor wire of a coaxial cable mounted on the tap assembly. 
   Connector assembly  10  is mounted on one end of coaxial cable  18  and includes coaxial cable connector  20  and tubular shield  22  which surrounds the connector. Cable  18  includes a central conductor wire and a ground braid surrounding the wire. Connector  20  includes a sleeve  24  mounted on the end of coaxial cable  18  and in electrical connection with the braid in the cable and a mounting nut  26 . 
   Nut  26  is rotatably mounted on the lead end of sleeve  24  and includes interior threads (not illustrated) engagable with threads on port  14 . The central wire in cable  18  extends into the nut for engaging the contact in port  14 . Nut  26  includes a number of flat tool-engaging surfaces  28  spaced around the nut. A tool may be mounted on surfaces  28  to facilitate tightening the nut on port  14 . The nut is threaded onto the port a sufficient distance to establish an electrical connection between the central wire and the contact in the port and between the nut and threaded port. 
   Annular seal member  29  is mounted on the lead end of nut  26 . Seal member  29  is formed from a resilient rubber material and forms a tight seal with port  14  when the nut is threaded onto the port. This seal protects the interior of the connector from moisture and contaminants. The connector  20  and seal member  29  are disclosed more fully in co-pending U.S. patent application for Nut Seal Assembly for Coaxial Connector, No. 10/876,386 filed Jun. 25, 2004 and published Aug. 11, 2005 as Pub. No. 2005/0176294, the disclosure of which is incorporated herein by reference in its entirety. 
   Connector assembly  10  is adapted to be mounted on tap assemblies with different length threaded ports  14 . The distance  30  between the lead end  32  of the seal member  29  when mounted on a port  14  and the plate  16  supporting the port will vary depending upon the length of the port. 
   Nut  26  includes two circumferential locking ridges or rings  34  and  36  which extend around the nut and are spaced apart a short axial distance. Ridges or rings  34  and  36  are located between surfaces  28  and the lead end  32  of the nut. Each ridge defines a latch retention surface  38  facing toward lead end  32 . Surfaces  38  are spaced apart axial distance  66  and form latch retention portions on the outer surface of coaxial cable connector  20 . 
   Tubular shield  22  has a generally tubular body  23  extending between the lead and trailing ends of the shield. Shield  22  includes tubular metal inner shield member  40  surrounded by tubular metal outer shield member  42 . Inner member  40  is rolled from sheet metal pre-form  44  shown in  FIG. 2 . The pre-form includes a flat rectangular sheet metal body  46  having opposed side edges  48 , lead edge  50  and trailing edge  52 . Two pairs of flexible latch fingers  54 ,  56  are cut from body  46 . Each finger  54 ,  56  includes opposed side edges  58 , a trailing end or latch surface  60  and a lead end  62  integral with the remainder of body  46 . Side edges  58  and latch ends  60  are cut from body  46 . 
   The inner shield member  40  is formed by rolling pre-form  44  into a tube with edges  48  abutting each other. The flexible fingers  54  and  56  are bent into the interior of the tube with the latch ends  60  extending away from lead edge  50 . 
   As shown in  FIG. 2 , the ends  60  of fingers  54  and  56  are spaced apart an axial distance  64  with the ends of fingers  56  nearer end  50  than the ends of fingers  54 . The ends of fingers  56  are separated from the ends of fingers  54  by axial distance  64 . Distance  64  is about one half the axial distance  66  between latch retention surfaces  38  on nut  22 . See  FIGS. 1 and 2 . 
   Fingers  54 ,  56  are bent into the interior of tubular member  40  with the latch ends  60  of each pair of fingers  54 ,  56  spaced apart across member  40  a distance less then the diameter of ridges or rings  34  and  36 . Fingers  54  and fingers  56  are located 180 degrees across from each other on member  40 . 
   Strong seam-free metal outer tubular member  42  is fitted tightly around inner tubular inner member  40  and has an axial length greater than the length of inner member  40  so that lead and trailing ends  68  and  70  extend beyond the ends of the inner member. The ends  68  and  70  are formed radially inwardly to overlie the ends of the inner member. If desired, ends  68  and  70  may be formed radially inwardly past the ends of the inner member as illustrated in  FIG. 1 . 
   Tubular shield  22  is loosely mounted on cable  18  adjacent coaxial cable connector  20  prior to threading the connector onto port  14 . Boot  72  is mounted on the cable for connection to the trailing end of shield  22  to form a weather seal between the cable and the trailing end of the shield. Boot  72  has an annular shape and closely surrounds cable  18 . The boot includes a circumferential latch groove  74  at the lead end thereof. Trailing end  70  of outer shield member  42  fits in groove  74  to form a seal between the boot and tubular shield  22 . The sliding fit between the boot and cable  18  permits free movement of the boot along cable  18 . 
   Mounting of coaxial cable  10  on a threaded port  14  extending from tap plate  16  will now be described. 
   The assembly  10  is positioned as shown in  FIG. 1  with mounting nut  26  positioned a short distance outwardly from the end of the port and the assembly in axial alignment with the port. The nut is then moved into engagement with the port and rotated to thread the nut onto the port until the nut is hand tight. The nut is then fully tightened onto the port using a conventional tightening tool, such as an end wrench, which engages surfaces  28 . Member  29  seals against the port. 
   Next, shield  22 , with boot  72  engaged or disengaged, is moved axially along the cable, over coaxial cable connector  20  and toward plate  16 . During movement of the shield toward plate  16  the latch fingers  54 ,  56  are moved along nut  26  and toward the plate. The latch ends  60  of lead fingers  56  move past trailing ridge  36 . The ridge elastically flexes the fingers radially outwardly toward shield member  40 . After the fingers pass the ridge they snap back or latch behind retention surface  38  of ridge  36 . Further movement of the shield toward plate  36  may move fingers  54  past ridge  36  so that the ends  60  of fingers  54  snap back or latch behind surface  38  of the ridge. Continued movement of the tubular shield toward plate  16  may move fingers  54  and  56  beyond ridge  34  so that the ends of the fingers pass ridge  34  and snap back or latch against surface  38  of ridge  34 . 
   The two ridges and two sets of fingers are axially spaced along the connector assembly to provide latching of the shield onto the nut with the lead end of the outer shield member against or closely adjacent plate  16 , independent of the length of the port  14  and the position of the nut on the port. The two axially spaced latch retention surfaces  38  on the nut and axially spaced fingers on the tubular shield facilitate hand latching of the shield onto the coaxial cable connector. If desired, the connector assembly may include a single latch retention surface on the nut and two or more latch fingers on the shield. The assembly  10  may include a plurality of latch retention surfaces on the nut and a single latch finger on the shield. After shield  22  has engaged nut  26 , boot  72  may be engaged onto trailing end  70 . The latch retention surfaces are located between nut  26  and sleeve  24 . 
   If desired, nut  26  may be removed from port  14  through use of a tool. The tool may be a wrench with a thin, elongate socket having an open side permitting fitting of the socket on cable  18  between the shield  22  and withdrawn boot  72 . The socket is extended along the cable into the shield  22  and forwardly to engage surfaces  28  of nut  26 . The wrench includes a handle permitting manual rotation of the socket to remove the nut from port  14 . 
   When connector assembly  10  is mounted on tap  12  as described, the shield protects the coaxial cable connector  20  from unauthorized tampering. Attempts to unthread the coaxial cable connector from the port by rotating shield  22  do not rotate the nut. Rather, the fingers holding the shield in place on the connector rotate around the engaged surface  24  without unthreading the nut. The seam-free and imperforate outer shield member  42  completely surrounds the metal inner shield member  40  to conceal the finger cut-outs  76  and the seam at abutting side edges  48  from tampering. 
   While I have illustrated and described preferred embodiments of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.