Abstract:
A connector for a coaxial cable includes a connector body and a fastening member for connecting said connector to an object such as an equipment port. A post is fitted at least partially inside the connector body for receiving a prepared end of the cable. A compression member is fitted to a back of the connector body. An elastomeric band is fitted inside a cavity formed at least in part by the compression member. Axial movement of the compression member onto said connector body causes the elastomeric band to seal an outer layer of the cable to the connector to isolate the inside of the connector from environmental influences.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates generally to the field of cable connectors for CATV systems, and more particularly to a cable connector with an elastomeric band which seals the cable connector to a cable.  
       BACKGROUND OF THE INVENTION  
       [0002]     A problem with cable connections exposed to the weather is that the connections are susceptible to moisture entering the connection whenever the cable connector is improperly or inadequately connected to the cable. Many attempts have been made to ensure that cable connections are sealed against moisture etc. from the environment. Many of the attempts require using a connector body made of two or more components in order to contain an adequate seal, thus increasing the complexity of the cable connector.  
       SUMMARY OF THE INVENTION  
       [0003]     Briefly stated, a connector for a coaxial cable includes a connector body and a fastening member for connecting said connector to an object such as an equipment port. A post is fitted at least partially inside the connector body for receiving a prepared end of the cable. A compression member is fitted to a back of the connector body. An elastomeric band is fitted inside a cavity formed at least in part by the compression member. Axial movement of the compression member onto said connector body causes the elastomeric band to seal an outer layer of the cable to the connector to isolate the inside of the connector from environmental influences.  
         [0004]     According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; a fastening member for connecting the connector to an object; a post fitted at least partially inside the connector body for receiving a prepared end of the cable; a compression member fitted to the connector body; and an elastomeric band fitted inside a cavity formed at least in part by the compression member; wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences.  
         [0005]     According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; first connection means for connecting the connector to an object; and second connection means for connecting a prepared end of the cable to the connector; wherein the second connection means includes an elastomeric band for sealing an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences.  
         [0006]     According to an embodiment of the invention, a method of constructing a connector for a coaxial cable includes the steps of providing a connector body; providing a fastening member for fastening the connector body to an object; providing a compression member; fitting an elastomeric band into a cavity formed at least in part by the compression member; inserting a prepared end of the cable through the compression member and the elastomeric band; and fitting the prepared cable end and the compression member to the connector body, wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  shows a partial cutaway perspective view of a connector according to an embodiment of the invention.  
         [0008]      FIG. 2  shows a perspective view of an embodiment of the invention, prior to installation, where the connector components are of plastic.  
         [0009]      FIG. 3  shows a perspective view of an embodiment of the invention, after installation, where the connector components are of plastic.  
         [0010]      FIG. 4  shows a partial cutaway perspective view of an embodiment of the invention where the connector components are of metal.  
         [0011]      FIG. 5  shows a perspective view of an embodiment of the invention, prior to installation, where the connector components are of metal.  
         [0012]      FIG. 6  shows a perspective view of an embodiment of the invention, after installation, where the connector components are of metal.  
         [0013]      FIG. 7  shows a partial cutaway perspective view of an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]     Referring to  FIG. 1 , a connector  5  includes a connector body  10  with a nut  12  on a front end  14  of body  10 . Nut  12  is shown in this embodiment as a nut for connecting connector  5  to an F-port, but the type of connection is not an essential part of the present invention. A compression nut  16  is connected to body  10  at a back end  18  of body  10  via a plurality of threads  20  on compression nut  16  engaging a plurality of threads  22  on body  10 . A post  24  is contained within connector  5 . An elastomeric band  26  is disposed within a cavity  32  formed in part by a shoulder  34  of compression nut  16 . “Band” is used in the sense of a flat strip, i.e., the width is greater than the thickness. (The “length” would be the circumference of the band, with the width being in the radial direction.) An O-ring is not considered a band and would not work as a replacement for the band of the present invention. Connector  5  is intended to be used with a conventional coaxial cable (not shown) which consists of an inner or center conductor surrounded by a dielectric material which in turn is surrounded by a braided ground return sheath. A cable jacket then surrounds the sheath. As a coaxial cable end (not shown) is inserted into back end  18  of connector  5 , an end  28  of post  24  fits between the sheath and the dielectric, so that the dielectric and center conductor fit inside post  24 , with the sheath and cable jacket between post  24  and connector body  10 . In this embodiment, post  24  is of metal with connector body  10 , nut  12 , and compression nut  16  being of plastic. The electrical ground path thus goes from the cable sheath to post  24  to a ground portion (not shown) of the terminal that connector  5  is screwed into. Post  24  can also be of plastic when not needed to conduct an electrical path.  
         [0015]     Post  24  preferably includes a barbed portion  30 , and as compression nut  16  is tightened onto body  10 , elastomeric band  26  is forced to deform around the cable jacket, resulting in decreased length and increased thickness. In it&#39;s “open” position, i.e., when compression nut  16  is not tightened onto body  10 , band  26  has enough clearance to allow the cable to pass through easily. By tightening compression nut  16  onto body  10 , which applies a compressive force to elastomeric band  26 , band  26  is squeezed inward onto the cable, thus creating a weather seal, as well as providing a great deal of normal force between elastomeric band  26  and the cable sheathing, thus providing retention force to the cable/connector combination. In addition to the tractive forces created by surface friction, the coaction of barbed portion  30  under the cable sheathing along with the inward pressure of elastomeric band  26  cause the cable sheath to conform closely to the profile of barbed portion  30 , thus creating a mechanical interlock.  
         [0016]     This type of connector easily accommodates a broad range of cable diameters within a given cable family because of the flowable nature of elastomeric band  26  which conforms to the surface irregularities of the cable. Elastomers are also “sticky” which enables elastomeric band  26  to create a better seal than otherwise. Types of connectors with which elastomeric band  26  can be used include tool-compressed, standard compression styles, hand tightened styles, etc. In addition, elastomeric band  26  could be added to an existing connector design as a redundant means of sealing.  
         [0017]     Because the sealing and gripping are done by a small, contained element of the connector, the exterior of the connector can be made of whatever material suits a particular application. For instance, for outdoor applications the exterior of the connector can be entirely of brass for increased customer appeal, while a hand-tightened all plastic version with only a metal post  24  could easily be injection molded for the indoor consumer market. Outdoor versions of connector  5  can include a brass nut  12 , a brass or stainless steel post  24 , a brass or die-cast zinc body  10 , and a brass or stainless steel compression nut  16 .  
         [0018]      FIG. 2  shows a plastic version of the embodiment of  FIG. 1  prior to installation, while  FIG. 3  shows the embodiment of  FIG. 2  after the embodiment has been installed on a cable (not shown). In the plastic version, all parts are preferably plastic except for post  24 . A pair of reveals  13  permit easy thumb and finger access to a knurled portion  15  of plastic nut  12 .  
         [0019]     Referring to  FIG. 4 , another embodiment of the present invention is shown. A connector  5 ′ includes a connector body  10 ′ with a nut  12 ′ on a front end  14 ′ of body  10 ′. Nut  12 ′ is shown in this embodiment as a nut for connecting connector  5 ′ to an F-port, but the type of connection is not an essential part of the present invention. A compression fitting  16 ′ is connected to body  10 ′ at a back end  18 ′ of body  10 ′ via a sleeve  21  on compression fitting  16 ′ engaging a portion  23  of body  10 ′. A post  24 ′ is contained within connector  5 ′. An elastomeric band  26  is disposed within a cavity  32 ′ formed in part by a shoulder  34 ′ of compression fitting  16 ′. As the coaxial cable end (not shown) is inserted into back end  18 ′ of connector  5 ′, an end  28 ′ of post  24 ′ fits between the cable sheath and the cable dielectric, so that the dielectric and center conductor fit inside post  24 ′, with the sheath and cable jacket between post  24 ′ and connector body  10 ′.  
         [0020]     Post  24 ′ preferably includes a barbed portion  30 ′, and as compression fitting  16 ′ is pushed onto body  10 ′, elastomeric band  26  is forced to deform around the cable jacket, resulting in decreased length and increased thickness. In it&#39;s “open” position, i.e., when compression fitting  16 ′ is not tightened onto body  10 ′, band  26  has enough clearance to allow the cable to pass through easily. By axial compression, band  26  is squeezed inward onto the cable, thus creating a weather seal, as well as providing a great deal of normal force between elastomeric band  26  and the cable sheathing, thus providing retention force to the cable/connector combination. In addition to the tractive forces created by surface friction, the coaction of barbed portion  30 ′ under the cable sheathing along with the inward pressure of elastomeric band  26  cause the cable sheath to conform closely to the profile of barbed portion  30 ′, thus creating a mechanical interlock.  
         [0021]      FIG. 5  shows an external view of a metal version of  FIG. 4  prior to installation, while  FIG. 6  shows the embodiment of  FIG. 5  after the embodiment has been installed on a cable (not shown). The metal version, intended primarily for outdoor use, can have a brass nut  12 ′, a brass or stainless steel post  24 ′, a brass or diecast zinc body  10 ′, and a brass or stainless steel compression fitting  16 ′.  
         [0022]     Referring to  FIG. 7 , an embodiment is shown in which the elastomeric band of the present invention is used in addition to the seal already present in a cable connector. A cable connector  40  includes a connector body  42  to which a nut  44  is connected. Nut  44  attaches cable connector  40  to a piece of equipment or another connector. A post  48 , extending inside body  42 , is connected to both nut  44  and body  42 . A driving member  50  overlaps a sealing portion  52  of body  42 . A compression member  46  fits over both driving member  50  and a part of body  42 . In normal operation, a prepared cable end (not shown) is inserted into connector  40  through a back end  56 . When compression member is forced axially towards a front end of connector  40 , driving member  50  forces sealing portion  52  radially against the cable, thus providing a seal against the outside environment. In this embodiment, an elastomeric band  54  fitted into a cavity  58  formed within compression member  46  and an end of driving member  50  provides extra sealing against the cable by axial compression. When band  54  is squeezed inward onto the cable, it creates a weather seal, as well as a great deal of normal force between elastomeric band  54  and the cable sheathing, thus providing retention force to the cable/connector combination.  
         [0023]     Examples of elastomers include any thermoplastic elastomer (TPE), silicone rubber, or urethane. The key properties are resilience, resistance to creep, resistance to compression set, and the creation of a good grip with the cable jacket. The length of band  26 , i.e., in the axial direction of connector  5 , can be equal to the length of the cavity in which it is seated. The important consideration is that any pre-compression done to band  26  must not affect insertion of the cable end, i.e., the thickness of elastomeric ring  26  cannot become so large during pre-compression as to impede insertion of the cable end.  
         [0024]     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.