Abstract:
The present invention incorporates a flexible RF seal into the ground face of a typical connector. The seal comprises a flexible brim, a transition band, and tubular insert with a insert chamber defined within the seal. In a first embodiment the flexible brim is angled away from the insert chamber, and in a second embodiment the flexible brim is angled inward toward the insert chamber. A flange end of the seal makes a compliant contact between the port and connector faces when the nut of a connector is partially tightened, and becomes sandwiched firmly between the ground surfaces when the nut is properly tightened. The present invention allows the connector to make a uniform RF seal on a port even with a range of tightening torques.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to connectors for coaxial cables used in CATV applications, and more specifically to the structure for providing solid mechanical and electrical connections between a cable port and connector face. 
       BACKGROUND OF THE INVENTION 
       [0002]    CATV systems continue to be plagued with service quality problems resulting from loose connections. For the most part, these connectors are loose because they were not installed to the proper torque, which can occur for a number of reasons from laziness, a lack of training, and improper use of/inadequate tools. An improperly installed connector will result in poor signals, because there are gaps between the devices, resulting in a leak of radio frequency (“RF”) signal. 
         [0003]    As an example, a cable port is used to transfer an RF signal to a coaxial cable that transmits the signal to video equipment, such as a television. The coaxial cable has, attached to its terminal end, a female cable connector, which is used to house the cable and assist its connection to a cable port. The connector contains a nut that engages the cable port and advances the connector with a coaxial cable to the port. In this instance, the cable connector nut is used to hold two mating surfaces, the cable port and the cable connector housing the coaxial cable. If these two surfaces are not tightly connected, a gap will exist creating a loss in RF signal, resulting in lower quality cable signal. 
         [0004]    Improvements on coaxial cable connectors have been proposed to deal with such a problem. An example of such an improvement on a connector is described in U.S. Pat. No. 6,716,062 (Palinkas, et al.), the disclosure of which is herein incorporated by reference. In this patent, a spring element is incorporated to a traditional coaxial cable connector, under a nut element and beneath the flange portion of a post member. The spring biases the connector face towards a port after the nut is rotated around the connector a certain number of times. While this device is effective, it requires time and cost in the manufacturing process of the connector. 
         [0005]    Therefore, it is desired in the art to have a flexible device that can be used with existing connectors to prevent RF signal leakage. 
         [0006]    Furthermore, it is desired in the art to have a connector capable of making a tight mechanical and electrical connection. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention incorporates a flexible RF seal into the ground face of a typical connector. A flange end of the seal makes a compliant contact between the port and connector faces, as in the above example, when the nut is partially tightened, and becomes sandwiched firmly between the ground surfaces when the nut is properly tightened. This allows the connector to make a uniform RF seal on a port even with a range of tightening torques. 
         [0008]    The present invention relates to a flexible RF seal which can be fitted into a coaxial cable connector, which decreases the amount of RF leakage produced by that coaxial connector when in place. The flexible RF seal is a simple device made of a conductive and resilient material having three regions: a flexible brim, a transition band for maintaining the flex of the resilient brim, and a tubular insert. Further, there is defined within the seal an insert chamber. In its first embodiment, the flexible brim is angled outward away from the insert chamber. In the second embodiment, the flexible brim is angled inward towards the insert chamber. 
         [0009]    Moreover, the invention relates to a coaxial cable connector for mounting on a RF port comprising: a post member having a flange end and a stem having a substantially cylindrical bore therethrough; a nut having at one end inner threading and at the other end a flange to engage the flange end of the post; a body member; a compression ring; and flexible means for providing a uniform electrical connection between the post and the RF port. 
         [0010]    The invention, also, relates to a method for making a connector for mounting on the terminal end of a coaxial cable. The method of making a connector for mounting on a RF port comprising: providing a post having a flange end and a stem having a substantially cylindrical bore therethrough; a nut having at one end inner threading and at the other end a flange; a body member; a compression ring, and a flexible RF seal having a flexible brim, a transition band, and a tubular insert; attaching the post to the flanged of the nut to engaged the flange end of the post; attaching the body member to the stem of the post; attaching the compression ring to the body member; and attaching the flexible RF seal to the post. 
         [0011]    Furthermore, the invention relates to a method for making a uniform RF seal between a RF port and a coaxial cable comprising: providing a connecter comprising a nut, a post, body member, a compression ring; a flexible RF seal comprising a flexible brim, a transition band, and a tubular insert; a coaxial cable; and a RF port; attaching the flexible RF seal to the connector; attaching the connector to a terminal end of a coaxial cable; and connecting the coaxial cable with the connector and flexible RF seal to a RF port. 
         [0012]    An advantage of the present invention is that the flexible RF seal provides a tight connection between a cable port and the connector face, when there is a gap between the faces due to improper installation. Thus, the RF seal can provide at the least a contact between the port and the connector to prevent RF signal leakage, and if properly installed firmly compressed between the port and the connector. 
         [0013]    A further advantage of the present invention is that the invention provides an easy to install, highly reliable solution to providing an electronic connection that provides an effective RF seal. The device thereby saves time and cost in the manufacturing process. Alternatively, connectors that may already be in use can be retrofitted with the device for providing a uniform RF seal. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1   a  is a cross-sectional view of the first embodiment of the flexible RF seal of the present invention; 
           [0015]      FIG. 1   b  is an isometric view of the first embodiment of the flexible RF seal of the present invention; 
           [0016]      FIG. 2   a  is a cross-sectional view of the second embodiment of the flexible RF seal of the present invention; 
           [0017]      FIG. 2   b  is an isometric view of the second embodiment of the flexible RF seal of the present invention; 
           [0018]      FIG. 3  shows a cross-section of the coaxial cable connector with the first embodiment of the flexible RF seal of the present invention; 
           [0019]      FIG. 4  shows a cross-section of the coaxial cable connector with the second embodiment of the flexible RF seal of the present invention. 
       
    
    
       [0020]    Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate two embodiments of the invention but should not be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION 
       [0021]    Referring to  FIGS. 1   a  and  1   b,  the present invention is a sealing element for coaxial cable connector. More specifically, the sealing element is designed to ensure a solid mechanical and electrical connection between a coaxial cable, connector, and port, and thereby termed a flexible radio frequency (“RF”) seal  10 . There are three regions that define the flexible RF seal  10 . First, there is a flexible or resilient brim  12  that is flexible for ensuring a tight connection between a connector and a cable port (not shown) to which is it coupled. Second, there is a transitional band  14 , and the band  14  transitions to a tubular insert portion  16 . The flexible RF seal  10  also has an insert chamber  18  defined within the seal  10 . 
         [0022]    The flexible brim  12  is a flange end that, when inserted into a coaxial cable connector, in its first embodiment, sits above a post member, as will be shown and described in greater detail below. The flexible brim  12 , in this position, can be pressed against a coaxial port causing the flexible brim  12  to be compressed and bent so that it creates a tight connection between the connector and port. In the first embodiment of the flexible RF seal  10 , the flexible brim  12 , because of the inner geometries of the coaxial cable connector, is angled, so that it can sit within the connector and seal the connector face to the cable port. Preferably, the flexible brim  12  is seventy-degrees (70°) from the horizontal. The flexible brim  12  is shaped such that the flexible brim  12  is angled away from an insert chamber  18 . 
         [0023]    The next region of the flexible RF seal  10  is the transitional band  14 . Due to the shape of cable connectors in general and the positioning of the flexible RF seal within the connector, there is a band  14  that transitions the flexible brim  12  to the tubular insert portion  16 . As shown in  FIGS. 1   a  and  1   b,  the transition band  14  is a flat, inclined portion on the inside of the seal  10 . The transition band  14  assists in the flexibility of the seal  10 , in that as a transition portion it allows the flexible brim  12  to further bend or create a greater angle of distance once the flexible brim  12  is engaged by a coaxial port on one end and further compressed by a post member of a connector on its other end. 
         [0024]    The last region of the flexible RF seal is the tubular insert portion  16 . The tubular insert portion  16  is below the transition band  14 . The tubular insert portion  16  is cylindrical in shape and depending on its embodiment can be used to sit on the inside or outside of a post within a coaxial cable connector. Defined within the tubular insert portion  16  is an insert chamber  18 . The tubular insert portion  16 , in the first embodiment of the flexible RF seal  10 , sits within a post member of a cable connector (as shown in  FIG. 3 ). As a result, the insert chamber  18  assists in housing a coaxial cable on which the cable connector is placed. 
         [0025]    Referring to  FIGS. 2   a  and  2   b,  there is a second embodiment of the flexible RF seal, denoted by a reference numeral  20 . The flexible RF seal  20  has the same three regions as the first embodiment: a flexible brim  12 , a transition band  14 , and a tubular insert  16 . Further, defined within the flexible RF seal  20 , as with the first embodiment  10 , is an insert chamber  18 . The flexible RF seal  20  of this second embodiment has a different shape than the first embodiment  10 . The shapes are different because the seal  20  is configured to sit on the outside of a post member of a coaxial cable connector, whereas the seal  10  is configured to sit inside a post member. The flexible brim  12  is spaced such that the brim  12  is angled inward towards the insert chamber  18 . Moreover, the tubular insert  16  of the flexible RF seal  20  may generally be larger in diameter than the seal  10  because it is configured to sit outside of a post member of the coaxial cable connector. 
         [0026]    The flexible RF seal  10 ,  20  can be made of any suitable material which can assist in providing a tight, solid connection between the surfaces of a coaxial cable connector and a cable port. Suitable materials can include metals such as beryllium copper, spring steel, and phosphor bronze, which are all resilient and allow for flexibility. Further, while the flexible RF seals  10 ,  20  are shown in with a solid, smooth surface, the seal can have a construction where there are fingered elements, or may further have a wavy construction. 
         [0027]    In  FIGS. 3 and 4 , there is shown a conventional coaxial cable connector  100  that is placed on the terminal end of a coaxial cable (not shown). The connector  100  has six elements. First, there is a nut  30  on the terminal end of the connector  100  that has inner threading  32  used to threadedly connect the connector  100  with a coaxial cable (not shown) to a cable port (not shown). The nut  30  rotates freely around a post  40 , so that it can advance the connector  100  and coaxial cable housed within it to a cable port. The nut  30  is interconnected to the post  40  under the flange end  44  of the post  40 , whereby there is a nut groove  46  created between the post  40  and a body member  60 . Specifically, the nut groove  46  is under the flange end  44  of the post  40  and above body flange end  62 . The corresponding nut flange  34  that fits within the nut groove  46  and allows the nut  20  to freely rotate about the connector  100 . The post  40  has a cylindrical bore defined through it to house a coaxial cable. 
         [0028]    Further, between the nut  30  and the body member  60  is a coupling element  90 , such as an O-ring to provide a solid connection between these elements. The body member  60  is also connected to the post  40  through a larger body groove  48 , in which the body flange  62  fits. Defined between the body member  60  and the post  40  is a coaxial cable material space  80 . A coaxial cable is typically made from several components. Working from the inside to the outside, the inner most part of a cable is a central conductor surrounded by an inner dielectric layer which is covered by a layer of aluminum. Above the aluminum layer is a braided metal layer, and the entire cable is then housed in another dielectric material. There is a lower separator member  50  of post  40  used to separate the coaxial cable between its aluminum layer and braided metallic layer, so that the outer dielectric layer and braided metal layer enter the coaxial cable material space  80 , and the aluminum layer, inner dielectric layer, and central conductor layer sit in the cylindrical bore of the post  40 . At the very end of the connector  100  is a compression ring  70  which assists in attaching the connector  100  to the terminal end of a coaxial cable. 
         [0029]    Referring now to  FIG. 3 , there is shown a first embodiment of the invention coupled to a conventional coaxial cable connector  100 . The post  40  has a lip  42  on which the flexible RF seal  10  sits. The tubular insert  16  sits within the post  40 , such that the insert chamber  18  assists in creating a continuous cylindrical bore within which a portion of a coaxial cable (not shown) would be housed. The flexible brim  12  sits above the flange end  44  of the post  40 , but is not flush with the flange end  44 . The flexible brim  12  is not flush with the flange end  44  so that it can conform to shapes of a cable port (not shown) and the connector  100 , and to a greater extent the cable housed within the connecter, as sometimes there can be gaps between the cable port and the inner portions of the connector  100  with a cable. As mentioned above, the flexible brim  12  can be, if necessary, pushed backward so that the angle from the horizontal increases from its manufactured positioning. Moreover, the flexible brim  12  can be deformed to ensure a tight connection between the post  40  and the cable port. 
         [0030]    Referring to  FIG. 4 , there is shown a second embodiment of the seal  20 . The seal  20  sits on the outside of the flange end  44  of the post  40 . In this position, the seal  20  sits between the nut  30 , above the nut flange  34  and the outside of the flange end  44  of the post  40 . The flexible brim  12  sits above the flange end  44 , but is not flush with the flange end  44  so that it can adapt to the shape of both a cable port (not shown) and the connector  100  with a coaxial cable (not shown) housed within it. In this embodiment, the post  40  does not require a lip  42 , as was shown in  FIG. 3  with the seal  10 . Once the connector  100  engages a cable port and is advanced to have an inner conductor of a cable enter the port, the seal  20  can be deformed to a position necessary to fill gaps or tightly connect the connector  100  to the port. 
         [0031]    While the invention has been described with reference to particular 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 without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. 
         [0032]    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 
       [0000]    
       
           10 —Flexible RF Seal, First Embodiment 
           12 —Flexible brim 
           14 —Transitional band 
           16 —Tubular insert 
           20 —Flexible RF Seal, Second Embodiment 
           30 —Nut 
           32 —Inner threading 
           34 —Nut Flange 
           40 —Post 
           42 —Lip 
           44 —Flange 
           46 —Nut groove 
           48 —Body groove 
           50 —Lower separating element 
           60 —Body member 
           62 —Body flange 
           70 —Compression ring 
           80 —Coaxial cable material space 
           90 —Coupling element 
           100 —Connector