Patent Publication Number: US-9419331-B1

Title: Flexible antenna with weatherproof protection system and method of weather proofing and adding a flexible feature to existing antennas

Description:
BACKGROUND 
     The present invention generally relates to antennas. More specifically, the present invention relates to flexible RF antennas with weather protection. 
     Standard adjustable antennas typically do not have a robust weatherproof interface between the antenna and the mounting location of the antenna. The mounting location can be anything from an electronic box to a vehicle. For simplicity, the mounting location will be referred to as a housing. One reason is that there is a lack of a robust weatherproof interface is the difficulty to design a weatherproof product using an off-the-shelf antenna that has already been designed for a specific purpose. A second reason might be that there is not a significant demand to produce such an antenna in flexible weatherproof version. Another issue with most adjustable antennas is it that the antenna design does not have a 3-dimensional flexible joint and only allows for rotation along one axis. Whereby, if the antenna is struck by accident, the antenna may transfer a large impact load to the housing or the antenna connector, potentially damaging the housing or antenna connector. 
     It is an object of the present invention to provide a weatherproof antenna that flexible in all directions, so the antenna does not transfer impact loads to the housing. 
     SUMMARY OF THE INVENTION 
     An antenna assembly including an antenna, an antenna cable, a bendable structure, a housing interface, a first protection section and a second protection section. The bendable structure is a malleable material that remains in a bent position when bent. The first protection section covers the antenna and provides a weatherproof cover over the antenna. The housing interface mounts to a housing and covers the antenna cable in an area of the antenna cable adapted to enter the housing and the housing interface prior to entrance providing a weatherproof cover over the area of the antenna cable adapted to enter the housing. The second protection section is overmolded over a portion of the housing interface, the antenna cable, the bendable structure and a portion of the first protection. The second protection section is a flexible material. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a flexible antenna with a waterproof protection system according to the present invention. 
         FIG. 2  is a cutaway view of a flexible antenna with a waterproof protection system according to the present invention. 
         FIG. 3  is a perspective view of a housing interface according to the present invention. 
         FIG. 4  is a perspective view of a flexible antenna with a waterproof protection system to the present invention. 
         FIG. 5  is a cutaway view of a housing interface mounted in a housing according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention is a flexible antenna with a waterproof protection system for attachment to a housing, as shown in  FIG. 1 . The present invention also includes the method of weatherproofing an existing antenna, while adding a flexible feature to the antenna. Examples of housings are electronic boxes or vehicles.  FIG. 1  shows the complete waterproof protection system using an off the shelf antenna  10  and coaxial cable  12 . The coaxial cable  12  is an RF cable that includes the usual RF connector  14  to be connected to a radio within the housing. The coaxial cable  12  extending from the waterproof protection system along with the RF connector  14  is to be inserted inside the housing. 
       FIG. 2  shows a cutaway view of the waterproof protection system. The waterproof protection system includes a housing interface  16 , a first protection section  18  and a second protection section  20 . The first protection section  18  includes the antenna  10  mounted within the first protection section  18 . The first protection section  18  has an antenna shape where it reduces in diameter from a bottom end  22  to a top end  24 .  FIG. 2  shows the coaxial cable  12  traveling through the housing interface  16 , the second protection section  20  and the first protection section  18 . The coaxial cable  12  is connected to the antenna  10  in the first protection section  18 .  FIG. 2  also shows a bendable wire  26  acting as a bendable structure that runs along the coaxial cable  12  in the second protection section  20  and extends into both the housing interface  16  and the first protection section  18 . 
     The housing interface  16  includes a top end  28  and a bottom end  30 , as shown in  FIGS. 3-5 . The bottom end  30  includes a straight tab  32  and a spring tab  34  extending from the bottom end  30 . The spring tab  32  includes a snap catch  36 . A seal  38  is mounted in a seal groove  40  around the bottom end  30 . The top end  28  is square shaped with an internal port  42  extending from the top end  28 . The bottom end  30 , top end  28  and internal port  42  form a continuous sealed body. There is a cable through hole  44  which runs from the bottom end  30  through to the end  46  of the internal port  42  to allow the coaxial cable  12  to run from between the tabs  32 ,  34 , through the bottom end  30  and the top end  30 , and exiting out the internal port  42 .  FIG. 5  shows a housing  48  having a round entrance channel  50  leading from a square shaped external port  52 . The entrance channel  50  includes an internal shoulder  54  on the end opposite the external port  52 . The housing interface  16  provides for the attachment of the flexible antenna to the housing  48 . The housing interface  16  is inserted into the external port  52  with the coaxial cable  12  leading the way. The spring tab  34  bends towards the coaxial cable  12  during insertion into the entrance channel  50 . The snap catch  36  includes an angle cut end  56  to ease insertion of the straight tab  32  and spring tab  34  in to the entrance channel  50 . Once the snap catch  36  clears the internal shoulder  54 , the spring tab  34  releases and springs back to its natural state. The snap catch  36  then catches on the internal shoulder  54  to lock the housing interface  16  to the housing  48 . During insertion, the square shape of the top end  30  of the housing interface  16  engages the squared shaped port  52  of the housing  48  to further lock the housing interface  16  in position to prevent rotation of the housing interface  16  and hence the antenna  10 . Other non-circular shapes for the top end  30  and the port  52  can be used, for example a triangle or hexagon, where there is a corner to prevent rotation. The seal  38  is used to seal the entrance channel  50  near the squared shaped port  52  to provide weather proofing at the housing opening. 
     The method of sealing an off the shelf antenna with an attached coaxial cable  12  is as follows. Assemble the Dipole antenna  10 , coaxial cable  12  and RF connector  14 . The housing interface  16  is overmolded about the coaxial cable  12  and the bendable wire  26 , so that the housing interface  16  is a sealed one piece unit. Where the process of overmolding is the molding of a material over a structure, in order to seal about the structure using the material used in the overmolding process. It is preferable that the housing interface  16  is of a harder plastic for strength and the seal  38  is slipped on afterwards. This also locks the coaxial cable  12  and bendable wire  26  in position at the housing interface  16 . The first protection section  18  is an overmold that is slid over the end of the antenna  10  to cover the antenna  10 , part of the coaxial cable  12  and part of the bendable wire  26 . The first protection section  18  can be of hard or soft materials. The second protection section  20  is overmolded over the remaining exposed section between the housing interface  16  and the first protection section  18 . The remaining exposed section includes a top face  58  of the housing interface  16 , the internal port  42  extending from the housing interface  16 , coaxial cable  12 , bendable wire  26 , and the bottom end  22  of the first protection section  18 . The internal port  42  of the housing interface  16  is shown with ribbing  60  to provide a gripping surface for the overmold of the second protection section  20 . The first protection section  18  includes grooves  62  near bottom end  22  to form ribbing between the grooves  62  to provide gripping surface for the overmold of the second protection section  20 . The second protection section  20  provides the seal between the housing interface  16  and the first protection section  18  by covering the top end  28  of the housing interface  16  and the bottom end  22  of the first protection section  18 . The second protection section  20  is of a flexible rubber material to allow for bending along the second protection section  20 . The flexible rubber allows strain-relieved bending of the bendable wire  26  which runs alongside the coaxial cable  12 . The flexible rubber provides the strain relief to prevent the bendable wire  26  from kinking, yet allow the coaxial cable  12  to be bent to whatever angle is desired to allow the antenna  10  to point in a particular direction. The bendable wire  26  is preferably copper, which is a metal that has memory characteristics. Bendable wire  26  is a wire that is malleable and has memory characteristics is able to hold the coaxial cable  12  at the desired bend angle. The bendable wire  26  could be replaced by having a bendable coaxial cable with memory characteristics, though it is more costly then the regular coaxial cable  12  and bendable wire  26 . 
     The flexible antenna with a waterproof protection system and method of making it provides an infinitely adjustable flexible joint with a copper memory element to hold desired bend angle; a strain-relieved bending joint and good impact protection to the parent housing since antenna is flexible and does not transfer antenna impacts loads to housing. 
     While different embodiments of the invention have been described in detail herein, it will be appreciated by those skilled in the art that various modifications and alternatives to the embodiments could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements are illustrative only and are not limiting as to the scope of the invention that is to be given the full breadth of any and all equivalents thereof.