Patent Publication Number: US-2013237089-A1

Title: Coaxial cable connector using a multi-contact spring washer

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to coaxial cable connectors and more particularly, to a coaxial cable for connecting a coaxial cable to a mating device, for example, cable TV distributor or set-top box, which uses a multi-contact spring washer to work with a locknut, ensuring positive grounding and enhancing signal transmission reliability. 
     2. Description of the Related Art 
     U.S. patent Ser. No. 13/274,308, invented by the present inventor, discloses a coaxial cable connector suitable for assembly with one of a series of coaxial cables having one same specification and different wire outer diameters, which uses a plastic bushing for compressing by a barrel to wrap about the coaxial cable and compress an inner tube against the aluminum foil and insulation spacer of the coaxial cable, protecting the coaxial cable against weather and extending the lifespan, an O-ring in a locating groove around a front neck of a body shell or on an annular rear contact face of a locknut to seal the gap between the locknut and the body shell, and a curved spring plate for stoppage between an annular front stop face of the body shell and an annular rear contact face of the locknut for grounding to enhance signal transmission reliability. 
     In the aforesaid prior art design, the curved spring plate has a substantially “8” shape profile when viewed from one lateral side. After installation, the curved spring plate provides two contact points between the body shell and the locknut. As this structure simply provides two contact points between the body shell and the locknut, the locknut may be not positively stopped against the inner tube in one of certain angles after installation of the F-connector of the mating device, resulting in signal transmission instability. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is main object of the present invention to provide a coaxial cable connector for assembly with one of a series of coaxial cables having one same specification and different wire outer diameters, which eliminates the drawbacks of the aforesaid various prior art designs. 
     To achieve this and other objects of the present invention, a coaxial cable connector connecting a coaxial cable having a center conductor to a mating device having an F-connector is disclosed. The coaxial cable connector comprises a locknut, a connector body, a multi-contact spring washer and an O-ring. The locknut comprises an inner thread for threading onto an outer thread of the F-connector of the mating device, a vertically extending annular rear contact face disposed at a rear side thereof, a horizontally extending tubular rear inner face, an inside stop face perpendicularly extended from a front side of the horizontally extending tubular rear inner face in a parallel manner relative to the vertically extending annular rear contact face, and an inside annular groove defined between the vertically extending annular rear contact face and the horizontally extending tubular rear inner face. The connector body consists of an inner tube, a body shell, a barrel and a plastic bushing, and is fastened to one end of the coaxial cable to keep the center conductor of the coaxial cable suspend in the locknut, the connector body, the inner tube being mounted in one end of the locknut and comprising an annular front end face radially outwardly extended from the front side thereof and an annular front stop face disposed in a parallel manner at a back side of the annular front end face, the body shell comprising a clamping hole axially extending through opposing front and rear sides thereof and wrapping about the inner tube, an annular front stop face vertically disposed at the front side, a front neck axially forwardly disposed at the front side around the clamping hole and a tapered face connected between the front neck and the annular front stop face. The multi-contact spring washer is mounted on the front neck of the body shell, comprising at least three equiangularly spaced first contact points kept in contact with the annular rear contact face of the locknut. The O-ring is mounted in the inside annular groove of the locknut and stopped against the periphery of the front neck of the body shell to seal the gap between the locknut and the front neck of the body shell. 
     Further, the multi-contact spring washer further comprises and at least three equiangularly spaced second contact points kept in contact with the annular front stop face of the body shell. 
     Further, the multi-contact spring washer further comprises a plurality of first oblique washer body portions and a plurality of second oblique washer body portions alternatively connected in an endless series and respectively sloping in reversed directions. The at least three equiangularly spaced first contact points and the at least three equiangularly spaced second contact points are respectively disposed at the connections between the first oblique washer body portions and the second oblique washer body portions and arranged at two opposite sides. 
     Alternatively, the multi-contact spring washer further comprises a plurality of planar body portions selectively connected between the first oblique washer body portions and the second oblique washer body portions to form the at least three equiangularly spaced first contact points. 
     Alternatively, the multi-contact spring washer further comprises a plurality of planar body portions respectively connected between the first oblique washer body portions and the second oblique washer body portions to form the at least three equiangularly spaced first contact points and the at least three equiangularly spaced second contact points. 
     Alternatively, the multi-contact spring washer comprises an annular spring washer body, and at least three lugs equiangularly protruded from one side of the annular spring washer body to form the at least three equiangularly spaced first contact points. 
     Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a coaxial cable connector in accordance with the present invention. 
         FIG. 2  is an elevational assembly view of the coaxial cable connector in accordance with the present invention. 
         FIG. 3  is a sectional view of the present invention, illustrating the coaxial cable connector fastened to a coaxial cable. 
         FIG. 4  is an enlarged view of part A of  FIG. 3 . 
         FIGS. 5A˜5C  are elevational side, side view and plain view of a first example of the multi-contact spring washer in accordance with the present invention. 
         FIGS. 6A˜6C  are elevational side, side view and plain view of a second example of the multi-contact spring washer in accordance with the present invention. 
         FIGS. 7A˜7C  are elevational side, side view and plain view of a third example of the multi-contact spring washer in accordance with the present invention. 
         FIGS. 8A˜8C  are elevational side, side view and plain view of a fourth example of the multi-contact spring washer in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-3 , a coaxial cable connector in accordance with the present invention is adapted for connecting a coaxial cable  9  having a center conductor  91  to a mating device (not shown). The coaxial cable connector comprises a locknut  1 , a connector body  2 , a multi-contact spring washer  3 , and an O-ring  4 . 
     Similar to the design of U.S. patent Ser. No. 13/274,308, the connector body  2  consists of an inner tube  21 , a body shell  22 , a barrel  23  and a plastic bushing  24 . However, this design of connector body is not a limitation, i.e., the connector body may be variously embodied for connecting a coaxial cable. 
     The locknut  1  comprises an inner thread  11  for threading onto an outer thread of a F-connector of a mating device (not shown), a vertically (radially) extending annular rear contact face  12  disposed at the rear side thereof, as shown in  FIGS. 3 and 4 , a horizontally (axially) extending tubular rear inner face  13 , an inside stop face  14  perpendicularly extended from the front side of the horizontally (axially) extending tubular rear inner face  13  in a parallel manner relative to the vertically (radially) extending annular rear contact face  12 , and an inside annular groove  15  defined between the vertically (radially) extending annular rear contact face  12  and the horizontally (axially) extending tubular rear inner face  13 . 
     The connector body  2  is fastened to one end of the coaxial cable  9 , enabling the center conductor  91  of the coaxial cable  9  to suspend in the locknut  1 . As stated above, the connector body  2  consists of an inner tube  21 , a body shell  22 , a barrel  23  and a plastic bushing  24 , wherein the barrel  23  and the plastic bushing  24  are same or similar to the corresponding barrel and plastic bushing of the design of U.S. patent Ser. No. 13/274,308. 
     The inner tube  21  is mounted in one end of the locknut  1 , comprising an annular front end face  214  radially outwardly extended from the front side thereof, and an annular front stop face  213  disposed in a parallel manner at the back side of the annular front end face  214 . The body shell  22  surrounds the inner tube  21 . comprising a clamping hole  221  axially extending through opposing front and rear sides thereof, an annular front stop face  224  vertically (radially) disposed at the front side, a front neck  222  axially forwardly disposed at the front side around the clamping hole  221 , and a tapered face  223  connected between the front neck  222  and the annular front stop face  224 . 
     The main feature of the present invention is the design of the multi-contact spring washer  3 . The multi-contact spring washer  3  is mounted on the front neck  222  of the body shell  22  and kept in contact with the annular rear contact face  12  of the locknut  1  at three or more first contact points  3   a  thereof, and also kept in contact with the annular front stop face  224  of the body shell  22  at three or more second contact points  3   b  thereof. In accordance with a first example of the present invention, as illustrated in  FIGS. 5A-5C , multi-contact spring washer  3  comprises a plurality of first oblique washer body portions  31  and a plurality of second oblique washer body portions  32  alternatively connected in an endless series and respectively sloping in reversed directions, defining the first contact points  3   a  and the second contact points  3   b  at the junctions between each two adjacent ones of the first oblique washer body portions  31  and second oblique washer body portions  32 . The first contact points  3   a  and the second contact points  3   b  are alternatively disposed at two opposite sides of the multi-contact spring washer  3 . 
     Subject to the aforesaid design of multi-contact spring washer  3 , the annular rear contact face  12  of the locknut  1  is kept in contact with the three or more first contact points  3   a.  Thus, when threading the locknut  1  onto the outer thread of the F-connector of the mating device, the inside stop face  14  of the locknut  1  is constantly kept in positive contact with the annular front stop face  213  of the inner tube  21  to provide excellent grounding, assuring optimal signal transmission between the coaxial cable and the mating device. 
     Further, the O-ring  4  is mounted in the inside annular groove  15  of the locknut  1  and stopped against the periphery of the front neck  222  of the body shell  22  to seal the gap between the locknut  1  and the front neck  222  of the body shell  22 , providing excellent waterproof function. 
     As the multi-contact spring washer  3  has the three or more first contact points  3   a  thereof constantly kept in contact with the annular rear contact face  12  of the locknut  1 , the inside stop face  14  of the locknut  1  is constantly kept in positive contact with the annular front stop face  213  of the inner tube  21  when the locknut  1  is rotated to any particular angle relative to the F-connector of the mating device, eliminating the problem of signal transmission interruption of the prior art design upon rotation of the locknut to a particular angle relative to the F-connector of the mating device. 
       FIGS. 6A˜6C  illustrate a second example of the multi-contact spring washer  3 . This second example is substantially similar to the aforesaid first example with the exception that the multi-contact spring washer  3  of this second example further comprises a plurality of planar body portions  33  selectively connected between the first oblique washer body portions  31  and the second oblique washer body portions  32 , defining the first contact points  3   a.  Thus, the contact area between the first contact points  3   a  and the annular rear contact face  12  of the locknut  1  is relatively increased, keeping the locknut  1  in positive contact with the inner tube  21 . 
       FIGS. 7A˜7C  illustrate a third example of the multi-contact spring washer  3 . This third example is substantially similar to the aforesaid first example with the exception that the multi-contact spring washer  3  of this third example further comprises a plurality of planar body portions  33  respectively connected between the first oblique washer body portions  31  and the second oblique washer body portions  32 , defining the first contact points  3   a  and the second contact points  3   b.  Thus, the contact area between the first contact points  3   a  and the annular rear contact face  12  of the locknut  1  and the contact area between the second contact points  3   b  and the annular front stop face  224  of the body shell  22  are relatively increased, keeping the locknut  1  in positive contact with the inner tube  21 . 
       FIGS. 8A˜8C  illustrate a fourth example of the multi-contact spring washer  3 . According to this fourth example, the multi-contact spring washer  3  comprises an annular spring washer body  34  and at least three lugs  35  equiangularly protruded from one side of the annular spring washer body  34 . The lugs  35  are formed of a part of the annular spring washer body  34  by stamping. This fourth example has the advantages of ease of fabrication and low manufacturing cost. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.