Abstract:
An end connector for coaxial cable usable for connecting a coaxial cable to an electronic device or a threaded interface connector, the end connector being able to accept a coaxial cable coaxially. The connector includes an outer sleeve, a sleeve body coaxially disposed in the outer sleeve, an adapter, and a nut lock encircling around the sleeve body. At least one annular protrusion is formed around the outer surface of the outer sleeve, when the cable is inserted into the end connector, both outer sheath and the braided conductor of the cable are filled into an annular hollow portion of the outer sleeve. When being squeezed, the outer sleeve is curled inwardly such that the annular protrusion is squeezed and forced to directly in tight engagement with the cable outer sheath.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to an end connector for coaxial cable, and more particularly, to an end connector for sealably connecting a coaxial cable to a wired television receiver or other electronic terminal device using an adapter therebetween. 
     (2) Description of the Prior Art 
     It is a well-known conventional technique to connect a coaxial cable with one of electronic devices such as TV, CB, FM radio receiver or amateur radio systems by means of a typical F series end connector screwing to an auxiliary interface connector. 
     It is one of the fatal disadvantages of a connector making a joint with a coaxial cable that it is susceptible to moisture infringement from incomplete sealing between the connector body and the cable shield. A typical example for a conventional F series coaxial cable connector  10  is illustrated in FIG. 1. A coaxial cable connector  10  is composed of a connector body  11 , a sleeve  12 , a threaded tube  13  rotatably disposed at one end of the sleeve  12 , and a nut  14  fitted over around the thread tube  13 . 
     The connector  10  is inserted into the sleeve  12  together with a coaxial cable  15  such that the cable insulation layer with a center conductor  16  is held in the nut  14  thereby completing an assembly of the cable connector  10  with the coaxial cable  15 . Braided cable shield and outer sheath of the coaxial cable  15  is disposed between the thread tube  13  and the sleeve  12 . A hexagonal compression tool is used to apply a compressive force on the sleeve  12  so as to forcibly make a sealed engagement between the sleeve  12  and the outer sheath of the coaxial cable  15 . However, the strength of force exerted on the cable joint by the compression tool operators differs considerably so that degree of tightness between the sleeve  12  and the cable  15  cannot be maintained at a desired level, accordingly, there exists a passage for moisture infringement therefrom and reaching the braided shield resulting in degrading signal transmission property at the joint. Hence, the possibility of moisture infringement therefrom shall be absolutely eliminated. 
     Accordingly, it is a must to provide an end connector which can be tightly engaged with the cable so as to prevent entry of rain water and corrosion so as to ensure durable mechanical engagement between the joint portions. 
     SUMMARY OF THE INVENTION 
     It is a first object of the present invention to provide an end connector for coaxial cable forming an annular protrusion around the end of the outer wall surface of an outer sleeve, the annular protrusion is made to reduce the diameter at the end of the outer sleeve after being squeezed so as to make a perfectly tight engagement between the end of the outer sleeve and the cable outer sheath. 
     It is a second object of the present invention to provide an end connector for coaxial cable forming at least an annular protrusion around near the end of the outer wall surface of an outer sleeve such that when the outer sleeve is compressed to cure inwardly, the annular protrusion is depressed inwardly by squeezing thereby perfectly engaging with the cable outer sheath to form a multiple water tight protection. 
     It is a third object of the present invention to provide an end connector for coaxial cable wherein a easily breakable ditch is formed between the annular protrusion and the outer wall surface of the outer sleeve so as to easily deform the annular protrusion. 
     The invention as well as its many advantages may be further understood by the following detailed description of the embodiments with reference to the accompanied drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a three-dimensional perspective view showing a conventional end connector in engagement with a coaxial cable; 
     FIG. 2 is a cross sectional view showing an end connector of the present invention in engagement with a coaxial cable; 
     FIG. 2A is an enlarged fragmentary view taken along dotted line  2 A of FIG. 2; 
     FIG. 3 is a cross sectional view of the end connector according to the present invention; 
     FIG. 3A is an enlarged fragmentary view taken along dotted line  3 A of FIG. 3; 
     FIG. 4 is a cross sectional view of the inwardly compressed end connector of the present invention; 
     FIG. 5 is a cross sectional view of an end connector in another embodiment of he present invention; 
     FIG. 5A is an enlarged fragmentary view taken along dotted line  5 A of FIG. 5; 
     FIG. 6 is a cross sectional view showing an end connector of the present invention in engagement with a coaxial cable; 
     FIG. 7 is a cross sectional view of an adaptor according to the present invention; 
     FIG. 8 is cross sectional view showing wherein the adapter of FIG. 7 is pre-clad on the outer sleeve; 
     FIG. 9 is a cross sectional view wherein the end connector of FIG. 8 is in engagement with a coaxial cable; 
     FIG. 10 is a cross sectional view of the squeezed end connector of FIG. 8; 
     FIG. 11 is a cross sectional view of an adaptor in an embodiment of the present invention; 
     FIG. 12 is a cross sectional view showing wherein the end connector is engaged with the adaptor of FIG. 11 by squeezing; 
     FIG. 13 is a cross sectional view of an adaptor in another embodiment of the present invention; 
     FIG. 14 is a cross sectional view showing wherein the adaptor of FIG. 13 is pre-clad on the connector of the present invention; 
     FIG. 15 is a cross sectional view wherein the end connector of FIG. 14 is in engagement with a coaxial cable; 
     FIG. 16 is a cross sectional view of an end connector in one more embodiment of the present invention, and; 
     FIG. 17 is a cross sectional view showing wherein the end connector of FIG. 16 is engagement with a coaxial cable. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiment 1 
     As shown in FIG. 2, a center conductor  16 , an insulation layer  18 , a braided shield conductor  19  and an outer sheath  17  constitute a well-known coaxial cable  15 . In order to be effectively connected to terminal electronic devices, the center conductor  16  and the insulation layer  18  is removed a prescribed length to expose the center conductor  16 . The braided shield conductor  19  is cambered from its terminal a prescribed length and covered on the outer sheath  17 , and the cable  15  is inserted in the end connector  20 . 
     Referring to FIGS. 2,  3 , together with FIG. 4, an end connector  20  includes a sleeve body  21  with a through hole  22  thereon, and having an outer flange  23  formed at the front end and an extended portion  28  from the rear end. 
     The end connector  20  further includes an outer sleeve  24  having an inner flange  25  encircling on the sleeve body  21 , and a rear end extended portion  26  whose outer diameter and wall thickness being smaller than those of an outer sleeve body  27 . The outer sleeve  24  is coaxially encircling the rear end extended portion  28  of the sleeve body  21  and an annular cavity  29  is formed therebetween. The inner wall surface of the rear end extended portion  26  is formed flat and smooth, while the outer wall surface thereof has a conventional serrated portion  214 . The end of outer wall surface of the rear end extended portion  26  is formed into an annular protrusion  211 A, and an easily breakable annular ditch is interposed between the annular protrusion  211 A and the rear end extended portion  26 , as shown in FIG.  3 A. 
     The end connector  20  further includes a nut lock  30  at its front end, and a flange  31  inwardly bent at the end connector. The flange  31  is sandwiched between the outer flange  23  and the outer sleeve body  27 . Several screw threads  32  are provided on the inner wall surface of the nut lock  30 , while its outer surface is formed into a flat shaped screw nut  33  so that the end connector  20  can be tightened to a receiver or a terminal electronic device with a spanner or other equivalent tools. A sealant  34  is filled between the outer flange  23  and the flange  31  so as to evade infringement of moisture through the contact surface between the outer sleeve body  27  and the flange  31 . 
     As shown in FIG. 2A, in order to conjoin the end connector  20  with the cable  15 , the cable  15  is inserted into the end connector  20  while the center conductor  16  exposed outside and insulation layer  18  stretch into the sleeve body  21 , while the braided conductor  19  and the outer sheath  17  stretch to the place between the rear end extended portion  28  of the sleeve body  21  and the rear extended portion  26  of the outer sleeve  24 . A compression tool which causes reduction of diameter of portion  26  compresses the latter portion  26  radially inward. Since the diameter of the outer sleeve end is reduced by squeezing the annular protrusion  211 A so that the annular protrusion  211 A can be forcibly engaged with the cable outer sheath  17 . 
     Since there is a ditch  212  formed between the rear end extended portion  26  and the annular protrusion  211 A such that the annular protrusion  211 A is easily deformed thereat and reduces the diameter of the outer sleeve  24  at its end thereof. As a result, the deformed annular protrusion  211 A can be perfectly engaged with the cable outer sheath  17  so as to prevent moisture from entering into the connector thereby ensuring durable mechanical connection between the components. 
     Referring to FIGS. 5 and 6, in this embodiment, another annular protrusion  211 B is formed near the end of the outer wall surface of the rear end extended portion  26 . With this structure, in case the portion  26  of the outer sleeve  24  is compressed, the annular protrusion  211 B would be depressed inwardly while the inner wall surface of the portion  26  upheavals. Thus, both annular portions  211 A and  211 B can be forcibly and directly in a tight engagement with the cable outer sheath  17  (see FIG. 6A) resulting in multiple moisture proof sealing. As shown in FIG. 5A, an annular ditch  212  formed between the rear end extended portion  26  and the annular protrusion  211 B facilitates deformation of the annular protrusion  211 B from the ditch  212 . 
     Referring to FIGS. 7 through 10, in the present invention, a common compression means (such as a compression tool and an adaptor) can be used to compress the rear end extended portion  26  of the outer sleeve  24  inwardly in a radiant state so as to reduce the diameter of the portion  26 . 
     Furthermore, an adapter  40  including an adapter body  41  and a fitting ring  42  around the body is covering the rear end extended portion  26  of the outer sleeve  24 . A truncated cone shaped hole  43  and a cylindrical hole  44  are bored both facing to longitudinal direction in the adapter body  41 , and an annular groove  45  is formed near the base of the truncated cone shaped hole  43 . When assembling, the adapter  40  may be pre-installed with the outer adapter  24 , and inlaid in the annular groove  45  by the annular protrusion  211 A so as to simplify the operator&#39;s working procedure. 
     After the cable  15  has been completely inserted into the end connector  20 , a compression tool is used to compress the adapter  40  so as to force the portion  26  into the hole  43  thereby deforming the portion  26  inwardly into a radiant state having a reduced diameter. The annular protrusion  211 A makes the diameter at the end of the outer sleeve  24  reduced in accordance with the ramp of the truncated cone shaped hole  43 . On the other hand, the annular protrusion  211 B is squeezed and depressed inwardly, such that both annular protrusions  211 A and  211 B are forced to directly in tight engagement with the cable outer sheath  17 . Finally an annular protuberance  213  on the rear end extended portion  26  is inlaid in the annular groove  45 . With this structure the end connector and the cable achieve multiple tight annular sealing therebetween. 
     Referring to FIGS. 11 and 12, the adaptor  40  in an embodiment of the present invention is shown. An annular protruded flank  46  is formed around the inner wall surface of a cylindrical hole  44 . When the adaptor  40  is squeezed to engage with the outer sleeve, the annular protrusion  211   a  which is inlaid in the annular protruded flank  46  is squeezed herein to obtain a further greater deformation so that the annular protrusion  211   a  exacerbatingly increases conjoining force with the cable outer sheath  17  by more deeply biting with the latter as shown in FIG.  12 A. 
     Referring to FIGS. 13 and 14, the drawings show an adaptor  50  in another embodiment of the present invention. The adapter  50  includes a first adapter body  51 , a second adapter body  52 , and an annular moisture proof sealant  53  interposed between the first adapter body  51  and the second adapter body  52 . The first adapter body  51  has an end portion  54  and an interface  55 , and a truncated cone shaped hole  59  therein facing against the longitudinal direction. An annular groove  511  is formed at the front end of the hole  59 . The second adapter body  52  has a flange  56  and a tubular end portion  57 . The interface  55  of the first adapter body  51  is tightly conjoined to the inner wall of the tubular end portion  57  mechanically, and forming a clearance  58  between the end portion  54  and the tubular end portion  57 . The annular moisture proof sealant  53  is made of an elastic rubber. 
     By means of a compression tool to compress the adaptor  50  so as to force the portion  26  into the hole  59  thereby deforming the portion  26  inwardly into a radiant state having a reduced diameter. At this time, the annular protrusion  211 A and/or the annular protrusion  211 B are/is deformed, the protrusion  211 A is compressed inwardly and reduces its diameter, on the other hand, the protrusion  211 B is inwardly depressed so that the annular protrusion  211 A and/or the annular protrusion  211 B are/is forced to directly in tight engagement with the cable outer sheath  17 . At the last compression the tubular end portion  57  is forced to remove forward and clogs the clearance  58  so as to cause the tubular end portion  57  to contact the end surface of the end portion  54 . At this moment, due to accuracy of compression between the first adapter body  51  and the second adapter body  52 , the sealant  53  is squeezed to deform so as to directly and tightly engage with the cable outer sheath  17 . The sealant  53  after compression is removed to a place between the rear end extended portion  26  and the outer wall of the cable sheath  17  thereby achieving a tight annular sealing effect as shown in FIG.  15 . 
     Referring to FIGS. 16 and 17, the drawings show an outer sleeve  24 A used in more embodiment of the present invention. The annular protuberance  213  is formed near the front end of the outer wall surface of the rear end extended portion  26 A. Since the terminal of the outer wall surface is a flat and smooth surface, therefore, in case the adaptor  50  (see FIG. 13) is compressed with a compression tool, the rear end extended portion  61  is squeezed by the truncated cone shaped hole  59  to deform inwardly into a radiant state having a reduced diameter. At the last compression stage, the tubular end portion  57  is forced to remove forward and clogs the clearance  58  so as to cause the tubular end portion  57  to contact the end surface of the end portion  54 . At this moment, due to compression between the first and the second adapter bodies  51 ,  52 , the sealant  53  is squeezed to deform so as to directly and tightly engage with the cable outer sheath  17 . The sealant  53  after compression is removed to a place between the rear end extended portion  61  and cable sheath  17  thereby the rear end extended portion  26 A can be perfectly in tight engagement with the outer cable sheath  17 . 
     Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be constructed to cover all equivalent structures, which fall within the true scope and spirit of the invention.