Patent Publication Number: US-4929195-A

Title: Shield connector

Description:
This application is a continuation-in-part of co-pending application Ser. No. 015,118, filed Feb. 17, 1987 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a shield connector for connecting shield wires with each other, and particularly relates to a connector for connecting effectively multi-core shield wires with each other which have been widely used for weak electric appliances. 
     FIGS. 5 and 6 show the first example of a male terminal of one of a conventional shield connector. As shown in FIG. 5, a holding member 52 composed of an insulating material has a plurality of electrical contacting pieces 51 extending outwardly. A metallic guiding tube 53 is used in coupling the contacting pieces with a female terminal. An attaching flange 54 is integrally installed to the guide tube 53. 
     A plurality of cable cores 56 of a multi-core cable 55 are soldered to the above described contacting pieces 51. An end portion of an insulting coating 57 is cut out a predetermined length, and an end portion 58a of an exposed shield coating 58 of metal netting is twisted to form a thread shape. 
     The reference number 59 designates a metal shield cover of rectangular shape and being divided at the central portion into two similarly shaped upper and lower pieces 59a and 59b. The end of the upper pieces 59a is provided with an arcuate grasping piece 60a into which the upper half of the multi-core shield cable 55 is inserted. Similarly, a grasping piece 60b of a semi-circular shape is provided on lower piece 59b for receiving the lower half of the multi-core shield cable 55. 
     As shown in FIG. 6, the lower pieces 59a and 59b are soldered or spot-welded to the flange 54. Both the grasping pieces 60a and 60b are caulked to the multi-core shielded cable 55 so that when tension is applied to the multi-core shielded cable 55, the cable cores 56 may not be cut by an accidental tension. In addition, when the shield cover 59 is assembled, by drawing out the twisted end portion 58a of the shield coating 58 and soldering is to the outer surface of the shield cover 59, a conducting state is kept between them. 
     A female terminal of the shield connector is different merely in the shapes of the contacting piece and the holding member from those of the above mentioned male terminal, but is otherwise similar to the male terminal, so that no description or drawing is given therefor. 
     In FIGS. 7 and 8 there is shown the second example of a male terminal of a conventional shield connector. The reference numbers 71, 72, 73 and 74 shown in FIG. 7 designate a contacting piece, a holding member, a guide tube and a flange, respectively. 
     The reference numbers 75, 76, 77 and 78 indicate a multicore shield cable, a core wire, an insulating coating and a shield coating, respectively. At the end portion of the shielded coating 77 there is provided a fall-off preventing annulus 79 formed with a thick linear material so that it may wind and squeeze the thread formed end portion 78a of the shield coating 78. A shield cover 80 is a rectangulr tubular shape and has a bottom part. A shield wire 75 is inserted into a penetrating hole (not shown) bored on the bottom part. 
     As shown in FIG. 8, the open end portion of the shield cover 80 is secured to the flange 74. The fall-off preventing annulus 79 contacts the bottom part of the shield cover 80, so that the core wire 76 is protected and so that it may not be broken. 
     The end portion 78a of the shield coating 78 is drawn out along the multi-core shield cable 75 and is soldered to the shield cover 80. 
     The first example of the conventional shield connector shown in FIG. 5 and 6 can not have strong grasping forced between thick shield cable 55 and the grasping pieces 60a and 60b because of the upper limit to the thickness of the shield cover 59. In the second example of the conventional shield connector there is apprehension of intruding noises from a gap between the penetrating hole of the shield cover 80 and the shield wire 75 which penetrates the hole, so that it is undesirable to widen the gap. Accordingly, it has been hard to draw out the end portion 78a of the shield coating 78. 
     Furthermore, in both examples of the conventional shield connectors, it is necessary to twist the end terminals 58a and 78a of the respective shield casings 58 and 78 to form a thread. The twisted end portions 58a and 78a are secured to the respective shield covers 59 and 80 and/or to each of the flanges 54 and 74, such as by soldering. 
     SUMMARY OF THE INVENTION 
     In view of the aforementioned disadvantages of the conventional shield connector, the present invention aims to eliminate the disadvantages of the conventional shield connector. It is an object of the present invention to provide an improved shield connector which comprises a stopper made of electric conductive synthetic resin and formed integrally with the insulating coating and the shield coating at the end portion of the shield wire. Two shield case pieces are coupled with each other. An annular groove is provided on the outer surface of the stopper. A penetrating hole for preventing the shield wire from falling out is provided on the bottom part of the two shield case pieces. An attaching flange made of synthetic resin may be formed. 
     The penetrating hole bored on the bottom part of the shield case engages the stopper which is formed integrally with the isolating coating and the shield coating at the end terminal portion of the shield wire. An electric conductive condition exists between the shield case and the shield coating. Even if a large tensile force is applied to the shield wire, there is no necessity for tangling and twisting the core wires. 
     Further, when the attaching flange is formed the shield case pieces are coupled with each other to form a guide tube, so that troublesome works which have been indispensable in the conventional art, such as manufacturing the guide tube and the attaching flange separately and manually coupling the shield cover with them, can be eliminated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view showing a male terminal of one embodiment of a shield connector according to the present invention. 
     FIG. 2 is a perspective view of the male assembled terminal of the embodiment of the shield connector shown in FIG. 1. 
     FIG. 3 is a perspective view of the male terminal shown in FIG. 1 having been assembled. 
     FIG. 4 is a longitudinally sectional side view cut along the central line. 
     FIG. 5 is an exploded perspective view of a male terminal of the conventional shield connector. 
     FIG. 6 is a side view of the male terminal of the conventional shield connector shown in FIG. 5. 
     FIG. 7 is an exploded perspective view of another male terminal of the conventional shield connector. 
     FIG. 8 is a side view of the connector shown in FIG. 7. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     One of the embodiments of the present invention is shown in FIGS. 1 to 4, in which the reference numbers 1 and 2 indicate a contacting piece and a holding member, respectively, similar to those of the contacting piece 51 and the holding member 52 of the conventional shield connector. On the upper and the lower sides of the holding member 2 an engaging groove 3 is provided. 
     A plurality of core wires 5 of a multi-core shield cable 4 are connected to the holding member 2. The end portion of an insulated coating 6 of the outer layer of cable 4 is cut out with a predetermined length on the cut out portion. A column shaped stopper 8 made of electric conductive synthetic resin covers coating 6 and an exposed shield coating 7. On the peripheral surface of the stopper 8 there is provided annular groove 9. 
     The reference number 10 designates a shield case which corresponds to the one which is made by integrally coupling the above described guide tube 53 and the shield cover 59. As shown in FIG. 1, case 10 is divided into an upper piece 10a and a lower piece 10b and each of their divided edges is overlapped with each other to fit matingly. In both shield case pieces 10a and 10b, there is formed a projection 11 projecting inwardly and a semi-circular hole 12. As shown in FIGS. 1 and 2, upper piece 10a has inwardly flared sides and lower piece 10b has outwardly flared sides, such that the pices form a tubular shape with a trapezoidal cross section when assembled. 
     As shown in FIG. 3, by setting both shield case pieces 10a and 10b on opposite sides of the holding member 2, the projection 11 and an engaging hole 13 formed by the upper and the lower semi-circular holes 12 engage the engaging groove 3 and the annular groove 9, respectively. An attaching flange 14 of synthetic resin is formed on the outer circumference of the projection 11 on both shield case pieces 10a and 10b such that these shield case pieces are coupled with each other to assemble the shield case 10. In this embodiment, the attaching flange 14 serves as a flange for engaging the male connector with a female connector. 
     Further, the female terminal of the shield connector is different merely in shapes of the contacting pieces and holding members from those of the male terminal, and structures of all the remaining parts are the same as those of the male terminal, so that description and illustration by the drawing are abbreviated. 
     The shield connector according to the present invention is adapted so that, as described above, the penetrating hole formed on the bottom surface of the shield case engages the stopper. The stopper is made of electrically conductive synthetic resin and is formed integrally with the insulating coating and the shield coating at the end of the shield wire, so that the shield case is automatically electrically conducted with the shield coating. Further, even if accidental large tensile force is applied to the shield wire no tensile force applies to the core wires, and there is also no necessity for soldering the core wires to the shield case. 
     In addition, in the case of an attaching flange being formed, the shield case pieces are coupled with each other simultaneously and a guide tube is formed. Accordingly, the conventional problem of separately manufacturing the guide tube and the attaching flange and then manually connecting the guide tube and flange with the shield cover is eliminated. Thus, shield connector according to the present invention can be made easily and inexpensively.