CONNECTOR FOR COAXIAL CABLE

Abstract: A supporting projecting section (4) protruded downward from the periphery of a fitting hole (2) into which a cylindrical conductive cover (30) is fitted and a contact holding section (6) which is passed through the hole (2) and provided to a bridge section (5) formed on the projecting section (4) are formed integrally with the insulating base (1). A fitting section (32) which is fitted between the inner periphery of the hole (2) and the outer periphery of the holding section (6) is formed at the lower end section of the cover (30). A fitting flange (33) which is engaged with the periphery of the hole (2) from above is protruded from the uppermost section of the fitting section (32) and an engaging groove (34) is formed below the flange (33) separately from the flange (33). The engaging piece section (41) of an earth contact terminal (40) is bifurcated so that the section (41) can be engaged and connected with the groove (34) of the cover (30). The fitting flange (33) of the cover (39) fitted in the holding section (6) of the base (1) is engaged with the upper surface of the base (1). The section (41) of the terminal (40) is engaged with the groove (34) of the cover (30) inserted in the hole (2) on the lower surface side of the base (1). Therefore, the assembly of the connector for a coaxial cable is facilitated, because the number of parts is reduced.

Description: Technical Filed The present invention relates to a coaxial cable connector which is easier to produce and assemble and is capable of reducing the number of parts, wherein its cover can be attached by engaging a ground contact terminal with the cover. Background Art A typical configuration of a coaxial cable connector of this type calls for inserting a plug contact portion of a contact terminal in a plug contact portion insertion hole, which is so bored in a cylindrical insulating bush for maintaining the contact as to extend along the axis of the insulating bush; inserting the insulating bush having the contact terminal inserted therein into a conductive cover; holding another insulating bush that is inserted in the conductive cover by means of crimping the cover, fitting the conductive cover in a mounting hole of the base; attaching the conductive cover to the base while the base is sandwiched, at the upper and the lower ends of the mounting hole thereof, by a mounting collar of the conductive cover and a nut screwed around a threaded portion of the conductive cover; and fastening a ground contact terminal with a nut in the state where the ground contact terminal is fitted to the conductive cover which is snugly inserted in the base. However, the above configuration of the conventional coaxial cable connector calls for fitting the conductive cover, which maintains the contact through the insulating bushes, in the mounting hole of the base, then fitting the ground contact terminal to the conductive cover and finally screwing a nut around the threaded portion of the conductive cover. As the conventional configuration requires a large number of parts and assembling steps, it presents such problems as poor productivity and high production costs. An example of a means for solving this problem is offered in Japanese Utility Model Publication No. 13344/1989, which discloses a coaxial cable connector having a conductive cover and a ground contact terminal, the conductive cover having a mounting collar that juts out from the middle of the outer surface of the conductive cover and a stopper groove formed below the mounting collar, and the ground contact terminal having a forked catching piece portion to be fitted in the stopper groove of the conductive cover, wherein the cover can be attached to a base of the coaxial cable connector by means of fitting the conductive cover in a mounting hole of the base, thereby bringing the mounting collar into contact with the upper end of the mounting hole, and fitting the catching piece portion of the ground contact terminal in the stopper groove that is now located below the underside of the base as a result of the insertion of the cover through the mounting hole of the base so that the base is firmly sandwiched between the mounting collar and the ground contact terminal. The configuration of the coaxial cable connector disclosed in the above Japanese Utility Model Publication No. 13344/1989, however, requires a particular process to secure an insulating bush in the conductive cover in order to insulate a plug contact portion of the contact terminal from the cover. Furthermore, the configuration of the conductive cover is complicated in that a positioning step has to be formed in the conductive cover in order to secure the insulating bush. In order to solve the above problems, an object of the present invention is to provide a coaxial cable connector which is easier to produce and assemble and is capable of reducing the number of parts, wherein a cover can be attached by snugly inserting a plug contact portion of a contact terminal into a contact holding portion that is integrally formed with the base of the connector, inserting the contact holding portion through a mounting hole of the base with a cover snugly fitted around the contact holding portion, and engaging a ground contact terminal with the cover. Disclosure of Invention The present invention relates to a coaxial cable connector having an insulating base; a cylindrical conductive cover to be attached to the insulating base; a ground contact terminal which is provided with a catching portion to be engaged with and connected to the conductive cover; and a contact terminal which is provided with a plug contact portion to be insulated and snugly inserted into the conductive cover; wherein at least one mounting hole for permitting the conductive cover to be inserted therethrough is bored through the insulating base; raised supporting portions jutting downward from the edge of the mounting hole, bridging portions that connect the raised supporting portions, and a contact holding portion are provided as an integral body with the insulating base in such a manner that the contact holding portion is inserted through the mounting hole so as to project above the insulating base; the contact holding portion is provided with an insertion hole for a plug pin of a coaxial connector and a plug contact portion insertion hole for the plug contact portion of the contact terminal to be inserted therein, the plug pin insertion hole and the plug contact portion insertion hole directly communicating with each other and respectively opened at the upper end and the lower end of the contact holding portion; a fitting portion to be fitted between the inner surface of the mounting hole of the insulating base and the outer surface of the contact holding portion is formed at the lower part of the conductive cover; a horizontally jutting mounting collar to contact with the upper end of the mounting hole is formed at the upper end of the fitting portion; a stopper groove is formed below the mounting collar; the catching portion of the ground contact terminal is formed in the shape of a two-pronged fork so as to be fitted in the stopper groove of the conductive cover; the conductive cover is attached to the insulating base by means of fitting the conductive cover around the contact holding portion of the insulating base, inserting the fitting portion of the conductive cover between the inner surface of the mounting hole of the insulating base and the outer surface of the contact holding portion so that the mounting collar comes into contact with the upper end of the mounting hole, and fitting the catching piece portion of the ground contact terminal in the stopper groove of the conductive cover located below the underside of the insulating base in the state where the conductive cover is inserted through the mounting hole of the insulating base, thereby securely supporting the insulating base between the mounting collar and the ground contact terminal; and the plug contact portion of the contact terminal is securely inserted in the contact holding portion of the insulating base. With the configuration as above, the cover can be attached to the base by inserting the plug contact portion of the contact terminal into the plug contact portion insertion hole of the contact holding portion, which is an integral body with the base, inserting the conductive cover through the mounting hole of the base by fitting the cover around the contact holding portion, and sandwiching the base between the mounting collar and the ground contact terminal by bringing the mounting collar into contact with the upper end of the mounting hole and fitting the ground contact terminal in the stopper groove of the cover, which is located below the underside of the base because of the insertion of the cover through the mounting hole. The plug contact portion may be inserted into the plug contact portion insertion hole of the contact holding portion after the cover is attached to the base. The contact holding portion and the base of the coaxial cable connector assembled as above are formed as an integral body. As there is no need of a working step to fit an insulating bush in the conductive cover, and the number of parts is reduced, a coaxial cable connector according to the invention is more convenient to assemble. According to another feature of the invention, rotation-stop catching surfaces are formed on the inner surface of the mounting hole of the insulating base, and rotation-stop surfaces which will come into contact with the rotation-stop catching surfaces are formed on the fitting portion of the conductive cover. Therefore, by bringing the rotation stop surfaces of the fitting portion of the cover into the rotation-stop catching surfaces on the inner surface of the mounting hole of the insulating base, the cover is secured so as not to turn in the circumferential direction. Brief Description of Drawings Fig. 1 is an exploded oblique view of a coaxial cable connector according to an embodiment of the present invention; Fig. 2 is an exploded oblique view of same viewed from the opposite side; and Fig. 3 is a vertical sectional view of same in the assembled state. Best Mode Carrying Out the Invention Next, the configuration of a coaxial cable connector according to an embodiment of the invention is explained hereunder, referring to the drawings. Referring to Fig. 1, numeral 1 denotes a mounting base formed in the shape of a plate using insulating material, such as synthetic resin. One or more essentially circular mounting holes 2 are bored through the planar surface of mounting base 1. In cases where a plurality of mounting holes 2 are provided, they are arranged in a straight line. Each mounting hole 2 is provided with two rotation-stop catching surfaces 3 which are respectively defined by flat planes and formed by cutting out two opposing sections of the hole. Raised supporting portions 4,4 formed as an integral body with mounting base 1 jut downward, i. e. facing towards the left as presented in Fig. 1, from the perimeter of mounting hole 2. The ends of raised supporting portions 4,4 are connected by means of bridging portions 5,5 and an essentially cylindrical contact holding portion 6, which is provided between bridging portions 5,5 in such a manner as to project above mounting base 1 through mounting hole 2. Thus, raised supporting portions 4,4, bridging portions 5,5 and contact holding portion 6 are formed as a single body. As shown in Fig. 3, a plug pin insertion hole 10 for a coaxial connector is coaxially bored in contact holding portion 6. Plug pin insertion hole 10 is open at the upper end and consists of an upper insertion portion 7 whose upper end is narrower than the remaining portion, a lower insertion portion 8 whose lower part is wider than the upper part, and a narrower step portion 9 located between the upper and lower insertion portions. Plug pin insertion hole 10 is directly communicated with a groove-shaped plug contact portion insertion hole 11 which is open at the lower end so as to permit the plug contact portion of a contact terminal to be inserted therein. Numeral 21 denotes a contact terminal which is formed of a conductive plate. As shown in Fig. 1, one end of contact terminal 21 comprises a plug contact portion 22 which has a plug pin catching notch 23 open at the end. A contact-point portion 24, which becomes narrower towards the end, protrudes inward from the end of each side of plug pin catching notch 23 so that the two contact-point portions 24 face each other. The other end of contact terminal 21 extends straight, thus forming a connecting piece 25 for a conductive wire. Furthermore, a catching protrusion 26 shaped in the inverted V is formed at the middle of each side edge of contact terminal 21. Numeral 30 denotes a cover formed of conductive metal in an essentially cylindrical shape. As shown in Fig. 1, a fitting hole 31 which permits contact holding portion 6 to be fitted therein is coaxially bored through cover 30. The lower part of fitting hole 31 is formed into a fitting portion 32 having a smaller diameter so as to be fitted between the inner surface of mounting hole 2 of mounting base 1 and the outer surface of contact holding portion 6. Fitting portion 32 is provided with a mounting collar 33 and a stopper groove 34 such that mounting collar 33 horizontally juts out from the upper end of fitting portion 32 so as to be capable of coming into contact with the perimeter of mounting hole 2 and that stopper groove 34 is located below mounting collar 33. Formed on the outer surface of the wall of fitting portion 32 of cover 30, at the portion between mounting collar 33 and stopper groove 34, are flat rotation-stop surfaces 35 which will respectively come into contact with rotation-stop catching surfaces 3 of mounting hole 2 of mounting base 1. Numeral 40 denotes an essentially L-shaped ground contact terminal, whose one end comprises a catching piece portion 41 and the other end a connecting piece portion 42. Catching piece portion 41 is in the shape of a U-like fork which is capable of fitting in catching groove 34 of cover 30. Mounting base 1 also has at an appropriate position a jutting portion (not shown) that has a mounting hole so as to permit mounting base 1 to be attached to a housing or the like. Next, the procedure for assembling the present embodiment is explained hereunder. First of all, insert plug contact portion 22 of contact terminal 21 upward into plug contact portion insertion hole 11 of contact holding portion 6 that is formed integrally with mounting base 1 until catching protrusions 26 of contact terminal 21 are caught in plug contact portion insertion hole 11. Then, from above, fit cover 30 over contact holding portion 6, which has contact terminal 21 inserted therein, so that contact holding portion 6 is fitted in fitting hole 31 of cover 30. At that time, by fitting cover 30 in a manner such that rotation-stop catching surfaces 3 of mounting hole 2 are so positioned as to respectively correspond to rotation-stop surfaces 35, fitting portion 32 of cover 30 is pushed between the outer surface of contact holding portion 6 and inner surface of mounting hole 2 of mounting base 1, and mounting collar 33 of cover 30 comes into contact with the upper surface of mounting base 1. In this state, cover 30 is secured with its rotation-stop surfaces 35 abutting against rotation-stop catching surfaces 3 of mounting hole 2. Then, by fitting catching piece portion 41 of ground contact terminal 40 in stopper groove 34 of cover 30, cover 30 is snugly attached to mounting base 1, with mounting collar 33 and ground contact terminal 40 securely sandwiching mounting base 1. The invention is explained referring to the above embodiment, wherein cover 30 is attached after plug contact portion 22 of contact terminal 21 is inserted into plug contact portion insertion hole 11 of contact holding portion 6, which is formed as an integral body with mounting base 1. However, plug contact portion 22 may be inserted into plug contact portion insertion hole 11 of contact holding portion 6 after cover 30 is attached to mounting base 1. Furthermore, although connecting piece portion 25 of contact terminal 21 and connecting piece portion 42 of ground contact terminal 40 project perpendicular to mounting base 1 in the above embodiment, they may be so formed as to project parallel to mounting base 1. According to the above configuration of the embodiment that has a mounting base 1, a cover 30, a contact terminal 21, a ground contact terminal 40 and a cylindrical conductive cover 30, mounting base 1 has, as an integral body therewith, a contact holding portion 6 which projects from mounting base 1 and permits contact terminal 21 to be inserted therein. Therefore, the connector can easily be assembled by fitting cover 30 in mounting hole 2 of mounting base 1 to bring mounting collar 33 of cover 30 into contact with the upper end of mounting hole 2, fitting catching piece portion 41 of ground contact terminal 40 in a stopper groove of cover 30 in the state where cover 30 is fitted through mounting hole 2 of mounting base 1 so that the portion where the stopper groove is formed projects downward from the mounting hole, attaching cover 30 to mounting base 1 with mounting base 1 sandwiched between mounting collar 33 and ground contact terminal 40, and inserting contact terminal 21 into contact holding portion 6. Thus, the invention is capable of providing a connector which requires only a minimal number of parts, is easier to assemble, is of better quality and has lower production costs. As cover 30 is secured to prevent turning because of engagement of rotation-stop surfaces of cover 30 with rotation-stop catching surfaces of the mounting hole, stable connection of a coaxial plug is ensured. Industrial Applicability The present invention relates to a coaxial cable connector which is used in a receiver, a transmitter or the like.

Claims: A coaxial cable connector having an insulating base (1); a cylindrical conductive cover (30) to be attached to said insulating base (1); a ground contact terminal (40) which is provided with a catching portion (41) to be engaged with and connected to said conductive cover (30); and a contact terminal (21) which is provided with a plug contact portion (22) to be insulated and snugly inserted into said conductive cover (30) ; wherein: said insulating base (1) has at least one mounting hole (2) for permitting said conductive cover to be inserted therethrough, raised supporting portions (4,4) jutting downward from the edge of said mounting hole (2), bridging portions (5,5) that connect said raised supporting portions (4,4), and a contact holding portion (6), said raised supporting portions, bridging portions and contact holding portion being formed as an integral body with said insulating base (1) in such a manner that the contact holding portion (6) is inserted through said mounting hole (2) so as to project above said insulating base and is provided with an insertion hole (10) for a plug pin of a coaxial connector and a plug contact portion insertion hole (11) for a plug contact portion (22) of a contact terminal (21) to be inserted therein, said plug pin insertion hole (10) and plug contact portion insertion hole (11) directly communicating with each other and respectively opened at the upper end and the lower end of said contact holding portion; a fitting portion (32) to be fitted between the inner surface of said mounting hole (2) of said insulating base (1) and the outer surface of said contact holding portion (6) is formed at the lower part of said conductive cover (30), said fitting portion (32) having a horizontally jutting mounting collar (33) and a stopper groove (34), said mounting collar (33) being formed at the upper end of said fitting portion (32) and in contact with the upper end of said mounting hole (2), and said stopper groove (34) being formed at some distance below said mounting collar (33); the catching portion (41) of said ground contact terminal (40) is formed in the shape of a two-pronged fork so as to be fitted in said stopper groove (34) of said conductive cover (30); and said conductive cover (30) is attached to said insulating base (1) in such a manner that said conductive cover is fitted around said contact holding portion (6) of said insulating base, said fitting portion (32) of said conductive cover is inserted between the inner surface of said mounting hole of said insulating base and the outer surface of said contact holding portion with said mounting collar (33) in contact with the upper end of said mounting hole, and that said catching piece portion (41) of said ground contact terminal (40) is fitted in said stopper groove (34) of said conductive cover that is located below the underside of the insulating base because of the insertion of the conductive cover through the mounting hole of the insulating base, said insulating base thus being securely sandwiched between said mounting collar and said ground contact terminal in the state where the plug contact piece portion of said contact terminal is inserted in said contact holding portion of the insulating base and supported below the insulating base. A coaxial cable connector as claimed in claim 1 wherein rotation-stop catching surfaces (3) are formed on the inner surface of said mounting hole (2) of said insulating base (1), and rotation-stop surfaces (35) that will come into contact with said rotation-stop catching surfaces (3) are formed on said fitting portion (32) of said cover (30).

Inventors: KURAHASHI YOSHIO, KURAHASHI, YOSHIO
Applicants: EMUDEN MUSEN KOGYO KABUSHIKI K, EMUDEN MUSEN KOGYO KABUSHIKI KAISHA
Application year: 1995
Main classification: H01R17
IPC codes: H01R13, H01R24