A shield connector, a set of shielded connectors and method for connecting a shielded connector with a shielded cable

The present invention relates to a shielded connector, a set of shielded connectors and a method for connecting a shielded connector with a shielded cable.

A known shielded connector of this type is disclosed in Japanese Unexamined Utility Model Publication No. 5-27983. This terminal 1 is provided with three crimping portions: an inner conductor crimping portion 2a, an outer conductor crimping portion 3b and a sheath crimping portion 3c as shown in FIGS. 6 to 8.

A shielded cable 2 and the prior art shielded connector 1 are connected as follows. An inner conductor 51 is exposed by stripping a sheath 54, an outer conductor 52 and an insulating element 53 at an end of the shielded cable 50, and the inner conductor crimping portion 2a is fastened to the exposed inner conductor 51. Subsequently, only the sheath 54 is stripped at this end of the shielded cable 50 to expose the outer conductor 52, and the outer conductor crimping portion 3b is fastened to this exposed portion 56 of the outer conductor 52. Finally, the sheath crimping portion 3c is fastened to the sheath 3c at the end of the shielded cable 50 located behind the exposed portion 56.

The three crimping portions are simultaneously crimped after the aforementioned shielded connector 1 is placed in a crimper. Particularly, since the inner terminal 2 is crimped after being accommodated in the outer terminal 3, it is essential for the outer terminal 3 to be formed with openings 3a in its top and bottom walls in order for crimping molds of the crimper to reach the inner terminal 2 accommodated in the outer terminal 3.

However, because of the presence of the openings 3a, a portion of the inner conductor 51 not covered by the outer conductor 52 and the inner terminal 2 are exposed to the outside through the openings 3a. This causes a problem of a reduced shielding characteristic. Depending on the situation, it is necessary to apply shielding using an other member.

Document US 5 667 404 discloses a circular shielded connector for the use with a coaxial cable. In this connector, the inner terminal is connected to the inner conductor before inserting the inner terminal into the outer terminal with a dielectric element provided therebetween. The outer terminal comprises a cylindrical portion which is provided with an axial slit such that it may be elastically deformed to be fitted into a molding cover and a joint to connect the cylindrical portion of the outer terminal with a crimping portion to be crimped with an outer conductor. Further, this connector includes a shielding cylinder to shield a portion of the inner terminal to be fastened with the inner conductor.

Document US-A-5 145 409 discloses a connector according to the preamble of claim 1 and a method according to the preamble of claim 4.

The object of the invention is to reduce the number of parts of a shielded connector and to facilitate the assembly procedure, while maintaining good shielding characteristics.

This object is achieved by a set of shielded connectors having the features according to claim 1 and a respective method according to claim 4. Further developments of the invention are defined in the dependent claims.

According to a preferred embodiment, the outer terminal is formed such that it can be fastened to the outer conductor of the shielded cable with the inner terminal connected with the inner conductor.

Preferably, the outer conductor is at least partly folded back over the sheath thereby forming a folded portion, and the outer terminal is formed with a crimping portion which can be at least partly fastened to the folded portion.

Further preferably, the outer conductor is folded back over the sheath, and the outer terminal is formed with a crimping portion which can be fastened both to the outer conductor and to the sheath.

Accordingly, since the outer terminal can be fastened to the outer conductor and the sheath by one crimping operation, the crimping molds for crimping the outer terminal can be so constructed as to crimp one crimping portion without needing to be constructed in conformity with a plurality of crimping portions. Therefore, the crimping molds are allowed to have a simple construction and portions thereof corresponding to the crimping portion can be made shorter.

According to claims 1 and 4, by connecting the male and female shielding connectors with the open surfaces thereof faced in opposite directions, radiation characteristic which is influential in the high-frequency signal transmitted through the inner outer can be balanced, with the result that shielding characteristic can be improved.

According to a preferred embodiment of the invention, the method further comprises the step of fastening the outer terminal to the outer conductor of the shielded cable after the inner terminal is connected with the inner conductor in the inner terminal fastening step.

Preferably, the method further comprises the following steps:

• stripping the sheath to substantially expose the outer conductor;
• fastening a crimping portion of the outer terminal to both the sheath and the outer conductor being preferably folded back over the sheath.

Most preferably, in the fastening step crimping pieces of the crimping portion are so crimped as to at least partly wind on or around the outer conductor with the end of a first crimping piece substantially placed or placeable on that of a second crimping piece.

These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings in which:

• FIG. 1 is an exploded perspective view showing parts constructing a shielded connector according to one embodiment of the invention,
• FIG. 2 is a section of an assembled male shielded connector,
• FIG. 3 is a section of an assembled female shielded connector,
• FIG. 4 is a side view of the shielded connectors after connection,
• FIG. 5 is a section of the connected shielded connectors,
• FIG. 6 is a perspective view of a prior art shielded connector,
• FIG. 7 is a plan view of the prior art shielded connector, and
• FIG. 8 is a side view partly in section of the prior art shielded connector.

Hereinafter, one embodiment of the invention is described with reference to the accompanying drawings.

Shielded connectors 10a, 10b according to this embodiment are connectable with each other and have such an integral construction that inner terminals 20a, 20b are accommodated in outer terminals 40a, 40b with dielectric elements 30a, 30b provided therebetween. Shielded cables 50 are connectable with the shielded connectors 10a, 10b (see FIG. 1).

Here, the female shielded connector 10b differs from the male shielded connector 10a in that the inner terminal 20b is a female terminal, the outer terminal 40b is or can be at least partly accommodated in the outer terminal 40a and is not provided with contact pieces 43 and a touching or contact piece 48, and a contact portion 33 is provided at the leading end of the dielectric element 30b. However, since the female and male shielded connectors 10a, 10b are similarly constructed and assembled, only the male shielded connector 10a is described here to avoid repetitive description and the same or similar construction is identified by the same or similar reference numerals.

Hereinbelow, a side (right side in FIG. 2) of the inner terminal 20a of the connector 10a to be connected with an unillustrated mating inner terminal is referred to as a front side and an opening direction (an upward direction in FIG. 2) of a covering portion 45 is referred to as an upward direction.

The shielded cable 50 has such a substantially coaxial construction that an insulating element 53 is provided between an inner conductor 51 formed e.g. by bundling a plurality of strands and an outer conductor 52 made e.g. of a braided wire or a metal sheet and the outer surface is covered by a sheath 54 made of, e.g. vinyl. The sheath 54 is stripped at one end of the shielded cable 50 to partly expose the outer conductor 52, which is then folded back at least partly over the sheath 54, thereby forming a folded portion 55, and the insulating element 53 is stripped before the folded portion 55 to partly expose the inner conductor 51 (see FIG. 1). The exposed leading end of the inner conductor 51 is or can be connected with the inner terminal 20a, and the outer conductor 52 is or can be connected with the outer terminal 40a via the folded portion 55.

The inner terminal 20a of the male shielded connector 10a is an electrically conductive male terminal as shown in FIG. 1 and a front part thereof is formed into a tab connectable with the inner terminal 20b of the female shielded connector 10b. In the middle of the inner terminal 20a are provided a pair of biting or engaging projections 23 for biting into or engaging the inner wall of an accommodating hole 31 when the inner terminal 20a is inserted into the dielectric element 30a described later to fix the inner terminal 20a. Behind the biting projections 23 is provided an inner crimping portion 24 preferably comprised of at least one pair of crimping pieces for fastening the inner conductor 51.

The dielectric element 30a is made of an insulating material such as resin and electrically insulates the inner and outer terminals 20a, 40a from each other. Inside the dielectric element 30a is formed the accommodating hole 31 for accommodating and fixing the inner terminal 20a. Further, a locking recess 32 is formed in the outer surface of the top of the dielectric element 30a and the contact portion 33 is provided on the outer surface of the bottom of the dielectric element 30a in order to fix the dielectric element 30a in the outer terminal 40a (see FIGS. 1 and 2).

The outer terminal 40a is formed e.g. by bending an electrically conductive plate, and a front part thereof is an accommodating portion 41 preferably in the form of a substantially rectangular tube. In order to lock the aforementioned dielectric element 30a in a specified position in the accommodating portion 41, an elastically deformable locking portion 42 is so formed in the top wall of the outer terminal 40a as to project inward and obliquely backward and a contact piece 48 is cut in the bottom wall of the outer terminal 40a and bent inward at an angle different from 0° or 180°, preferably substantially at right angles. Further, the contact pieces 43 for elastically contacting the female shielded connector 10b are so formed in the right and left walls of the outer terminal 40a as to project inward and obliquely forward.

Behind the accommodating portion 41 is provided the covering portion 45 and is so constructed as to be substantially closed on three sides by the left, right and bottom walls. The covering portion 45 improves a shielding characteristic for the inner conductor 51 and the inner crimping portion 24 of the inner terminal 20a which are to be accommodated therein. This improvement in the shielding characteristic is described later. At the upper ends of the covering portion 45 are provided stabilizers 44 which project outward along the transverse direction of the outer terminal 40a (see FIG. 1). The stabilizers 44 are designed to prevent an upside-down insertion of the shielded connector 10a into an unillustrated connector housing to introduce the outer terminal 40a in a right direction and to substantially stably fix the shielded connector 10a in the connector housing. The stabilizers 44 also function to substantially lock an unillustrated retainer for securely locking the inserted shielded connector 10a in the connector housing.

Behind the covering portion 45 is provided an outer crimping portion 46 for fastening the outer conductor 52, preferably the folded portion 55 of the shielded cable 50. At least one pair of strip-shaped crimping pieces 47 substantially extend from the bottom of the outer crimping portion 46, are spaced apart wider from each other toward their leading ends, and preferably have such a length that they can substantially surround shielded cables of various diameters.

The shielded connector 10a is assembled as follows. First, the inner crimping portion 24 of the inner terminal 20a is fastened to the partly exposed inner conductor 51 before the inner terminal 20a is inserted into the outer terminal 40a.

Next, the dielectric element 30a is at least partly inserted into the accommodating portion 41 of the outer terminal 40a from front. Then, the touching piece 48 substantially comes into contact with the contact portion 33 and the locking portion 42 substantially slips into or is positioned in the locking recess 32, thereby substantially locking the dielectric element 30a in the specified position in the accommodating portion 41. Thereafter, when the inner terminal 20a connected with the inner conductor 51 is at least partly inserted into the accommodating hole 31 of the dielectric element 30a, the biting projections 23 bite into or engage the wall of the accommodating hole 31 to stably fix the inner terminal 20a (see FIG. 2).

Then, the shielded connector 10a is placed in an unillustrated crimper after the folded portion 55 is placed on the bottom of the outer crimping portion 46 of the outer terminal 40a. The outer crimping portion 46 is substantially tightly held between unillustrated crimping molds and are crimped or folded such that the crimping pieces 47 are brought into substantially close contact at least partly with the outer surface of the folded portion 55 with the end of one crimping piece 47 preferably placed on that of the other crimping piece 47. In this way, the male shielded connector 10a is assembled.

When the shielded connector 10a is assembled as shown in FIG. 2, the inner conductor 51 not covered by the outer conductor 52 and the inner crimping portion 24 of the inner terminal 20a fastened to the leading end of the inner conductor 51 are at least partly accommodated in or covered by the covering portion 45.

Since the inner conductor 51 behind the folded portion 55 is covered by the outer conductor 52 and a front part of the inner terminal 20a accommodated in the accommodating portion 41 is surrounded by the walls of the accommodating portion 41, they are both surrounded on their four sides by the conductive elements. Thus, there is no problem in shielding. It is most desirable in terms of shielding characteristic to similarly substantially cover or enclose the inner conductor 51 not covered by the outer conductor 52 and located before the folded portion 55 and a portion of the inner terminal 20a at and near the inner crimping portion 24 not covered by the accommodating portion 41 preferably on their four sides by the conductive elements.

However, in this embodiment, only the upper surface of the covering portion 45 is open and the remaining three surfaces are closed since the shielded connectors 10a, 10b are locked by locking portions when being accommodated in the unillustrated connector housing. Although a slight clearance is formed between the covering portion 45 and the outer crimping portion 46 in order to easily form the outer crimping portion 46, it is desirable to substantially close this clearance. In this embodiment, this clearance is made as narrow as possible while realizing the above purpose.

According to the thus constructed shielded connectors 10a, 10b of this embodiment, the inner conductor 51 not covered by the outer conductor 52 and the portion of the inner terminal 20a at and near the inner crimping portion 24 are substantially covered by the left, right and bottom (top wall in the case of the shielded connector 10b) walls (see FIGS. 2 and 3). Thus, shielding characteristic can be remarkably improved with respect to leftward, rightward and downward (upward in the case of the shielded connector 10b) directions. Further, shielding characteristic can be further improved by making the clearance between the covering portion 45 and the outer crimping portion 46 as narrow as possible.

In the shielded connectors 10a, 10b according to this embodiment, after being fastened to each other, the inner terminals 20a, 20b and the inner conductors 51 are at least partly accommodated in the outer terminals 40a, 40b, which are then fastened to the folded portions 55. Accordingly, the outer terminals 40a, 40b can be fastened by applying crimping in only one position. Thus, the crimping molds used to crimp the outer terminals 40a, 40b can be so constructed as to crimp only the outer crimping portion 46 without needing to be constructed in conformity with a plurality of crimping portions. Thus, the crimping molds are allowed to have a simple construction and the entire length of a portion of each mold corresponding to the outer crimping portion 46 can be made shorter. Further, since the outer terminals 40a, 40b are crimped only once, efficiency in crimping operation can be improved since the adjustment of a crimping force and confirmation as to whether or not fastening has been satisfactorily performed are made only for the single crimping portion 46.

FIGS. 4 and 5 show a state where the male and female shielded connectors 10a, 10b are connected with each other. In FIGS. 4 and 5, the shielded connectors 10a, 10b are connected with the open surfaces of their covering portions 45 facing in different directions.

The covering portions 45 of the shielded connectors 10a, 10b having an open surface, the intensity of a high frequency signal may slightly change due to its radiation to the outside via the open surface and/or noise may enter from the outside. If the open surfaces of the male and female connectors 10a, 10b are facing in the same direction, the signal radiates in the same direction and noise enters from the same side. This causes a variation in the high-frequency signal, which then causes a variation in the performance characteristic of the side surfaces of the connector, causing a problem.

By connecting the male and female shielded connectors 10a, 10b with their open surfaces faced in different directions, the radiation of the high-frequency signal and the intrusion of noise can be symmetrically balanced. Therefore, a performance reduction in a specific direction can be prevented when the high-frequency signal transmitting through the inner conductor 51 passes the shielded connectors 10a, 10b, with the result that shielding characteristic can be improved.

< Other Embodiments>

The present invention is not limited to the foregoing embodiments. For example, an embodiment as described below is also embraced by the technical scope of the present invention as defined in the claims. Besides the following embodiment, a variety of changes can be made without departing from the scope of the present invention as defined in the claims.

The covering portion 45 may be provided as a separate or as an integral or unitary part of the outer terminal 40.

LIST OF REFERENCE NUMERALS

10a, 10b...

Shielded Connector

20a, 20b...

Inner Terminal

30a, 30b...

Dielectric Element

40a, 40b...

Outer Terminal

46 ...

Outer Crimping Portion (Crimping Portion)

51 ...

Inner Conductor

52 ...

Outer Conductor

53 ...

Insulating Element

54 ...

Sheath