WO2008117132A1

WO2008117132A1 - Shielded connector

Info

Publication number: WO2008117132A1
Application number: PCT/IB2007/051438
Authority: WO
Inventors: Erwan Guillanton; Jacky Lebreton
Original assignee: Fci
Priority date: 2007-03-23
Filing date: 2007-03-23
Publication date: 2008-10-02

Abstract

The present invention relates to a connector (10) comprising a casing and a contact terminal carrier accommodated in said casing, the casing defining a passageway for receiving a shielded cable for connection to said terminal carrier. The connector is characterized in that said casing (20) is a shielded unitary construction having two casing portions movable relative to each other so as to bring the casing in a closed condition while forming said cable passageway, the casing comprising a shielding layer capable of contacting a cable shield .

Description

Shielded connector

Field of the invention

This invention generally relates to connectors assemblies, for instance for automotive applications and, more precisely, to a connector assembly having shielding protection.

Connectors are used to transmit power from a power source to an appropriate appliance and /or to interconnect signal transmission lines to printed circuit boards, other electronic devices or to other complementary connectors.

Background of the invention

Conventional connectors employ various types of shield structures or the like to protect against electrostatic discharges, and/or to protect against electromagnetic interference, and/or to provide ground or earth continuity.

In essence, an electromagnetic interference shield protects the electrical circuitry from externally generated radiated emissions as well as prevents electromagnetic interference from radiating outwardly of a connector.

Typically, known shield structures are provided by several sheet metal covers having complementary coupling means to form a shielded casing which conventionally surrounds and abuts against the housing members of the connector.

A traditional fully shielded connector solution uses also a metallic ferrule applied around the cable and which engages the cable shield. However, the shielded connectors as described above have the drawback of requiring a great number of parts, assembling steps and labour work, which makes it difficult to reduce the manufacturing costs.

Summary of the invention In consideration of the above-described problems, it is an object of the present invention to provide a shielded connector that has a smaller number of parts and is easier to assemble.

Accordingly, the present invention provides a connector comprising a casing and a terminal carrier accommodated in said casing, the casing defining a housing for the terminal carrier and a passageway for receiving a shielded cable for connection to said terminal carrier, said casing being a shielded integral construction having two casing portions movable relative to each other so as to bring the casing in a closed condition while forming said cable passageway, the casing comprising on its whole extent a shielding layer capable of contacting a cable shield.

According to a convenient and easy-to-manufacture construction, the casing comprises a main casing portion defining an inner chamber for said terminal carrier, an opening in communication with said chamber for allowing insertion of the terminal carrier, and a first cable retaining region, a secondary casing portion movable relative to the main casing portion via a hinge portion of reduced thickness and comprising a wall for at least partially closing said opening and a second cable retaining region.

So as to obtain good ground contact and shielding effect, said first and second cable retaining regions preferably have a generally semi-cylindrical shape so as to form together a ferrule closed around the cable, and still preferably at least one of said first and second cable retaining regions has at least one protrusion for contacting a cable shield.

The shielding performance and ground continuity are advantageously obtained with a casing made from an insulating material coated with at least one layer of conductive material, such as a copper/nickel dual layer or a copper/tin layer, so as to decrease electrical resistance, preferably arranged so as to provide electrical continuity between the inside of the cable passageway and at least one protrusion on its external surface for securing electrical contact with the shielding of a complementary connector.

The connector according to the present invention provides a shielded connector free from the additional metal parts to carry out the shielding and saving up pieces compared to traditional shielding solutions.

Thanks to the invention, one may also improve the shielding of a connector by suppressing clearance between its different parts and/or provide a shielded connector with which the manufacturing cost and time can be reduced and/or provide a more efficient and easier-to-assemble shielded connector.

Other embodiments of the invention correspond to the features of claims 2 to 15 considered either separately or in combination Brief description of the drawings

Other aims, features and advantages of the invention will be apparent from the following detailed description, taken in connection with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which :

- Figure 1 is a perspective view of a connector installed on one end of a cable, the connector incorporating the concepts of the invention;

- Figure 2 is an exploded perspective view of the components of the connector to be installed on one end of a cable; - Figures 3a and 3b are respectively a perspective view of the connection of an end of a cable with a terminal carrier and a lateral view of said terminal carrier; and

- Figure 4 is a perspective view of the connector of figure 1 showing the shielding continuity contact areas of the connector for contact with an external complementary connector.

Detailed description of a preferred embodiment

Referring to the drawings and initially to figure 1, there is shown a perspective view of a connector and cable assembly according to the present invention.

The connector 10 is shown to include a casing, globally depicted as 20, provided with a first part for engagement with an end of a cable 30 along a first axis and a second part in which a terminal carrier 40 is inserted for connecting the cable leads along a second axis. Hereinafter, the first axis for the engagement of the cable 30 with the casing 20 will be referred to as the "engaging axis" as indicated by axis C-C in figure 1, and corresponds to the longitudinal axis of the end of cable 30.

In addition, the second axis will be referred to as the "mating axis" as indicated by axis X-X in figure 1, and corresponds to the axis along which the cable leads are connected to the terminal carrier 40.

Of course, in a variant embodiment of the present invention, axes C-C and X-X can have different mutual orientations, and in particular can be parallel to each other or aligned.

According to the present invention, the casing 20 is configured as a one- piece component i.e. has a unitary construction. As shown in figure 2, the casing 20 is a generally L-shaped rigid part having a main casing portion 200 and a secondary, moveable casing portion 300 articulated by an intermediate hinge flap 330 made of a region of a reduced thickness to the main casing portion 200. Said secondary casing portion 300, when it is engaged with the main casing portion 200, acts as a cap for maintaining the casing 20 in a close, shielded condition.

The shielding effect is obtained by the main casing portion 200 and the secondary casing portion 300 being electrically conductive. This conductivity can result either from the selection of an appropriate casing material having inherent conductivity (such as a charged thermoplastic material) or by providing the casing with a metallic coating, as described further below.

The L-shape of the main casing portion 200 defines a leading limb 210 extending along the mating axis and a cable retaining limb 220 extending along the engaging axis.

The main casing portion 200 defines an inner chamber 230 opening to the outside along the whole length of the concave or inner side of the L-shape.

In particular, an opening 240 extends over the length of the main casing portion 200 to allow the insertion therethrough of the terminal carrier 40 and of the end of the cable 30 connected thereto.

Opening 240 comprises first 241 and second 242 opening regions through which respectively the cable 30 and the terminal carrier 40 can be engaged, and an intermediate opening region 243 extending between the first and second opening regions 241, 242. The leading limb 210 of the main casing portion 200 is adapted to accommodate the terminal carrier 40 and the cable retaining limb 220 is adapted to partly accommodate and support the end of cable 30.

In the present species and as shown in particular in figure 2, the leading limb 210 defines, a substantially parallelepiped-shaped housing for the terminal carrier 40.

The leading limb 210 is a casing portion having a substantially square C- shape in cross-section. This portion is formed integrally with a pair of long sidewalls 211 and 212 facing each other and extending along the mating axis, and has a hollow front end 213 extending in a plane generally perpendicular to said axis and having a central opening 214 to the outside. Said opening 214 is arranged to allow the terminal carrier 40 to receive electrical contact pins carried by an external, complementary connector (not shown).

The cable retaining limb 220 has the shape of a semi-cylindrical extension whose axis defines the above-mentioned C-C axis.

As mentioned above, the secondary casing portion 300 is attached onto the cable retaining limb 220 of the main casing portion 200 by the hinge flap 330 extending radially to axis C-C and defining a flexible hinge. The secondary casing portion includes a generally semi-cylindrical cable retaining region 320 adjacent to said hinge flap 330 and a generally flat region 340 extending in a plane perpendicular to the axis of the semi-cylindrical region, as will be described in greater detail below.

As shown in figure 1, when the moveable secondary casing portion 300 is closed towards said main casing portion 200 as allowed by the hinge, a passageway 350 for cable 30 is jointly defined by regions 220, 320 of said main and secondary casing portions 200 and 300, while the intermediate opening region 243 of main casing portion 200 is covered by flat region 340 of secondary casing portion 300.

By partially closing the opening 240 of the inner chamber 230, the secondary casing portion 300 ensures that the terminal carrier 40 and the end of the cable 30 are retained at their respective location.

More specifically, the casing 20 forms an integral crimpable ferrule 60 which surrounds the cable 30: the cable retaining region 320 of the secondary casing portion 300 is adapted, when brought into engagement with the semi- cylindrical limb 220 of the main casing portion 200, to form at their inner faces 321, 221, respectively, this ferrule 60 which fully surrounds the end of the cable 30.

It should be noted that the internal diameters of the cable retaining regions 320 and 220 are preferably equal to each other and close to the external diameter of the cable. However, in order to properly catch the cable, at least one of these regions does not extend through 180°, but through a smaller angle span.

This feature, in addition to the possibility of a variable clearance between these two portions, as permitted by the deformable hinge flap 330, allows the connector 10 to be mounted on cables having slightly different diameters with a good cable contact in each case.

The above-described integral ferrule 60 receives the cable 30 in the manner described below. The cable 30, as shown in figure 3, comprises a plurality of insulated leads 32 which are bundled so that the cable 30 has a substantially circular cross-section. The bundled leads 32 are surrounded by a film or sheath 31 to provide continuous shielding along the length of the cable 30.

This film 31, which can be made of polyester or other suitable material, is metallized.

In another embodiment, the cable can incorporate a double shielding, with a metallic braid and a metallized plastic film, both surrounding the lead bundle. The braid ensures the low resistivity necessary for the ground connection of the cable 30 and for shielding low frequency electromagnetic radiation, while the metallized plastic film provides shielding of high frequency electromagnetic radiation.

The cable 30 extends inside the integral ferrule 60, which is adapted to be compressed or crimped onto the cable shield. Such crimping effect may be strengthened by the presence of ribs 222, 322 extending axially on the inner faces of the cable retaining limb 220 and of the semi-cylindrical region 320 of secondary casing portion 300. To this end, the insulating sheath is removed in the end portion of the cable corresponding to the ribs 222, 322 so as to give access to the shield.

These ribs 222, 322 firmly engage the cable shield 31 and secure the electrical continuity between the cable shield and the connector casing 20.

Thus the integral ferrule 60 provides good cable retention and good electrical continuity and therefore good shield continuity between the cable shield 31 and the shielded casing 20.

Locking means 50 such as a tightenable plastic collar maintains engagement between the main and the secondary casing portions 200 and 300 and prevents the relative movement therebetween. Alternatively locking means may consist of complementary latches made of unitary construction relatively with casing portions 200,300. Advantageously, the locking member 50 is placed around ferrule 60 after the secondary casing portion 300 has been closed against main casing portion 200 and is tightened so as to exert a compression force thereon.

The inside diameter of ferrule 60 is only slightly smaller than the cable diameter before compression, so as to avoid that the cable shield 31 is perforated by the ferrule 60 during tightening.

As already mentioned, the flat region 340 of the secondary casing portion 300 is adapted to partially close the intermediate opening 240 of the main casing portion 200 along the mating axis, in order to prevent the withdrawal of the terminal carrier 40 from its housing.

This flat region 340 extends substantially parallel to the mating axis X-X and cooperates with the major sidewalls 211 and 212 of the main casing portion 200. These sidewalls 211 and 212 define on their free edges 218 and 219 corresponding recesses 215 and 216 of different lengths extending along the mating axis that are adapted to receive corresponding lateral ledges 343, 344 of the flat region 340.

The latter can take the form of a rectangular plate 342 provided with a shoulder 341 along one (343) of its lateral ledges.

When the secondary casing portion 300 is closed against the main casing portion 200, the two longitudinal side ledges 343 and 344 engage the respective recesses 215 and 216 of the main casing portion 200. The shoulder

341 comes in abutment with a corresponding shoulder which delimits recess

216, so as to ensure that the flat region 340 reaches the correct position.

Once the secondary casing portion 300 is closed, the flat region 340 forms a wall extending between the sidewalls 211 and 212, perpendicularly thereto.

The terminal carrier 40 is made of an electrically insulating material and comprises a substantially parallelepiped-shaped body 400 having a front face 401 and an opposite rear face 402 connected by two respectively major lateral faces 403, 404 and two minor lateral faces 405, 406. The terminal carrier 40 is first inserted into the chamber 230 via the second opening region 242. In this regard, and as shown in figure 2, a pair of elongated protrusions or ribs 217 are formed on the inner faces of the sidewalls 211, 212, extend along the insertion axis of the terminal carrier and cooperate with shoulders 430 formed on the walls 403, 404 of the terminal carrier 40 to act as guiding members during the insertion of terminal carrier 40 into chamber 230. After insertion, their act as retainers preventing the terminal carrier to move inside chamber 230.

In the exemplary embodiment shown in the figures, and in a conventional manner, the terminal carrier 40 has one or several rows 420 of contacts (not shown) arranged in respective cavities 421 having a generally square cross- section and extending parallel to one another in the mating direction X-X.

In order to connect the cable 30, the shielding film 31 is removed from the end of the cable 30 so that the leads 32 can be attached, usually by crimping, to the terminals, which ones are afterwards inserted through rear face 402 into the terminal carrier. The terminal carrier 40 includes clamping members 440 for maintaining the terminals into the terminal carrier.

As shown in figures 3a and 3b, these clamping members 440 may include a pair of movable locking wings 441 provided on the outer faces of major sidewalls 403 and 404 of the terminal carrier 40. Once the terminal carrier 40 together with the cable end to which connection has previously been made, is inserted in main casing chamber 230, the front wall 401 of the terminal carrier registers with the front end opening 214, so that electrical contact pins of an external complementary connector can be connected. The cable is attached to the terminal carrier 40 before the latter is inserted as described in the foregoing, together with the cable end attached thereto, inside the main casing portion 200.

According to the present invention, the connector casing 20 is a self- shielded one-piece component ensuring the essential shielding functions expected from such casing.

A first function is to provide the shielding electrical continuity between the electric ground of the cable 30 and the ground of a circuitry or other cable to which the connector is to be connected. This is achieved by the integral ferrule 60, and in a preferred embodiment by the ribs 222, 322 protruding at the inner faces of the cable receiving portions 220, 320 and providing a good electrical contact between the cable shield 31 and the casing 20.

The electrical continuity between the casing 20 and the casing of the external complementary connector, for instance a pin header (shown in figure 4) to which the connector is to be connected may be achieved by means of several shield continuity contact regions 250, 260 as illustrated in figure 4. A first shield continuity contact region 250 is provided on the outer face of at least one of the major sidewalls 211 and 212 of main casing portion 200. It comprises in the present example two protruding ramps 251, 252 on either side of a central locking protrusion 253. A second shield continuity contact region is provided on the outer face of limb 210. It comprises in the present example a protrusion 263. Those protrusions 251, 252, 263 are adapted to create a contact pressure with a shielding surface of the complementary connector.

Shielding continuity contact arrangements 322 are also provided as described above on the cable engaging region 320 of the secondary casing portion 300. All these contact regions are provided with a highly conductive coating, while being in electrical contact with each other.

The second shielding function is to constitute a barrier against low and high frequencies electromagnetic radiation, whether radiating from the connector or towards the connector. This is achieved by providing a continuous conductive layer on a great extent of the surface of the casing, especially on the outer surface, and preferentially the full extent of the casing. For this purpose, the main and secondary casing portions 200 and 300 are made of a plastic material coated by metallization, for instance by a conventional electroplating method.

However, in a preferred embodiment of the present invention, the metallization process is the one disclosed in WO 03/104526.

According to this known technique, the main and secondary casing portions 200 and 300 may be made, for example, by injection moulding with thermoplastic material such as polyamide or PBT (polybuthyleneterephthalate) and then full-face plating with at least one metal layer. Metals are preferably selected from the group comprising copper, nickel and tin.

For instance, a first layer or cooper is plated, and then covered by an outer tin layer. Alternatively, nickel may be used instead of tin for the outer layer. Copper has the advantage of a better electrical conductivity and tin or nickel have the advantage of a better corrosion resistance.

As mentioned above, the connector of the present invention has the advantage of decreasing the number of parts and assembly steps of its construction to a minimum, while allowing an excellent inherent shielding effect. Although the present invention has been be described with reference to the embodiments shown in the drawings, it should be understood that it can be embodied in numerous alternative forms.

Claims

1. A connector (10) comprising a casing (20) and a terminal carrier (40) accommodated in said casing, the casing defining a housing (230) for the terminal carrier and a passageway (350) for receiving a shielded cable for connection to said terminal carrier, characterized in that said casing (20) is a shielded unitary construction having two casing portions (200, 300) movable relative to each other so as to bring the casing in a closed condition while forming said cable passageway.

2. A connector according to claim 1, wherein the casing (20) comprises a shielding layer capable of contacting a cable shield.

3. A connector according to claim 1 or 2, wherein the casing (20) comprises a main casing portion (200) defining an inner chamber (230) for said terminal carrier, an opening (240) in communication with said chamber for allowing insertion of the terminal carrier, and a first cable retaining region (220).

4. A connector according to claim 3, wherein the casing (20) further comprises a secondary casing portion (300) movable relative to the main casing portion and comprising a wall (340) for at least partially closing said opening and a second cable retaining region (320).

5. A connector (10) comprising a casing (20) and a terminal carrier (40) accommodated in said casing, the casing defining a passageway (350) for receiving a shielded cable for connection to said terminal carrier, characterized said casing (20) is a shielded unitary construction having a main casing portion (200) defining an inner chamber (230) for said terminal carrier, an opening (240) in communication with said chamber for allowing insertion of the terminal carrier, and a first cable retaining region (220), and a secondary casing portion (300) comprising a wall (340) for at least partially closing said opening and a second cable retaining region (320), the main and secondary casing portions being movable relative to each other so as to bring the casing in a closed condition while forming said cable passageway, and the casing comprising a shielding layer capable of contacting a cable shield.

6. A connector according to claim 4 or5, wherein the secondary casing portion (300) is hinged to the main casing portion (200) via a hinge portion (330) of reduced thickness.

7. A connector according any one of claims 4 to 6, wherein said first and second cable retaining regions (220, 320) have a generally semi-cylindrical shape so as to form together a ferrule (60) adapted to be closed around the cable (30).

8. A connector according to claim 7, wherein at least one of said first and second cable retaining regions (220, 320) has at least one protrusion (222, 322) for contacting a cable shield.

9. A connector according to any one of claims 7 and 8, further comprising a tightenable collar (50) arranged around said ferrule.

10. A connector according to any one of claims 1 to 9, wherein the main casing portion (200) defines two limbs (210, 220) at an angle relative to each other, comprising a first limb (210) for abutment of said contact terminal carrier and a second limb (220) defining the first cable retaining region.

11. A connector according to any one of claims 1 tolO, wherein a layer of conductive material extends with electrical continuity over all external surfaces of said casing as well as on the internal surface of the cable passageway.

12. A connector (10) comprising a casing (20) and a terminal carrier (40) accommodated in said casing, the casing defining a passageway (350) for receiving a shielded cable for connection to said terminal carrier, characterized said casing (20) is a shielded unitary construction having a main casing portion (200) defining an inner chamber (230) for said terminal carrier, an opening (240) in communication with said chamber for allowing insertion of the terminal carrier, and a first cable retaining region (220), as well as two limbs (210, 220) at an angle relative to each other, comprising a first limb (210) for abutment of said terminal carrier and a second limb (220) defining said second cable retaining region, and a secondary casing portion (300) comprising a wall (340) for at least partially closing said opening (240) and a second cable retaining region (320), the secondary casing portion being hinged to the main casing portion via a hinge portion (330) of reduced thickness so as to bring the casing in a closed condition while forming said cable passageway, the first and second cable retaining regions (220, 320) have a generally semi-cylindrical shape so as to form together when the two casing portions are closed together a cable ferrule (60), and the casing being made from an insulating material coated with at least one shielding layer of conductive material.

13. A connector according to claim 12, wherein at least one of said first and second cable retaining regions has at least one protrusion (222, 322) for contacting a cable shield.

14. A connector according to any one of claims 12and 13, further comprising a tightenable collar (50) arranged around said ferrule.

15. A connector according to any one of claims 12 to 14, wherein the layer of conductive material extends with electrical continuity over all external surfaces of said casing as well as on the internal surface of the cable passageway.