The invention relates to a cable connector assembly comprising a cable connector with metallic cover shells and a cable, said cable comprising a shielding braid in electrical connection with at least one of said metallic cover shells.
U.S. Pat. No. 5,511,993 discloses a cable connector assembly comprising a cable connector and a cable. The cable has a cable jacket and a shielding braid folded back over the cable jacket and clamped by cover shells of the cable connector. The connector assembly can be assembled and disassembled easily by dismounting the cover shells, where after the cable can be modified and assembled into the cable connector.
A disadvantage of such a cable connector is that it has a poor strain relief and electromagnetic shielding performance.
It is an object of the present invention to provide a cable connector with an improved mechanical and electromagnetic shielding performance.
This object is achieved by providing a cable connector assembly characterized in that a portion of said shielding braid is folded back over a support member provided for said cable to clamp said portion of said shielding braid between said support member and at least one of said metallic cover shells in a clamping portion of said cable connector.
Consequently, the back folded portion of the shielding braid has a solid support at the side of the cable, i.e. the clamped shielding braid cannot penetrate into the cable when mounting the metallic cover shells to each other and clamping the shielding braid in the clamping section. Therefore, the cable connector assembly according to the invention has an improved performance. Strain relief is improved as this configuration prevents the clamped shielding braid to slip out of the cable connector; for detachment, the shielding braid must break which may only occur after exposing the braid to extreme forces. Electromagnetic shielding performance is improved as well as a higher probability of a sufficient electrical connec-higher probability of a sufficient electrical connection between the shielding braid and the metallic cover shells.
It should be appreciated that clamping between said metallic cover shells and said support member does not necessarily involve a physical contact between the back folded shielding braid and the metallic cover shell and/or the support member. Intermediate components or layers, preferably electrically conductive, may be present. As an example, separate inserted electrically conductive clamping members, as further described below, may be present between the back folded shielding braid and the metallic cover shells.
It is further noted that there are at least two advantageous embodiments of providing the support member for the cable. In a first arrangement, the support member is disposed on a cable jacket of the cable such that the support member is sandwiched between the portion of the back folded shielding braid and the cable jacket. In a second arrangement, the support member is disposed on the shielding braid such that the support member is sandwiched between the back folded portion of the shielding braid and the shielding braid itself. In the latter arrangement, a more compact assembly is obtained. It should be appreciated that the cable may have additional layers that may be present between the support member and the back folded portion of the shielding braid.
In a preferred embodiment of the invention, the support member is in a state slidably attached to and in an axial direction of said cable before mounting said metallic cover shells to clamp said shielding braid. In the art, a support member is typically crimped on the cable. Accordingly, if the length to which one or more cable wires are cut or assembly is inadequate, the cable has to be cut in its entirety and all wire terminations have to be made again. By having a support member that is not crimped on the cable jacket, but is slidable instead, some play is available for assembling or re-assembling the cable in the cable connector. On dismounting the cover shells and sliding the non-crimped support member in an axial direction of the cable, this play may avoid the need to make all wire terminations over again. Furthermore, preventing the crimping operation results in a shorter assembling time for cable to the cable connector.
In an embodiment of the invention, the metallic cover shells are adapted to comprise or accommodate one or more inserted clamping elements for said clamping portion. These inserted clamping elements allow the invention to be applied in or in combination with existing and approved components, such as the metallic cover shells. The clamping elements can be easily manufactured. If a cable of different dimensions should be terminated in the cable connector, only the inserted clamping elements may be adapted to the new cable.
In an embodiment of the invention, the clamping portion is formed by a first clamping element associated with a first metallic cover shell and a second clamping element associated with a second metallic cover shell and the first clamping element and said second clamping element are arranged to leave a gap between a first surface of said first clamping element and a second surface of said second element when said first and second metallic cover shells are closed. The gap between the clamping elements provides space for loose wires of the shielding braid on mounting the metallic cover shells, thereby preventing these loose wires to mechanically obstruct mounting the cover shells to each other to complete the cable connector.
In an embodiment of the invention, the cable connector comprises a cable entry for said cable and a closing structure near said cable entry. This closing structure or labyrinth closes the optical path near the cable entry and hence increases the electromagnetic shielding performance of the cable connector. This closing is especially preferred when the clamping elements have a gap in between.
In an embodiment of the invention, the cable connector comprises interference ribs for said shielding braid. These interference ribs may be present in the clamping portion of the cable connector and are adapted to cooperate with the shielding braid to enhance the electromagnetic shielding performance of the assembly. Further, the cable connector may comprise interference ribs adapted to cooperate with the cable jacket in the cable entry to enhance the mechanical performance of the cable connector assembly.
In an embodiment of the invention, the support member comprises a flange portion and the cable connector comprises a receiving structure adapted to cooperate with said flange portion. Accordingly, the support member can be easily positioned in the cable connector which facilitates the assembly of the cable connector. The flange portion may be shaped to provide clear guidance for an operator how to combine the individual parts of the cable connector to complete the assembly. Further, the flange portion and corresponding receiving structure in the cable connector contribute to the strain relief performance of the assembly. If the flange portion is non-circular, twist relief is obtained for the assembly as well when the metallic cover shells are closed. Further, the flange portion contributes to the electromagnetic shielding performance.
It is noted that the flange of the support member and the corresponding receiving structure of the cable connector may have any suitable shape. In an embodiment of the invention, the flange portion is provided only partially around the support member. Although for electromagnetic shielding performance, the optimal situation is to have an all around flange, the flange may hinder dimension changes due to temperature effects of the support member. As the cable connector assembly is usually exposed to conditions wherein the temperature may vary considerably, the dimensions of the components of the cable connector vary accordingly. A partial flange for the support member allows the support member to better adapt to a change in dimensions of the metallic cover shells or the clamping elements thereof as a result of temperature variations so as to ensure that the shielding braid remains clamped in the clamping portion.
In a preferred embodiment of the invention, the support member comprises at least two parts. A multi-part support member allows to first connect the wires of the cable to the terminal block housings before arranging the support member on the cable and mounting the cable in the cover shells. Accordingly, more space is available for connection of the wires, thereby facilitating the assembly of the cable connector. Preferable, the cable connector, e.g. the cable entry, has an inner structure adapted to cooperate with corresponding structures of said support member parts, thereby enhancing the mechanical performance of the cable connector assembly of the invention.
It should be appreciated that the above embodiments, or aspects thereof, may be combined.
The invention further relates to a cable connector comprising metallic cover shells with inserted clamping members accommodated within said metallic cover shells adapted to clamp a shielding braid portion of said cable. These inserted clamping elements allow the invention to be applied in or in combination with existing and approved components, such as the metallic cover shells. The clamping elements can be easily manufactured. If a cable of different dimensions should be terminated in the cable connector, the inserted clamping elements can be adapted to the new cable. The clamping elements are preferably shaped or arranged to perform one or more the functions described above for the assembly.
The invention moreover relates to a method for assembling a cable to a cable connector comprising metallic cover shells and a wire termination member, said cable comprising a shielding braid and one or more cable wires, the method comprising the steps of:
This method results in a cable connector assembly with improved mechanical and electromagnetic shielding characteristics.
In an embodiment of the invention, the support member is left slidably in an axial direction of said cable before closing said metallic cover shells. The thus obtained cable connector assembly has improved assembling characteristics as explained above.
In a particularly advantageous embodiment of the invention, the support member comprises at least two parts and said method comprises the step of connecting said wires to said terminal block housing before arranging said parts on said cable jacket. The multipart nature of the support member allows this sequence of assembly wherein more space is available for an operator to terminate the wires of the cable in the cable connector.
The invention will be further illustrated with reference to the attached drawings, which schematically show preferred embodiments according to the invention. It will be understood that the invention is not in any way restricted to these specific and preferred embodiments.
In the drawings:
A gap G, indicated by the dashed lines in
Finally, the cable connector 2 has a plurality of retention springs 10 to connect the cable connector 2 to a counterpart and to provide electrical contact with this counterpart to ensure electromagnetic shielding.
The first metallic cover shell 4 comprises a boundary surface 11 comprising holes 12 for accommodating the screws 6. The boundary surface 11 abuts with a corresponding surface (not shown) of the second metallic cover shell 5 when the cable connector assembly 1 is completed as shown in
The first metallic cover shell 4 has an interior structure to accommodate the inserted first clamping element 8. The clamping element 8, that may either be a separate electrically conductive component or an integral part of the cover shell 4 as mentioned above, comprises a semi-circular recess with interference ribs 14. The clamping element 8 further comprises a portion of a receiving structure or slot 15, a portion of a closing structure or labyrinth 16A, 16B and a half 7A of the cable entry 7. The complementary clamping element 9 has an identical structure to complete the clamping portion of the cable connector 2, the receiving structure or slot 15, the closing structure or labyrinth 16A, 16B, and the cable entry 7. The cable entry 7 comprises interference ribs 17 to cooperate with the cable jacket of the cable 3, i.e. the cable jacket digs between the interference ribs 17 when the cable 3 is pulled, thereby preventing the cable jacket from popping out of the cable connector during bending of the cable 3.
The first clamping element 8 further has a first surface 18 that is located beneath the boundary surface 11 of the first metallic cover shell 4. This first surface 18 is indicated by the lower dashed line in
A closure structure or labyrinth is provided to optically close the gap G of the clamping portion near the cable entrance 7 at the back side of the cable connector 2 to maintain the electromagnetic shielding for the cable connector assembly 1. In this embodiment, the portions of the labyrinth 16A, 16B of the clamping elements 8, 9 are such that on one side of the cable entrance 7, the portion 16A extends beyond the surface 18 while on the other side of the cable entrance 7 the portion 16B is beneath the surface 18 of the clamping element 8. It should be appreciated that alternatively each metallic cover shell 4,5 may have a shielding plate (not shown) with an opening for the cable entrance 7 instead of the labyrinth 16A, 16B of the clamping elements 8, 9. Finally it is noted that an additional labyrinth is formed by the structures 19 cooperating with the side walls of the metallic cover shields 4,5. In the embodiments wherein the clamping portion is formed of separate clamping elements 8,9 instead of integrated elements, these structures 19 can be used to position the clamping elements 8,9 as well.
The cable 3 is provided with a support member 33, commonly referred to as ferrule. This ferrule 33 is provided over the cable jacket 30 and afterwards the shielding braid 31 is folded back over the cable jacket 30. In an embodiment of the invention, it is essential that the ferrule 33 is a non-crimped ferrule 33, i.e. the ferrule 33 is slidably attached to the cable 3 since it can be moved in an axial direction A of the cable 3. Further, an outer ferrule is not required.
The ferrule 33 may have a flange 34, as shown in
Preferably, the ferrule 33 is made of metal.
The ferrule 33 is arranged on the shielding braid 31 of the cable 3 until the ferrule 33 meets the cable jacket 30. The shielding braid is subsequently folded back over the ferrule 33 such that the ferrule is sandwiched between the back folded portion of the shielding braid 31 and the shielding braid 31 itself as depicted in
For all embodiments of the cable 3, the shielding braid 31 is preferably back folded over the ferrule 33 all around the perimeter of the ferrule 33. As the cable jacket 30 generally provides a leak for electromagnetic radiation, the presence of the back folded shielding braid 31 over the entire perimeter of the ferrule 33 contributes to closing this leak. The same is true for the configuration wherein the ferrule 33 is arranged on the shielding braid 31 as depicted in
In
The flange portion 34 is positioned in the slot 15. The flange portion 34 is non-circular, such that the flange 34 provides twist relief for the cable connector assembly 1. Further, the flange 34, together with the labyrinth 16A, 16B provides a closed optical path at the back end of the cable connector 2, thereby increasing the electromagnetic shielding performance. The cable wires 32 (only one of which is shown) are subsequently connected to the wire termination members 13.
In
The cable connector assembly 1 can be assembled and disassembled easily as by dismounting the cover shells 4,5 and moving the slidable support member 33 when the cable wires 32 are modified in length.
The cable connector 2 has two metallic cover shells 4,5 that define a cable entry 7 for the cable 3. The cable entry 7 is an integral part of the metallic cover shells 4,5. The cable entry 7 has recesses 60 that will be discussed in further detail below. The cable entry 7 further comprises interference ribs 17. The cover shells 4, 5 comprise structures 61 for accommodating fastening means 62 to connect the cable connector assembly to a counterpart.
More particularly, the support member part 33A has a semi-circular or C-shape and comprises connection structures 70, 71 to connect the support member part 33A with an identical counterpart to complete the support member 33. Further, the support member part 33A has a protrusion 72, extending away from the outer surface 73 of the part 33A. The protrusion 72 is adapted to be inserted in the recesses 60 of the cable entry 7 of the metallic cover shells 4 and 5. The protrusion 72 is preferably provided near the back part of the cable connector 2 in order to not interfere with the initial part of the back folded shielding braid 31.
The outer surface 73 of the support member part 33A has a structure 74 profiled to cooperate with the interference ribs 17 in the cable entry 7. Finally, the support member part 33A has an internal rib 75 to interfere with the cable 3, more particularly the cable jacket 30, to improve cable bend relief.
By integrating as much as features as possible in the support member 33, the other components of the cable connector 2 do not have to be modified for terminating another cable 3. In such as case, only the more easily assembled support member 33 or parts 33A should be modified.
In
Completion of the support member 33 does not require dedicated tools. Accordingly, the cable connector 2 can be installed or repaired in the field by dismounting the metallic cover shells 4,5.
Finally, the metallic cover shell 5 is mounted to the metallic cover shell 4, thereby clamping the back folded portion of the shielding braid 31 between the metallic cover shells 4,5 and the two-part support member 33. The cable connector assembly of
A particular advantage of using a support member 33 comprising of several parts 33A is that the support member 33 can be arranged on the cable 3 after termination of the cable at the termination block housings 13. Accordingly, more space is available for termination of the wires 32.
It should be noted that the two embodiments of the cable connector assembly described above do not limit the invention; further modifications of the assembly 1, such as providing the parts 33A of the support member 33 with a flange or arranging a gap G in the cable connector 2 of
Number | Date | Country | Kind |
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1026698 | Jul 2004 | NL | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2005/007490 | 7/11/2005 | WO | 00 | 1/14/2008 |