Patent Application
20100285688
The present invention relates to the field of connectors, in particular electrical cable connectors.
In the field of connectors, in particular cable connectors, it is known to use a cable clamp, clamping the cable to the connector housing, for strain relief. Generally, the cable clamp is screwed to the housing. This requires screws, thus additional separate parts, and the screwing complicates assembly of the connector.
The connector housing and/or the cable clamp generally are formed providing an opening optimized for receiving a cable of a particular outer diameter and compressibility. Such connectors are not well suited for accommodating a cable of a different diameter and/or compressibility.
If the opening for the cable is small, portions of the cable may be pinched or crushed, which affects its transmissive and/or structural properties. This is in particular the case for cables for signal transmission, especially high speed signal transmission, and for multi-wire cables. Conversely, a large cable opening may allow slipping of the cable with respect to the housing, possibly affecting or compromising connections of and/or to the cable inside the housing. Thus, connectors having a cable clamp may have limited usefulness for many purposes. As a result, stocking and/or selling various sizes and types of connector housings and/or cable clamps for suitably clamping different cables is required. This substantially increases costs.
Therefore, a need exists for an improved cable connector reducing or alleviating the above-referenced problems.
An object of the present invention is to provide a cable clamp that can be used for different cable diameters. This object is achieved with a cable connector comprising a connector housing with an opening for receiving a cable, and a cable clamp mounted to the connector housing wherein the clamp comprises an intermediate section between two or more mounting portions, at least one of the mounting portions comprising locking means for interlocking with one of at least two cooperative locking means of the housing. When the cable clamp is put in place in the housing, one of the two or more present locking means in the housing can be selected, depending on the type of cable to be clamped. This way, the position of the cable clamp can selectively be adjusted between at least two alternative clamping positions so it can be used for more than one cable diameter.
Optionally, the housing comprises at least two slots, each being dimensioned to interlock a locking means formed by a matching extension of the cable clamp. Alternatively, the clamp can be provided with one or more slots dimensioned to cooperate with one or more matching interlocking means, such as hooks or projections, of the housing.
With only one slot of the two or more slots being used, the slots which have not been brought into engagement with the matching cable clamp extension, can for example be covered by a foil of electromagnetic shielding material. This prevents that the unused slot or slots forms a leak in the electromagnetic shielding. Alternatively, the slots can be replaced by blind holes.
The cable clamp extension forming the locking means comprise for example a hook.
To improve the grip of the cable clamp on the cable jacket, the intermediate portion of the cable clamp may be provided with one or more piercing teeth, e.g., piercing into the cable jacket. Optionally, the teeth may penetrate through the braid that has been folded back on the isolating jacket or sheath at the end of the cable, so as to bite into the isolating sheath so as to improve EMI shielding.
The intermediate portion can be provided with a flange bridging the gap between the intermediate portion and the adjacent edge of the cable receiving opening. The flange can be made of an electromagnetic shielding material.
In an alternative embodiment the intermediate cable clamp portion is provided with resilient teeth alternately folded in opposite directions. In use, the teeth resiliently clamp against the cable jacket. Such an arrangement of resilient teeth can effectively reduce freedom of forward movement of the clamped cable as well as backward movement.
In a further alternative embodiment, the intermediate section comprises at least two curved sections of different curving diameter. This way, the clamp can be used for stiffer cables having a diameter corresponding to one of the curved sections, and it can also be used for cables of larger diameter with higher compressibility.
An object of the invention is also achieved with a cable connector comprising a connector housing with an opening for receiving a cable, and a cable clamp mounted to the connector housing wherein the cable clamp comprises an intermediate section between two or more mounting portions, wherein the intermediate cable clamp portion is provided with resilient teeth alternately folded in opposite directions to resiliently clamp against the cable jacket. Optionally, the intermediate portion of the cable clamp is provided with a series of outwardly bent shielding teeth, to cover the gap between the intermediate portion and the interior edge or wall of the cable opening and to complete the electromagnetic shielding. These teeth may have rounded end parts, e.g., be mushroom shaped, to maximize coverage of the gap between the cable clamp and the cable opening.
The housing 2 is made of two matching casing sections 4, 5 both comprising a semi-circular collar section 6, 7 together forming a cylindrical collar 8 when both casing sections 4, 5 are joined together to form the housing 2.
The cable clamp 3 comprises a first mounting portion 11, a second mounting portion 12 aligned with respect to the first mounting portion, and a curved intermediate portion 13. The first mounting portion 11 has a rounded end and comprises an opening 14 allowing passage of a fixation screw, as shown in
The second mounting portion 12 forms a locking means provided with a slanting top edge 15.
The curved intermediate portion 13 has a concave side provided with five evenly distributed triangular teeth 16. On its convex side, the clamp 3 is provided with a collar or flange 17. To facilitate bending the flange 17, openings or slots 18 are provided on the folding line 19 of the flange 17.
The clamp 3 and the housing 2 are made of an electromagnetic shielding material.
The top side of the housing 2 is provided with locking means formed by slots 20, 21, both dimensioned to receive locking means 12 of the cable clamp 3. When the locking portion 12 is put into the first slot 20, the clamp leaves open a larger opening for passage of a cable than if portion 12 is put into the second slot 21. As a result, cables of different diameter can be clamped using the same cable clamp 3. If a smaller diameter cable is used, the cable clamp portion 12 is brought into engagement with slot 21. In that position, flange 17 covers the gap between the curved clamp portion 13 and the housing wall surrounding cable opening 9. Flange 17 can be made of an electro conductive material. The interior wall of the housing facing the flange 17 can be provided with projections or teeth contacting flange 17. This way, flange 17 completes the electromagnetic shielding of the connectors interior.
When a cable is clamped in the opening 9 by clamp 3, the triangular teeth 16 pierce into the cable jacket to give improved fixation of the cable. Optionally, the teeth penetrate through the braid that has been folded back on the isolating jacket or sheath at the end of the cable, so as to bite into the isolating sheath so as to improve EMI shielding. Alternatively, the teeth penetrate through the isolating sheath to such extent that it contacts the underlying conductive shielding braid.
Slots 20, 21 may be dimensioned to limit passage of electromagnetic wavelengths above a particular cut-off wavelength of electromagnetic noise, corresponding to a lower frequency limit for EMI noise. Optionally, slots 20, 21 can be sealed with a foil of an electromagnetic shielding material. When the clamp portion 12 is brought into engagement with one of the slots, the corresponding seal is broken while the other slot remains sealed.
The slanting edge 15 of cable clamp portion 12 juts out off the slot 20, 21, allowing visual inspection, particularly if the portion 12 and the housing 2 have different colours, shades or brightness.
The opening 9 in housing 2 is provided with ribs or protrusions or teeth 22 to further reduce movement of the cable.
The cable to be used comprises electro conductive wires to be connected to contact points in a terminal block 23 closing off the housing 2.
In
A set of different exchangeable cable clamps can be used having different sizes of flanges. Clamps for cables of smaller diameter have to bridge a larger gap between the clamp and the cable opening edge and can for that purpose be provided with larger flanges. A set can for instance include the clamp 3 of
Another embodiment of a cable clamp 103 according to the present invention is shown in
When mounted in a connector housing and after connecting a cable to the connector, hook 115 of portion 112 is brought into engagement with a corresponding slot in the housing 2 and a fixation screw fixes the clamp via opening 114 in end portion 111. Teeth 116 resiliently clamp on the cable. Due to the alternating orientation of the teeth backward as well as forward movement of the cable is effectively reduced. The mushroom shaped projections 117 resiliently engage with the interior wall of opening 109, effectively bridging the gap between the cable clamp 113 and the interior wall of opening 109 and completing the electromagnetic shielding. The resiliency of the mushroom shaped projections 117 increases the range of cable diameters that can be used with the cable clamp 103.
A third embodiment of a cable clamp 203 according to the invention is shown in
The described embodiments are intended to be illustrative rather than restrictive. Various modifications, variations and re-combinations of features of the embodiments as described can be made without departing from the spirit or scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/IB2008/051260 | Jan 2008 | IB | international |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2008/067800 | 12/17/2008 | WO | 00 | 6/28/2010 |
