Insulation displacement connector for a sheathed insulated cable

Abstract

The invention relates to an insulation displacement connector (10) for a sheathed insulated cable, configured so as to allow the connection of at least one cable to said connector (10), said connector (10) comprising: a terminal configured to allow the electrical connection between the cable and said connector (10), and a housing (11, 12) configured to house said terminal inside it and to isolate said terminal with respect to the outside. In this connector (10), said housing (11, 12) comprises a first portion (11) and a second portion (12) configured to mechanically engage with said first portion (11), wherein said first portion (11) is made of a different material from said second portion (12).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of insulation displacement connection systems for jacketed insulated cables. In particular, the present invention relates to insulation displacement connectors for jacketed insulated cables. BACKGROUND

[0002] In the last decades, a new solderless connection technology has been developed: the IDC (Insulation Displacement Connection).

[0003] This technology has been widely developed in the field of household appliances and in electronic devices, and more generally in the field of electrical signal transmission. This type of connection is mainly used for electrical connections not exceeding 25 A and effectively reduces production costs and makes the connection in the production process easier.

[0004] In this application, there is no need to preliminarily operate the electrical wires or cables to be handled, for example by stripping the insulation from the cable, thus effectively increasing the production speed and reducing the production costs.

[0005] Thanks to this technology, over the years various types of connection systems have been developed, which allow to electrically connect electrical wires or cables to connectors, which generally comprise an electrical terminal and a housing which houses the electrical terminal.

[0006] These connectors are commonly referred to as RAST connectors (from the German "Raster Anschluss SteckTechnik") (even in Italian). This connector is based on a standard (RAST standard) which indicates a connection type based on multiple connectors characterized by a certain "pitch". Usually, the acronym is followed by a number which represents a specific spacing between the different interconnection wires. For example, a RAST 5 interconnection comprises connectors with 5 mm pitch contacts.

[0007] The RAST standard involves many connector features, including external dimensions, color coding on the housing, polarization mechanisms for preventing incorrect assembly, and locking mechanisms for improving interconnection stability.

[0008] These connectors must be able to pass specific tests which simulate the extreme conditions that these connectors can encounter. Over time, these tests have become increasingly selective in order to obtain increasingly safe and able to meet the latest standards connectors.

[0009] For example, as described by the UL 749 standard, new domestic dishwashers are required to have components with defined flammability ratings, or must pass the "nichrome wire test" by 2020. During this test, the connector is used as a trigger point, a nichrome coil is energized inserted into one of the contacts, and is energized for 20 minutes at 11 A. Most connectors on the market today will produce a flame in the surrounding area when subjected to such a test. Therefore, in many cases, the connector must be made fire resistant to pass the test in the device.

[0010] Therefore, the object of the present application is particularly to provide a connection system having high fire resistance and thus able to pass the various tests required to meet the current safety parameters. SUMMARY

[0011] The present application is based on the idea of providing a connection system comprising a first portion and a second portion mechanically connected to each other and made of different materials.

[0012] According to one embodiment of the present application, an insulation displacement connector for a sheathed insulated cable is provided, configured to connect at least one cable to the connector. The connector comprises a terminal configured to allow an electrical connection between the cable and the connector, and a housing configured to house the terminal inside it and to isolate the terminal from the outside. In the connector, the housing comprises a first portion and a second portion configured to mechanically engage with the first portion, wherein the first portion is made of a different material than the second portion. This embodiment is particularly advantageous because it makes it possible to provide a connector having different properties in different portions of the connector. For example, the different portions can have different heat resistance. In fact, if a connector is required that is able to reach high temperatures for long periods in a certain portion, it is possible to construct the connector by mechanically coupling together several portions having different properties. In this way, instead of making the entire connector from an extremely expensive and heat-resistant material, it is possible to limit it to only the portion expected to be subjected to high thermal stress, thus reducing the cost of the connector. Thanks to the mechanical engagement between the first portion and the second portion, it is extremely easy to mechanically connect the two portions, thus providing a connector having the same geometry as one having a uniform body, as known in the prior art, but having different properties.

[0013] According to another embodiment of the present application, a connector is provided in which the first portion is made of a material having a higher fire resistance than the second portion. This solution is particularly advantageous because it provides a connector comprising two portions having different fire resistance. The portion subjected to higher thermal stress will have a material having a higher fire resistance than the rest of the connector.

[0014] According to a further embodiment of the present application, a connector is provided, wherein the first portion comprises at least one of the following components: polyurethane with 30% glass fiber, polybutylene terephthalate with 30% glass fiber, polyethylene terephthalate and polyphenylene sulfide, which are intrinsically liquid crystal polymers or another type of self-extinguishing polymer. This solution is particularly advantageous because it provides a connector able to withstand very high thermal stresses, thus able to pass the tests to meet the latest standard requirements, thus providing a particularly safe connector.

[0015] According to a further embodiment of the present application, a connector is provided, wherein the second portion comprises at least one of the following components: polyurethane, polyolefin or polybutylene terephthalate.

[0016] According to a further embodiment of the present application, a connector is provided, wherein the first portion and the second portion comprise a coupling system configured to allow the coupling between the first portion and the second portion. Thanks to this system, the first portion can be mechanically connected to the second portion by means of mechanical systems known in the state of the art.

[0017] According to a further embodiment of the present application, a connector is provided, wherein the second portion comprises at least one male coupling system comprising at least one engagement protrusion which engages the first portion with the second portion by elastic deformation of the engagement protrusion. This solution is particularly effective because it allows the mechanical coupling of the first portion to the second portion by elastic deformation, thus allowing the reversible coupling of the two elements. In addition, the elastic deformation ensures the connection between the two portions. BRIEF DESCRIPTION OF DRAWINGS

[0018] The application will be described with reference to the accompanying drawings, wherein like numbers and / or symbols of like parts denote like and / or corresponding parts throughout the several views.

[0019] Figure 1 A three-dimensional view of an insulation displacement connection system for a sheathed insulated cable according to the state of the art is schematically shown.

[0020] Figure 2 A three-dimensional view of an insulation displacement connection system for a sheathed insulated cable according to one embodiment of the present application is schematically shown.

[0021] Figure 3 A three-dimensional view of a first portion of an insulation displacement connection system for a sheathed insulated cable according to the present application is schematically shown.

[0022] Figure 4 A three-dimensional view of a second portion of an insulation displacement connection system for a sheathed insulated cable according to the present application is schematically shown. DETAILED DESCRIPTION

[0023] The application is described below with reference to specific embodiments, as described in the following figures. The application is not limited, however, to the specific embodiments described in the following detailed description and illustrated in the accompanying drawings, which are included as examples only, the purpose being to exemplify the various aspects of the application, the object of which is defined by the claims. Further variations relating to the application will become apparent to the skilled person.

[0024] Figure 1 A RAST type connector 100 with 5 mm pitch is shown, known in the prior art. In particular, the connector shown in the figure is commonly known as "AMP multifitting mark II", the technical characteristics of which can be found in the catalog "RAST CONNECTOR SYSTEM IDC & CRIMP CONNECTOR SYSTEM AND RAST TAB HEADER" by Tyco Electronics (catalog number 1-1773727-3, revision number 4-14). This connector 100 has four interconnection wires.

[0025] It will be apparent from the rest of the present description, however, that although a specific shape of the connector is shown in the figures ("AMP multifitting mark II" shape), it is clear that the same inventive concept presented here can be applied to any other type of connector having different shapes and characteristics from those described in the figures; for example, to any connector in the above-mentioned catalog.

[0026] It can be seen that the connector comprises a single body and comprises an upper portion 101 (here the cable is connected to the connector 100) and a lower portion 102 (here the connector 100 is electrically connected to an external element).

[0027] Although not shown, it is clear that inside the connector 100 there are terminals configured to allow electrical connection between the connector 100 and at least one cable to which the connector is connected.

[0028] The cable preferably comprises an electrically conductive internal portion and an insulating cover, commonly known as a sheath. The internal conductive portion can comprise a single wire or a plurality of twisted wires (twisted wires) to allow a uniform distribution of the current density through the cable.

[0029] Further technical details of the connector will be omitted here, as they are not necessary for the description of the application, as will be clarified later, not being limited to the specific connector shown in the figures ("AMP multifitting mark II connector"), but can be applied to any type of connector.

[0030] The present invention is based on the discovery that the thermal stresses to which a connector is subjected are not uniform, so that certain parts of the connector must bear a higher load, while others bear a lower load.

[0031] Figure 2 A connector 10 is shown having an external geometry similar to that of the connector 100 shown in the figure according to a particular embodiment of the present invention. Figure 1

[0032] As shown, the connector 10 comprises a first upper portion 11 and a second lower portion 12. In this way, the connector 10 is formed by a mechanical coupling between two distinct elements represented by the first portion 11 and the second portion 12.

[0033] The fact that the connector 10 is formed by two distinct mechanically coupled portions makes it possible to form the connector 10 from two bodies of different materials, therefore having different mechanical and chemical properties.

[0034] For example, if it has been determined that a higher thermal stress occurs in a particular area of the connector 10, it is possible to make one portion with a higher resistance to combustion and the other with a lower resistance to combustion.

[0035] For example, as mentioned previously, in the particular example shown in the figure, the inventors, by carrying out specific tests, determined that the upper portion 101 of the connector 100 shown in the figure was ignited when subjected to the "nichrome wire test". Therefore, the inventors envisaged making the first portion 11 with a material more resistant to combustion than the second portion 12.

[0036] This is achieved by dividing the connector 10 into two portions and inserting a material particularly resistant to combustion into the first portion 11.

[0037] For example, without being limited to the particular selection of materials listed here, the first portion 11 can comprise at least one of the following compositions: polyurethane with 30% glass fiber, polybutylene terephthalate with 30% glass fiber, polyethylene terephthalate and polyphenylene sulfide, which is a liquid crystal polymer, or another type of polymer that is self-extinguishing by nature.

[0038] The second portion 12 is preferably made of polyurethane, polyolefin or polybutylene terephthalate.

[0039] The geometric characteristics of the first portion 11 and the second portion 12 will be described in detail below with reference to Figure 3 and Figure 4 The geometric characteristics of the first portion 11 and the second portion 12 will be described in detail below with reference to

[0040] In particular, Figure 3 The first portion 11 is shown, as mentioned above, which is preferably made of a material with a higher resistance to combustion than the second portion 12.​

[0041] As shown, the first portion 11 has, at its lower part, a female coupling system which can mechanically connect the first portion 11 to the second portion 12, as will be described in detail hereafter.

[0042] In particular, in the example shown in the figures, the coupling system comprises a plurality of contact surfaces 112 against which protrusions on the second portion 12 can be fixed, as will be described later. Although not shown in the figures, as they are hidden in the first portion 11, it is clear from the rest of the present description that additional contact surfaces 112 on the first portion 11 are located in different planes, so as to provide an effective mechanical fixing between the first portion 11 and the second portion 12.

[0043] It is also clear that the coupling system can be made in any other way equivalent to that shown in the present description and known to the person skilled in the art.

[0044] For example, the first portion 11 can comprise a female coupling system with one or more engagement holes which allow one or more end portions of the second portion 12 to be inserted into these holes, so that the first portion 11 can be mechanically fixed to the second portion 12. Obviously, these holes (for example located on the inner or outer lateral walls of the first portion 11) can be used in combination with or alternatively to the contact surfaces 112.

[0045] In particular, the term "lateral surface" refers to all those surfaces which are perpendicular to the front surface (in the front view in Figure 3 ) and extend along the coupling direction between the first portion 11 and the second portion 12.

[0046] In addition, as Figure 3 shown, the first portion 11 comprises two grooves 199 configured to house Figure 4 the external coupling elements 123 shown.

[0047] As Figure 3 shown, the second portion 12 comprises a male coupling system comprising a plurality of protruding elements 121-122 which extend from the main body of the second portion 12 in the direction of the mechanical coupling of the second portion 12 to the first portion 11. These protruding elements 121-122 thus enable the second portion 12 to be mechanically coupled to the female coupling system of the first portion 11.

[0048] In particular, the plurality of protruding elements 121-122 extends perpendicularly from the main body of the second portion 12 and has a catch portion 121a-122a represented by the protrusion, configured to contact the contact surfaces 112 of the female coupling system of the first portion 11.

[0049] It is therefore clear that the protruding elements 121-122 are able to deform in a direction perpendicular to the direction of extension of the protruding elements 121-122, so that the catch portions 121a-122a can contact the contact surface 112 of the first portion 11.

[0050] In fact, during the coupling operation, the catch portions 121a-122a will contact the surface of the first portion 11 so that, once the catch portions 121a-122a contact the contact surface 112, the protruding elements 121-122 bend and return to their vertical position, substantially providing a snap-fastening system. Therefore, the protruding elements 121-122 are able to prevent the relative movement between the first portion 11 and the second portion 12 through the terminal portion thereof comprising the catch portions 121a-122a.

[0051] Therefore, when finally positioned between the first portion 11 and the second portion 12, the protrusions 121a-122a will be correctly positioned in the predetermined position along the contact surface 112.

[0052] Obviously, the number of protruding elements 121-122 can be varied as required. The protruding elements can also be located in different planes to ensure a better mechanical coupling.

[0053] Furthermore, the second portion 12 comprises second protruding elements 124 and 125.

[0054] Although the present application has been described with reference to the above examples, it is obvious for a person skilled in the art that various modifications, variations and improvements can be made to the present application according to the above teachings and within the scope of the appended claims.

[0055] For example, although it has been shown that the first portion 11 has a female coupling system and the second portion 12 has a male coupling system, the coupling systems can be made in the opposite way, i.e. the first portion 11 has a male coupling system and the second portion 12 has a female coupling system.

[0056] For example, although a particular mechanical connection between the first portion 11 and the second portion 12 has been described, it is obvious that this mechanical connection is not limited to the particular example described in the figures, but can be any mechanical connection known to a person skilled in the art.

[0057] Finally, it is obvious that the example shown in the figures describes a multiple connector configured to allow the coupling to four cables (and therefore having four interconnection lines), but the present application can be applied to larger or smaller connectors having more or fewer interconnection lines. Similarly, if the connector is larger or smaller than the one shown in the figures, the number of protrusions on the second portion thereof can be greater or smaller than the protrusions described in the figures.

[0058] Moreover, it is clear that, although the connector 10 has been shown made by mechanical connection between two elements (the first part 11 and the second part 12), it can also comprise more than two elements with different resistance to fire.

[0059] Finally, in order to avoid unnecessarily obscuring the application described, those areas known to the person skilled in the art have not been described.

[0060] The application is therefore not limited to the embodiments described above, but is limited only by the scope of the claims attached hereto.

[0061] List of reference signs

[0062] 100: connector

[0063] 101: upper part

[0064] 102: lower part

[0065] 10: connector

[0066] 11: first part

[0067] 12: second part

[0068] 112: contact surface

[0069] 121-122: protruding element

[0070] 121A-122a: catch portion

[0071] 124, 125: second protruding element

Claims

1. An insulation displacement connector (10) for a sheathed insulated cable, configured to connect at least one cable to the connector (10), the connector (10) comprising: Terminals configured to allow electrical connection between the cable and the connector (10); The housing (11, 12) is configured to house the terminals within it and isolate the terminals relative to the outside. The connector (10) is characterized in that: The housing (11, 12) includes a first portion (11) and a second portion (12), wherein the first portion defines a vertical groove (199) formed through its outer wall, and the second portion (12) is configured to mechanically engage with the first portion (11) and includes an external coupling element (123) that extends through the vertical groove when the first portion engages with the second portion, wherein the first portion (11) is made of a different material than the second portion (12).

2. The connector (10) as claimed in claim 1, wherein the first part (11) is made of a material with higher flame retardancy than the second part (12).

3. The connector (10) of claim 1, wherein the first part (11) comprises at least one of the following components: polyurethane having 30% glass fiber, polybutylene terephthalate having 30% glass fiber, polyethylene terephthalate and polyphenylene sulfide.

4. The connector (10) of claim 1, wherein the second part (12) comprises at least one of polyurethane, polyolefin or polybutylene terephthalate.

5. The connector (10) of any one of claims 1 to 4, wherein the first portion and the second portion (11, 12) include a connection system (112, 121-122, 121a-122a) configured to allow connection between the first portion (11) and the second portion (12).

6. The connector according to any one of claims 1 to 4, wherein the second portion (12) includes a male connection system including at least one engagement protrusion (121-122, 121a-122a) configured to engage the first portion (11) with the second portion (12) by elastic deformation of the engagement protrusion (121-122, 121a-122a).

Images