INSULATION PIERCING PLUGGING CONTACT

Abstract: A contact (2) comprises an IDC section (4) and a plugging contact section (6). Such contacts can be used for interconnecting conducting wires in stackable pluggable modules, for example, as used in the telecommunications industry. The plugging contact section comprises a slot (16) for plugging to a complementary blade of an IDC contact. Pointed tips (22) and strengthening ribs (30) are provided to enable piercing through insulation layers of a conductor terminated to the complementary IDC contact. To provide a particularly effective strengthening rib, but nevertheless effective piercing of the insulation, the outer oblique cutting edge (24) of the piercing section is stepped (36) with respect to a second cutting section (34).

Description: INSULATION PIERCING PLUGGING CONTACT This invention relates to an electrical contact for plugging connection to an insulation displacing contact. Patent application WO 9411922 describes an integral contact element having an insulation displacement contact (IDC) section integrally connected to a plugging contact section twisted in a plane orthogonal to the IDC section. Such contacts are mounted in housings receiving conducting wires terminated to the IDC sections, whereby the plugging contacts extend beyond an opposing side of the connector for plugging connection to complementary contacts. The complementary contact is an IDC blade for termination to a conducting wire. In WO 9411922, the plugging contact is provided with a chamfered end to cut through the outer insulation of conducting wires terminated in the complementary IDC blade. Depending on the thickness and toughness of the cable insulating layer, buckling or bending of the plugging contact may occur. It would be desirable to improve the reliability and quality of the electrical contact between the plugging contact and complementary IDC blade. It is an object of this invention to provide an improved plugging contact with insulation piercing function. The objects of this invention have been achieved by providing the plugging contact according to claim 1. Disclosed herein is a contact comprising a first contact section for IDC with a conducting wire, and a second plugging section integral therewith for plugging connection to a complementary IDC blade, the plugging section comprising a slot extending from a mating end to proximate the first section and having a contact portion for receiving the complementary IDC blade, the slot formed between blade portions, each blade having a base section and mating end section with insulation piercing tip, wherein the mating end section has an outer cutting edge that is stepped inwardly towards the slot in relation to an outer insulation cutting edge of the base section. Advantageously, the provision of reinforcement ribs prevents bending or buckling of the plugging contact whilst the inwardly stepped pointed tips assure effective piercing through of the insulation. Further advantageous features are described in the claims or will be apparent from the following description and drawings. An embodiment of this invention will now be described by way of example, with reference to the Figures, whereby; Figure 1 is an isometric view of a contact according to this invention; Figure 2 is a view in a direction orthogonal to the plane of the plugging contact section; Figure 3 is a view in a direction of arrow 3 of Figure 2; Figure 4 is a view in the direction of arrow 4 of Figure 2. Referring to the Figures, a contact 2 is stamped and formed from sheet metal in an integral part and comprises an IDC section 4 and a plugging contact section 6. The plugging section 6 is substantially orthogonal to the IDC section of 4 and interconnected by a twisted intermediate section 8. The IDC section 4 has a substantially planar base 10 comprising a centrally disposed slot 12 for receiving conducting core of an insulated conducting wire therein in a manner typical of conventional insulation displacement contacts (IDC) . The plugging contact section comprises a substantially planar base 14 comprising a pair of symmetrical blade portions 15 separated by a plugging contact slot 16 extending from a free mating end 18 toward the intermediate section 8. The slot 16 comprises a generally parallel contact portion 17, extending into a funnel shaped entry portion 21 at the mating end 18. The contact portion 17 is formed by opposed contact edges 20 that are for contacting a complementary blade contact inserted into the slot 16. The funnel shaped entry portion 21 enables guiding of the complementary blade contact into the slot. The tapered edges of the funnel portion 21 join at their apexes oblique first outer cutting edges 24 to form pointed tips 22. In applications, for example as described in WO 9411922, where the complementary blade is the base plate of an IDC contact, an outer insulating layer of a conducting wire terminated in the IDC contact may be present in the path of the plugging contact. The plugging contact is thus provided with pointed tips 22 at the mating end 18 in order to pierce through this insulating layer. The blade portions 15 are each provided with oblong reinforcement ribs 30 extending substantially in the plugging direction of the contact (i.e. in the direction of the slot contact section 17) . The reinforcement ribs prevent buckling or bending of the blade portions 15 of the plugging contact during piercing of insulating layers. The reinforcement ribs 30 are provided in a base sections 25 that extend from proximate the intermediate section end 19 of the plugging contact section, to proximate a mating end section 23 of the contact. In order to provide a particularly pointed tip 22, the tip oblique outer edge 24 is stepped inwardly (toward the slot 16) with respect to a second outer cutting edge 34 of the base section 25. The step 36 thus enables provision of a pointed insulation piercing tip 22, whilst nevertheless having a strengthening rib that extends a substantial length of the plugging contact to provide a rigid but compact structure. The two step piercing ensures that the plugging contact initially and easily embeds in the outer insulation layer with relatively low forces. Piercing with the wider base section of the blade 15 only occurs in the second step once the tip is already imbedded in the material, which helps to provide direction and support. The large piercing forces thus occur when the second cutting edges 34 enter the insulation layer. As the ribs 30 are provided alongside the second cutting edges they provide optimal strength against bending and buckling of the contact. Furthermore, the two stage process also assists increasing the contact force of the contact edges 20 against the complementary blade, by the inward force component of the step 36 and second oblique cutting surface 34 when piercing through the insulation. The latter, however, only occurs once initial piercing has occurred and initial entry of the blade into the slot 16,thus reducing mating forces.

Claims: CLAIMS 1. A contact (2) comprising a first contact section (4) for insulation displacement contact with a conducting wire, and a second plugging section (6) integral therewith for plugging connection to a complementary insulation displacement contact (IDC) blade, the plugging section comprising a slot (16) extending from a mating end (18) to proximate the first section (4) and having a contact portion (17) for receiving the complementary (IDC) blade, the slot formed between blade portions (15) , each blade having a base section (25) and mating end section (23) with insulation piercing tip (22) , characterized in that the mating end section (23) has an outer cutting edge (24) that is stepped inwardly towards the slot (16) in relation to an outer insulation cutting edge (34) of the base section (25) . 2. The contact of claim 1 wherein each blade portion (15) is provided with a reinforcement rib (30) . 3. The contact of claim 1 wherein each rib (30) extends a substantial length of the base section (25) with respect to a plugging direction of the contact (2) . 4. The contact of claim 3 wherein each rib extends from proximate a step (36) that joins the base section outer cutting edge (34) to the tip outer cutting edge (24) . 5. The contact of claim 4 wherein, viewed in the plugging direction towards the contact second section (6) , each step overlaps the respective rib (30) . 6. The contact of any one of the preceding claims wherein the outer cutting edge (24) of each mating end section (23) is oblique with respect to the plugging direction. 7. The contact of any one of the preceding claims wherein the slot (16) comprises a funnel shaped entry portion (21) extending from the mating end to the slot contact portion (17) to guide a complementary blade thereinto, the entry portion formed by substantially linear edges (21) .

Inventors: DURAN BOFILL PEDRO, SANABRA JANSA JOSEP, DURAN BOFILL, PEDRO, SANABRA JANSA, JOSEP
Applicants: DURAN BOFILL PEDRO, SANABRA JANSA JOSEP, WHITAKER CORP, DURAN BOFILL, PEDRO, SANABRA JANSA, JOSEP, THE WHITAKER CORPORATION
Application year: 1997
Main classification: H01R4
IPC codes: H01R4