Insulation displacement connector

Abstract: An insulation displacement connector prevents a sheathed cable from being readily moved by an external force after the sheathed cable is temporarily inserted in a cable insertion gap. A plurality of guide projections (13) stand on a connector housing (11) of the insulation displacement connector at a given distance in two rows. A cable insertion gap (15) is defined between the adjacent guide projections (13) for receiving a sheathed cable (14). The guide projection (13) is provided on each of the opposite sides of the top end with a shoulder (22) extending toward the gaps (15) to prevent the sheathed cable (14) from coming out of the gaps (15). The guide projection is provided on each of the opposite sides defining the gaps (15) with a holding ridge (21) having a triangular cross section and extending from the underside of the shoulder (22) to the proximal end. The holding ridges (21) on the opposite sides of the guide projection (13) compress an insulation sheath of the sheathed cable (14) to prevent the sheathed cable from coming out of the gaps (15).

Description: This invention relates to an insulation displacement connector in which a guide structure for a sheathed cable is improved. For convenience of explanation, an example of a conventional insulation displacement connector will be described below by referring to FIG. 12. FIG. 12 is a perspective view of the conventional insulation displacement connector. As shown in FIG. 12, a conventional insulation displacement connector comprises a connector housing 1, a plurality of guide projections 2 which stand on the connector housing 1 at a given distance to define cable insertion gaps 3, and an insulation displacement terminal 4 mounted on the connector housing 1. When a sheathed cable 5 is pressed into the cable insertion gaps 3, the sheathed cable 5 is pressed into contact edges of the insulation displacement terminal 4 while the cable 5 is being guided by the gaps 3. Then, the contact edges grip a sheath of the sheathed cable 5 so that the contact edges make contact with core conductors in the cable 5. In the insertion displacement connector, since a number of sheathed cables 5 are pressed into the insulation displacement terminal 4 at the same time, the cables 5 are subject to a substantial pressing resistance. Thus, a press machine is used upon a cable insertion work. In this case, all cables 5 are temporarily inserted in the cable insertion gaps and then the temporary assembly is set on the press machine to carry out the cable insertion work. However, the sheathed cables 5 inserted in the gaps 3 are readily moved longitudinally by an external force since a structure in which the sheathed cables 5 are temporarily inserted in the cable insertion gaps 3 cannot generate a sufficient force to hold the cables 5. When a short sheathed cable 5 is moved in the gaps 3, the cable 5 comes out of the connector housing 1. When a long sheathed cable 5 is moved in the gaps 3, a connecting portion of the cable is displaced from a predetermined position. This results in the troublesome task of correcting the displacement of the cable upon the cable insertion work. A connector according to the preamble of claim 1 is disclosed in DE-A-3602812 in which a cable is received in a V-shaped gap having serrations on opposed sides of the gap to grip the cable and prevent the cable coming out of the gap. An object of the present invention is to provide an insulation displacement connector which can effectively prevent a sheathed cable from being moved after being temporarily inserted into cable insertion gaps. In order to achieve the above object, an insulation displacement connector is provided having a plurality of cable insertion gaps defined between guide projections spaced apart a given distance on a connector housing, at least one of the two guide projections defining each gap being provided with a holding ridge providing a holding ridge on at least one side of the gap adapted to compress an insulation sheath of a sheathed cable inserted into the gap, and the connector housing being provided with an insulation displacement terminal adapted to grip the insulation sheaths of sheathed cables inserted into the gaps so that the terminal makes contact with core conductors in the sheathed cables characterised in that each holding ridge extends in the direction of insertion of the sheathed cables into the gaps whereby the cables are by the holding ridges prevented from moving in a longitudinal direction. By this invention, it is possible to prevent the sheathed cable temporarily inserted in the gaps from moving longitudinally thereby enhancing production efficiency when a cable is inserted. More particularly, the holding ridges on the guide projections grip the insulation sheath of the sheathed cable temporarily inserted in the cable insertion gaps to hold the cable in the gaps. It is also possible to enhance the holding force of the cable. The guide projections defining each gap may be provided on each of the opposite sides of the gap with a shoulder extending inwardly at an upper end of the gap to prevent the sheathed cable from coming out of the gaps. Each of the guide projections may be provided with a vertical slit extending from an upper free end thereof to a proximal end for permitting the projection to be elastically deformed. In use, a sheathed cable is inserted into the cable insertion gap between the guide projections and then pressed into the insulation displacement terminal to grip the insulation sheath of the sheathed cable. Holding ridges may be provided on one or both of the opposite sides defining the gaps and compress the insulation sheaths of the sheathed cables inserted in the cable insertion gaps. In particular, the sheathed cable is constrained from moving in a vertical direction by the shoulders as well as in a longitudinal direction by the holding ridges. In addition, the slit formed longitudinally in the guide projection permits the cable insertion gap to spread elastically upon insertion of the sheathed cable, thereby causing the holding ridge to grip the insulation sheath more strongly. FIG. 1 is an exploded perspective view of an embodiment of an insulation displacement connector of the present invention; FIG. 2 is an enlarged perspective view of guide projections of the insulation displacement connector shown in FIG. 1; FIG. 3 is a cross sectional view of the guide projections of the insulation displacement connector shown in FIG. 1; FIG. 4 is a similar view to FIG. 3, but illustrating sheathed cables inserted in insertion gaps between the guide projections of the insulation displacement connector; FIG. 5 is a cross sectional view of guide projections in another embodiment of the present invention; FIG. 6 is a cross sectional view of guide projections in still another embodiment of the present invention; FIG. 7 is a cross sectional view of guide projections in still another embodiment of the present invention; FIG. 8 is a cross sectional view of guide projections in still another embodiment of the present invention; FIG. 9 is a cross sectional view of guide projections in still another embodiment of the present invention; FIG. 10 is a cross sectional view of guide projections in still another embodiment of the present invention; FIG. 11 is a cross sectional view of guide projections in still another embodiment of the present invention; and FIG. 12 is a perspective view of a conventional insulation displacement connector. A first embodiment of the present invention will be described below by referring to FIGS. 1 to 4. FIG. 1 shows a general structure of an insulation displacement connector of the present invention. A connector housing 11 made of a plastic resin material is provided on a base 12 with a number of guide projections 13 in two rows. Each guide projection 13 is disposed on the base 12 by a distance corresponding to an outer diameter of a sheathed cable 14 to define a cable insertion gap 15 between the adjacent guide projections 13 for receiving the sheathed cable 14. Terminal holding projections 16 are disposed on the base 12 between the rows of the guide projections 13. An insulation displacement terminal 17 is mounted on the terminal holding projections 16. The terminal 17 has connection gaps 18 corresponding to the respective cable insertion gaps in the connector housing 11. When the sheathed cable 14 is pressed in the connector gaps 18, the insulation displacement terminal 17 breaks an insulation sheath 14a (FIG. 2) of the sheathed cable 14 to make electrical contact with core conductors 14b. On the other hand, a cover 19 is formed into a box-like body which is open at the bottom. The cover 19 is provided on its upper interior with a plurality of press ridges (not shown) corresponding to the respective connection gaps 18 in the terminal 17. When the cover 19 is mounted on the connector housing 11 the sheathed cables 14 are pushed down by the press ridges in the cover 19, thereby pressing the sheathed cables 14 in the connection gaps 18 in the terminal 17. As shown in FIG. 2, the guide projection 13 is provided on each of the opposite sides of the top end (the upper end in FIG. 2) with a shoulder 22 extending toward the insertion gap 15 so that the guide projection 15 is formed into a T-shape. The shoulder 22 is provided on each of its upper portions with a slant face 22a extending down to the cable insertion gap 15. The distance between the shoulders 22 is set to be slightly narrower than an outer diameter of the sheathed cable 14. The guide projection 13 is provided on each of its opposite sides facing the cable insertion gaps 15 with a holding ridge 21 which extends from the underside of the shoulder 22 to the proximal end and has a triangular shape in cross section. Next, an operation of this embodiment will be described below. In order to connect a group of the sheathed cables 14 to the insulation displacement connector, a single sheathed cable 14 is inserted into the cable insertion gaps 15 in the connector housing 11. During insertion of the cable, when the sheathed cable 14 makes contact with the slant faces 22a on the shoulders 22, the distance between the adjacent guide projections is elastically increased, thereby permitting the sheathed cable 14 to enter the cable insertion gaps 15. When the sheathed cable 14 enters the cable insertion gaps 15, the holding ridges 21 gently grip the insulation sheath 14a of the sheathed cable 14, as shown in FIG. 4, so that the sheathed cable 14 is prevented from moving longitudinally. Then, the next sheathed cable 14 is inserted into another cable insertion gap 15. After all of the sheathed cables 14 are inserted in the gaps 15, the cover 19 is mounted on the connector, the connector with the cover 19 is set on the press machine not shown, and the cover 19 is pushed down by the press machine. Then, the press ridges on the cover 19 push down each sheathed cable 14 in the gaps 15, thereby pressing the sheathed cables 14 into the connector gaps 18 in the insulation displacement terminal 17. Thus, insertion of the respective cables is finished. According to the present embodiment, it is possible to surely prevent the sheathed cables 14 from moving longitudinally even if a worker touches the sheathed cable 14 inserted in the gaps 15 when the next cable 14 is inserted into the gaps 15 after one cable 14 has been inserted in the gaps 15, since the holding ridges 21 grip the sheathed cables 14 to prevent the cables 14 from moving longitudinally when the sheathed cables 14 is inserted into the gaps 15. Accordingly, it is possible to carry out the task of inserting the next sheathed cable 14 without worrying about any movement of the cables 14 which have already been inserted in the gaps 15; it is also possible to carry out the job efficiently, to eliminate having to correct the displaced cables, and eventually to improve production efficiency. Further, since each guide projection 13 is provided on its top end with the shoulders 22, it is possible to prevent the sheathed cables 14 from coming out of the gaps 15 even if the inserted cables 14 are pulled upwardly during insertion of the next cable 14. The present invention should not be limited to the above embodiment. For example, the following embodiments may also be carried out. (1) A shape of the holding ridges on the guide projection is not limited to the above embodiment. For example, as shown in FIG. 5, a pair of holding ridges 31 may be alternately provided on the guide projections 30. Also, as shown in FIG. 6, a holding ridge 33 may be provided on one of the sides of the guide projection 32, or as shown in FIG. 7, holding ridges 33 may be alternately provided on both sides of the guide projection 32. Alternatively, as shown in FIG. 8, a holding ridge 34 having a semi-circular shape in cross section may be provided on one of the sides of the guide projection 32, as shown in FIG. 9, holding ridges 35 having a semi-circular shape in cross section may be provided in opposition to each other on both sides of the guide projection 32, or the holding ridges 35 may be alternately provided on both sides of the guide projection 32 as shown in FIG. 10. (2) As shown in FIG. 11, the guide projection 13 may be provided with a vertical slit 36 extending from the top end to the proximal end to cause the projection 13 to be elastically deformed. The slit 36 makes it easy to insert the cable 14 into the cable insertion gaps 15 and enhances a holding force of the cable.

Claims: An insulation displacement connector having a plurality of cable insertion gaps (15) defined between guide projections (13;30;32) spaced apart a given distance on a connector housing (11), at least one of the two guide projections (13;30;32) defining each gap (15) being provided with a holding ridge (21;31;33;34;35) providing a holding ridge (21;31;33; 34; 35) on at least one side of the gap (15) adapted to compress an insulation sheath (14a) of a sheathed cable (14) inserted into the gap (15), and the connector housing (11) being provided with an insulation displacement terminal (17) adapted to grip the insulation sheaths (14a) of sheathed cables (14) inserted into the gaps (15) so that the terminal (17) makes contact with core conductors (14b) in the sheathed cables (14) characterised in that each holding ridge (21;31;33;34;35) extends in the direction of insertion of the sheathed cables (14) into the gaps (15) whereby the cables (14) are by the holding ridges (21;31;33;34;35) prevented from moving in a longitudinal direction. An insulation displacement connector according to claim 1 characterised in that the guide projections (13) defining each gap (15) are provided with opposed inwardly directed shoulders (22) at an upper end of the gap (15) for preventing the sheathed cables (14) from coming out of the gaps (15), and each shoulder (22) preferably has a slant face (22a) on its upper portion extending towards the gap (15). An insulation displacement connector according to claim 1 or claim 2 characterised in that each guide projection (13) is provided with a vertical slit (36) extending from an upper, free end to a proximal end for permitting said guide projection to be elastically deformed. An insulation displacement connector according to any preceding claim characterised in that each holding ridge (21;33) has a triangular shape in cross-section. An insulation displacement connector according to any one of claims 1 to 3 characterised in that each holding ridge (34;35) has a semi-circular shape in cross-section. An insulation displacement connector according to any one of the preceding claims characterised in that each gap (15) has a holding ridge (33;35) on one side only. An insulation displacement connector according to any one of claims 1 to 5 characterised in that each gap (15) has a holding ridge (21;31;33;35) on each side (15). An insulation displacement connector according to claim 7 characterised in that holding ridges (21;35) are aligned opposite each other. An insulation displacement connector according to claim 7 characterised in that the holding ridges (31;33;35) are offset relative to each other. An insulation displacement connector according to any one of the preceding claims characterised in that the insulation displacement terminal (17) has a plurality of connector gaps (18) corresponding to the insertion gaps (15) and the sheathed cables (14) are pressed into the connector gaps (18) when a cover (19) is mounted on the connector housing (11).

Inventors: ATSUMI KEIGO, ATSUMI, KEIGO, Atsumi, Keigo, c/o Sumitomo Wiring Syst.,Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1995
Main classification: H01R13
IPC codes: H01R4, H01R13