Joint terminal and joint connector including said terminal.

Abstract: A joint connector (10) comprises first and second unitary connector assemblies (13) respectively including an insulator plate (12) and a joint terminal (11) fixed thereto. The joint terminal (11) comprises unit terminals (11A, 11B, and the like), each of which includes: a stem portion (11a) with first and second faces and side rim portions; a first cramping connector (11d) extending from a side rim portion in a direction substantially perpendicular to said first face of said stem portion (11a), a second cramping connector (11e) extending from a third side rim portion in a direction substantially perpendicular to said second face of said stem portion (11a). When the first unitary connector assembly (13) is superposed to the second unitary connector assembly (13), the second cramping connector (11e) of the first unitary connector assembly (13) cramps the second electrical cable, whereby the first electrical cable carried on the first unitary connector assembly (13) can be connected to the second electrical cable carried on the second unitary connector assembly (13).

Description: The present invention relates to joint terminals and a joint connector including such terminals. The invention also concerns a way of establishing connections between the unit terminals which form a joint terminal, and between the joint terminals which form a joint connector. The invention further concerns means for achieving these connections in a flexible way, as a function of the particular type of circuit connection system used. Joint connectors are sometimes employed for interconnecting the electrical cables which are used in common circuit systems such as earthing (or grounding) lines. Fig.1 shows a joint connector 1 comprising a joint connector housing 1a, a connecting bus bar 2 adapted for a desired type of connection and inserted into the joint connector housing, and a connector C fitted into the joint connector housing 1a. The connector C includes terminals 3 previously bound to corresponding electrical cables D. The construction of above joint connector 1 has the drawback of requiring too many component parts. Further, various kinds of connecting bus bar 2 and joint connector housings 1a must be available, depending on the type of connector circuit. Moreover, in the above joint connector 1, it is not easy to adapt to the increasing number of connections caused by circuit modifications. In view of the above, a variant joint connector 1' shown in Fig.2A has been contemplated and disclosed in Japanese patent application published under No.HEI 8-306451. The variant joint connector 1' comprises a variant connector housing 1a' including terminal enclosures 1b', into each of which is inserted a connector terminal 3' such as shown in Fig.2B. Such a variant connector housing 1a' includes a multi-stage structure for the terminal enclosures 1b' (a four-stage structure is shown in Fig.2A). Partition walls defining these terminal enclosures 1b' have openings for establishing electrical connections in the vertical direction (in Fig.2A). The front face 1c' (left-hand side in Fig.2A) of the variant connector housing 1a' includes a respective insertion orifice 1d' corresponding to the position of each terminal enclosure 1b'. The connector terminal 3' is provided with a first elastic contact member 3a', a second elastic contact member 3b' and a connector portion 3c', respectively extending on the top, middle and bottom levels of each connector terminal 3' (Figs.2A and 2B). When such connector terminals 3' are inserted into a variant connector housing 1a' such as to form a layer, the first elastic contact member 3a' of the connector terminal 3' positioned on the lower level is brought into contact with the connector portion 3c' of the connector terminal 3' positioned on the upper level. Accordingly, the superposed connector terminals 3' can be connected without applying connecting bus bars 2 as was the case before. Further, a male terminal 4 may be inserted into each terminal enclosure 1b' through a corresponding insertion orifice 1d' provided in the front face 1c' of the variant connector housing 1a'. The male terminal 4 can thus be connected to the corresponding second elastic contact member 3b' of the connector terminal 3'. Such a configuration makes it easier to respond to the increase of the number of connections to be made. As mentioned above, the variant joint connector 1' has increased, to a certain degree, the number of connections to be made compared to the joint connector 1. However, in the variant joint connector 1', the number of connections is restricted by the number of terminal enclosures 1b' included in the variant connector housing 1a'. As a result, a certain range of connector housing products must be prepared in view of responding to the varieties of circuit type. Further, when the connector terminals 3' are superposed, connections are made forcibly, even if all the connections are not needed. As a result, the variant joint connectors 1' cannot be employed in a fully appropriate way. Document US 5 762 517 A discloses a joint terminal having a first and a second cramping connector which are arranged on the same face of a bottom plate. The axis of two connected cables are disposed in a horizontally parallel position on the same face. Further, when mounting a wire harness, sub-harnesses K-1, K-2 and K-3 are first formed by preliminary bundling, as shown in Fig.3. At this stage, the cable's end portions T-1, T-2 and T-3, which are envisaged to be led out over to another sub-harness, are kept unengaged with the connector of any sub-harness, yielding the so-called "yet-to-be connected terminals". These sub-harnesses are then subjected to a main bundling using an assembling design board. Consequently, the "yet-to-be connected" terminals must be inserted into the connectors of other sub-harnesses, while performing the main bundling. Such a mounting process impairs assembly efficiency. Usually, the preliminary bundling and the main bundling for a wire harness W/H are carried out in different workshops. As a result, the unengaged, "yet-to-be connected" terminals T-1, T-2 and T-3 contained in the sub-harnesses K-1, K-2 and K-3 tend to suffer deformation or damage during transfer. Such deformation or damage may render it difficult or unreliable to insert these "yet-to-be connected" terminals into another sub-harness connector in a proper way. The present invention has been contemplated to solve such problems. The invention relates to a joint connector in which sub-harnesses contain no "yet-to-be connected" terminal, and which flexibly responds to the increase in the number of electrical cables to be joined and to possible modifications of circuitry. The invention also contemplates to provide joint terminals adapted for such a joint connector. This is done by a joint terminal, a unitary connector assembly, a joint connector and a method of manufacturing the joint connector having the features of the independent claims 1, 3, 5, 10 respectively. Further embodiments of the invention are defined in the dependent claims. In the above configuration, an end portion of an electrical cable is placed on each stem portion, clamped by the first cramping connector, and may be fixed by the cable holder. As each stem portion is bound to another through a link portion, the clamped electrical cables are electrically connected to one another. When a first joint terminal, with a first electrical cable clamped by a first cramping connector, is superposed on a similarly prepared second joint terminal, a second cramping connector of the first joint terminal clamps an end portion of a second electrical cable clamped by the second joint terminal. In this manner, the electrical cables clamped by the first and the second cramping connector are electrically connected to each other. When the above joint terminal is to be fixed on an insulator plate, the former may be insert-molded together with the insulator plate. Alternatively, the stem portion of the joint terminal may be provided with a protrusion, whilst the insulator plate is provided with a corresponding recess, and the stem portion is flanked on a first or a second face of the insulator plate, so that the protrusion and the recess are fitted. In such a construction, at least those end portions of electrical cables of a sub-harness which are envisaged to be connected to those contained in other sub-harnesses are connected to a first unitary connector assembly by clamping. Thereafter, in the main bundling step, the first unitary connector assembly is superposed to a second unitary connector assembly connected to another sub-harness. Accordingly, the electrical cables of different sub-harnesses are connected to one another through the second cramping connector of a corresponding joint terminal. In this manner, the electrical cables, hitherto left over for later insertion, can be handled in the final form of a sub-harness, by means of making connections with a unitary connector assembly. Further, while the first and second unitary connector assemblies are superposed, some portions thereof may need no connection therebetween, hence no need of using the second cramping connector. In such a case, the end portion of an electrical cable may be clamped such that it does not extend beyond the first cramping connector. The connection through the second cramping connector can thus be cut away selectively. The housing may include a guiding means, through which the superposed unitary connector assemblies are positioned and inserted into the housing. Preferably, the housing further comprises a locking means, by which the unitary connector assemblies are fixed in the housing, once they are moved thereinto completely. The unitary connector assemblies are thus held together, after they have been superposed and the necessary connections have been made therebetween. The mounted unitary connector assemblies can then be easily fixed at a desire position in a wire harness. When a connection in a same unitary connector assembly is not needed between the adjacent electrical cables held by the corresponding first cramping connectors, the link portion in the joint terminal is cut out through the opening by using a cutting tool. Various kinds of new circuit settings can thus be responded to very quickly. Further, an electrical cable may be clamped to a joint terminal with unnecessary link portions cut off, before the joint terminal has been fixed to an insulator plate by insert-molding or the like. Unnecessary work steps at the level of the joint terminals can thus be avoided. Suitably, the height of a rib portion is designed such as to define an available space when the unitary connector assemblies are superposed. By defining this height, a deflection of the cramping blade portion can be avoided, and the cramping connections are made more reliably when cable's end portions are being clamped by the cramping connectors. Further, when the unitary connector assemblies are superposed and the electrical cables of the superposed unitary connector assemblies are fixed by the cramping connectors, the rib portion can be used as a stopper for regulating the vertical movement. The above and the other objects, features and advantages of the present invention will be made apparent from the following description of the preferred embodiments, given as non-limiting examples, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a known joint connector when it is being mounted; Fig.2A is a cross-sectional side view of another known joint connector; Fig.2B is a perspective view of a terminal used in the joint connector of Fig.2A; Fig.3 is a schematic diagram showing a known construction of preliminarily bundled sub-harnesses and a bundled wire harness; Fig.4 is a perspective view of a joint connector according to the invention; Fig.5 is a perspective view of a joint terminal according to the invention; Fig.6A is a perspective, upper-side view of a unitary connector assembly of the invention, when it is connected with electrical cables; Fig.6B is a perspective, under-side view of the unitary connector assembly of Fig.6A; Fig.7 is a cross-sectional view of a first cramping connector of the invention; Fig.8A is a perspective view of a unitary connector assembly of the invention; Fig.8B is a cross-sectional view of the unitary connector assembly of Fig.8A; Fig.9 is a cross-sectional enlarged view when a middle link is cut away; Fig.10A is a side view when a joint connector is carried into a housing; Fig.10B is a front view when the joint connector of Fig.10A is stored in the housing; Fig.11 is a cross-sectional view of a variant fixture in which a joint terminal is fixed to an insulator plate. Fig.4 shows a joint connector 10 according to one aspect of the present invention. A joint terminal 11 is connected to end portions of corresponding electrical cables W, and fixed on a substantially flat insulator plate 12, thereby forming a unitary connector assembly 13. A joint connector 10 is formed by superposing a plurality of such unitary connector assemblies 13. In this manner, the electrical cables W mounted in a single unitary connector assembly 13 can be electrically connected to one another, while those mounted in different unitary connector assemblies 13 can also be electrically connected to one another. Fig.5 shows a joint terminal 11 formed by folding a metal plate stamped out in a given shape. In the joint terminal 11, a plurality of unit terminals 11A, 11B, etc., which respectively include a stem portion 11a having an elongate shape, are arranged in parallel. The stem portions 11a of each unit terminal 11A,11B, etc. are bound to one another through a middle link 11b located at a substantially central point over the length of each stem portion 11a, so as to yield a necessary number of unit terminals to be connected. A portion adjacent a first end of the stem portion 11a (right-hand upper side in Fig.5) may be provided with a cable holder 11c which extends therefrom and may form a barrel shape when in use. Each cable holder 11c press-fixes the end portion of an electrical cable W received on the stem portion 11a. There is also provided a first cramping connector 11d located farther from the first end of the stem portion 11a and adjacent the cable holder 11c. The first cramping connector 11d includes a pair of first sidewalls 11d-1 formed by upwardly bending a pair of enlarged side portions of the stem portion 11a. Further, each of the first sidewalls 11d-1 includes a pair of first cramping blades 11d-2 extending therefrom towards the corresponding first cramping blades 11 d-2 of the opposing first side-wall 11d-1. Likewise, a second end of the stem portion ) 11a (left-hand lower side in Fig.5) is provided with a pair of second sidewalls 11e-1 with a respective pair of second cramping blades 11e-2, thereby forming a second cramping connector 11e. However, the second cramping connector 11e is formed such as to extend opposite to the direction of the first cramping connector 11d. The second cramping connector 11e can thus serve for cramping an electrical cable W connected to another joint terminal 11. When establishing the mechanical and electrical links between unit terminals 11A, 11B, etc., the means used are not limited to the above-mentioned middle link 11b. An end link 11b-1, which has been used as a manufacturing conveyer when the unit terminals were made, can also be used appropriately. However, the middle link 11b is better suited for miniaturizing the joint terminal 11. When such is the case, the end link 11b-1 is cut away after a joint terminal 11 has been formed. The joint terminal 11 thus manufactured is then fixed on an insulator plate, thereby forming a unitary connector assembly 13. To this end, amongst the electrical cables included in a sub-harness, at least those which are to be connected to the electrical cables W in other sub-harnesses are first selected. Those selected electrical cables W are then cramped by the first cramping connector 11d of the joint terminal 11, such that the latter is brought into contact with a core wire Wb contained in an electrical cable W (see Fig.7). In addition, the electrical cable W is cramped such that an end portion thereof is laid at a position of stem portion 11a which corresponds to the rear side of the second cramping connector 11e which is located near the second end of the stem portion 11a. If the unit terminals 11A, 11B, etc. are to be electrically shut, the middle link 11b is cut out beforehand. A plurality of unitary connector assemblies 13 are then superposed so that electrical cables W are connected in the vertical direction too. When a connection is not needed, the electrical cable W concerned is not extended to the back of the second cramping connector 11e, while the same electrical cable W is cramped by the first cramping connector 11d. As can be understood from Figs.6 and 7, the joint terminal 11 connected to an electrical cable W through cramping connector may be insert-molded, together with an insulator plate 12. The joint terminal 11 fixed on a first surface of the insulator plate 12 may thus include a first cramping connector 11d and a cable holder 11c respectively projecting upwardly from the first surface, as well as a second cramping connector 11e projecting downwardly from a second surface of the insulator plate 12. The first surface of the insulator 12 may be provided with a first rib portion 12a between the first cramping connectors 11d of respective unit terminals 11A, 11B, etc.. Likewise, the second surface thereof is provided with a second rib portion 12b between the second cramping connectors 11e of respective unit terminals 11A, 11B, etc.. The first and second rib portions 12a and 12b may be formed integrally with the insulator plate 12, and prevent the flexion of corresponding cramping blades 11d-2 and 11e-2 when they cramp an electrical cable W. These rib portions 12a and 12b have a height slightly greater than that of the first and the second cramping connectors 11d and 11e such that, when unitary connector assemblies 13 are superposed, the rib portions 12a and 12b define an available space and protect the first and the second cramping connectors 11d and 11e. Alternatively, as shown in Figs.8A and 8B, a joint terminal 11, unconnected to electrical cables W, may be insert-molded together with an insulator plate 12. Moreover, an orifice 12c may be provided in the insulator plate 12, at a position corresponding to that of the middle link 11b bridging the stem portions 1a of each unit terminal 11A, 11B, etc. As shown in Fig.9, this orifice 12c serves for inserting a cutting tool 14 which cuts away the middle link 11b. The cutting tool 14 thus can shut the electrical connection between the adjacent unit terminals 11A, 11B, and the like, by cutting off a desired middle link 11b. In the manner described above, the sub-harnesses can take a final form which contains no "yet-to-be connected" terminals. Such sub-harnesses are subjected to a main bundling process on an assembly board. In this process, as shown in Figs.4 and 10A, the unitary connector assemblies 13 attached to the end portions of the cables of each sub-harness are superposed. To this end, the unitary connector assemblies 13 are arranged vertically, and pushed from above by an assembly tool. In this manner, a first electrical cable W extending from the first cramping connector 11d in a first unitary connector assembly 13 is clamped by the cramping blades 11 e-2 of the second cramping connector 11e in a second unitary connector assembly 13, so that the superposed unitary connector assemblies 13 are electrically connected through their electrical cables W. In this case, a second electrical cable Wa staying at the position of the first cramping connector 11d in the first unitary connector assembly 13 is not caught by the second cramping connector 11e in the second unitary connector assembly 13, so that electrical connections are not established between the superposed unitary connector assemblies 13. As shown in Figs.10A and 10B, the superposed unitary connector assemblies 13 may be contained, for example, in a housing 15. The housing 15 may include, for example, a plurality of enclosures 15a, each of which can contain a unitary connector assembly 13. The housing 15 may also include a guiding means 15b formed into a groove, through which both side rims of an insulator plate 12 are carried into an enclosure 15a. Further, each unitary connector assembly 13 may be fixed in the housing 15 by a locking means 16. The locking means 16 includes a protrusion 16a provided on each side face of the insulator plate 12, and a corresponding recess 16b provided on the guiding means 15b. In the above embodiment, the joint terminal 11 is fixed onto the insulator plate 12 by insert-molding. Fig.8 shows another embodiment, in which the stem portion 11a of joint terminal 11 is provided with a stud 11f, whilst the insulator plate 12 is provided with a corresponding stud hole 12d. The stem portion 11a is then flanked along a surface of the insulator plate 12, and fixed thereto by these stud and stud hole. According to the present invention, when sub-harnesses are to be mounted, at least those electrical cables hitherto left over for later connections are arranged into a joint terminal in a unitary connector assembly. When such unitary connector assemblies are superposed on each other in the main bundling process, the electrical cables are electrically connected to those of other sub-harnesses through a corresponding joint terminal. Accordingly, the sub-harnesses no longer contain left-over, "yet-to-be connected" terminals. Handling steps and the time required for fixing such terminals are thus reduced, so that wire harness can be mounted more efficiently. Further, damage to the terminals, which often occurs during the transfer of sub-harnesses, can be avoided, so that the wire harness acquires a better quality and is rendered more reliable. Furthermore, the joint terminal of the invention can easily respond to changes of the circuits to be joined. Alternatively, electrical cables may be first clamped to a joint terminal, unnecessary unit terminals forming such a joint terminal may be cut off, and the joint terminal is fixed on an insulator plate or board. The joint terminal can thus be configured rationally and economically.

Claims: A joint terminal (11) comprising a plurality of unit terminals (11A, 11B, and the like), each unit terminal including: a stem portion (11a) in the form of an elongate strip having a first face with a first side rim portion, a second face with a second side rim portion, and a third side rim portion; at least one link portion (11b) extending from said third side rim portion on substantially the same plane as said stem portion (11a), characterized in that at least a first cramping connector (11d) projects upwardly from said first side rim portion in a direction substantially perpendicular to said first face of said stem portion (11a), said first cramping connector (11d) including a first cramping blade portion (11d -2) adapted to be connected to a first electrical cable; at least a second cramping connector (11e) projects downwardly from said second side rim portion in a direction substantially perpendicular to said second face of said stem portion (11a), said second cramping connector (11e) including a second cramping blade portion (11e-2) adapted to be connected to a second electrical cable; wherein said plurality of unit terminals (11A, 11B, and the like) are arranged substantially in parallel relation to one another over the length thereof, and bound through said at least one link portion (11b). The joint terminal (11) according to claim 1, wherein said each unit terminal (11A, 11B, or the like) further includes at least one cable holder (11c) extending from a side rim portion of said stem portion (11a), and adapted for holding said first electrical cable placed on said stem portion (11a). A unitary connector assembly (13) comprising an insulator plate (12) and a joint terminal (11) fixed therewith, said joint terminal (11) comprising a plurality of unit terminals (11A, 11B, and the like), each unit terminal includes: a stem portion (11a) in the form of an elongate strip having first and second faces, and first, second and third side rim portions; at least a first cramping connector (11d); at least a second cramping connector (11e); and at least one link portion (11b); said joint terminal (11) being fixed with said insulator plate (12) characterised in that : said at least a first cramping connector (11d) projects upwardly from said first side rim portion in a direction substantially perpendicular to said first face of said stem portion (11a), said first cramping connector (11d) including a first cramping blade portion (11d-2) adapted to be connected to a first electrical cable; said at least a second cramping connector (11e) projects downwardly from said second side rim portion in a direction substantially perpendicular to said second face of said stem portion (11a), said second cramping connector (11e) including a second cramping blade portion (11e-2) adapted to be connected to a second electrical cable; and said at least one link portion (11b) extends from said third side rim portion on substantially the same plane as said stem portion (11a); wherein said plurality of unit terminals (11A, 11B, and the like) are arranged substantially in parallel relation to one another over the length thereof, and bound through said at least one link portion (11b); and said insulator plate (12) comprising an opening (12c) at a position corresponding to the position of said at least one link portion (11b), said opening (12c) being adapted to receive a cutting tool (14) for cutting said at least one link portion (11b). The unitary connector assembly (13) according to claim 3, wherein said each unit terminal (11A, 11B, or the like) further includes at least one cable holder (11c) extending from a side rim portion of said stem portion (11a), and adapted for holding a first electrical cable placed on said stem portion (11a). A joint connector (10) comprising at least first and second unitary connector assemblies (13) respectively including an insulator plate (12) and a joint terminal (11) fixed therewith, said joint terminal (11) comprising a plurality of unit terminals (11A, 11B, and the like), each unit terminal includes: a stem portion (11a) in the form of an elongate strip having first and second faces, and first, second and third side rim portions; at least a first cramping connector (11d); at least a second cramping connector (11e); and at least one link portion (11b); said joint terminal (11) being fixed with said insulator plate (12) characterised in that : said at least a first cramping connector (11d) projects upwardly from said first side rim portion in a direction substantially perpendicular to said first face of said stem portion (11a), said first cramping connector (11d) including a first cramping blade portion (1d-2) adapted to be connected to a first electrical cable; said at least a second cramping connector (11e) projecting downwardly from said second side rim portion in a direction substantially perpendicular to said second face of said stem portion (11a), said second cramping connector (11e) including a second cramping blade portion (11e-2) adapted to be connected to a second electrical cable; and said at least one link portion (11b) extends from said third side rim portion on substantially the same plane as said stem portion (11a); wherein said plurality of unit terminals (11A, 11B, and the like) are arranged substantially in parallel relation to one another over the length thereof, and bound through said at least one link portion (11b); and said at least first unitary connector assembly (13) being superposed on said at least second unitary connector assembly (13), so that said second cramping connector (11e) of said at least first unitary connector assembly (13) cramps said second electrical cable; whereby said first electrical cable to be carried on said at least first unitary connector assembly (13) can be connected to said second electrical cable to be carried on said at least second unitary connector assembly (13). The joint connector (10) according to claim 5, wherein said each unit terminal (11A, 11B, or the like) further includes at least one cable holder (11c) extending from a side rim portion of said stem portion (11a), and being adapted for holding a first electrical cable placed on said stem portion (11a); The joint connector (10) according to claim 5 or 6, further comprising a housing (15) which contains said at least first and second unitary connector assemblies. The joint connector (10) according to any one of claims 5 to 7, wherein said insulator plate (12) is provided with an opening (12c) at a position corresponding to the position of said at least one link portion (11b), such that said opening (12c) can receive a cutting tool (14) for cutting said at least one link portion (11b). The joint connector according to any one of claims 5 to 8, wherein said insulator plate (12) comprises a rib portion (12a, 12b) placed adjacent a side of said first or second cramping connector (11d, 11e), opposite to the side where said pair of cramping blades is mounted, such that said first or second cramping connector (11d, 11e) is prevented from flexing when said first or second electrical cable is inserted thereinto. A method of manufacturing the joint connector (10) defined by any one of claims 5 to 9, said method comprising the steps of: (a) providing, in said stem portion (11a), first and second pairs of enlarged side portions with a corresponding first or second pair of cramping blades indented therefrom, and (b) bending said first and second pairs of enlarged portions, respectively, so that said first pair of cramping blades face each other, whilst said second pair of cramping blades face each other, whereby said first and second cramping connectors (11d, 11e) are formed. The method according to claim 10, further comprising the step of (c) fixing said joint terminal (11) with said insulator plate (12) by means of insert-molding.

Inventors: ITO YASUO, KUSUMOTO KUNIHARU, ITO, YASUO, KUSUMOTO, KUNIHARU
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2000
Main classification: H01R31
IPC codes: H01R31, H01R4, H01R9