MULTIPLE JUNCTION DEVICE

Abstract: A connection tab (2, 2′) for making contact with an electric wire (3) at a wire contact, having a connecting end remote therefrom, and being offset from the wire contact in a direction longitudinal of and/or perpendicular to the electric wire (3). A junction device including a wiring board (1) having a connection area (7) and one or more electric wires (3) to be connected. The wires (3) are located beneath the wiring board (1) and there is also provided one or more of the connection tabs (2, 2′). The junction device may have a plurality of wiring boards (1) and the invention provides a very compact means for making a plurality of complex connections.

Description: The present invention relates to a multiple-layered junction device for making electrical shunt within electrical circuit in an integrated joint unit. The junction device of the present invention is especially useful for automotive-junction devices where electrical circuit is provided by means of electric wires having an insulation through which electrical contact is made by means of a connecting tab having a blade cutting through the insulation of the wire. In wiring harness assemblies, electrical connection is usually made by using connectors or couplers which are designed to be mated together. As the number of electrical circuit increases the connection is often made using an integrated connection unit in which a plurality of connections is made within a single junction device consisting of wiring board either of one or multi-layers with insulating layer or layers of plastic substrate between electrical terminals and a plastic housing or case. The circuit is often provided by wiring insulated wire on the backside surface of the insulation board, the lower tips of the connection tabs being fitted with the wire at pre-determined shunt point and being held in a direction perpendicular to the insulation board through it. The opposite top portions of the connection tabs are aligned in a row with specific intervals in order to be engaged with a coupling connection means such as another mated connector respectively. The conventional connection tab is usually designed in such way that the lower wire-fitting part has a relatively wide throat portion in its lower end since electrical contact to the wire conductor is made here by squeezing the wire until its insulation is penetrated. In a junction device with multiple-layered structure, the connection tabs therefore should be aligned with a large interval in order to avoid contact with the connection tabs which will be used in the upper circuit layer and thus poor space factor of the total device results. Document EP-A-0 171 737 discloses an electric wire branching connecting device having upper and lower cases adapted to clamp therebetween a first group of electric wires arranged in a side-by-side fashion. The device also has a plurality of terminal strips, each of the terminal strips being provided at its one end with at least one male terminal and at its other end with a wire grip position having a U-shaped slot. It is a main object of the present invention to provide a multiple-layered junction device with increased density of connection utilizing a connection tab having a wire contact throat in one end portion while another end portion will be engaged with a mating member of another electrical connector. This object is achieved by the features mentioned in claim 1. A multiple junction device having high density of electrical connection is disclosed comprising an upper wiring board with connecting areas for making an electrical contact with a connector from outside of the device respectively, an insulating board under which electric wire with insulation is wired, and suitable number of connection tabs projecting through openings in the insulation board for making electrical contact with the conductor of the wire at their lower end portion and standing in upright position, another wiring board of necessary number which is located under the upper wiring board consisting of the same elements as described for the preceding upper wiring board except connecting areas, a bottom frame or casing with suitable number of grooves for receiving the lowest tips of the throats of the wire connection end portions of the connecting tabs which have direct contact with the wire conductor through insulation. The connection tab has a flattened structure and one end portion is designed either as a male or a female terminal for mating with opponent tab in a connector from outside of the device. The other end portion of the tab has a direct contact with the wire conductor. In the junction device of the present invention the longitudinal axes of the upper and lower end portions are shifted from each other in either direction of the wire path going through the contacting throat or in the direction perpendicular to that wire path. By shifting the axes of both ends of tab, and by holding the wire contact throat through a slit in the adjacent lower insulating board a junction device of high density of connection is achieved. Further features, advantages and alternatives of the present invention will become more apparent as the description proceeds with reference to the accompanying drawings wherein: Fig. 1 is an explanatory block diagram of a single-layered junction device of the present invention; Fig 1(a) shows an upper wiring board; Fig. 1(b) shows pieces of an insulated electric wire placed on the bottom casing; Fig. 1(c) shows a bottom casing with grooves on the surface; Fig. 2 is a block diagram of a multiple-layered junction device of the present invention; Fig. 2(a) illustrates an upper wiring board with connecting areas; Fig. 2(b) illustrates a lower wiring board; Fig. 2(c) shows a bottom casing with grooves on the surface; Fig. 3 shows a configuration of a connection tab used in the present invention with shifted axis in a Y- direction between the wire-connecting end portion and the contact portion; Fig. 4 shows a configuration of a connection tab used in the present invention with a shift in a X-direction axis between the wire-connecting end portion and the contact; Fig. 5 to 7 illustrate the state of wiring in a board(s) or panel(s) of the device of the present invention; Fig. 8 shows a cross-sectional view of a part of the multiple junction device of the present invention in which the contact portion 9 placed in a slit 12 is illustrated. Fig. 1 is a explanatory block diagram of the single-layered junction device showing components of the junction device of the present invention where the contact portion appears in the upper case and the opponent end portion of connection tabs 2 is connected to the conductor of an insulation wire 3 on the backside of an upper wiring board 1, at a throat of the tab. The electrical circuit is wired on the backside plane of the upper wiring board 1 with a plurality of shunts provided by the connecting end portions 2a of the tabs 2 whose bottom portions are held within grooves engraved upon an upper surface of a lower substrate or bottom casing 4. One of the characteristic feature of the multiple junction device of the present invention is incorporation of a connection tab with a configuration as illustrated in Fig.3 and Fig.4 where the longitudinal axis of wire-contact end is shifted in either direction of the path of wire X in a throat 2c or in the direction Y which is perpendicular to the wire path from the longitudinal axis of the contact portion of the tab 2. This shift enables the contact portion 2b of the tab 2, which is connected to the conductor of a wire located on the lower layer 6, to be free from interaction with the connecting end portion 2a of the tab 2 used in the neighbouring upper layer 1. Another characteristic feature of the present invention which provides high density of electrical junction in one unit device of limited volume is to increase the distance between the substrates of the two wiring boards by holding, in a hanging manner, the wire-contact end portion 2b of the tab 2 within a space between the two layers through a slit in the substate of the lower wiring layer. The wire for use in the multiple junction device of the present invention is made either of twisted wires or a single conductor wire with electrical insulation. For practical wiring operation an insulated wire having a single non-twisted, hard copper conductor is suitable to have wires being aligned in a common wiring plane. Referring again to Fig. 1, the single-layered junction device includes an upper wiring board 1 having a number of connecting areas 7, connection tabs 2 and pieces of wires 3 to which the throat 2c of the connection tab 2 has electrical contact in order to form a shunt in the circuit. In Fig. 2 a double-layered junction device is illustrated in which the upper wiring board 1 has connecting areas 7 and electric insulated wire 3. Fig. 2(b) shows a lower wiring board 6 with electric wire pieces on the backside of an insulation board 9 through which the upper portions 2a of the connection tabs 2, i.e. the connecting end portions are projecting for making a coupling alignment with electrical connector from outside of the device. The bottom casing 4 has grooves for receiving the wire contact portions 2b of the tabs 2 which are projecting beyond the surface of the insulation board 9. The bottom end of the connection tab 2 is provided with a throat and there is provided a blade so as to make an electrical contact with the conductor of the electric wire by penetrating its insulation layer. The configuration of the connecting tab 2 is described further in details by referring to Fig. 3 and Fig. 4. In Fig. 3, the contact end portion 2a is either a male or a female connecting terminal and on the opposing end portion 2b there is provided a wire-contacting throat structure 2c. As the tab 2 has a flat structure, the end portions 2a and 2b are both positioned in a common plane. In Fig. 3, axis X is a direction of the wire path and Y is an axis perpendicular to X. As can be seen in the Fig. 3, the longitudinal axis of the throat 2c is shifted in Y-direction with respect to the longitudinal axis of the end portion 2a. In Fig. 4, the connection tab 2 has a deviated structure in which the two longitudinal axes of the end portion 2a and 2b are shifted both in X and Y directions. Referring to Fig. 5, the wire contact end portion 2b of the connection tab 2 is positioned in a zigzag formation in order to achieve close alignment of the opposing connecting end portions 2a whose pitch is determined by another mating connector coming from electric/electronic device to be coupled. When the longitudinal axis of the connecting end portion 2a is shifted in Y direction and also a bend 2d is directed toward X direction, the contact end portion 2b on the upper wiring board 2 is ultimately located in both X and Y deviated position from the original coordinate of the throat where X=0 and Y=0. On the other hand, the connecting end portion 2b of the tab 2 used for the lower wiring board 6 is not shifted from the original throat position, and is held on the insulation board 9 through a slit 8. Further, as shown in Fig. 8, the contact end portion 2b of the tab 2 used for the upper wiring board 1 also passes through the insulation board 9 and rests on the bottom casing 4. On the backside of the connecting area 7, electric wires 3 are aligned on Y axis and corresponding slits 8 in the insulation board 9 are aligned on X axis. As described above, the connecting end portion 2a is inserted into the slit 8 and the contact end portion 2b of the tab 2 used for the upper wiring board 1 is shifted in X direction due to the bending portion 2d in X direction. Thus, the contact end portion 2b on the tab 2 for the upper wiring board 1 does not meet with the connecting end 2a which is coming up through 9 into connector area 7. All the slits 8 on the insulation board 9 are located between the passages of electric wires 3, and no interference therefore may occur when connecting end portion 2a is inserted beneath the board 9 through the slit 8 in an upright position against wires. As understood by above description, a multiple junction device with improved space factor is thus obtained. List of reference signs: 1. upper wiring board 2,2'. connection tab 2a. connecting end portion 2b. wire contact end portion 2c. throat 2d. bend 3. electric wire 3a. electric wire 3b. conductor 4. bottom casing 5. frame 6. lower wiring board 7. connecting area 8,8'. slit 9. insulation board

Claims: A multiple junction device for making an electrical contact, having connection tabs (2) standing perpendicularly with respect to a wiring board (1, 6) and comprising a connecting end portion (2a) for making a mating engagement with another electrical connection means and a wire contact end portion (2b) where a throat (2c) is provided for making direct contact with a wire conductor (3) through the insulation of a wire, characterized in: that the multiple junction device comprises a plurality of wired electrical circuit boards (1, 6), that the wire contact end portions (2b) of the connection tabs (2) in an upper wiring board (1) are shifted in a wire path direction X and/or a direction Y which is perpendicular to X in such a way that the connecting end portions (2a) of a connection tabs (2) in an adjacent lower wiring board (6) pass through the insulation board of the upper wiring board (1) so as to go beyond the upper wiring board, but being free from interaction with said wire contact end portions (2b)of the tabs (2) in the upper wiring board (1). The multiple junction device of claim 1 in which the wire contact end portions (2b) of the connection tabs (2) in an upper wiring board (1) are maintained in a slit (8) which is provided in an insulation board (9) of the adjacent lower wiring board (6). The multiple junction device of claim 1 or 2 in which the electric circuit is formed by wiring an insulated electric wire (3) a having single copper conductor. The multiple junction device of claim 1 or 2 in which the electric circuit is formed by wiring an insulated electric wire (3) having compressed twisted copper conductors.

Inventors: NOZAKI, TAKAO, SAKA, YOUJI
Applicants: SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1988
Main classification: H01R9
IPC codes: H01R9, H01R4