Flat cable with conductor ends connectable to connector

Abstract: A flat cable including a plurality of conductor strips which are formed by punching a single metal foil and are embedded within an insulating sheet, in which at an end portion of the flat cable, bifurcated portions are folded back one on another such that end terminals of conductor strips of one bifurcated portion are inserted between end terminals of conductor strips of another bifurcated portion, so that an order in which end terminals of the conductor strips are aligned can be changed. Therefore, an electric connection between connectors requiring crossings of conductor strips can be established by a single flat cable.

Description: Background of the Invention Field of the Invention The present invention relates to a flat cable comprising a plurality of foil-like conductor strips having end portions connectable to terminals of a connector, and an insulating sheet in which said foil-like conductor strips are embedded in a manner such that the conductor strips are electrically isolated from each other. Related Art Statement The flat cable of kind mentioned in the preamble has been widely used in automobiles for connecting various electric parts. In case of manufacturing a flat cable, a metal foil is punched to form a plurality of foil-like conductor strips and then these conductor strips are sandwiched between insulating films made of synthetic resin such as PET to form a laminated structure. Recently the number of electric parts has been increased and the circuit arrangement has become very complicated. Therefore, it has become difficult to establish an electrical connection between connectors by means of a single flat cable. For instance, in automobiles, plural kinds of flat cables having different structures have been used. This results in that a design of a circuit arrangement, manufacturing and cable fitting operation are liable to be complicated and the number of operation steps is increased so that an efficiency of manufacture is decreased. Therefore, a manufacturing cost is increased. Fig. 1 is a plan view showing a circuit arrangement, in which a first connector 1 includes terminals a1, a2, a3, a4 and a5 aligned in this order and second connector 2 has terminals b5, b4, b1, b2 and b3 aligned in this order. It should be noted that terminals of the first and second connectors 1 and 2 having the same suffixes have to be connected to each other. That is to say, the terminal al of the first connector 1 should be connected to the terminal bl of the second connector 2, the terminal a2 of the first connector 1 has to be connected to the terminal b2 of the second connector 2, and so on. If the corresponding terminals of the first and second connectors 1 and 2 are connected by means of a single flat cable Fc, the flat cable should have conductor strips c1-c5 some of which are crossed with each other. That is, the conductor strips c4 and c5 have to be crossed with the other conductors c1-c3 and further the conductor strips c4 and c5 should be crossed with each other as illustrated in Fig. 1. The circuit arrangement shown in Fig. 1 is sometimes used in automobiles. In automobiles, a main harness is commonly used for different kinds of cars or at different portions of a car in order to reduce the number of different kinds of parts and a manufacturing cost. For instance, an inner door unit to be connected to the terminals a4 and a5 situates below the terminals b1-b3. In such a basic structure or specification, it is required to arrange the terminals b4 and b5 above the terminals b1-b3 in another kind of car or specification due to a layout within the inner door space. In such a case, it is impossible to perform the connection between the connectors 1 and 2 by means of a single known flat cable, and at least two flat cables are required, one having a pattern for connecting the terminals a1, a2 and a3 to the terminals b1, b2 and b3, respectively and the other having a pattern for connecting the terminals a4 and a5 to the terminals b4 and b5, respectively. In a known flat cable illustrated in Fig. 2, one end of the flat cable 6 includes end terminals connectable to terminals d1, d2, d3, d4, d5 and d6 of a first connector 3, and the other end of the flat cable has a first set of end terminals connectable to terminals e4 and e5 of a second connector 4 and a second set of end terminals connectable to terminals e3, e1, e2 and d6 of a third connector 5. Also in this case, foil-like conductor strips of the flat cable 6 have to be crossed with each other, so that it is practically difficult to perform the electrical connection between the first connector 3 and the second and third connectors 4 and 5 by means of a single flat cable. That is, in order to connect the first connector 3 to the second and third connectors 4 and 5, it is required to use a first flat cable connecting the terminals d4 and d5 of the first connector 3 to the terminals e4 and e5 of the second connector 4 and a second flat cable connecting the terminals d3, d1, d2 and d6 of the first connector 3 to the terminals e3, e1, e2 and e6 of the third connector 5. As explained above, when an electric connection between connectors requires crossings of conductor strips, it is difficult to perform an electric connection by means of a single flat cable, so that a plurality of flat cables have to be used. Therefore, when a circuit arrangement becomes complicated, a larger number of flat cables of different structures are required. Therefore, the number of steps in designing is increased and the fitting operation of flat cables becomes cumbersome. Moreover, when the number of kinds of flat cables is increased, the number of blanking dies for manufacturing the flat cables is increased accordingly, and thus the manufacturing cost is increased. DE-B-2743648 discloses a flat cable according to the preamble of claim 1 of the accompanying claims. The flat cable has a plurality of foil-like strips which are folded back on one another. The present invention has for its object to provide a novel and useful flat cable which can establish an electrical connection between connectors even if the electrical connection requires crossings of conductor strips. According to the invention there is provided a flat cable comprising a plurality of foil-like conductor strips having end terminals connectable to terminals of a connector and an insulating sheet in which said conductor strips are embedded such that they are electrically isolated from each other, and the flat cable having an end section, including said end terminals, where the conductor strips are arranged in parallel, the end section having a fold extending along a line parallel to the conductor strips in the end section characterized in that a space is provided in said end terminals and a part of said end section which does not include said space is folded back along said line so that an end terminal of at least one of the conductor strips of the folded part is placed in said space so that an order of the end terminals of the conductor strips is changed and the end terminals of all the conductor strips lie in the same plane. In one embodiment of the invention said space is formed in said end section of the cable at a position remote from said folded part of the end section. In another embodiment of the invention said space is formed between end terminals of adjacent foil-like conductor strips. In a yet further embodiment of the invention said plurality of conductor strips includes first, second and third foil-like conductor strips and said conductor strips are initially arranged in said end section of said flat cable in an order of said second conductor strip, said first conductor strip and said third conductor strip with said space provided between said first and third conductor strips and said fold is arranged between said second and first conductor strips so that after folding said end section, said conductor strips are arranged in a straight line in an order said first conductor strip, said second conductor strip and said third conductor strip. Brief description of the Drawings: Figure 1 is a schematic view showing an electrical connection including crossings of conductors; Figure 2 is a plan view illustrating a known flat cable; Figure 3 is a schematic view depicting a principal construction of the flat cable according to the invention; Figure 4 is a schematic plan view showing a first embodiment of the flat cable according to the invention; and Figure 5 is a schematic plan view representing a second embodiment of the flat cable according to the invention. Figure 3 is a schematic view showing a principal construction of the flat cable according to the invention. A connector 15 in Figure 3 is identical with the connector 1 shown in Figure 1 and includes terminals a1, a2, a3, a4 and a5 aligned in this order. A connector 16 is identical with the connector 2 in Figure 1 and comprises terminals b5, b4, b1, b2 and b3 arranged in this order. It should be noted that the terminals having the same numerical suffixes are to be connected to each other by means of a flat cable 17 including foil-like conductor strips c1, c2, c3, c4 and c5. At one end portion of the flat cable 17, end terminals of the conductor strips c1, c2, c3, c4 and c5 are arranged in this order at a pitch which is identical with a pitch at which the terminals a1, a2, a3, a4 and a5 of the connector 15 are aligned. At the other end portion of the flat cable 17, end terminals of conductor strips c1, c2 and c3 form a first set of end terminals and end terminals of the conductor strips c4 and c5 form a second set of end terminals as a bifurcated end portion 17'. The end terminals of the conductor strips c1, c2 and c3 are arranged at a pitch at which the terminals b1-b5 of the connector 16 are arranged, and the end terminals of the conductor strips c4 and c5 of the bifurcated end portions 17' are separated from each other by said pitch. According to the invention, the bifurcated end portion 17' is folded back along a line A-A over the end terminal portion of the conductor strips c1-c3 as shown by chain lines in Figure 3 such that the end terminals of the conductor strips c4 and c5 are positioned above the end terminals of the conductor strips c1-c3. In this manner, the end terminals of the conductor strips c5, c4, c1, c2 and c3 are aligned in this order at said pitch, so that they can be connected to the terminals b5, b4, b1, b2 and b3 of the connector 16. In the flat cable according to the invention, at one end portion the end terminals of the conductor strips c1, c2, c3, c4 and c5 are arranged in this order and at the other end portion, the end terminals of the conductor strips c5, c4, c1, c2 and c3 are arranged in this order. Therefore, a given electrical connection between the connectors 15 and 16 including crossings of conductor strips can be established by the single flat cable 17. Figures 4 and 5 are schematic plan views depicting a first embodiment of the flat cable according to the invention. As shown in Figure 4, a flat cable 22 of the present embodiment is used to establish an electrical connection between first and second connectors 20 and 21 and a third connector 23, and comprises a plurality of foil-like conductor strips F1, F2, F3 ---F6. The first connector 20 includes terminals d3, d1, d2 and d6 arranged in this order, the second connector 21 has terminals d4 and d5 and the third connector 23 comprises terminals e1, e4, e3, e4, e5 and e6 aligned in this order. The flat cable 22 comprises a main portion 22a including the conductor strips F3, F1, F2 and F6, a first bifurcated end portion 22b including the conductor strips F5 and F4, a second bifurcated portion 22c including the conductor strips F5, F4 and F3, and a third bifurcated portion 22d including the conductor strips F1, F2 and F6. End terminals of the conductor strips of the main portion 22a are to be connected to the terminals of the first connector 20 and end terminals of the conductor strips of the first bifurcated portion 22b are to be connected to the terminals of the second connector 21. End terminals of the conductor strips F5, F4 and F3 of the second bifurcated portion 22c and end terminals of the conductor strips F1, F2 and F6 of the third bifurcated portion 22d are to be connected to the terminals of the third connector 23. In the third portion 22d, the conductor strips F1, F2 and F6 are arranged such that between the end terminals of the conductor strips F2 and F6, there is formed a space having such a width that three end terminals of the conductor strips can be inserted therebetween. According to the invention, the second bifurcated portion 22c is folded back about a line B-B over the third bifurcated portion 22d such that the end terminals of the conductor strips F3, F4 and F5 of the second bifurcated portion 22c are inserted into said space formed between the end terminals of the conductor strips F2 and F6 of the third bifurcated portion 22d. It should be noted that said line B-B should extend perpendicular to an edge of the end terminals. Figure 5 shows the flat cable 22 after the above mentioned folding operation. As shown in Figure 5, at the end portion of the flat cable 22 to be connected to the third connector 23, the end terminals of the conductor strips F1, F2, F3, F4, F5 and F6 are aligned in this order, so that these end terminals of the conductor strips F1-F6 can be connected to the corresponding terminals e1-e6 of the third connector 23. It should be noted that in the present embodiment, the end terminals of the conductor strips F1-F6 at the end portion connectable to the third connector 23 are aligned on a single plane. After that, the end terminals of the conductor strips F1-F6 are connected to metal terminals in a synthetic resin housing not shown. The present invention is not limited to the embodiments explained above, but many modifications and alternatives may be conceived by those skilled in the art within the scope of this invention. For example, a bifurcated portion may be folded back about a plurality of lines. As explained above, in the flat cable according to the invention, by folding back a bifurcated portion of the flat cable such that an order in which the end terminals of the conductor strips are arranged can be changed. Therefore, a design of circuit arrangements can be simplified and a flat cable including crossings of conductor strips can be simply manufactured. Then, a manufacturing cost of flat cables can be decreased. Furthermore, the number of kinds of flat cables to be prepared for establishing desired electrical connections between various connectors can be reduced.

Claims: A flat cable comprising a plurality of foil-like conductor strips (F1-F6) having end terminals connectable to terminals (e1 ... e6) of a connector (23) and an insulating sheet in which said conductor strips (F1-F6) are embedded such that they are electrically isolated from each other, and the flat cable having an end section, including said end terminals, where the conductor strips (F1-F6) are arranged in parallel, the end section having a fold (B-B) extending along a line parallel to the conductor strips in the end section characterized in that a space is provided in said end terminals and a part of said end section which does not include said space is folded back along said line (B-B) so that an end terminal of at least one of the conductor strips (F3,F4,F5) of the folded part is placed in said space so that an order of the end terminals of the conductor strips (F1-F6) is changed and the end terminals of all the conductor strips (F1-F6) lie in the same plane. A flat cable as claimed in claim 1, wherein said space is formed in said end section of the cable at a position remote from said folded part of the end section. A flat cable as claimed in claim 1, wherein said space is formed between end terminals of adjacent foil-like conductor strips (F2,F6). A flat cable according to claim 3, wherein said plurality of conductor strips includes first, second and third foil-like conductor strips (F2,F3,F6) and said conductor strips are initially arranged in said end section of said flat cable in an order of said second conductor strip (F3), said first conductor strip (F2) and said third conductor strip (F6) with said space provided between said first and third conductor strips (F2,F6) and said fold (B-B) is arranged between said second and first conductor strips (F3,F2) so that after folding said end section, said conductor strips (F2,F3,F6) are arranged in a straight line in an order said first conductor strip (F2), said second conductor strip (F3) and said third conductor strip (F6). A flat cable according to claim 1, wherein the end section has more than one said fold.

Inventors: AKOU HIROMASA, KISHI TAKAFUMI, MIYASAKA EIICHI, NAKAGAWA CHIHIRO, SUGITA TAKAO, WATANABE KENJI, AKOU,HIROMASA, KISHI,TAKAFUMI, MIYASAKA, EIICHI, NAKAGAWA, CHIHIRO, SUGITA, TAKAO, WATANABE,KENJI
Applicants: MITSUBISHI CABLE IND LTD, MITSUBISHI CABLE INDUSTRIES LTD
Application year: 1995
Main classification: H01B7
IPC codes: H05K3, H02B1, H05K1