MULTI CONTACT CONNECTOR HAVING GROUND TERMINAL BLOCK CONNECTED WITH TAPE WIRES AND METHOD OF CONNECTING TAPE WIRES TO MULTI CONTACT CONNECTOR

Abstract: A multi contact connector includes a ground terminal block and signal and power source terminals connected with tape wires. Bare wires of the tape wires connected to the signal and power source terminals are provided with roundabout portions respectively to form slacks in the bare wires. With this arrangement, when external tensile forces act upon the connector, the slacks prevent disconnection of bare wires for signal and power source terminals indispensable for operation of the connector, even if a few bare wires among a number of bare wires connected to the ground terminal block are disconnected.

Description: This invention relates to a multi contact connector having a ground terminal block connected with tape wires and a method of connecting tape wires to a multi contact connector having a ground terminal block. In electronic instruments such as electronic computers, connectors have been widely used, for example, for connecting printed circuit boards constituting devices to each other and connecting printed circuit boards and external devices. In this case, for example, as shown in Fig. 1 which is a perspective view illustrating a typical connector of prior art, a printed circuit board 1 is connected to an external circuit by inserting into a receptacle connector 2 connected and fixed to the printed circuit board 1 a plug connector 5 having a ground terminal block 4 and signal and power source terminals 3 respectively corresponding to ground terminals and signal and power source terminals of the board 1. The plug connector 5 is connected through wires to the external circuit. In this case, instead of conventional single wires, flexible tape wires 6 are often used which comprise bare wires 7 corresponding in number and interval to contacts of the connector and coated by an insulator 8 in the form of a tape as shown in Fig. 1. On the other hand, in connecting the bare wires of the tape-like wires to the signal and power source terminals of the plug connector, the bare wires 7₁ and 7₂ which have been cut so as to be positioned on the signal and power source terminals 3 and the ground terminal block 4, respectively, are embraced between welding electrodes to weld these bare wires to the terminals 3 and the block 4 while the wires abut thereagainst as shown in Fig. 1. Recently, electronic parts have been minimized to increase the number of parts on printed circuit boards. The increase of the number of parts requires to minimize connectors and to increase the number of contacts of the connectors. As the result, width of connecting terminals of connectors and intervals of the terminals have been narrowed limitlessly and diameters of bare wires have become thinner limitlessly. Therefore, as the connectors have been minimized and greatly increased their contacts, there is a risk of welding strength being lowered to allow the wires to be disconnected relatively easily by external tensile forces acting upon the tape wires. Moreover, as the diameters of the bare wires have become thinner, the mechanical strength of the bare wires themselves resisting to the extenal tensile forces have lowered. Accordingly, in the event that the partial bare wires are concentrically subjected to external forces, there is a risk of disconnection of the partial bare wires between the insulatingly coated portions and the welded terminals, even if the bare wires in the insulating coating subjected to distributed tensile forces do not disconnect. This risk is relatively slight in the bare wires 7₂ connected to the ground terminal block 4 but particularly acute in the bare wires 7₁ connected to the signal and power source terminals and extending from the coated portions to the welded portions. In other words, there is a tendency of the signal and power source wires to be easily disconnected, which are important because disconnection of only one wire causes an obstruction of the operation of the device. On the other hand, the bare wires for the ground terminals are more difficult to disconnect in comparison with the signal and power source wires, in spite that any obstruction of the operation of the device is not caused, even if a few strands for the ground terminals are disconnected. It is a principal object of the invention to provide a multi contact connector having a ground terminal block connected with tape wires, which prevents disconnection of bare wires for signal and power source terminals indispensable for the operation of the connector, even if a few bare wires among a number of bare wires connected to the ground terminal block are disconnected. In order to achieve this object, in a multi contact connector having signal and power source terminals extending from the connector, and a ground terminal block extending beyond and across the signal and power source terminals, and bare wires of a flexible wire tape connected with the ground terminal block and the signal and power source terminals, wherein the bare wires connected to the ground terminal block are straight and shorter than those connected to the signal and power source terminals, according to the invention, the bare wires connected to the signal and power source terminals contain a slack portion extending over the ground terminal block. In a preferred embodiment, each of said slack portion is formed by bending the bare wire at four locations to have a portion substantially parallel to an extending direction of the bare wire and spaced from the ground terminal block. It is another object of the invention to provide a method of connecting tape wires to a multi contact connector having signal and power source terminals extending from the connector and a ground terminal block extending beyond and across the signal and power source terminals comprising connecting bare wires of a flexible wire tape with the ground terminal block and the signal and power source terminals wherein the bare wires connected to the ground terminal block are straight and shorter to those connected to the signal and power source terminals, which provides the multi contact connector capable of preventing disconnection of bare wires for the signal and power source terminals. To this end, a method according to the invention further comprises connecting the bare wires to the signal and power source terminals to include a slack portion extending over the ground terminal block. The invention will be more fully understood by referring to the following detailed specification and claims taken in connection with the appended drawings. Fig. 1 is a perspective view of a multi contact connector of the prior art; Fig. 2 is a perspective view of one embodiment of a multi contact connector according to the invention; and Fig. 3 is a perspective view of another embodiment of a multi contact connector according to the invention. Fig. 2 is a perspective view illustrating one embodiment of a multi contact connector according to the invention. Bare wires 7₂ of tape wires 6 to be connected to a ground terminal block 4 are connected thereto substantially linearly in a conventional manner. Bare wires 7₁ of the tape wires 6 to be connected to signal and power source terminals 3 are provided with roundabout portions 9 having suitable lengths and heights to form slacks. In the embodiment shown in Fig. 2, each of the bare wires 7₁ to be connected to the signal and power source terminal 3 is bent at four locations to have a bare wire portion substantially parallel to an extending direction of the bare wire and spaced from the ground terminal block to form the roundabout portion or the slack. With this arrangement, when external tensile forces act upon the tape wires 6, the bare wires 7₂ connected to the ground terminal block 4 and their welded portions will be directly subjected to the external forces, but the bare wires 7₁ connected to the signal and power source terminals 3 are not directly subjected to the external forces with the aid of the slacks or the roundabout portions 9. Accordingly, even if the partial bare wires 7₂ connected to the ground terminal block 4 are cut or their welded portions are removed, the bare wires 7₁ connected to the signal and power source terminals 3 are prevented from being disconnected, thereby eliminating any obstruction of operation of the device. In the prior art as shown in Fig. 1, the signal and power source terminals 3 are shifted vertically relative to the ground terminal block 4 in order to insulate the bare wires 7₁ connected to the signal and power source terminals 3 from the ground terminal block 4. By providing the roundabout portions 9 above the ground terminal block according to the invention, the signal and power source terminals 3 can be positioned in flush with the ground terminal block 4. Fig. 3 illustrates such an embodiment. On the other hand, in case of the signal and power source terminals 3 shifted vertically relative to the ground terminal block 4, the slacks may be formed in wave shapes in respective vertical planes.

Claims: A multi contact connector having signal and power source terminals (3) extending from the connector (5), and a ground terminal block (4) extending beyond and across the signal and power source terminals (3), and bare wires (7) of a flexible wire tape (6) connected with the ground terminal block (4) and the signal and power source terminals (3), wherein the bare wires (7₂) connected to the ground terminal block (4) are straight and shorter than those connected to the signal and power source terminals (3), characterized in that the bare wires (7₁) connected to the signal and power source terminals (3) contain a slack portion (9) extending over the ground terminal block (4). A multi contact connector as set forth in claim 1, characterized in that each said slack portion (9) is formed by bending the bare wire (7₁) at four locations to have a portion substantially parallel to an extending direction of the bare wire and spaced from the ground terminal block (4). A multi contact connector as set forth in claim 1, characterized in that a plane of the signal and power source terminals (3) is located shifted relative to a plane of the ground terminal block (4). A multi contact connector as set forth in claim 1, characterized in that a plane of the signal and power source terminals (3) is substantially flush with a plane of the ground terminal block (4). A method of connecting tape wires to a multi contact connector having signal and power source terminals (3) extending from the connector (5) and a ground terminal block (4) extending beyond and across the signal and power source terminals (3) comprising connecting bare wires (7) of a flexible wire tape (6) with the ground terminal block (4) and the signal and power source terminals (3) wherein the bare wires (7 2 ) connected to the ground terminal block (4) are straight and shorter to those connected to the signal and power source terminals (3), characterized in that it further comprises connecting the bare wires (7₁) to the signal and power source terminals (3) to include a slack portion (9) extending over the ground terminal block (4).

Inventors: HASHIMOTO, KAZUYA, KATO, MATSUO, NAKAIDE MASAMI, OHTSUKI TOMONARI
Applicants: DAIICHI DENSHI KOGYO KABUSHIKI KAISHA, HITACHI, LTD.
Application year: 1986
Main classification: H01R23
IPC codes: H01R13, H01R12