Patent Publication Number: US-6217393-B1

Title: Appliance connector and production method thereof

Description:
TECHNICAL FIELD 
     The present invention relates to an appliance connector and the production method thereof. 
     BACKGROUND TO THE INVENTION 
     A prior multipole appliance connector, one end of which is attached to a printed circuit board prior to use, has a plurality of terminals installed in a connector housing; these terminals are aligned in rows in order to save space, etc., and these rows are distributed in multiple layers on the side of the connector fitting with a corresponding connector. Contact members extend from each terminal on the side of the connector attached to the printed wiring board. These contact members need to be aligned in a single plane so as to be attached by wire bonding with contact points aligned on the edge of the printed circuit board. 
     Conventionally, when this type of appliance connector is produced, each terminal is formed individually in a shape such that one end can be positioned in the multiple layers and the contact points of the other end can be positioned in a single plane. The housing in which attachment holes for these terminals are aligned is formed separately. Each terminal is attached by being press-fitted into a corresponding attachment hole, with the tab protruding. 
     However, this conventional production method is extremely cumbersome, particularly as the multipolarity of connectors is increasing, and an improved production method is required. 
     The present invention has been developed after taking the above problem into consideration and aims to present an appliance connector with a simplified production, and the production method thereof. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided an insert-moulded electrical connector having a housing, a first row of spaced terminals each having a respective contact member in a single plane, and a second row of spaced terminals interspersed within said first row and each having a respective contact member in said single plane, said rows of terminals being fixed and located as said housing is moulded thereabout. 
     Such a construction avoids the need for individual location of each terminal in a separately moulded housing. 
     The terminals may be in two or more mutually parallel planes, but what is important is that the contact members thereof are uni-planar for connection to the edge of a printed circuit board. 
     The connector may further include a position fixing member for the terminals, each terminal being located in a respective aperture of the position fixing member. This position fixing member may also be insert-moulded into the housing. 
     The invention also provides a method of manufacturing an electrical connector having on one side a row of terminals in a single plane, and another side two or more rows of terminals in spaced planes, the method comprising the steps of: 
     a) forming a first row of spaced terminals in a common plane, the terminals having a common first row carrier, 
     b) forming a second row of spaced terminals in a common plane, the terminals having a common second row carrier in a plane parallel to the plane of said second row, 
     c) placing said carriers one above the other such that said first and second row of terminals are interspersed adjacent said carriers, 
     d) forming a plastics housing to fix and locate said terminals by insert moulding; and 
     e) shearing said carriers from said first and second rows of terminals, thereby rendering each of said terminals electrically independent whilst being fixed in said housing. 
     The method may include the preliminary step of forming mutually alignable apertures in the common carriers, and aligning those apertures in the mould with mould alignment pins. Such an arrangement ensures precise location and positioning prior to insert moulding. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     Other features of the invention are disclosed in the following description of a preferred embodiment shown by way of example only in the accompanying drawings, in which: 
     FIG. 1 is a diagonal view of a control box of an embodiment of the present invention. 
     FIG. 2 is a disassembled diagonal view of an insert for connector housing. 
     FIG. 3 is a diagonal view of the assembled insert. 
     FIG. 4 is a cross-sectional view of a forming die of the connector housing, the die being in an open state. 
     FIG. 5 is a cross-sectional view of the die in a closed state. 
     FIG. 6 is a cross-sectional view of the moulded housing. 
     FIG. 7 is a cross-sectional view of the moulded housing after carriers have been cut off. 
     FIG. 8 is a diagonal view of the moulded housing. 
     FIG. 9 is a diagonal view of the moulded housing after the carriers have been cut off. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     An embodiment of the present invention is explained below with the aid of FIGS. 1 to  9 . This embodiment illustrates a connector suitable for use in a control box of an automobile. 
     First, the overall configuration of the control box will be explained with reference to FIG. 1. A main body  1  of the control box is made from plastic by moulding, and an upper face thereof forms a square box shape in which a recess  2  is provided. Two hoods  3  and  4  are formed side by side in a unified manner on a side face of the main body  1 , this side being the left anterior side face in FIG.  1 . Rows of terminals  15 A and  15 B (explained in detail later) are provided as upper and lower layers within the hood  3  located on the far side, this forming a first connector member  11 . In the same manner, rows of terminals  35  are provided as upper and lower layers within the hood  4 , this forming a second connector member  31 . Rows of contact members  5  and  6  are formed within the recess  2  of the upper face, the row of contact members  5  being on the side wall directly behind the connector members  11  and  31 , and the row of contact members  6  being on the opposite side wall. A supporting frame  8  is formed between the rows of contact members  5  and  6 , this supporting a printed circuit board  7 . 
     Contact members  18 A and  18 B are horizontally aligned within the row of contact members  5  located at the closer side, these contact members  18 A and  18 B extending from tabs or coupling members  16 A and  16 B of the first connector member  11 . Contact members  38  are horizontally aligned within the row of contact members  6  located at the farther side, these contact members  38  extending from tabs of the second connector member  31 . After the board  7  has been fitted into the supporting frame  8 , contact points provided on the sides of the board  7  make contact with the corresponding contact members  18 A and  18 B or the contact members  38 , and are fixed by wire bonding. 
     Next, the production sequence is explained, with the focus on the first connector member  11 . 
     As FIG. 2 shows, the first connector member  11  is provided with an upper bus bar  12 , a lower bus bar  13 , and a position fixing plate  14 . 
     The upper bus bar  12  is formed by press forming an electrically conductive metal sheet, and the twelve pictured tabs  16 A which comprise the upper row of terminals  15 A are connected in a unified manner by a carrier  17 A. The twelve tabs  16 A are divided into three groups each comprising four tabs, the tabs  16 A within each group being horizontally aligned with a prescribed distance between each tab, and with a wider distance separating the groups from one another. 
     The contact members  18 A extend from the posterior of each tab  16 A. The contact members  18 A, after being formed sideways to the extent required, extend in a posterior direction and are consequently horizontally aligned in a manner whereby the space between each adjoining contact member  18 A is greater than the space which separates the contact members  18 B (to be described later) of the lower bus bar  13 . One end of each contact member  18 A is formed again at right-angles so as to protrude in a downwards and posterior direction, and is connected to the carrier  17 A by a connecting member  19 A. position fixing holes  20  are formed on both ends of the carrier  17 A. 
     The lower bus bar  13  is also formed by press forming an electrically conductive metal sheet, and the twelve pictured tabs  16 B which comprise the lower row of terminals  15 B are connected in a unified manner by a carrier  17 B. The twelve tabs  16 B are also divided into three groups each comprising four tabs, the tabs  16 B within each group being horizontally aligned with a prescribed distance between each tab, and with a wider distance separating the groups from one another. As will be explained below, when the upper and lower bus bars  12  and  13  are placed together, the upper and lower rows of terminals  15 A and  15 B mutually correspond and are separated by a prescribed distance. 
     The contact members  18 B extend from the posterior of each tab  16 B. When the upper and lower rows of terminals  15 A and  15 B are positioned so as to mutually correspond while being separated by a prescribed distance, these contact members  18 B are horizontally aligned and fit between the contact members  18 A of the upper bus bar  12 . For this purpose, the contact members  18 B are formed sideways from the posterior end portion of each tab  16 B to the extent required, these then being raised to a height equivalent to that of the corresponding space between the upper and lower rows of terminals  15 A and  15 B, and For this purpose, a forming die is provided such as that in FIG.  4 . This forming die comprises, for example: a fixed lower mould  41 ; an upper mould  42  above the lower mould  41  and capable of being moved up and down; and a moveable mould  43  located to the left of the lower mould  41  and the upper mould  42  and capable of being moved to the left and right. A moulding cavity  44  for moulding the housing  26  is formed on the joining faces of the three moulds  41 ,  42  and  43 . Fitting holes  45  are formed on the joining face of the moveable mould  43 , the upper and lower tabs  16 A and  16 B fitting therein. Further, pins  46 , pins  47 , and pins  48  protrude upwards from the upper face of the lower mould  41 . The pins  46  fit with the position fixing holes  20  of the carriers  17 A and  17 B, the pins  47  support the lower faces of the contact members  18 A and  18 B, and the pins  48  protrude upwards so as to extend along the posterior of the upwards-rising portion of the contact members  18 B of the lower bus bar  13 . 
     In order to mould the first moulded member  27 , the forming die is positioned in an open state as shown in FIG. 4, and the insert  25  is positioned on the upper face of the lower mould  41 , with the position fixing holes  20  of the carriers  17 A and  17 B being fitted onto the pins  46 , the lower faces of the contact members  18 A and  18 B making contact with the pins  47 , and the posterior faces of the rising portion of the contact members  18 B extending along the pins  48 . Next, the tabs  16 A and  16 B are fitted into the fitting holes  45 , the moveable mould  43  is moved in a rightwards direction relative to FIG. 4, and the upper mould  42  is lowered. The forming die is thereby closed and the moulding cavity  44  is formed between the joining faces of the moulds  41 ,  42  and  43 . 
     From this state, molten plastic such as ABS resin etc., is injected into the moulding cavity  44  through a gate (not shown), the forming die is opened after the plastic has hardened and, as shown in FIGS. 6 and 8, the first moulded member  27  with the housing  26  being moulded around the insert  25  is removed. The housing  26  surrounds the base of the upper and lower rows of terminals  15 A and  15 B and supports the lower side faces of the contact members  18 A and  18 B which are aligned horizontally. At this juncture, the plastic has entered the window holes  23  of the plate  14 , thereby unifying the housing  26  and the plate  14 . Moreover, a plurality of bosses  28  protrude from the upper face of the portion of the housing  26  surrounding the base of the rows of terminals  15 A and  15 B, these bosses  28  being used for binding when secondary moulding (to be explained later) is performed. then being made to extend in a posterior direction. The extending end of each contact member  18 B is formed twice at right-angles so as to extend in a downwards and posterior direction, and is connected to the carrier  17 B by a connecting member  19 B. As shown in FIG. 4, the carrier  17 B is stepped downwards, the size of this step corresponding to the thickness of the carrier  17 B. Position fixing holes  20  are formed on both ends of the carrier  17 B, the location of these corresponding to that of the position fixing holes  20  in the carrier  17 A of the upper bus bar  12 . 
     The carriers  17 A and  17 B of the upper and lower bus bars  12  and  13  are positioned one above the other with the position fixing holes  20  being together, the upper and lower rows of terminals  15 A and  15 B correspond with each other, separated by a prescribed distance, and the contact members  18 A or  18 B are aligned along a plane by mutually fitting together. A position fixing plate  14  is made from a plastic such as PBT resin or ABS resin, and the upper and lower rows of terminals  15 A and  15 B of the upper and lower bus bars  12  and  13  are inserted therethrough. Insertion holes  22  are aligned on the plate  14  to allow the upper and lower tabs  16 A and  16 B to be inserted. Moreover, window holes  23  pass through the plastic at prescribed locations between the insertion holes  22 . 
     The upper and lower bus bars  12  and  13  are positioned one above the other by aligning the carriers  17 A and  17 B as described above, and then the tabs  16 A and  16 B are inserted through the corresponding insertion holes  22  of the plate  14  as far as the base of the upper and lower rows of terminals  15 A and  15 B. As a result, as shown in FIG. 3, the upper and lower bus bars  12  and  13  are joined together in a unified manner by the plate  14  and form an insert  25 . This insert  25  comprises the upper and lower rows of terminals  15 A and  15 B corresponding to each other and separated by a prescribed distance, and the contact members  18 A and  18 B aligned along a plane. Furthermore, the position fixing holes  20  of the upper and lower carriers  17 A and  17 B match together. 
     Next, a first moulded member  27  is formed in which a housing  26  is moulded around the insert  25 . 
     After the first moulded member  27  has been formed in the manner described above, the carriers  17 A and  17 B of the two bus bars  12  and  13  are cut off and removed. Specifically, this cutting off occurs on a portion slightly behind the lower edge of the descending portion of the connecting members  19 A and  19 B, these connecting members  19 A and  19 B connecting the contact members  18 A and  18 B to the carriers  17 A and  17 B. The portions extending behind the connecting members  19 A and  19 B are aligned along an identical face, and consequently the carriers  17 A and  17 B can be cut off by supporting this portion in the mould and press shearing a single time. FIGS. 7 and 9 show the first moulded member  27  after the carriers  17 A and  17 B have been cut off. 
     The second connector member  31 , which will be explained in less detail, is prepared by providing two rows of tabs  35  as upper and lower layers. Horizontally aligned contact members  38  protruding from the tabs are grouped together to form an insert, a housing surrounding the insert is formed within a first moulded member, and carriers are cut off in the same manner as above. 
     The first moulded members of the first connector member  11  and the second connector member  31 , the carriers of both having been cut off, are joined together in a unified manner in a prescribed position, this forming another insert which is secondary moulded to form the main body  1  of the control box shown in FIG.  1 . 
     According to the embodiment explained above, a simplification of the production process results from using insert moulding to form a connector (first moulded member  27 ) whereby the terminals  15 A and  15 B are provided in two layers on one side of the housing  26  so as to form the insert  25  during the moulding of the main body  1  of the control box, and the other side of the housing  26  has contact members  18 A and  18 B aligned along a face. 
     The upper and lower bus bars  12  and  13  comprising the first moulded member  27  are formed in a unified manner and joined by the carriers  17 A and  17 B respectively, these carriers  17 A and  17 B being cut off and removed after the first moulded member  27  has been moulded. As a result, handling is convenient during the production process, such as when the bus bars  12  and  13  are joined together, etc. Further, these are joined together with the portions of the carriers  17 A and  17 B to be cut off being one above the other and, consequently, the carriers  17 A and  17 B can be cut off by shearing a single time. In this manner, in order to facilitate cutting, the carriers  17 A and  17 B are one above the other prior to being cut off, and the upper and lower bus bars  12  and  13  are in a contacting state. However, the upper and lower bus bars  12  and  13  are in a non-contacting state after the carriers  17 A and  17 B are cut off. 
     The position fixing holes  20  are provided on both carriers  17 A and  17 B, these matching together when the carries  17 A and  17 B are joined together. The pins  46  in the moulding cavity  44  of the forming die fit into these position fixing holes  20 , and the position of the carriers  17 A and  17 B within the moulding cavity  44  is thereby easily fixed. 
     Furthermore, after the bus bars  12  and  13  are joined together, the plate  14  is fitted onto the base of the upper and lower rows of terminals  15 A and  15 B, thereby preventing the tabs  16 A and  16 B from shifting position whole, for example, receiving pressure from the resin during moulding. The position of the tabs  16 A and  16 B is thereby reliably maintained during production. 
     The present invention is not limited to the embodiments described above with the aid of figures. For example, the possibilities described below also lie within the technical range of the present invention. In addition, the present invention may be embodied in various other ways without deviating from the scope thereof. 
     (1) The rows of tabs may also be provided as three or more layers. 
     (2) The present invention is not limited to the production of the moulded housing described in the above embodiment. It is equally suitable for the production of a single connector in which rows of tabs are provided in multiple layers on one side of a housing, and contact members thereof are provided along an identical face on the other side of the housing. 
     (3) In the preferred embodiment, the connecting members are short; they could however be much larger depending on the configuration of the connector assembly.