Method of producing an electric connector, and semifinished part produced thereby

Abstract

 A method of producing an electric connector (1) having a casing (2) made of synthetic insulating material and defining a number of longitudinal cavities (3); a number of electric terminals (4) housed respectively inside the cavities (3); primary retaining means (5) for retaining the terminals (4) inside the respective cavities (3); and a secondary retaining element (7), which, in use, is separate from the casing (2), is connectable to the casing (2) in a retaining position, and cooperates, in the retaining position, with the primary retaining means (5) to determine correct engagement, and prevent release, of the terminals (4) by the primary retaining means (5); the method including the step of molding in one piece a semifinished part (8) made of synthetic insulating material and having a main body (2') defining the casing (2) in use, and a secondary body (7') defining, in use, the secondary retaining element (7) and connected to the main body (2') by a number of breakable connecting elements (9).

Description

[0001] The present invention relates to a method of producing an electric connector, and to a semifinished part of synthetic insulating material produced thereby.

[0002] Electric connectors are known, which substantially comprise an insulating casing with a number of longitudinal cavities; a number of electric terminals housed respectively inside the cavities; primary retaining means for retaining the terminals inside the cavities; and a secondary retaining device for determining correct engagement, and preventing release, of the terminals by the primary retaining means.

[0003] The secondary retaining device normally comprises a movable element, which is only connectable to the casing in a retaining position when all the terminals are correctly inserted and retained inside the respective cavities by the primary retaining means. In the event any one of the terminals is not inserted properly or fully, the primary retaining means are so deformed as to prevent assembly of the movable element, thus enabling the fault to be detected.

[0004] The movable element may either be hinged to and integral with the casing, or form a separate element.

[0005] The first solution has the advantage of being easier to manage, on account of the movable element and the casing forming a single body, but is only suitable for certain types of electric connectors.

[0006] The second solution, on the other hand, though suitable for various types of electric connectors, involves storing and assembling two separate bodies as opposed to one; and the movable element and casing must be formed in two separate molds, thus increasing cost.

[0007] It is an object of the present invention to provide a method of producing an electric connector designed to overcome the aforementioned drawbacks typically associated with known connectors.

[0008] According to the present invention, there is provided a method of producing an electric connector comprising a casing made of synthetic insulating material and having at least one longitudinal cavity for receiving at least one electric terminal to be housed inside said cavity; primary retaining means for retaining said terminal inside said cavity; and secondary retaining means in turn comprising a movable element, which, in use, is separated from said casing, is connectable to the casing in a retaining position, to cooperate, in said position, with said primary retaining means to determine correct engagement, and prevent release, of said terminal by the primary retaining means; said method being characterized by comprising the step of molding in one piece a semifinished part made of synthetic insulating material and comprising a main body defining said casing in use, and a secondary body defining, in use, said movable element and connected to said main body by breakable connecting means.

[0009] According to the present invention, there is also provided a semifinished part of synthetic insulating material for an electric connector, said electric connector comprising a casing made of synthetic insulating material and having at least one longitudinal cavity; at least one electric terminal housed inside said cavity; primary retaining means for retaining said terminal inside said cavity; and secondary retaining means in turn comprising a movable element, which, in use, is separate from said casing, is connectable to the casing in a retaining position, and cooperates, in said position, with said primary retaining means to determine correct engagement, and prevent release, of said terminal by the primary retaining means; said semifinished part being characterized by being molded in one piece, and comprising a main body defining said casing in use, and a secondary body defining, in use, said movable element and connected to said main body by breakable connecting means.

[0010] A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a longitudinal section of an electric connector formed using the method according to the present invention and in the work position;

Figure 2 shows a different longitudinal section of the electric connector in Figure 1;

Figure 3 shows a small-scale view in perspective of a semifinished part formed using the method according to the present invention;

Figure 4 shows a front view of a detail of the semifinished part in Figure 3.

[0011] Number 1 in Figures 1 and 2 indicates an electric connector.

[0012] Connector 1 substantially comprises a casing 2 made of synthetic insulating material and defining a number of longitudinal through cavities 3; a number of male electric terminals 4 housed inside respective cavities 3; primary retaining means 5 for retaining terminals 4 inside respective cavities 3; and a secondary retaining device 6 in turn comprising a movable plate 7, which, in use, is separate from casing 2, is connectable to casing 2 in a retaining position, and cooperates, in said position, with primary retaining means 5 to determine correct engagement, and prevent release, of terminals 4 by primary retaining means 5.

[0013] According to the present invention, connector 1 is formed from a semifinished part 8 (Figures 3 and 4) molded in one piece from synthetic insulating material, and comprising a main body 2' defining casing 2 in use, and a secondary body 7' defining, in use, plate 7 and connected to body 2' by four breakable bridge type connecting elements 9.

[0014] More specifically, body 2', and therefore also casing 2 defined by it in use, comprises a substantially parallelepiped box portion 13 having cavities 3 for terminals 4, and elongated in a longitudinal direction A coincident with the connection direction to a complementary connector (not shown); and a substantially flat rectangular peripheral flange 14 crosswise to direction A and extending outwards from an intermediate portion of portion 13. More specifically, portion 13 comprises a first portion 15 in which cavities 3 for terminals 4 are formed; and a hollow second portion 16 defining a cavity 17 for housing a portion of corresponding shape of the complementary connector and communicating with each cavity 3.

[0015] From the side of flange 14 facing portion 15 of portion 13, there project, parallel to direction A, four guide elements 18 by which to connect casing 2, in use, to a supporting element (not shown), and four teeth 19 for snapping casing 2 onto the supporting element, and each interposed between a respective pair of guide elements 18.

[0016] Each guide element 18 is substantially L-shaped and located adjacent to a respective corner portion of flange 14. More specifically, each guide element 18 comprises a portion 20 elongated in direction A and concave towards portion 15 of portion 13; and a substantially flat appendix 21 shorter than portion 20 and extending laterally with respect to portion 20 along flange 14. More specifically, appendixes 21 are arranged in two coplanar pairs parallel to and facing respective longitudinal walls 22, 23 of portion 13 and perpendicular to flange 14.

[0017] Body 7', and therefore also plate 7 defined by it in use, is in the form of a substantially flat rectangle, is interposed between a respective pair of guide elements 18, is parallel to the longitudinal insertion direction, coincident with direction A, of terminals 4 inside respective cavities 3, is positioned facing and substantially parallel to wall 22 of portion 13, and is connected to the adjacent guide elements 18 by connecting elements 9. More specifically, two of connecting elements 9 connect body 7' to respective appendixes 21 of the adjacent guide elements 18, and the other two connecting elements 9 connect body 7 to respective portions 20 of guide elements 18.

[0018] Body 7' comprises, at one end, a U-shaped first opening 24 engaged by a respective tooth 19; and, at the opposite end, a pair of U-shaped second openings 25 housing respective teeth 26 for retaining plate 7 to casing 2 in use.

[0019] With reference to Figure 1, each terminal 4 comprises a box-shaped intermediate portion 27 having two outer shoulders 28 defining respective stop edges for retaining means 5; a blade type contact portion 29 projecting from portion 27; and a connecting portion 30 for connection to a respective electric cable 31 and located on the opposite side of portion 27 with respect to portion 29.

[0020] Each terminal 4 is inserted inside respective cavity 3 through a respective opening 32 in cavity 3, from which cable 31 extends in use; and portion 29 projects axially inside cavity 17 of casing 2 through an opposite opening 33 in cavity 3.

[0021] Retaining means 5 comprise, for each terminal 4, a pair of flexible lances 35, which project inside respective cavity 3 from respective walls 22, 23 and in direction A towards respective opening 32, and which in turn comprise respective teeth 36 having a substantially saw-tooth profile, projecting inwards of cavity 3, and which snap onto shoulders 28 to prevent withdrawal of terminal 4.

[0022] Teeth 36 in each cavity 3 therefore permit insertion of respective terminal 4, which slides along respective oblique sides of teeth 36 to flex respective lances 35 towards respective walls 22, 23; and, once terminal 4 is inserted fully inside cavity 3, lances 35 snap back into the undeformed position, so that teeth 36 snap behind respective shoulders 28 of terminal 4 to define a stop preventing withdrawal of terminal 4.

[0023] With reference to Figures 1 and 2, plate 7 - the structure of which has already been described with reference to body 7', and the component parts of which are obviously the same as those of body 7' - is detachable from body 2' by breaking connecting elements 9, and is insertable longitudinally inside portion 15 of portion 13 of casing 2, along wall 22 and between wall 22 and respective lance 35.

[0024] Plate 7 is only insertable fully inside casing 2 if terminals 4 are all inserted properly inside respective cavities 3 and retained inside the cavities by respective lances 35. In the event any one of terminals 4 is not properly or fully inserted, respective lances 35 are deformed towards respective walls 22, 23, thus preventing assembly of plate 7 and enabling detection of the fault.

[0025] Finally, wall 22 of portion 13 of casing 2 comprises, integrally, a pair of teeth 40 projecting inwards of portion 13, and which snap onto respective teeth 26 of plate 7 to define, when engaged by teeth 26, the final retaining position of plate 7 with respect to casing 2.

[0026] Connector 1 is assembled as described below commencing with semifinished part 8.

[0027] Terminals 4 are inserted inside respective cavities 3 of semifinished part 8 through respective openings 32, and are pushed in direction A along cavities 3 to deform respective lances 35. If assembled properly, each terminal 4 is inserted fully inside respective cavity 3, so that shoulders 28 are pushed past teeth 36 of respective lances 35, which snap back into the undeformed position against respective shoulders 28 to define respective axial stops preventing withdrawal of terminal 4.

[0028] Once terminals 4 are inserted, assembly of connector 1 is completed by breaking connecting elements 9 to detach body 7' from body 2' and so obtain plate 7 and casing 2, and by inserting plate 7 inside casing 2 along wall 22.

[0029] If terminals 4 are all inserted fully and lances 35 all snap back into the undeformed position, plate 7 slides longitudinally between wall 22 and lances 35 into the retaining position with respect to casing 2, wherein teeth 26 of plate 7 snap onto teeth 40 of wall 22.

[0030] Conversely, in the event any one of terminals 4 is not inserted properly, respective lances 35 do not snap back into the undeformed position, thus enabling the fault to be detected by preventing plate 7 from being inserted into the retaining position with respect to casing 2.

[0031] The advantages of semifinished part 8 and connector 1 produced according to the method of the present invention will be clear from the foregoing description.

[0032] In particular, casing 2 and plate 7 are used as separate parts but are molded in one piece, thus providing for troublefree management of a single body from the time semifinished part 8 is produced to when connector 1 is actually assembled. More specifically, being located outside cavities 3 and parallel to direction A, body 7' may be detached from body 2' after terminals 4 are inserted inside respective cavities 3, thus simplifying assembly.

[0033] Moreover, cost is reduced by forming plate 7 and casing 2 in one mold.

[0034] Clearly, changes may be made to semifinished part 8 and connector 1 as described and illustrated herein without, however, departing from the scope of the present invention.

Claims

1. A method of producing an electric connector (1) comprising a casing (2) made of synthetic insulating material and having at least one longitudinal cavity (3) for receiving at least one electric terminal (4) to be housed inside said cavity (3); primary retaining means (5) for retaining said terminal (4) inside said cavity (3); and secondary retaining means (6) in turn comprising a movable element (7), which, in use, is separated from said casing (2), is connectable to the casing (2) in a retaining position, to cooperate, in said position, with said primary retaining means (5) to determine correct engagement, and prevent release, of said terminal (4) by the primary retaining means (5); said method being characterized by comprising the step of molding in one piece a semifinished part (8) made of synthetic insulating material and comprising a main body (2') defining said casing (2) in use, and a secondary body (7') defining, in use, said movable element (7) and connected to said main body (2') by breakable connecting means (9).

2. A method as claimed in Claim 1, characterized by comprising the step of breaking said breakable connecting means (9) to detach said secondary body (7') from said main body (2') and obtain said movable element (7) and said casing (2).

3. A method as claimed in Claim 2, characterized by comprising the further steps of inserting said terminal (4) inside said cavity (3), and connecting said movable element (7) to said casing (2) in said retaining position.

4. A method as claimed in Claim 3, characterized in that said step of inserting said terminal (4) inside said cavity (3) is performed prior to said step of breaking said breakable connecting means (9) to detach said secondary body (7') from said main body (2').

5. A semifinished part (8) of synthetic insulating material for an electric connector (1), said electric connector (1) comprising a casing (2) made of synthetic insulating material and having at least one longitudinal cavity (3); at least one electric terminal (4) housed inside said cavity (3); primary retaining means (5) for retaining said terminal (4) inside said cavity (3); and secondary retaining means (6) in turn comprising a movable element (7), which, in use, is separate from said casing (2), is connectable to the casing (2) in a retaining position, and cooperates, in said position, with said primary retaining means (5) to determine correct engagement, and prevent release, of said terminal (4) by the primary retaining means (5); said semifinished part (8) being characterized by being molded in one piece, and comprising a main body (2') defining said casing (2) in use, and a secondary body (7') defining, in use, said movable element (7) and connected to said main body (2') by breakable connecting means (9).

6. A semifinished part as claimed in Claim 5, characterized in that said secondary body (7') is a plate located outside said cavity (3) and connected to said main body (2') in a position parallel to a longitudinal direction (A) in which said terminal (4) is inserted inside said cavity (3).

Drawing