FR2785727A1 - Printed circuit connector has guide film to keep pins aligned correctly prior to fitting - Google Patents

Abstract

The connector (1), consisting of a series of metal pins (3, 4, 5) projecting from a flat base (6), has a layer of guide film (2) perforated at intervals corresponding to the spacing between the connector pins to keep the pins correctly aligned before insertion into holes (10, 11, 12) in the printed circuit (13). The pins are of needle-eye type, and the guide film is fitted to them on a level corresponding to the height of the pins' greatest radial dimensions.

Description

Connector with centered contacts
The present invention relates to a connector comprising metal pins refocused with respect to an expected position. It finds more particularly its use in the mounting of connectors on a printed circuit, in particular in the mounting of connectors provided with metal pins in the shape of a needle eye. Connectors of this type have contact pins to be force-fitted (of the press-fit type) into metallized holes in a printed circuit. The advantage of the invention lies in the ease of fitting such a connector.

 Connectors currently manufactured include metal pins, in the shape of a needle eye, erected, parallel to one another, out of a flat base of a connector. Before inserting the metal pins into metallized holes in a printed circuit, it must be ensured that the metal pins are parallel to each other.

 There are problems with this type of connector. Indeed, one or more metal pins of a connector can be in a position different from an original position. An original position of a metal pin is a position in which a metal pin is erected outside a flat base of the connector parallel to an axis perpendicular to this flat base. Thus, following this position different from an original position, at the time of insertion of the connector on a printed circuit, the engagement of the metal pins in the metallized holes of this printed circuit cannot be done without deterioration of the pins and therefore the connector. This connector must be replaced, which results in an increase in the overall cost of manufacturing the printed circuit on which the connector must be mounted. In addition, in some cases the connector has a large number of metal pins. The insertion effort to be provided is such that one may not realize that a metal pin is not engaged in a corresponding metallized hole. This has the effect of bending one or more metal pins and therefore making the connection defective. Indeed, the metal pins thus bent can cause short circuits by touching other metal pins while causing an absence of contact.

 A different position of a metal pin compared to its original position is obtained, for example, following an impact on a metal pin. This shock can occur during handling of this connector.

During this handling, a connector can, for example, fall and bend one of the metal pins of the connector, thus rendering this connector unusable subsequently.

 In the case of manual mounting of this connector on the printed circuit, it is checked that the pins are all in their original position.

Otherwise, this connector is replaced. A replacement of the connector therefore induces an additional cost which in the context of a production of connectors in large series, that is to say produced by automated machines, can become significant.

 In the case of an automated mounting of a connector on a printed circuit, an mounting process may not detect that a metal pin is offset from its original position. The assembly of the connector is therefore considered to be good. In this case, the additional cost is even higher than previously, because it is the printed circuit containing the connector that will have to be changed when it becomes apparent in a test phase that the connection is defective.

Connectors of this type present another problem in the case of a large number of metal pins. Indeed, a connector can have from thirty to six hundred and thirty metal pins. In that case,
The insertion effort necessary to provide for inserting metal pins of such a connector into a printed circuit is large. That is to say, we will have difficulty inserting these metal pins into metallized holes provided for this purpose in a printed circuit.

 The object of the invention is to remedy the problems mentioned by proposing a connector provided with a guide film, engaged on the metal pins of the connector, ensuring a fixed distance between the metal pins of the connector. The solution provided by the invention consists in using a first support, the guide film, thus maintaining the metal pins in a position in which a gap between two successive pins is fixed for a whole period of handling of this connector. This difference corresponds to the pitch of the contacts and therefore of the metallized holes of the printed circuit. This first support, therefore the guide film, is of negligible thickness compared to a thickness of the printed circuit. A thickness of the guide film is negligible compared to a thickness of the printed circuit when, thin the thickness of the guide film, a metal pin of the connector has its portion of largest radial dimension inserted inside a metallized hole provided for this purpose in the printed circuit. Thus, a space constraint provided by the guide film is ignored. It then suffices to provide the thickness of the film of the order of 0.2 millimeters. It is therefore possible, in the invention, to use the connectors used in the state of the art with a slight dimensional adjustment.

 The invention therefore relates to a connector comprising metal pins erected outside a flat base, characterized in that it comprises a guide film perforated at a pitch corresponding to the positioning of the metal pins, engaged on the metal pins and capable of sliding on these last, this film now maintains a fixed distance between the metal pins in a position away from the plane of the base.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These are presented for information only and in no way limit the invention. The figures show:
-Figure 1: a connector, according to the invention, before insertion on a printed circuit;
-Figure 2: a connector, according to the state of the art, of which several metal pins are offset from their original position;
FIG. 3: a strip from which a guide film according to the invention is obtained;
FIG. 4: a device for positioning the guide film on metal pins of a connector, before the installation of this first on the latter;
-Figure 5: a device for placing the guide film on metal pins, after the installation of this first on the latter.

 Figure 1 shows a connector 1 according to the invention. This connector 1 comprises a guide film 2. This guide film 2 is engaged on metal pins 3, 4 and 5 erected out of a flat base 6 of the connector 1. These metal pins 3, 4 and 5 are erected along an axis. perpendicular to the flat base 6 of the connector 1. More precisely, the metal pins 3,4 and 5 respectively are drawn up along axes 7,8, and 9 respectively. These axes 7, 8, and 9 are aligned and parallel to each other and perpendicular to the flat base 6 of the connector 1. The axis 8 is located between the axis 7 and the axis 9 so that the distance between the axis 7 and the axis 8 is the same as the distance between the axis 8 and the axis 9. This corresponds to the pitch of the contacts of the connector and the metallized holes of the printed circuit.

 In a preferred example, the pins 3, 4, and 5 are of the needle eye type. This type of metal pin ensures pressure contact between a metal pin and an inner wall of a metallized hole in which the metal pin is inserted. This is made possible by making holes 10, 11, and 12 respectively, in a printed circuit 13, of diameter slightly less than the largest of the radial dimensions of the metal pins 3,4, and 5. This pressure is sufficient to ensure a good electrical contact between the metal pins and the metallized holes. It is generally sufficient to also ensure a fixing between the connector 1 and the printed circuit 13. This pressing force is used in the invention. Indeed, holes 14, 15, and 16 are respectively made in the guide film 2 into which the metal pins 3, 4 and 5 are inserted respectively. Two consecutive holes, 14, 15 or 15, 16, in the guide film 2, are separated by a distance (step) d, for example equal to two millimeters. This distance d is identical to a distance separating the axes 7 and 8 or 8 and 9. The distance d between two successive holes is measured relative to the center of the holes.

 Thus the metal pins 3,4, and 5 respectively are inserted into the holes 14, 15 and 16 respectively of the guide film 2. The insertion continues until the guide film 2 is at a height corresponding to the most large of the radial dimensions of a metal spindle. At this location the pressing force is sufficient to maintain the guide film 2 at this height. Indeed, the holes 14, 15 and 16 are of slightly smaller diameter than the largest of the radial dimensions of the metal pins.

A metal spindle 3,4 or 5 or more can be shocked. This shock can have the effect of shifting metal pins from their original position. However, the metal pins 3,4, and 5 are, in the invention, interconnected by the guide film 2. Thus, a stress applied to one of the metal pins is transmitted to the other metal pins via the guide film. 2. The guide film 2 provides a rigid connection between the metal pins and thus maintains a constant gap. When inserting the connector 1 into the printed circuit 13 the metal pins 3, 4 and 5 respectively of the connector 1 are all engaged in the holes 10, 11, and 12 respectively of the printed circuit 13 which are associated with them. In fact, the more metal pins there are, the more rigid the structure resulting from the connection between them and the guide film. Thus, a shock on a metal pin is all the more easily absorbed by this structure the greater the number of pins on the connector 1.

 FIG. 2 shows a connector 17, according to the state of the art, devoid of a guide film such as 2. In this case, a shock transmitted to one of the pins 18, 19 or 20 erected outside a base 21 of the connector 17 will not be transmitted to the other pins of the connector, thus creating gaps, between two successive pins, which are not identical. Thus, when inserting the metal pins 18, 19 and 20 into the holes 10, 11, and 12 respectively of the printed circuit 13 cannot therefore be produced. Indeed, if a distance between the free end of the metal pins 19 and 20, for example, is different from the distance d while the distance between two consecutive holes of the printed circuit 13 is equal to d, it is then impossible to insert these metal pins 19 and 20 respectively into the holes 11 and 12 respectively. Likewise, the distance between the free end of the metal pin 18 and the free end of the metal pin 19 is different from the distance between the metallized hole 10 and the metallized hole 11 of the printed circuit 13.

 FIG. 3 shows a strip 22 from which a guide film is obtained, such as guide film 2 for example. This strip 22 comprises a series of holes intended to receive metal pins of a connector. These holes are uniformly distributed over the strip 22. In addition, a homogeneous distribution is produced by following lines parallel to the different sides of the guide film 22. The distance, with respect to the centers of the holes, between two successive lines is equal to the length d and this regardless of the side of the guide film 22 taken for reference. This arrangement forms a grid in the intersections from which the holes are made.

 A row of holes, possibly of the same diameter as the holes intended to receive metal pins, is drilled parallel to one of the edges of the strip 22. Preferably this row of holes is arranged along a longitudinal axis 23. This longitudinal axis 23, which can serve as an axis of symmetry of the strip 22, extends along the greatest length of the strip 22 and divides this strip 22 into two equal parts. This row of holes is parallel to the other rows of holes extending along the longitudinal axis 23 but is offset with respect to them, that is to say, using the previous image of the grid, that the holes are no longer made at the intersection points but inside the squares thus delimited by the intersection points. Thus a cutting plane 24 perpendicular to the greatest length of the film 22 and passing through a hole in this row will only contain this hole in its cutting plane.

 In order to obtain guide films according to the invention, the strip 22 is cut along cutting planes such as the cutting plane 24. The choice of the cutting plane according to which the strip 22 is cut depends on the number of rows metal pins that the connector has. By performing a shearing along a cutting plane such as 24, the hole contained in this cutting plane is split into two parts. A part is found on an edge of the guide film and another part is found in an edge of the strip 22.

These two parts in the form of notches make it possible to correctly position the strip 22 with respect to the metal pins of a connector which will be inserted in a certain number of holes in the strip 22. This insertion is done automatically, so it the strip 22 must be positioned so that the insertion of the metal pins takes place correctly. The shearing of the strip 22, in order to obtain a guide film, is carried out after insertion of the metal pins of a connector into the holes provided for this purpose in the strip 22. To position the strip 22, it is advanced along the longitudinal axis 23 and this until the edge of the strip 22 containing the notch comes into abutment on an index finger 25. The notch is placed in an edge of the strip 22 so that when the strip 22 arrives in abutment on index 25, index 25 is in the notch.

 Figures 4 and 5 show an example of a device for mounting a guide film, according to the invention, on metal pins of a connector before and after mounting of this guide film. This device comprises a frame 26. On the same face of this frame 26 rises two uprights 27 and 28. The free end of the upright 27 may include a toothed wheel 29. Teeth are arranged around the periphery of the toothed wheel 29 respecting the arrangement of the holes located on the longitudinal axis 23 in the strip 22. The teeth of the toothed wheel 29 are, in a preferred example, of cylindrical shapes with a diameter less than the diameter of the holes made on the longitudinal axis 23 in the strip 22. The strip 22 is placed tangentially on the toothed wheel 29 so that a row of teeth of this toothed wheel 29 is engaged in a row of holes in the strip 22. Thus, during a rotation of the toothed wheel 29, for example by means of an electric motor, the strip 22 advances in a direction parallel to the longitudinal axis 23 previously defined. The toothed wheel 29 is therefore arranged in such a way that its axis of rotation is perpendicular to a direction in which the upright 27 rises.

The upright 28 serves as a guide in translation for a movable element 30. The stroke of the movable element 30 on the upright 28 is limited on one side by the frame 26 and on the other side by a stop 31, in the form of a 'square, disposed at the other end of the upright 28. The stop 31 is obtained by association of two blocks 32 and 33 in the form of a parallelepiped. The blocks 32 and 33 are arranged so as to form a square. The block 32 is fixed to one end of the upright 28, opposite the end connected to the frame 26. The block 32 is placed in such a way that the upright 28 is perpendicular to one face 34 of the block 32. This face 34 is that which is in contact with the movable element 30 when the latter comes into abutment on 32. A face 35 of the block 32 has a block 33. This face 35 is perpendicular to the face 34 and is arranged perpendicular to the direction in which the strip 22 advance. This block 33 extends beyond one of the edges of the face 35, that formed by
The right angle between face 34 and face 35. In addition, this face 35 is such that the upright 28 is located between the toothed wheel 29 and this face 35. Thus the face 34 and the overflow of the block 33 form an angle law. When the movable part 30 abuts on the face 34, it is, by means of a face 36, perpendicular to the direction in which the strip 22 advances, in plan contact with one face of the overflow of the block 33.

 The movable element 30 has a slot 37 on a face 38 opposite the face 36. The slot 37 opens out on the opposite face 36. This slot 37 receives, by its entry located on the face 38, the strip 22 which is set in motion by the toothed wheel 29. The side 36 comprises a block 39 of thickness equal to the length separating the face 34 and the exit from the slot 37 on the side of the face 36, when the movable element 30 is in abutment on the block 32 of the abutment 31. The block 39 is in contact with the side 36 via the thickness, previously defined, of this block 39. This block 39 has a recess 40 in which the overflow of the part 33 is housed when the movable element 30 is in abutment on the stop 31. In this case the overflow opens at the level of a face 41 of the block 39. When the strip 22 opens from the slot 37, on the face side 36, it continues its advance by being in plan contact with the emerging end of the overflow and the face 41. These two surfaces, formed by the end of the overflow and of face 41, are in the same plane. The overflow of the block 33 blocks the recess 40, when the movable element 30 is in abutment on the stop 31, in order to allow the passage of the strip 22 at its exit from the slot 37. After having crossed these two surfaces the strip 22 comes into abutment on an index finger 42, ensuring positioning of the strip 22.

 The block 39 includes through holes drilled from the face 41 and opening onto an opposite face 43. These through holes have a diameter greater than the largest of the radial dimensions of the metal pins. Opposite face 41 of block 39, the metal pins of a connector are positioned using a positioning device 43.

From now on, the strip 22 is located between the metal pins and the face 41 of the block 39. The holes in the block 39 are arranged in the same way as the holes in the strip 22.

 FIG. 5 shows the device carrying out the mounting of the guide film, according to the invention, on metal pins of a connector after the mounting of this guide film on the metal pins of the connector. For this, the movable element 30 is made to translate which also drives the block 39. The displacement of the movable element 30 on the upright 28 can be obtained, for example, by making a helical slide connection between the upright 28 and the element movable 30. To make the helical slide connection, the upright 28 comprises, for example, an endless screw which, by rotating it allows a translation of the movable element 30. When the metal pins are engaged in the holes in block 39 the strip 22 is pushed by block 39 and slides along the metal pins of the connector until it reaches a height corresponding to the part of the metal pins for which there are the largest radial dimensions.

At this instant the movable element 30 comes into abutment on the side of the chassis 26. At the same instant a plate 44, bevelled at one end and fixed to the chassis 26 by an opposite end, produces a shears with an edge 45 formed by the face 41 and a wall of the recess 40. When these two parts come into contact the strip 22 is sheared along a cutting plane such as 24. From this instant the guide film is placed on the metal pins of the connector.

 After that, the movable element 30 is brought back to an initial position by actuating the worm screw, and the same operation can be repeated with a new connector. An initial position of the mobile element 30 is a position where the mobile element 30 is in abutment on the abutment 31.

 The end of the strip 22 contains a notch. After cutting a guide film along an axis 24, a second notch is obtained on an edge opposite the edge containing the first notch. Each guide film thus produced has two notches, these two notches being placed symmetrically on either side of the guide film.

 The guide film used makes a connection between metal pins intended to provide electrical conduction in order to make a connection between two electrical systems. It must therefore be electrically isolated and rigid. For this, the guide film is made, in a preferred example, of polyester fiber. In addition, this material while being rigid is flexible enough to withstand without deterioration the deformations due to the movements of the movable part 30 of the mounting method. The movements of the mobile part 30 are translations of approximately three millimeters.

 In order to facilitate the insertion of the metal pins 3, 4, and 5 respectively into the holes 10, 11, and 12 respectively of the printed circuit 13, the holes 14, 15, and 16 are made in the guide film 2 so that the holes of the guide film are slightly smaller than the diameter of holes 10, 11, and 12 of the printed circuit. In this case during the insertion of the connector 1 into the printed circuit 13 there is no insertion effort to be made as long as the printed circuit 13 and the guide film 2 are not in contact. Once this contact is made, the guide film 2 is slid along the metal pins 3, 4, and 5 of the connector, to bring it closer to the base 6 of the connector 1. At the same time the part which contains the largest of the radial dimensions. of a metal pin is compressed by a hole of smaller diameter in the printed circuit 13. This allows this part to be easily inserted at the start into a metallized hole in the printed circuit.

Then when the guide film 2 leaves this part, it no longer has any action on the metal pins 3, 4, and 5 of the connector 1. From now on, the metal pins 3, 4 and 5 can produce their pressure force on the walls. holes 10, 11, and 12 of the printed circuit 13.

Claims (7)

 1-Connector (1) comprising metal pins (3,4,5) standing out of a flat base (6), characterized in that it comprises a guide film (2) perforated at a pitch corresponding to the positioning of the pins metal, engaged on the metal pins and being able to slide on the latter, this film now guides a fixed gap between the metal pins in a position away from the plane of the base.  2-connector according to claim 1, characterized in that the metal pins are of the needle eye type.  3-connector according to one of claims 1 to 2, characterized in that a hole of the guide film has a diameter at most equal to the largest of the radial dimensions of a metal pin.  4-connector according to claim 3, characterized in that the guide film is maintained at a height corresponding to this greater of the radial dimensions.  5-connector according to one of claims 1 to 4, characterized in that the guide film is made of polyester fiber.  6-connector according to one of claims 1 to 5, characterized in that the guide film has a notch in order to position the latter relative to the metal pins.  7-connector according to one of claims 1 to 6, characterized in that the guide film has two notches, formed on the edges of the guide film, in order to position the latter relative to the metal pins, these two notches being placed symmetrically on either side of the guide film.