LECUIVRE, Michel (17 Avenue du Maréchal Koenig, Troarn, Troarn, F-14670, FR)
CAPPE, Patrice (7 Route de Rambouillet, Faverolles, F-28210, FR)
MULOT, Gérard (26 rue du Général de Gaulle, Nogent Le Roi, Nogent Le Roi, F-28210, FR)
LECUIVRE, Michel (17 Avenue du Maréchal Koenig, Troarn, Troarn, F-14670, FR)
CAPPE, Patrice (7 Route de Rambouillet, Faverolles, F-28210, FR)
CLAIMS
1. An electrical terminal comprising :
- a contact portion (12) for being connected to a complementary terminal,
- a cable connecting portion (14; 114; 214) for being connected to a flat cable (46), the cable connecting portion (14; 114; 214) being in electrical contact with the contact portion (12), the cable connecting portion (14; 114; 214) comprising : - a strip (25; 125; 225) extending along a strip direction (X-X') delimiting a receiving surface (26, 28; 120A; 220) on which the flat cable (46) is to be laid, the receiving surface having a width perpendicular to the strip direction (X-X'),
- at least one tooth (22A, 24A, 22B, 24B; 222, 224) projecting from the receiving surface (26, 28; 120A; 220) in a substantially perpendicular manner for perforating the flat cable (46) as the flat cable is laid on the receiving surface (26, 28; 120A; 220), the tooth (22A, 24A, 22B,
24B; 222, 224) defining an elongated junction section (3OA, 32A, 3OB,
32B; 230, 232) on the receiving surface (26, 28; 120A; 220) along a first direction (Xi-Xr, X 2 -X 2 , X 3 -X 3 , X 4 -X 4 ), characterized in that the junction section is entirely located at a distance, from a median line of the receiving surface extending along the strip direction (X- X'), smaller than one sixth of the width of the receiving surface.
2. An electrical terminal according to claim 1 , characterized in that the junction section (3OA, 32A, 3OB, 32B; 230, 232) is located entirely at a distance, from the median line of the receiving surface, smaller than one tenth of the width of the receiving surface (26, 28 ; 120A; 220).
3. An electrical terminal according to claim 1 or 2, characterized in that the first direction (XrXy, X 2 -X 2 , X 3 -X 3 ', X 4 -X 4 ), is parallel to the strip direction (X- X').
4. An electrical terminal according to claim 3, characterized in that the junction section of the tooth has a side extending on the median line of the receiving surface.
5. An electrical terminal according to claim 3 characterized in that the junction section (230, 232) is centered on the median line of the receiving surface (220).
6. An electrical terminal according to anyone of claims 1 to 5, characterized in that the cable connecting portion comprises a second tooth (24A,
24B) lying at a distance (d) from the first tooth (22A, 22B), the distance (d) being taken perpendicular to the first direction, said first tooth having a thickness perpendicular to the first direction (XrXy, X2-X2), and the distance (d) being smaller than half of the thickness of the first tooth (22A, 22B).
7. An electrical terminal according to claim 6, characterized in that the second tooth (24A, 24B) defines an elongated junction section (32A, 32B) on the receiving surface (26, 28; 120A) along a second direction (X3-X'3, X4-X4), and the second direction is parallel to the first direction.
8. An electrical terminal according to claim 7, characterized in that the tip (39A, 39B) of the first tooth is shifted relative to the tip (41 A, 41 B) of the second tooth along the first direction.
9. An electrical terminal according to any one of claims 1 to 8, characterized in that the strip (25) comprises :
- a first sheet portion (20),
- a second sheet portion (22) pleated on the first sheet portion (20),
- a pleat (P1 ) connecting the two sheet portions (20, 22), wherein the first tooth (22A, 22B) extends from an end of the second sheet portion (26) opposite the pleat (P1 ).
10. An electrical terminal according to any one of claims 6 to 8, characterized in that the strip (125) comprises a sheet portion (120) from which the first tooth (22A, 22B) extends by making a bend (B1 , B2), wherein the sheet portion (120) extends directly from the bend (B1 , B2) toward the second tooth (24A, 24B).
11. An arrangement comprising a flat cable (46) and an electrical terminal (10) according to any of the preceding claims, wherein:
- the flat cable (46) is lying on the receiving surface (26, 28 ; 120A; 220) ;
- the first tooth perforate the flat cable (46),
- the first tooth is bent away from the strip direction (X-X') so as to cover the flat cable (46) for maintaining the flat cable against the receiving surface (26, 28 ; 120A ; 220). |
Electrical terminal
The invention relates to an electrical terminal, especially for a flat cable, comprising: - a contact portion for being connected to a complementary terminal,
- a cable connecting portion for being connected to a flat cable, the cable connecting portion being in electrical contact with the contact portion, the cable connecting portion comprising :
- a strip extending along a strip direction delimiting a receiving surface on which the flat cable is to be laid, the receiving surface having a width perpendicular to the strip direction, and being longitudinally devided in two by a median line extending parallel to the strip direction (X-X'),
- at least one tooth projecting from the receiving surface in a substantially perpendicular manner for perforating the flat cable as the flat cable is laid on the receiving surface, the tooth defining an elongated junction section on the receiving surface along a first direction. WO 2004/021517 discloses such an electrical terminal. An object of the present invention is to produce an improved and different electrical terminal. This object is obtained with an electrical terminal of the above type, characterized in that the junction section is located entirely at a distance, from the median line of the receiving surface, smaller than one sixth of the width of the receiving surface.
This position of the tooth lowers the deformation of the flat cable. During perforation of the flat cable, it is important that the flat cable, and more particularly the conductive track of the flat cable, are not deformed or warped.
Further, the electrical terminal can be used with flat cable of any width, since the perforation will always occur near the middle of the flat cable. During perforation of the flat cable, it may also happen that a tooth collapses and does not perforate the cable. It is another advantage of the present invention to produce an electrical terminal with teeth which are less likely to collapse during perforation of the flat cable. This can be obtained first through the
lower deformation of the flat cable, and/or second through the use of at least one pair of teeth, each tooth of the pair forming a stop for stopping the collapsing of the other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in greater detail with reference to the examples of embodiments shown in the drawings.
Figure 1 is a perspective view of an electrical terminal according to a first embodiment of the invention, before the forming of the cable connecting portion,
Figure 2 is a perspective view of the electrical terminal of figure 1 after forming of the cable connecting portion,
Figure 3 is a perspective view of the electrical terminal of figures 1 and 2 connected to a flexible flat cable,
Figure 4 is a perspective view of a tool used for connecting the electrical terminal to the flexible flat cable,
Figures 5 and 6 are views similar to the views of figures 1 and 2 showing a second embodiment of the invention, and Figures 7 and 8 are plane views of a cable connecting portion according to a third embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to figure 1 , there is shown an electrical terminal 10.
The electrical terminal 10 comprises a contact portion 12 for being connected to a complementary terminal (not shown) and a cable connecting portion 14 for being connected to a flexible flat cable. The cable connecting portion 14 of figure 1 needs to be formed in order to be connected to the flexible cable, as will be explained later.
The contact portion 12 is well known in the art and will not be described any further. The contact portion 12 is intended to be mated to the
complementary terminal along a direction X-X'. Adjectives such as "forward" or "backward", will refer to the direction X-X' in the following description.
The cable connecting portion 14 is in electrical contact with the contact portion 12. The cable connecting portion 14 comprises, before forming, an elongated plane sheet of metal 16 extending along the direction X-X'. In the example described, the sheet of metal 16 has a thickness extending between 100 micrometers and 300 micrometers, preferably 200 micrometers.
The sheet of metal 16 is cut so as to define a rectangular central portion 20 extending along the direction X-X' and surrounded by two rectangular lateral portions 22, 24 extending along each side of the central portion 20. Each rectangular lateral portion 22, 24 carries two teeth, referenced respectively 22A, 22B and 24A, 24B. One 24 of the lateral portions has a length along the X-X' direction smaller than the length of the other 22 lateral portion and extends longitudinally centred on the longest lateral portion 22. Each of the two teeth carried by a lateral portion 22, 24 is located at a respective end of the lateral portion and extends in a direction opposite the central portion 20. The teeth 22A, 22B, 24A, 24B will be further described with reference to figure 2.
The previous portions are just delimited by geometrical boundaries illustrated by dot lines on figure 1. Actually, the central portion 20, the lateral portions 22, 24 and the teeth 22A, 22B, 24A, 24B are made in a single continuous piece, namely the sheet of metal 16.
The cable connecting portion 14 illustrated on figure 1 needs to be formed so as to be connected to a flexible flat cable. The forming comprises pleating each lateral portion 22, 24 onto the central portion 20 to form a strip 25, and bending back each tooth 22A, 22B, 24A, 24B so as to be substantially perpendicular to the central portion 20. The pleating creates two respective pleats P1 , P2, each connecting a lateral portion 22, 24 to the central portion 20. The bending creates, for each tooth, a respective bend B1 , B2, B3, B4 (the bend B2 is partially hidden on the figures).
The resulting cable connecting portion 14 is illustrated on figure 2. The pleated lateral portions 22, 24 rejoin each other in the middle of the central portion 20 and can stay at a distance from each other because of manufacturing
clearance. Advantageously portions 22, 24 can be urged against each other. The pleated lateral portions 22, 24 are intended to form a support for a flexible flat cable. More precisely, faces 26, 28 of the lateral portions 22, 24 located opposite the central portion 20, i.e. which are not facing the central portion 20, delimit a receiving surface 26, 28 on which the flexible flat cable is to be laid, said receiving surface 26, 28 having a width perpendicular to the direction X-X'.
Each tooth 22A, 22B, 24A, 24B projects from the receiving surface 26,
28 in a substantially perpendicular manner. Advantageously, they can be all identical. Each tooth 22A, 22B, 24A, 24B defines a longitudinal elongated junction section on the receiving surface 26, 28 along a respective direction. The junction sections are respectively referenced 3OA, 3OB, 32A, 32B on figure 2, while their directions are referenced Xi-X'i, X2-X'2, X3-X'3, X 4 -XV These directions also define what is called the direction of each tooth in the following description.
The length of a tooth 22A, 22B, 24A, 24B is defined as the length of the junction section along a direction Xi-X'i, X2-X'2, X3-X'3, X4-X4, while the thickness of a tooth is defined as the dimension of the junction section perpendicular to this direction. The teeth are formed from the plane sheet 16, their thickness corresponds to the thickness of the sheet, namely between 100 micrometers to
300 micrometers, preferably 200 micrometers.
The pleated lateral portions 22, 24 rejoin each other in the middle of the central portion 20. The junction section of each tooth is entirely located at a distance, from a median line of the receiving surface extending along the direction X-X', smaller than one sixth of the width of the receiving surface 26, 28.
The median line is represented by the line X-X' on the figures.
The junction sections are located in a longitudinal central band centred on the middle of the width of the receiving surface, said central band having a width equal to one third (33%) of the width of the receiving surface.
The perforating effort is therefore placed near the middle line of the cable conductive track, where the stiffness of this track is greater, what minimises the deformation of the track.
As an alternative, the distance is smaller than one tenth of the width of the receiving surface 26, 28.
In the first embodiment, all the directions Xi-X'i, X2-X'2, X3-X'3, X4-Xα of the teeth are parallel to each other and parallel to the direction X-X'. Each tooth has a lower portion 34A, 34B, 36A, 36B, i.e. joining the receiving surface 26, with a brick shape having a length and thickness corresponding to the length and the thickness of the junction section.
Above the lower portion 34A, 34B, 36A, 36B, i.e. opposite the receiving surface 26, 28, each tooth is provided with a higher portion 38A, 38B, 4OA, 4OB shaped like a triangle, i.e. whose dimension parallel to the direction of the tooth decreases while going away from the lower portion 34A, 34B, 36A, 36B, and thus from the receiving surface 26, 28. Each tooth is provided with a tip 39A, 39B, 41 A, 41 B opposite the receiving surface 26, 28, which corresponds to the apex of the triangle. So as to perforate easily the flexible flat cable, each tooth 22A, 22B,
24A, 24B is further provided with two opposite sharpening chamfers 42A, 42B, 44A, 44B leading to the tip 39A, 39B, 41 A, 41 B of the tooth laterally, along its thickness.
The tip 39A, 39B, 41 A, 41 B of each tooth is located above the junction section 3OA, 3OB, 32A, 32B, in the middle of the junction section along the direction XrXr, X2-X2, X3-X3', X 4 -X 4 ' of the junction section.
The tooth, i.e. 22A, 22B, located at one end of a lateral portion i.e. 22, is advantageously facing the tooth, i.e. 24A, 24B, located at the corresponding end of the other lateral portion, and overlaps with it, defining a pair of teeth. In figure 2, the teeth 22A and 24A form a first pair and the teeth 22B and 24B form a second pair.
The teeth of each pair are shifted relative to one other. Their tips are consequently shifted in the same way. Preferably, the teeth overlap on 40% to 80% of their length. As will be explained later, the teeth are intended to be bent outwardly by using a tool described later. Because of the shifting of the tips, the teeth can easily be caught by the tool.
In case there is a gap between the lateral portions 22, 24, the junction sections of the teeth of a pair are at a distance d from each other, the distance d being perpendicular to their directions.
The distance d is small enough so that if one tooth of the pair collapses, during perforation, towards the other tooth of the pair, that other tooth will form a stop stopping the collapsing, such that the collapsed tooth is still able to perforate the flat cable. Therefore, it is unlikely that a tooth will not perforate the flexible flat cable.
For a good stopping effect, the distance d is smaller than half of the thickness of the teeth. Advantageously for a better stopping effect the teeth of the pair are urged against each other such a way d is null.
In figure 2, the teeth 24A and 24B carried by the lateral portion 24 are closer from each other than the teeth 22A and 22B carried by the lateral portion 22. This configuration simplifies the shape of the bending tool as will be explained later.
Turning now to figure 3, a flexible flat cable 46 comprises a plurality of parallel elongated plane conductors 48 surrounded by a common isolative sheath 50. The cable 46 is laid on the receiving surface 26, 28 and extends along the direction X-X'. Advantageously the width of the strip 25 is approximately equal to the width of the elongated plane conductor 48. It is possible to have several terminals side by side, i.e. one for connecting each conductor 48, while using for the connexion the full width of the conductor 48.
The teeth have perforated the cable 46 through both the conductor 48 and the isolative sheath 50. The teeth are bent outwardly, away from the direction X-X' for maintaining the flat cable against the receiving surface.
Moreover, the teeth provide electrical connection between the strip 14 and the conductor 48 they perforate.
Turning to figure 4, there is shown a tool for bending the teeth 22A, 22B, 24A, 24B, once the cable 46 has been laid down on the receiving surface 26, 28 and has been perforated by the teeth.
The tool comprises an elongated head 52 intended to extend parallel to the direction X-X'.
The head 52 has three parts 54, 56, 58 located one after the other along the direction X-X'.
Each part comprises a rib 54A, 56A, 58A extending parallel to the central direction X-X' but shifted laterally relative to that direction. Each rib 54A, 56A, 58A is intended to catch a tooth and bend it as the tool 52 is brought closer to the receiving surface, perpendicularly to it.
More precisely, the rib 56A of the central part 56 is intended to bend the central teeth 24A, 24B. Because the central teeth 24A, 24B are on the same side of the pairs, they can be caught by the same rib. The ribs 54A, 58A of the two other parts 54, 58 are each intended to bend one of the other teeth 22A, 22B. The ribs 54A, 58A extend along the same direction.
Turning to figures 5 and 6, there is shown another embodiment of the invention. This embodiment is similar to the previous one except for the design of the strip, which is now referenced 125.
The teeth 22A, 22B, 24A, 24B are similar to the previous embodiment and located similarly. In particular, they are located at a distance, from a median line of the receiving surface extending along the X-X' direction smaller than one sixth of the width of the receiving surface. The median line X-X' has the same definition as for the first embodiment.
As can be seen on figure 5, the teeth 22A, 22B, 24A, 24B are cut directly in the central portion now referenced 120 : there is no lateral portion. The strip 125 is thus formed by the central portion 120 only. The forming of the cable connecting portion 114 simply comprises lifting up the teeth 22A, 22B, 24A, 24B from the central portion 120 by bending each tooth.
The formed cable connecting portion 114 is illustrated on figure 6. The resulting bends are again referenced B1 , B2, B3, B4 (the bend B2 is still partially hidden). The central portion extends, for each tooth, directly from the bend of the tooth toward the other tooth of the corresponding pair.
The receiving surface is delimited this time on the central portion 120. It is referenced 12OA.
This embodiment requires less material since there is no pleating.
Advantageously, for the two previous embodiments, the distance d between two teeth of a pair is null, which leads to the junction section of each tooth having a long side extending along the strip direction X-X', on the median line.
Turning to figures 7 and 8, there is shown a connecting portion 214 according to a third embodiment of the invention, respectively before and after the forming of teeth.
The connecting portion 214 comprises a strip 225 extending along the direction X-X'. The strip 225 defines a receiving surface 220. Two teeth 222, 224 are cut out from the strip 225 such that their junction section extends along a respective direction Xi-X'i, X2-X ! 2 which is parallel to the strip direction X-X'.
Moreover, the junction sections are each centered on the median line (represented by the X-X' line) of the receiving surface 220. The teeth 222, 224 are identical to the teeth of the previous embodiments.
In all third shown embodiments, the teeth are aligned with direction X- X'. It is also possible to have at least part of those teeth at a slight angle relatively to the direction X-X'.