EP0818047B1 - Contact unit, especially for electric switches - Google Patents

Description

The invention relates to a contact unit, in particular for electrical switches, with a lead frame electrically conductive material, in which the electrical Punch paths representing current paths connected via webs and protruding connection contacts provided from the punching plane are, whereby the space between the punching tracks is smaller is the length of a connector. (GB-A-1 493 377)

Such contact units for electrical switches are known. 1 to 3 is a lead frame of such Contact unit shown. So that the contact unit and thus the switch gets a compact design, they are the ones Stamping paths representing current paths are arranged closely to one another net. The connection contacts are still on the lead frame, connected to the current paths inside the switch consist. The compact structure also for the area to get the connection contacts and order them there compact connector plug that accommodates several connection contacts To be able to use the connection contacts always in a predetermined close grid to each other. How from 1 can be seen, the space between the Punching lines not out, the connecting contacts in one piece on the To connect the lead frame. To keep the narrow grid spacing two techniques are usually used. In the first type, a right and a left partial punch grid is used with bent, existing on the partial punching grids Connection contacts made. With at least one the ends the punch webs of the overlapping contact plate the punch bars are connected, creating a one-piece Lead frame is created. In the second type, a large, continuous lead frame made. At this The connecting contacts are not yet available in the lead frame, because the distance between the punch bars for the one-piece Forming the connection contacts on the lead frame is not sufficient is. In a separate operation, the connectors are with a contact surface for fastening to the lead frame manufactured. Connecting the connector with the Punched grids are usually made by welding or riveting. Every connection point is from the quality side to make high demands. For one thing, an adequate one electrical connection must be guaranteed, which in turn a high level of cleanliness of the parts is required before connecting is. On the other hand, the connection must also be mechanical have sufficient cohesiveness.

For the lead frames of the contact units according to the state of the Technology requires several individual parts that are in diverse Operations must be put together. So are at 2 requires five individual parts, which are combined with a total of six connection points become. In the embodiment according to FIG. 3 there are even eight individual parts required that merged with seven connection points become.

The invention has for its object a contact unit to create the kind mentioned in the one-piece Configuration has a compact structure, is inexpensive to manufacture and has the highest quality requirements corresponds.

This object is achieved in that the Terminal contacts formed in one piece with the lead frame are, and the lead frame at least one in the longitudinal direction the terminal contacts has a lying loop that bends out of the contacts from the punch plane of the lead frame and a spacing of the contacts on predefined grid size enables.

Through these measures, the lead frame is with the connection contacts as a one-piece part in compliance with a predetermined, narrow grid size inexpensively while The highest quality standards can be met. There are therefore no additional work steps are required.

According to an advantageous embodiment of the invention the stretched length of the loop the length of the the leadframe bent out and the Width of a clearance between the free end of the connection contacts and opposite areas of the lead frame in the longitudinal direction of the loop taking into account the Bending correction factor. Through a different length of training the loop can thus be different from a lead frame Contact units are made that are different Take grid dimensions and connection contact lengths into account.

In the lead frame are according to an advantageous development the invention in the bending direction of the loop connection contacts Opposite embedded at right angles from the lead frame bendable and by bending the loop on the desired grid dimensions can be brought. This can be done in grid dimensions the connection contacts arranged directly opposite become, i.e. the connection contacts do not have to be offset must have to each other.

In an advantageous embodiment, at least two spaced apart in the lead frame, parallel to each other Punching tracks each have a loop. So that gets Lead frame a rigid and solid structure, which in the Assembly easier handling is made possible. By different Introducing the loop, offset or opposite, assembly errors are avoided.

So that the loops in different places in the Punching tracks can be introduced without this leading to delay of the lead frame are preferred between each the punched tracks and the through Bend out the connecting contacts Punching webs there are no webs connecting the punching webs.

According to a further embodiment of the invention runs transversely to align the connection contacts at least one contact strip, that on the punching tracks after punching as a contact point serves. This configuration increases the requirements corresponded to the electrical resilience, whereby for making the more durable and electric better quality lead frames after punching no additional Operations are required, such as by riveting contact rivets.

The contact strips lie on the inlay or as a toplay Die cut strips in one direction. Because in the counter or on one Connection contact different electrical requirements it is necessary to meet these requirements to meet the presence of a certain contact material. However, to avoid applying too many contact strips having to incur costs is expedient by at least one loop in the punching path of the connection contact the contact point to the desired position brought.

So that the connection contacts after positioning the contact points have the same length, expediently the connector contacts embedded in the lead frame are different Length on. After positioning, the are Connection contacts of the same length and the turn can be made via a Bending edge take place.

It is not always possible to manufacture the lead frame make the connection contacts the same length. That's the way it is For example, necessary from a tooling point of view, thin cutting punches for reinforcement to make coherent, what a Offset of the cut edges leads. Therefore preferably get the different length of connection contacts by a Loop the same length.

For one, contact points must be on the electrical Requirement correct place and on the other hand the connection contacts be brought to the required grid size. According to a further embodiment, this is achieved by that a punching track has at least two loops through the at least one contact point and / or a connection contact is positioned.

In a further advantageous embodiment, the Grinding in the lead frame on the opposite of the connection contacts Page available. So there is an accommodation the loops inside the switch, which means no additional Measures are necessary to protect the loops from damage or to protect touch.

The leadframe representing the contact unit must still be in the individual current paths are separated, the die Current paths realizing punch bars electrically from each other must be fixed in isolation. The handling of the contact unit should be done as part for cost reasons. thats why According to a development of the invention, the lead frame attached an insulating plastic part, according to the Fasten the lead frame between the webs of the lead frame the punching tracks are separated.

According to an advantageous embodiment, the fastening takes place of the lead frame on the plastic part by extrusion coating Plastic, the contact surfaces of the lead frame and the Terminal contacts are not overmolded, and being overmolded in a tool that produces the plastic part is carried out. Through these measures, the lead frame held electrically insulated, and when molding at the same time the switch part that is required anyway, for example a base made.

Fig. 1

eine Draufsicht auf ein Stanzgitter einer bekannten Kontakteinheit,

Fig. 2

eine Seitenansicht auf das Stanzgitter und Fig. 1 in Richtung des Pfeiles II,

Fig. 3

eine alternative Ausführung der Darstellung nach Fig. 2,

Fig. 4

eine Draufsicht auf ein Stanzgitter zur Herstellung eines Stanzgitters einer erfindungsgemäßen Kontakteinheit,

Fig. 5

eine Seitenansicht auf eine aus dem Stanzgitter hergestellte Kontakteinheit in Richtung des Pfeiles V nach Figur 4,

Fig. 6

eine Ansicht auf die Kontakteinheit gemäß Fig. 5 in Richtung des Pfeiles VI,

Fig. 7

eine Draufsicht auf eine umspritzte erfindungsgemäße Kontakteinheit,

Fig. 8

eine Seitenansicht auf die Kontakteinheit gemäß Fig. 7 in Richtung des Pfeiles VIII mit einem Teilschnitt im Bereich der Schleife,

Fig. 9

eine Draufsicht auf ein Stanzgitter mit Kontaktstreifen zur Herstellung einer nach der Erfindung,

Fig. 10

eine Draufsicht auf das Stanzgitter gemäß Fig. 9 nach Einbringung kleiner Schleifen,

Fig. 11

eine Seitenansicht auf das Stanzgitter gemäß Figur 10 in Pfeilrichtung XI,

Fig. 12

eine Draufsicht auf die aus dem Stanzgitter gemäß Fig. 10 hergestellten Kontakteinheit und

Fig. 13

eine Seitenansicht in Pfeilrichtung XIII gemäß Figur 12.

In the following description, the prior art and then the invention are explained in more detail using the exemplary embodiments shown in the drawing. Show it:

Fig. 1

a plan view of a lead frame of a known contact unit,

Fig. 2

a side view of the lead frame and Fig. 1 in the direction of arrow II,

Fig. 3

an alternative embodiment of the representation of FIG. 2,

Fig. 4

2 shows a plan view of a lead frame for producing a lead frame of a contact unit according to the invention,

Fig. 5

3 shows a side view of a contact unit made from the lead frame in the direction of arrow V according to FIG. 4,

Fig. 6

5 in the direction of arrow VI,

Fig. 7

a plan view of an overmolded contact unit according to the invention,

Fig. 8

7 in the direction of arrow VIII with a partial section in the area of the loop,

Fig. 9

2 shows a plan view of a lead frame with contact strips for producing a device according to the invention,

Fig. 10

9 shows a plan view of the lead frame according to FIG. 9 after introducing small loops,

Fig. 11

10 shows a side view of the lead frame according to FIG. 10 in the direction of arrow XI,

Fig. 12

a plan view of the contact unit made from the lead frame according to FIG. 10 and

Fig. 13

a side view in the direction of arrow XIII of Figure 12.

1-3 show the prior art a contact unit 1, which in its large extent from a essentially rectangularly shaped lead frame 2 consists. At the contact unit 1 protrude from the level of Lead frame 2, the contacts 3 out. In the plane of the lead frame 2, the punched tracks 4 provide the current paths over webs 5 between the punching tracks 4 hang Punching tracks 4 together and thus form the lead frame 2. In the plane of the lead frame 2 are diagonally opposite Retained holes 12 with which the lead frame 2 is positioned. There are also large openings 13 provided in the lead frame 2, which for other functions within an electrical switch can be used. All in all The contact unit 1 has seven connection contacts 3 according to 1 on. Each three connection contacts 3 are opposite arranged. All seven connection contacts 3 lie in a grid with each other. The stamping 14 in the Level of the lead frame 2 between the contacts 3 is by no means wide enough to match the length of the bent contacts 3 to be able to record. The contact unit 1 2 consists of a right lead frame 6 and a left lead frame 7 on which the connection contacts are made in one piece 3 are present and bent. About the to the Long sides 8 continuous punching tracks 4a, 4b and 4c the right lead frame 6 is connected to the left lead frame 7. With the help of the width of the punch webs 4a, 4b and 4c corresponding contact plates 9, which on the top 10 of the Punching grids 6, 7 are welded onto the punching grids 6, 7 connected to the contact unit 1. An alternative to this is shown in Fig. 3. Here is the contact unit 1 from a flat continuous lead frame 2, on its underside 11 angled contacts 3 welded are.

A lead frame 2 for a contact unit 1 according to the invention is shown in Figure 4. The lead frame 2 also has the openings 13 and holding holes 12. In the The level of the lead frame 2 is still the connection contacts 3 folded, which are integrally connected to the lead frame 2 are. Is between the free end of the contacts 3 enough space for the punching 14. The outer Areas of the lead frame 2 in which the holding bore 12 and the openings 13 are provided are identical to that Punching grid 2 according to the prior art. Only the one the long sides 8 existing punching tracks 4a, 4b and 4c run longer, making the lead frame 2 a larger Has length.

Figures 5 and 6 show the corresponding side views the contact unit made from the lead frame 2 of Figure 4 1. The contacts 3 are from the level of Lead frame 2 bent out by 90 ° on the underside 11. In order to the contacts 3 brought to the required pitch can be arranged on the long sides 8 Punching strips 4a, 4b and 4c each have a U-shaped one Loop 15 on. The bending direction of the loop lies here 15 in the longitudinal direction of the contacts 3, and the loop 15, or the punched strips 4a, 4b and 4c are made so long that a spacing of the contacts 3 on the predetermined grid dimension is enabled. The legs 16 of the Loop 15 run at an acute angle to each other, causing Dip a bending punch forming loop 15 slightly and can be pulled out.

So that the existing contacts on the contact unit 1 3 can be brought to the required grid size the stretched length of the loop 15 is equal to the length of the the lead frame 2 bent out contacts 3 plus the width of the clearance 14, which is between the free End of the contact 3 and the opposite part of the lead frame 2 is present. Only the Width of the clearance 14 in the longitudinal direction or bending direction the loop 15 is taken into account. When calculating the stretched length of the loop 15 will continue to be the bending correction factor considered.

As can be seen from FIG. 4, there are 2 in the lead frame the connection contacts 3 opposite in the bending direction of the loop 15, and the bending edge 17 of the contacts 3 runs perpendicular to the long sides 8 of the lead frame 2. When calculating the stretched length of the loop 15 will always the opposite end of the free contacts 3 Part considered. In the design according to 4 there are two free ends of connection contacts 3 across from. The clearance 14 is thus the area between the free ends of the contacts 3.

5 and 6 that the loops 15 bent towards the top 10 of the contact unit 1 are. In FIG. 5 there is only the one in the punching path 4c Loop 15 can be seen. The in the punching tracks 4a and 4b existing loops 15 are congruent behind it. Thus, in all punching tracks 4a, 4b and 4c, which is the connection for the contacts 3 supporting parts of the Represent lead frame 2, a loop 15 bent.

So that the connection contacts 3 from the plane of the lead frame 2 bent out and the loops 15 can be formed there are no connecting ones between these punching tracks Bars 5. Bars 5 attached in this area would have been used Consequence that on the one hand the webs 5 after bending the connection contacts 3 and after bending the loops 15 very much would be difficult to separate as they are no longer in one level would be present. If, on the other hand, between the punch bars 4a and 4b, the loops 15 are bent in different places so it would come alongside the first ones Difficulties in a delay between the punch webs 4a and 4b.

9 to 13 are contact units 1 or lead frames 2 shows the transversely to the alignment of the connection contacts 3rd wear two contact strips 18 each. The contact strip 18 is introduced in the manner of an inlay, as shown in the figures 11 and 13 emerges. But you can also use a toplay material use the contact material on the top 10 of the lead frame 2 is applied. Both rolled on Strips as well as an electroplated thin layer of strips come into use. After punching remain from the contact strip 18 only contact points 19 on the Punching tracks 4 of the lead frame 2, or the contact unit 1 obtained (see Fig. 9, 10 and 12).

As can also be seen from FIG. 9, the Lead frame 2 embedded contacts 3 a different Length. The contact points 19 are still in the Area of the previously existing contact strip 18. Since on the Top 10 of the contact unit 1 different electrical Requirements exist to meet these requirements be taken into account with a contact point 19. In order to avoid that too many contact strips 18 are required, becomes the contact point by introducing a loop 15 19 moved in the lead frame 2 or the contact unit 1. This is clearly evident from FIG. 10 in the case of the introduction of three loops 15 from the contact points 19 the area of the contact loops 18 have been moved out. Consequently is taken into account on the one hand that on the top 10 different contact points 19 are required and on the other hand that 3 different at the connection contacts Contact points 19 are necessary. So that the connection contacts 3 in spite of everything, the loops 15 have the same length in the terminal contact feet 20 designed so that these requirements are fulfilled.

In the case of the contact unit 1 shown in FIG. 12, in the punching tracks 4a and 4b three loops 15 incorporated. The loops 15 are at different lengths of the respective punch path 4a and 4b and have a different deep expression, but with the legs 16 of the Loops 15 run at an acute angle to each other. This makes it possible that all contact points 19 on the Stamping tracks 4 one to the original contact strip 18th get spaced position.

11 and 13 represent side views of contact units 1. In FIG. 11, they are rectangular in shape Loops 15 only in the direction of the bottom 11 of the contact unit 1 bent. This state represents an intermediate status represents, in which the connection contacts 3 are not yet from the Level of the lead frame 2 were bent out. In the following Then the contacts 3 are bent out and added the further loops 15. One too the contact unit 1 similar in FIG. 11 is in FIG. 13 shown that has already gone through this step and thus carries the loops 15 on the upper side 10.

7 and 8, the contact unit 1 is already at one Plastic part 21 attached. The plastic part 21 is the Socket of a switch that does not have clip lugs 22 in one shown housing is supported. The attachment of the Contact unit 1 in the electrically insulating plastic part 21 is made by overmolding with plastic in one Tool, the contact unit 1 in its holding holes 12 is adjusted. The base gets its form of use directly. The contact surfaces 23 and the connecting contacts 3 the contact unit 1 are not molded. The connection contacts 3 protrude from the underside 24 of the plastic part 21 out and are protected by a plug collar 25. The on the long sides 8 of the contact unit 1 in the direction of Top 10 curved loops 15 are also overmolded and thus protected.

The punching tracks 4 are in their individual after fastening Current paths separated. For this purpose, the webs 5 at separation points 27 punched out. Through different die cuts the webs 5 are thus still different Current paths can be implemented.

In the area of the openings 13 in the lead frame 1 are in the plastic part 21 latching scenes 26 molded in with the switch supported, not shown locking elements cooperate.

Claims (13)

1. Contact unit, more especially for electric switches, having a stamped grid formed from electrically conductive material, wherein the stamped tracks, representing the electric current paths, are connected via webs, and connection contacts are provided which protrude from the stamping plane, the intermediate space between the stamped tracks being smaller than the length of the connection contacts, characterised in that the connection contacts (3) are integrally formed with the stamped grid (2), and the stamped grid (2) has at least one loop (15) lying in the longitudinal direction of the connection contacts (3), said loop permitting the connection contacts (3) to be bent from the stamping plane of the stamped grid (2) and permitting the connection contacts (3) to be spaced over a predetermined grid pattern.
2. Contact unit according to claim 1, characterised in that the stretched length of the loop (15) corresponds to the length of the connection contacts (3), bent from the stamped grid (2), and to the width of a freely stamped portion (14) between the free end of the connection contacts (3) and oppositely situated regions of the stamped grid (2), when viewed with respect to the longitudinal direction of the loop (15), with consideration for the bend correction factor.
3. Contact unit according to one of claims 1 or 2, characterised in that connection contacts (3) are embedded in the stamped grid (2) so as to lie opposite one another when viewed with respect to the bend direction of the loop (15), which connection contacts can be moved from the stamped grid (2) at right angles and brought to the desired grid pattern by bending the loop (15) inwardly.
4. Contact unit according to claim 1 or 3, characterised in that at least two stamped tracks (4a, 4b, 4c), spaced apart from one another and extending parallel to one another, each have a loop (15).
5. Contact unit according to one of claims 1 to 4, characterised in that there are no webs (5) connecting the stamped tracks (4, 4a, 4b, 4c) between the stamped tracks (4a, 4b, 4c), which each have the loop (15), and the stamped tracks (4), which make the connection contacts (3) available by being outwardly bent.
6. Contact unit according to one of claims 1 to 5, characterised in that at least one contact strip (18), which serves as contact point (19) on the stamped tracks (4, 4a, 4b, 4c) after the stamping process, extends transversely relative to the orientation of the connection contacts (3).
7. Contact unit according to claim 6, characterised in that the contact point (19) is brought to the desired position by at least one loop (15) in the stamped track (4) of the connection contact (3).
8. Contact unit according to one of claims 6 or 7, characterised in that the connection contacts (3), embedded in the stamped grid (2), have different lengths.
9. Contact unit according to one of claims 6 to 8, characterised in that the connection contacts (3) of different lengths become the same length through a loop (15).
10. Contact unit according to one of claims 1 to 9, characterised in that one stamped track (4, 4a, 4b, 4c) has at least two loops (15), through which at least one contact point (19) and/or one connection contact (3) is positioned.
11. Contact unit according to one of claims 1 to 10, characterised in that the loops (15) in the stamped grid (2) are provided on the side situated opposite the connection contacts (3).
12. Contact unit according to one of claims 1 to 11, characterised in that the stamped grid (2) is secured on an insulating plastics material part (21), the webs (5) of the stamped grid (2) being interrupted between the stamped tracks (4, 4a, 4b, 4c) after the stamped grid (2) is secured.
13. Contact unit according to one of claims 1 to 12, characterised in that the stamped grid (2) is secured to the plastics material part (21) by injection-moulding with plastics material, the contact faces (23) of the stamped grid (2) and the connection contacts (3) not being injection-moulded, and the injection-moulding process being carried out in a tool which produces the plastics material part (21).

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