EP0793301A1 - Flat contact spring - Google Patents

Abstract

A flat-spring type contact (10) having a troughed plug contact housing (12) with a basic spring formed out of upper and lower contact limbs (14,16). The latter (14,16) are arranged spaced apart and opposite one another on the plug contact housing (12) and are spring-positioned against one another or against an intermediate knife contact by their free ends, which converge towards one another and are provided with crimp-form lip ends. At least one of the two contact limbs or arms (14,15) has spacing or distance pieces (30,31) moulded on the opposite-facing contact lamellae (20,22,32,34), with the spacing pieces supported on the mutually opposite-facing contact limbs (14,16)

Description

The invention relates to a flat spring contact with a box-shaped plug contact housing with a base spring formed from lamellar upper and lower contact legs, which contact legs are arranged on the plug contact housing at a distance from each other and resiliently connected to one another or to one between them with their converging free ends provided with receiving lips Apply the inserted knife contact, as well as with a spring and with receiving means for the electrical conductors to be connected

Flat spring contacts for transmitting electrical power or electrical signals are generally known. They are usually manufactured as a sheet metal stamped and bent part and have a box-shaped contact housing, on which one end of connection elements for an electrical conductor is formed and the other end opposite flat contact springs with bent free ends, which form a receiving opening for receiving an intended one flat counter contact.

Such a contact, referred to as a double flat spring contact, with lamellar contact springs provided in pairs and a crimp connection for receiving an electrical conductor has become known from German utility model DE 85 02 106 U1. In this known flat spring contact, each lamella contact is provided with an over-spring which is intended to increase the contact force of the lamella contact springs and, moreover, is to prevent their expansion during operation.

Here, the increase in the closing force of the contact springs and thus their contact force fulfills the intended purpose, but the increased contact force leads to a more difficult handling of these connectors, because despite the existing locating lips, which favor the attachment of the relevant counter-contact, the insertion of the respective counter-contacts is correspondingly more difficult due to the increased closing force of the spring contacts which are additionally acted upon.

In addition, if the manufacturing tolerances of the flat spring contacts manufactured as sheet metal stamped and bent parts are too large, contacting problems can easily occur despite the increased contacting force if the contact surfaces of the flat contact springs arranged opposite one another do not run parallel to one another, but rather their distance from one side to the other others diverged. In such cases, the entire existing contacting cross-section is not used, but depending on the dimensions of the wedge-shaped gap extending transversely to the plugging direction between the contact legs, the actual contact area is only a fraction of the intended contact area.

A design similar to that described above for a double flat spring contact has become known from German patent DE 32 48 078 C2. To avoid the difficulties described above, each lamella contact has a cross-section that is curved on one side toward the contacting side, so that the inserted mating contact is contacted by the surface of the bulge during operation.

The production of such contacts with contact lamellae which are curved on one side is complex and requires precise production. This is very complex and therefore undesirable in mass production.

Starting from this prior art, it is an object of the present invention to improve a flat spring contact of the type mentioned at the outset, so that the contact spring has a defined pre-opening with a simple construction. A uniform contact pressure is also to be achieved and inexpensive production is to be made possible without disadvantage for the perfect functioning of the contact.

This object is achieved by the characterizing features of claim 1. Further advantageous refinements and improvements are the subject of the dependent claims.

According to the invention it is provided to achieve the object that at least one of the upper or lower contact legs have integrally formed spacers on the opposite leg surfaces, which are supported on the opposite contact leg. As a result, the opposing leg surfaces of the contact legs are held at a distance defined by the respective spacer, so that a corresponding pre-opening of the contact blades is established.

Advantageously, according to a preferred embodiment, the spacers are designed as tabs that are angled away from the contact limbs and rest with the free end on the opposite contact lamella.

In a further embodiment of the invention, the tabs, which are preferably angled in a Z-shape, are located on the long sides of the contact spring. Each contact plate has only one spacer, while a support surface is formed on the contact plate opposite the spacer, on which the spacer is supported.

An advantageous development of the invention is further characterized in that a spacer is also arranged on one of the two contact lamellae of the contact spring according to the invention, that is to say at half the width.

This central spacer is also designed as a tab angled out of the contact lamella, which is supported on the opposite contact lamella in the same way as the outer spacers and thus equalizes the opening width of the pre-opening of the contact lamellae.

At the same time, the central spacer serves as a centering for a knife-like counter-contact to be inserted into the contact spring, which has an elongated recess in the region of the spacer, parallel to its longitudinal axis, into which the central spacer engages.

According to the invention, the contact legs are kept at a distance with the aid of the spacers for the pre-opening of the contact lamellae, preferably at a distance between 0.25 and 0.6 mm, in particular at a distance of 0.43 mm, between the contact legs or between their contact lamellae consists.

According to a development of the invention, the spacers formed on the outer contact lamellae of the upper and / or lower contact legs also serve as side guides, which each form a stop on the side of the contact surface formed by the contact lamellae for mating contact pieces to be inserted.

Furthermore, the spacer formed on one of the middle contact lamellae of the upper and / or the lower contact legs advantageously serves as a centering for a mating contact piece to be inserted.

According to a further advantageous embodiment of the invention, the contact lamellae are also provided with local bulges which, in the rest position, are each at a distance from the opposite contact leg in accordance with the aforementioned opening of the contact lamellae.

These bulges are preferably dome-shaped in the lamellae, so that each contact lamella has a defined support or contact point for the knife-like counter contact to be introduced, regardless of a possible inclination of the contact lamella in question. In this way, perfect contacting with the mating contact is guaranteed at any time.

According to a preferred embodiment of the invention, the bulges are arranged at a distance from the end edge of the contact lamellae. Their height can be equal to or less than the thickness of the respective intended counter contacts. The insertion of the mating contacts is facilitated by the spacers mentioned, which are arranged on the contact legs, since these cause the desired opening of the contact legs.

In a further development of the invention it can be provided that the bulges on the contact lamellae on the contact legs located opposite each other are arranged in the same position, so that the bulges lie opposite one another.

According to an advantageous embodiment of the invention, four, namely two middle and two outer contact lamellae are provided with separating joints arranged therebetween, wherein the respectively adjacent outer and inner contact lamellae can be U-shaped with separating joints open on the plug side, with the rear end facing away from the plug-in side Cross bars for connecting the contact blades.

A preferred embodiment of the invention provides that the joint width of the joint between the middle contact lamellae of the upper contact leg is smaller than the joint width of the joint between the middle and the outer contact lamellae, while the middle joint in the lower contact leg is wider than that in the upper contact leg .

According to a further embodiment of the invention, adjacent contact lamellae of a contact leg can be connected to one another by means of a connecting web. The connecting web is preferably arranged at the end of the contact lamellae.

In particular, the connecting web of the middle contact lamellae of the lower contact legs can advantageously terminate here with the end edge of the contact lamellae.

Another advantageous embodiment of the invention provides that the connecting web provided on the plug-in side of the middle contact lamellae of the lower contact legs is curved in an arc shape, while the remaining rear connecting webs of the inner or middle contact lamellae are each flat with the outer contact lamellae of the contact legs.

It is preferably provided that all the connecting webs of the contact blades are integrally formed on them.

With regard to an equally simple and trouble-free production and a reliable function, the flat spring contact according to the invention and its refinements and developments is made as a stamped and bent part from electrically conductive flat material. Here, the outer contact lamellae are each integrally connected to the box-shaped plug contact housing, and the distance between the contact legs is bridged laterally by side walls of the plug contact housing.

These and other advantageous refinements and improvements of the invention are the subject of the dependent claims.

Using an exemplary embodiment shown in the schematic drawing, the invention, advantageous refinements and improvements of the invention and special advantages of the invention are to be explained and described in more detail.

• Fig. 1 eine Draufsicht auf die oberen Kontaktschenkel eines erfindungsgemäßen Flachfederkontakts;
• Fig. 2 eine Seitenansicht der Anordnung gemäß Fig. 1;
• Fig. 3 eine Teilschnittansicht eines erfindungsgemäßen Flachfederkontakts mit Sichtbarmachung der unteren Kontaktschenkel in Draufsicht,
• Fig. 4a eine Ausführungsform eines Kontaktmessers zum Einsatz in eine Anordnung gemäß Fig. 1 bis 3 und
• Fig. 4b einen Querschnitt durch das Kontaktmesser gemäß Fig. 4a entlang Schnittlinie IV-IV;
• Fig. 5 einen Teillängsschnitt durch einen erfindungsgemäßen Flachfederkontakt entlang der Schnittlinie V-V in Fig. 1 mit Sichtbarmachung eines mittleren Distanzstücks.

Show it:

• Figure 1 is a plan view of the upper contact legs of a flat spring contact according to the invention.
• FIG. 2 shows a side view of the arrangement according to FIG. 1;
• 3 is a partial sectional view of a flat spring contact according to the invention with the lower contact limbs visible in a top view,
• 4a shows an embodiment of a contact knife for use in an arrangement according to FIGS. 1 to 3 and
• 4b shows a cross section through the contact knife according to FIG. 4a along section line IV-IV;
• Fig. 5 is a partial longitudinal section through a flat spring contact according to the invention along the section line VV in Fig. 1 with visualization of a middle spacer.

In Fig. 1 is a flat spring contact 10 according to the invention in plan view with a box-shaped contact housing 12 with molded on the plug contact side legs 14, 16, which are each provided with receiving lips 15 on the plug side, and with a connection on the opposite side, in a known manner as a crimp contact trained conductor connection 18 for an electrical conductor to be connected, not shown here, which serves as a connector, preferably for low-voltage plug connections.

1, only the upper contact legs 14 can be seen, while in the side view of the flat spring contact 10 according to the invention shown in FIG. 2 and in the partial sectional view shown in FIG. 3, the lower contact legs 16 and their pre-opening 15 are also visible are recognizable.

The invention aims primarily at the configuration of the contact legs 14, 16 and at their pre-opening 15, so that this will be discussed in particular in the following.

From Fig. 1 it can be seen that the upper contact legs 14 are formed from paired inner contact lamellae 20 and outer contact lamellae 22, the outer contact lamellae 22 being laterally integral with the contact housing 12 are connected. In plan view, the outer and inner contact lamellae 20, 22 of the upper contact limbs 14 each form a U which is open towards the plug side, the inner contact lamellae 20 being connected to the outer contact lamellae 22 by means of a broad crosspiece 24. Between the inner contact lamellae 20 there is a parting line 26, the width of which is less than the distance of the inner contact lamellae 20 from the outer contact lamellae 22.

This configuration offers the advantage of exceptional flexibility of the contact lamellae 20, 22 of the upper contact leg 14, so that practically every knife-like counter contact introduced is reliably contacted.

In order to increase the contact security, local bulges 28 are stamped into the contact lamellae 20, 22, which are preferably dome-shaped and protrude from the contact surface of the contact lamellae and thus form a defined contact point for the respective counter contact.

The production of the bulges is not a problem in the course of the manufacture of the flat spring contact 10, which is provided as a stamped, bent and pressed part, from flat material, preferably sheet metal from electrically conductive material, since the bulges 28, unlike in the case of contact lamellae with a bulge cross-section, already, for example, when punching out the Sheet pre-product can be generated by a corresponding stamp.

Spacers 30, which are formed on both sides of the longitudinal sides of the lower contact leg 16 and are indicated in FIG. 1 only by dashed lines, are used to set the pre-opening of the contact legs 14, 16 provided according to the invention. They are designed as approximately Z-shaped angled tabs, which are supported with their free end on associated support surfaces 23 on the upper contact lamella 22.

The side view of the flat spring contact 10 according to FIG. 1 shown in FIG. 2 leaves one of the so-called spacers 30, which is formed in the outer contact lamella 32 of the lower contact leg 16 from the side. These spacers 30 serve, as the name suggests, on the one hand to set a distance between the contact legs 14, 16 according to the pre-opening 15 according to the invention and on the other hand to guide and in particular the lateral limitation for the respective mating contacts, one of which is exemplary in FIGS. 4a and 4a 4b is shown.

In Fig. 3, the lower contact leg 16 of the flat spring contact 10 according to FIG. 1 can be seen in partial section. Here, too, inner contact lamellae 32 and outer contact lamellae 34 form the contact leg 16, wherein between the individual contact lamellae 32, 34 there is in each case an equally wide parting line 33, into which a Z-shaped angled spacer arranged on the right inner contact lamella projects. The width of the spacer 31 is corresponding to the wide parting line greater than the parting line 26 between the inner contact lamellae 20 of the upper contact leg 14, on which the spacer 31 is supported, whereby the two contact legs 14, 16 are kept at a distance from each other and a defined opening of the Contact blades 20, 22, 32, 34 is ensured.

However, unlike the inner contact lamellae 20 of the upper contact leg 14, the inner contact lamellae 32 are connected to one another here by means of a bow-like cross piece 36, in order to ensure the basic stability of the flat spring contact required for reliable contacting of a mating contact. Without this crosspiece, the resilience of the individual contact lamellae 32, 34 could lead to an undesired separation of the connecting parts, namely flat spring contact 10 and mating contact, which must definitely be excluded.

The thickness and the width of the cross piece, ie its cross section, determine the deflection of the inner contact lamella 32 of the lower contact leg 16, that is to say the smaller the cross section is, the more flexible the arrangement of the contact blades 32.

The contact lamellae 32, 34 of the lower contact leg 16 are also each provided with bulges 38, which are both designed in the same way as the bulges 28 on the upper contact leg 14, namely likewise preferably in the form of a dome, and also arranged in a manner corresponding to the position, in particular from the partial section according to FIG 3 emerges from the cutting line on the right inner contact lamella 32.

In addition to the secure contacting, the bulges fulfill another purpose which is pursued with the invention. Due to the distance between the contact legs 14, 16 generated by the bulges, a pre-opening of the contact legs 14, 16 is effected, which facilitates the insertion of a mating contact without the contact force of the contact legs 14, 16 and thus the contact security being reduced thereby.

4 finally shows a knife-like plug contact 40 which can be provided as a mating contact for insertion into the flat spring contact 10 according to the invention. 4a shows a plan view of the knife contact 40; 4b shows a cross section through the knife contact 40 along section line IV-IV.

The knife contact according to FIG. 4 a has two contact knives 42, the end edge of which is chamfered, in order to make it easier to insert into the flat spring contact 10. A separation joint 44 is also provided between the contact blades 42. In cooperation with the contact blades 20, 22, 32, 34 and the spacers 30 of the flat spring contact, a pre-centering is effected for the contact knife 40.

The contact knives are preferably cut out transversely to the rolling direction of the flat product in question, for example sheet metal. Lugs can be on the long sides of the contact knife 46 be formed, which are used to fasten the contact blades 40 in an insulating housing.

Like the flat spring contact, the contact blades are also made of electrically conductive material, the contacting surfaces preferably being able to be provided with a coating of noble metal, for example gold or tin.

5 shows a partial longitudinal section through the contact spring 10 according to the invention along the section line V-V in FIG. 1, in which the middle spacer 31, which is angled approximately Z-shaped from the contact lamella 32, can be seen in longitudinal section. There is a distance between the two contact legs 14, 16, which represents the pre-opening 15 according to the invention.

While the first leg of the Z-shaped spacer 31 connects to the contact lamella 32 virtually parallel to it, the second leg connected to the first leg via an inclined web rests at a distance from the opposite contact lamella 20. The illustration of the arrangement of the pre-opening 15 according to the invention of the contact legs 14, 16 is clear.

A further task which the middle spacer 31 has to do concerns the guiding and insertion limitation of the respective counter contact, as is shown in a top view in FIG. 4 a. The middle spacer 31 serves both as a centering by engaging in the longitudinal slot 44 formed in the center of the counter-contact and at the same time preventing further insertion by contacting the slot base.

With the above-described configuration of the flat spring plug contact 10 according to the invention with flexibly arranged contact lamellae 20, 22, 32, 34 with bulges 28, 38 provided thereon, on the one hand a sufficient opening for easy insertion of the mating contact is ensured with simultaneous safety from the rear.

The middle opening of the connected inner fins 32 of the lower contact leg 16 leads to the lifting of the separate contact fins of the upper contact leg 14. Also, due to the curved design of the front crosspiece 36 of the inner contact fins 32 of the lower contact leg 16, the width thereof is quasi variable, so that contact knives also larger dimensional tolerances than can be used as a counter contact since then.

The provided bulges 28, 38 ensure defined support points at the respective embossing points, that is to say at the respective contact points.

Through the pre-opening, the inserted counter contact is also pre-centered, since the centering does not take place over the tips of the contact knife, but over its flanks, which serve as contact surfaces.
This increases the usability and usability of the flat spring contact 10 according to the invention.

The outer contact lamellae 22, 34 can advantageously be larger than the inner contact lamellae 20, 32, while the parting lines 28, 33 are unchanged. Furthermore, it can be advantageous with correspondingly wide flat spring contacts, instead of the embodiment described above, to provide more than two inner and two outer contact lamellae 20, 22, 32, 34, which are each provided with bulges and thereby obtain the desired flexibility, on the one hand for easy handling and on the other hand for safe contacting is to be seen as an advantage according to the invention. This means that practically any required width of plug contacts can be implemented without loss of plug security.

Reference list

10th

Flat spring contact

12th

Plug contact housing

14

upper contact leg

15

Receiving lip

16

lower contact leg

18th

Receiving means

20th

inner lower contact blades

22

outer lower contact blades

24th

Crossbar

26

Parting line

28

Bulge

30th

Spacer

31

Spacer

32

inner upper contact blades

33

Parting line

34

outer upper contact blades

36

Crossbar

38

Bulge

40

Knife contact

42

Contact knife

44

Parting line

46

Latches

Claims (14)

Flat spring contact (10) with a box-shaped plug contact housing (12) with a base spring formed from lamellar upper and lower contact limbs (14, 16), which contact limbs (14, 16) on the plug contact housing (12) are arranged opposite each other at a distance and with them Free ends that are designed to be converging to one another and provided with receiving lips (15) resiliently against one another or against a knife contact inserted therebetween, as well as with a spring and with receiving means (18) for electrical conductors to be connected,
characterized,
that at least one of the two contact limbs (14, 16) has spacers (30, 31) formed on the mutually opposite contact lamellae (20, 22, 32, 34), which are each supported on the opposite contact limb (14, 16) at a distance. Flat spring contact according to claim 1, characterized in that at least two outer spacers (30) and a middle spacer (31) are provided. Flat spring contact according to Claim 1 or 2, characterized in that the contact legs (14, 16) are kept at a distance in accordance with the height of the spacers (30, 31), preferably between 0.25 and 0.6 mm, in particular at a distance of 0.43 mm. Flat spring contact according to one of the preceding claims, characterized in that the upper and / or lower contact legs (14, 16) are provided with local bulges (28, 38). Flat spring contact according to one of the preceding claims, characterized in that at least four, namely two middle and two outer contact lamellae (20, 22, 32, 34) are provided per contact leg (14, 16), between each of which separation joints (26, 27 , 33) are provided. Flat spring contact according to claim 5, characterized in that the joint width of the parting line (26) between the middle contact lamellae (20) of the upper contact leg (14) is smaller than the respective joint width of the parting line (27) between the middle contact lamellae (20) and the outer contact blades (22) of the upper contact leg (14). Flat spring contact according to Claim 5 or 6, characterized in that each contact lamella (32, 34) of the lower contact leg (16) is connected to an adjacent contact lamella (32, 34) by a connecting web (36). Flat spring contact according to claim 7, characterized in that the connecting web (36) is arranged in each case at the end of the contact lamellae (32, 34). Flat spring contact according to claim 8, characterized in that the connecting web (36) of the middle contact lamellae (32) of the lower contact legs (16) ends with the plug-side end edge of the contact lamellae (32, 34). Flat spring contact according to claim 7, characterized in that the connecting web (36) of the middle contact lamellae (32) of the lower contact legs (16) is curved in an arc. Flat spring contact according to one of the preceding claims, characterized in that spacers (30) are formed on the outer contact lamellae (22, 34) of the upper and / or lower contact legs (14, 16) and are attached to the contact lamellae (20 , 22, 32, 34) formed contact surface to the side form a stop for counter-contact pieces. Flat spring contact according to one of the preceding claims, characterized in that the flat spring contact (10) is made as a stamped and bent part from electrically conductive flat material. Flat spring contact according to one of the preceding claims, characterized in that the outer contact blades are each connected in one piece to the box-shaped plug contact housing. Flat spring contact according to one of the preceding claims, characterized in that the distance between the contact legs (14, 16) is bridged by the side walls of the plug contact housing (12).

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