EP0859431A2 - One-piece contact spring - Google Patents

Abstract

A single-piece contact spring comprising a box-type contact part (1) on which is formed a base wall (11) and a cover wall (15). On the plug-in side, a spring arm (25;27) is bent back into the inner cavity of the contact part, in which the spring arms (25,27) mutually converge and are provided with springy contact crests (31) on their ends. Each of the two spring arms (25,27) is supported at a support device (29) in order to relieve the bend of the respective spring arm (25,27), the support device (29) is displaced backwards into the inner cavity of the box, from the front end of the bend running from the plug-in side, by approx. two-to-five-times the thickness of the base wall (11) or cover wall (15).

Description

The invention relates to a one-piece contact spring a box-shaped contact part, on which one Bottom wall and a top wall is molded from which each have a spring arm in the Contact part inside is bent back, the spring arms run towards each other and at their ends with free resilient contact tips are provided, and with a molded on opposite side of the connector.

Contact springs are used, for example, on a large scale Connectors used in automotive technology and have often over two parts to be manufactured separately, namely a base spring and one over the base spring too slipping over spring or also called locking sleeve. The The base spring has the plug side of the contact spring facing end of two spring arms, on the plug side the contact spring remote end in one piece a connector is molded for an electrical conductor. The basic spring is preferably a stamped and bent part and exists because of necessary good electrical property preferably from galvanized brass, galvanized copper or so-called Feather bronze. The over-spring to be put over the base spring essentially has the function of the spring force of the Increase contact spring and by training with or several locking tongues a releasable locking of the Contact spring in a contact chamber of a housing To enable insulation material. The releasable locking of the Contact spring through such latches is also called Primary locking designated. The spring is in the Usually made of a material with good spring properties and can also be manufactured as a stamped and bent part. As Material is suitable for example sheet metal.

Contact springs with two to be manufactured separately Element spring and over spring have the disadvantage that a relatively high effort must be made to the spring over against slipping on the base spring fasten. In addition, the well-known Contact springs with base springs and put on spring due to a relatively high material and Assembly effort.

However, they are also cheaper, one-piece Contact springs become known. Such a one-piece Contact springs, for example, show the two documents US-A-4,152,042 and FR-A-2,157,490. In both documents are described box-shaped contact parts of a contact spring, which have spring arms bent back into the interior of the box.

FR-A-2,157,490 describes a box-shaped contact part a contact spring, either of each of the four Sidewalls bent back spring arms or only in each case has two spring arms bent back opposite. At the embodiment described there with the four in the spring arms bent back inside the box lie above them a relatively long area on the associated Side wall on flat, then diagonally over the remaining length to be bent obliquely inwards. In which Embodiment described there with only two in the inside of the box is bent back Spring arms are approximately V-shaped and lie with their ends again on the associated inner walls of the side walls on. The opposing spring arms are relatively far apart. Through the relatively wide spacing of the spring arms to each other is only flawless with these contact springs Connection with an inserted plug contact possible if the plug contact has a sufficient thickness or width having. If the plug contact is too small in this Contact spring introduced is either no or only a very bad contact possible.

In US-A-4,152,042 there is an improved contact spring for this described. The contact spring is characterized by two of two opposite side walls into the box interior spring arms bent back. The spring arms are outgoing bent back by 180 ° from the attached side walls, and then converge towards each other in an arc. The free ends these spring arms are relatively narrow opposite contact tips provided, which also with Inserting a small plug contact is a safe one Allow plug connection. To relieve the bending of the Both spring arms are the spring arms in the area of the bend provided with a recess on the inside. This will achieved a greater elasticity of the bend. Outgoing however, the spring arms run in an arc from the bend towards each other. This inevitably leads to the introduction of one Plug contact in the contact spring and the associated Pushing apart the ends of the spring arms so that the Bending is relatively heavily loaded. This can U. even to damage or break the Guide the contact spring at the bending points.

The invention is therefore based on the object to develop such contact spring so that this one has greater strength and thus even with repeated Inserting an appropriate plug contact does no damage takes.

This object is achieved in the aforementioned contact spring in that each of the two spring arms is supported on a support device to relieve the bending of the respective spring arm, and that this support device from the front end of the bending directed to the plug side by about two to five times the thickness the bottom wall or ceiling wall is set back into the inside of the box.
Such a design of the contact spring can be a very inexpensive, reliable and robust miniature socket contact, also suitable for so-called mat seals, e.g. B. for a plug contact size 0.63 mm x 0.63 mm, with crimp or IDC cable connection. Such a contact spring can be secured in position in a simple manner by means of a latching hook suitable for this purpose within a plug housing.

By the support device according to the invention, the whole certain predetermined location of the contact spring on the ground or Ceiling wall is to be arranged in one piece Relieving molded spring arms can even with multiple insertion of a plug contact an effective Breakage protection can be achieved at the bending points.

The support device is according to the invention from the front end the bend by about two to five times the thickness of the Floor or ceiling wall set back inside the box arranged. This arrangement of the support device optimal relief of the bending point of the Reach the spring arm.

The support device can be in different ways and Way to be realized. In one embodiment of the Invention are the two spring arms in each of the above Area shortly after the 180 ° bend with a kink provided with which they are on the bottom wall or Support the top wall of the contact part, so that in their Relieve 180 ° bend affecting strength.

Instead of the kink mentioned in the ceiling wall or in the bottom wall also one pointing towards the spring arm Recess or wart are formed on the bent spring arm supports.

With higher demands on the contact force, such as. B. for tinned contacts, the spring arms of the contact spring by one from the bottom wall and the top wall bent out support arm, which is preferably at its distal End has a chamfer to enlarge the contact surface, supported. On the one hand, the overall length of the box-shaped Not unnecessarily enlarge contact part and on the other hand the greatest possible elastic deflection of the spring arms reach, the support is provided by the support arms not at the contact point itself, i.e. in the Contact tip area of the spring arms, but at least about almost in the middle of the spring arms.

In a development of the invention, the spring arms are like this designed that this with heavy load on the inner walls bump the bottom wall and ceiling wall and thus protect yourself against bending.

Fig. 1

Ein erstes Ausführungsbeispiel einer erfindungsgemäßen Kontaktfeder in Draufsicht von oben auf das Innere des U-förmig gebildeten Anschlußteiles, eine Draufsicht von hinten und vorn, eine Seitenansicht und auf eine Schnittansicht,

Fig. 2

die in Fig. 1 gezeigte Kontaktfeder in perspektivischer Darstellung,

Fig. 3

ausschnittsweise die Kontaktfeder der Fig. 1 und 2 im Bereich eines Federarmes im Schnitt mit einem Knick des Federarmes als Abstützeinrichtung,

Fig. 4

eine ähnliche Darstellung wie Fig. 3, jedoch mit einer in der Bodenwandung ausgebildeten Ausnehmung als Abstützeinrichtung,

Fig. 5

verschiedene Biegeschritte, um aus einem gestanzten Blechteil die Kontaktfeder der Fig. 1 bis 3 zu bilden,

Fig. 6

eine teilweise Schnittansicht durch das Kontaktteil der Kontaktfeder nach den Fig. 1 bis 3 mit eingestecktem Kontaktstift,

Fig. 7

eine ähnliche Darstellung wie Fig. 6, jedoch ohne die Federarme unterstützende Stützarme.

Other advantages and developments of the contact spring according to the invention are explained in more detail below in connection with several figures using exemplary embodiments. Show it:

Fig. 1

A first embodiment of a contact spring according to the invention in a top view from above of the interior of the U-shaped connecting part, a top view from the rear and the front, a side view and a sectional view,

Fig. 2

the contact spring shown in Fig. 1 in a perspective view,

Fig. 3

1 and 2 in the area of a spring arm in section with a kink of the spring arm as a supporting device,

Fig. 4

3 shows a representation similar to FIG. 3, but with a recess formed in the bottom wall as a support device,

Fig. 5

different bending steps in order to form the contact spring of FIGS. 1 to 3 from a stamped sheet metal part,

Fig. 6

2 shows a partial sectional view through the contact part of the contact spring according to FIGS. 1 to 3 with the contact pin inserted,

Fig. 7

a representation similar to FIG. 6, but without supporting arms supporting the spring arms.

The same reference numerals are used in the following figures same parts with the same meaning.

In Fig. 1 are different views of a first Embodiment of a one-piece contact spring after presented the invention. Fig. 1a shows the one-piece Contact spring with a view from above of the inside of the here exemplary U-shaped connector 3, which has a U-shaped connecting web 9 with a box-shaped Contact part 1 is integrally connected. The whole Contact spring consists of a stamped sheet metal part that 5 bent in a special way according to the explanation of FIG becomes.

1b and 1c show the top views from behind the contact spring or from the front onto the contact spring. In Fig. 1d is a side view and in FIG. 1e a sectional view along the section line A-A of Fig. 1a of the contact spring shown.

In the illustrated embodiment, the connector is as Crimp connection formed. However, it could be another Connection part, e.g. B. a so-called IDC connection, here be provided. In the illustrated embodiment points the crimp connection a rear insulation claw 5 and one adjoining conductor wire claw 7 in the plugging direction. The conductor wire claw 7 is above that already mentioned Connecting web 9 to the box-shaped contact part 1 molded.

The box-shaped contact part has a bottom wall 11 and a top wall 15 which has a first side wall 17 are connected to each other. On the bottom wall 11 a second closes parallel to the side wall 17 Side wall 13, one at its upper end orthogonally in the direction of opposite side wall 17 jumping box rag 19. This box cloth 19 engages over the top wall 15 and thus serves for one secure clamping of the box-shaped contact part 1.

Like the different views of Fig. 1 and in particular also the perspective view of the contact spring of Fig. 2 shows, this box flap 19 does not quite reach to the front end of the box-shaped contact part. Of the Box flap 19 is shorter. As the 2 shows the perspective view of FIG. 2 particularly clearly, the side wall 13 has an L-shaped in the front region recess 47, into which a projection 45, which is molded onto the ceiling wall 15, lies flat. The recess 47 thus serves as a stop for the projection 45. The stop is identified by reference numeral 43 in FIG. 2 designated.

The box flap 19, which, as mentioned, only about half Middle of the ceiling 15 is enough, not only serves secure clamping of the box-shaped contact part 1, but thanks to its design it can also be used as Serve polarization. Unless a case in which this Insert the contact spring, a corresponding one Has inner wall is only a right-sided Ensure that the contact spring is inserted.

The perspective view of FIG. 2 additionally shows one in the side wall 13 incorporated hole 41, which also can be formed as an embossing. This perforation 41 serves as a stop for a bending process in connection with Fig. 5 will be explained.

The one-piece contact spring shows how special the sectional view of Fig. 1e clearly shows two spring arms 25, 27, which are integral with the bottom wall 11 or Ceiling 15 molded and by 180 ° bend in the Are bent back inside the box. The two spring arms 25, 27 run towards each other with their distal ends and are at their ends with freely springy contact tips 31st Mistake. The two contact tips 31 are proportionate close to each other so that even when introducing small Contact pins secure contacting is guaranteed. In the illustrated embodiment of Fig. 1e, the range distal ends of the two spring arms 25, 27 to about Half back into the interior of the contact part 1. At least the two spring arms 25, 27 are in the contact tip area preferably with a metallization layer, e.g. B. one Gold or tin plating 39 provided, so that an even better Contacting an inserted contact pin possible is.

The two support each other to relieve the 180 ° bend Spring arms 25, 27 on a support device 29 which in 3 and 4 explained in detail will be starting.

Furthermore, in the bottom wall 11 and top wall 15 Support arms 21 and 23 incorporated. These support arms 21, 23 are bent inside the box and support the spring arms 25, 27 approximately in the middle and thus clearly spaced from Contact area. For a good support of the spring arms 25, 27 on the support arms 21, 23 ensure that Support arms 21, 23 chamfered at their front end.

The support arms 21, 23 serve to limit the bending stress. Since the support arms 21, 23 are self-resilient, a much longer travel with the same contact force ensured.

3 is based on a detailed view the front end of the contact part 1, the formation of the mentioned support 29 and the dimensioning of Spring arms 25, 27 and the support arms 21, 23 explained in more detail. In the detailed view shown in Fig. 3 is only sections of the bottom wall 11, the support arm 21 and the Spring arm 25 shown. The dimensioning of the support arm 23 and the associated spring arm 27 is similar.

A

= 2 ... 5 x S;

B/C

= 2/3 ... 3/2;

D

= 0,8 ... 1,2 x B.

It is assumed that the bottom wall 11 has a thickness S. The support device 29 is offset from the front end of the 180 ° bend by the distance A to the rear. At this point, the spring arm 25 has a kink and lies flat on the bottom wall 11 until then. From this point, the spring arm 25 extends obliquely upward over a length B + C to its contact point K. From this contact point K, the spring arm 25 again runs somewhat towards the bottom wall 11. The support arm 21 has a length D and supports the spring arm 25 at the connection point of B + C. According to the invention, the lengths A, B, C and D mentioned are dimensioned approximately as follows:

A

= 2 ... 5 x S;

B / C

= 2/3 ... 3/2;

D

= 0.8 ... 1.2 x B.

To further relieve the 180 ° bend and increase the elasticity of the spring arm 25 can at the 180 ° bend a recess 37 can be provided, which by a Tapering of the sheet metal part is formed at this point.

Instead of the support device formed by a kink 29, as shown in Fig. 3, it is also possible in the Bottom wall 11 a wart or a dome-shaped Press in bulge, on which the spring arm 25th supports. This example is shown schematically in FIG. 4. The specified dimensions also apply here.

6 is box-shaped Contact part 1 if not yet completely between the Contact springs inserted contact pin 51 shown. The Bottom wall 11 and ceiling wall 15 have relief the support arms 21, 23 each have a stiffening bead 35 on. The spring arms 25, 27 can be completely inserted contact pin 51 with its distal ends support this stiffening beads 35 and are thus in front protected from overbending.

As Figure 7 shows, it is also within the scope of the invention explained one-piece contact spring without the described Training support arms. However, the arrangement is essential the support device 29 than the kink or the mentioned Wart, in the specified area.

In connection with Fig. 5, the required Bending processes described, which are necessary to the in 1 and 2 explained in one piece Manufacture contact spring.

5a is an already completely stamped sheet metal part shown, from which the contact spring is bent. The Sheet metal part has an approximately rectangular area that adjacent sections for the top wall 15, a side wall 17, a bottom wall 11, another Has side wall 13 and a box flap 19. In the Section of the ceiling wall 15 are already incisions for a support arm 23 and 11 incisions in the bottom wall a support arm 21 incorporated. From the front section of the Top wall 15 and from the front portion of the bottom wall 11 extend two elongated metal strips, which for Formation of the two spring arms 25, 27 are provided. In the Side wall 13 has already an embossing 41 inserted as a stop during the bending process for the upper box section serves.

In Fig. 1b, the two support arms 21, 23 are already up bent, as well as the two spring arms 25, 27. According to Fig. 1c After a further bending, the two spring arms 25, 27 orthogonal to the sections of the bottom wall 11 and Ceiling wall 15.

In the next step (see FIG. 1d) the spring arm 27 is still bent further so that it is bent back by 180 °. The other spring arm 25, however, remains in its orthogonal Position. In the next step (cf. Fig. 5e) the Side wall 13 together with the box flap 19 upwards and the side wall 17 together with the top wall 15 bent upwards. In contrast, the bottom wall 11 remains flat lie on a mat. Just before the box-shaped Contact part is closed (see. Fig. 5f and 5g), the Spring arm 25 bent back 180 ° and then that box-shaped contact part completely closed by the Box flap 19 engages over the top wall 15 (see FIG. 5a).

Claims (13)

One-piece contact spring with a box-shaped contact part (1) on which a bottom wall (11) and a top wall (15) are formed, of which a spring arm (25, 27) is bent back into the inside of the contact part on the plug side, the spring arms (25 , 27) run towards one another and are provided at their ends with freely resilient contact tips (31), and with a connecting part (3) molded on opposite to the plug side,
characterized in that each of the two spring arms (25, 27) is supported on a support device (29) in order to relieve the bending of the respective spring arm (25, 27), and in that this support device (29) extends from the front end of the bending directed towards the insertion side about two to five times the thickness of the bottom wall (11) or top wall (15) is set back into the interior of the box. One-piece contact spring according to claim 1,
characterized in that the support device (29) is formed in each case by a kink of the spring arm (25, 27) and each spring arm (25, 27) is supported in the kink region on the bottom wall (11) or the top wall (15). One-piece contact spring according to claim 1,
characterized in that the support device (29) is formed in each case by a recess or wart pointing in the direction of the spring arm (25, 27) in the bottom wall (11) or ceiling wall (15), and in that each spring arm (25, 27) is thereon supports. One-piece contact spring according to one of claims 1 to 3,
characterized in that the spring arms (25, 27) are tapered in the region of the bend, a hole-shaped recess (37) being formed in the region of the bend. One-piece contact spring according to one of claims 1 to 4,
characterized in that a support arm (21, 23) is torn out of the bottom wall (11) and ceiling wall (15) and bent in the direction of a spring arm (25, 27), each support arm (21, 23) at the end approximately in the middle rests on a spring arm (25, 27) and thus clearly supports the respective contact tips (31). One-piece contact spring according to claim 5,
characterized in that each of the two support arms (21, 23) is chamfered at the end. One-piece contact spring according to claim 5 or 6,
characterized in that the bottom wall (11) and top wall (15) each have a stiffening bead (35) in the region of the support arms (21, 23). One-piece contact spring according to one of claims 5 to 7,
characterized in that each of the spring arms (25, 27) has a length B + C from the position of the support device (29) to the contact tip (31), the ratio of B / C being approximately between 2/3 and 3/2 is that each support arm (21, 23) has a length D, which corresponds to approximately 0.8 to 1.2 of the length B, and that each support arm (21, 23) approximately at the transition between B and C to support the spring arm (25 , 27) attacks. One-piece contact spring according to one of claims 1 to 8,
characterized in that the contact spring has a box tab (19) which engages over approximately half the width of the outer wall of the ceiling wall (15). One-piece contact spring according to one of claims 1 to 9,
characterized in that the top wall (15) has a projection (45) which lies flat on a recess (47) in one of the side walls (13). One-piece contact spring according to one of claims 1 to 10,
characterized in that at least one of the side walls (13) has an opening (41) pointing into the interior of the box or an embossing which serves as a stop during the bending process of a sheet metal part forming the contact spring. One-piece contact spring according to one of claims 1 to 11,
characterized in that the spring arms (25, 27) are provided with a gold plating at least in the area of the contact dome. One-piece contact spring according to one of claims 1 to 11,
characterized in that the spring arms (25, 27) are provided with a tin surface at least in the area of the contact dome.

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