Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
CONNECTING PIN AND METHOD FOR MANUFACTURING A CONNECTING PIN
Document Type and Number:
WIPO Patent Application WO/2020/229341
Kind Code:
A1
Abstract:
What is disclosed is a connecting pin for producing an electrical and mechanical connection to the through-contact, having a shaft section and a spring section, wherein the spring section has at least two spring elements, wherein, between the at least two spring elements, at least one material split is arranged running in the longitudinal direction of the connecting pin, and wherein the spring elements protrude beyond the shaft section radially outwards, at least in certain regions. Furthermore, a method for manufacturing a connecting pin and a connecting arrangement are disclosed.

Inventors:
ZITZ ANDREAS (DE)
SCHABERT FRANK (DE)
BLEICHER MARTIN (DE)
BURESCH ISABELL (DE)
BRANDT JOCHEN (DE)
GOEGELEIN GERHARD (DE)
Application Number:
PCT/EP2020/062846
Publication Date:
November 19, 2020
Filing Date:
May 08, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TE CONNECTIVITY GERMANY GMBH (DE)
International Classes:
H01R12/58; H01R43/16; H01R13/03
Foreign References:
US20130244512A12013-09-19
US20030236009A12003-12-25
JPH10241760A1998-09-11
US4793817A1988-12-27
EP0023296B11983-06-01
DE2742716A11979-04-05
Attorney, Agent or Firm:
MURGITROYD & COMPANY (GB)
Download PDF:
Claims:
Claims

1. A connecting pin (2) for producing an electrical and mechanical connection to a through-contact (4), having a shaft section (8) and a spring section (6), characterised in that the spring section (6) has at least two spring elements (10), wherein, between the at least two spring elements (10), at least one material split (32) is arranged running in the longitudinal direction of the connecting pin (2), and wherein the spring elements (10) protrude beyond the shaft section

(8) radially outwards, at least in certain regions.

2. The connecting pin (2) according to Claim 1, wherein the at least two spring elements (10) of the spring section (6) extend in the longitudinal direction of the connecting pin (2) along an axis (S) and the spring elements (10) have the same radial spacing from the axis (S), wherein the spring elements (10) are connected to one another at least at one end on the shaft section (8), wherein the radial spacing between the spring elements (10) and the axis (S) increases at least in certain regions starting from the shaft section (8) .

3. The connecting pin (2) according to Claim 2, wherein the at least two spring elements (10) of the spring section (6) project radially beyond an outer edge of the at least one shaft section (8) starting from the axis (S) of the

connecting pin (2) running in the longitudinal direction of the connecting pin (2) .

4. The connecting pin (2) according to any one of Claims 1 to 3, wherein the spring section (6) opens into a pin end (16) at an opposite end to the shaft section (8), wherein the pin end (16) has a radially tapering shape.

5. The connecting pin (2) according to any one of Claims 1 to 4, wherein the connecting pin (2) has a cross-sectional shape in the region of the spring section (6), wherein the cross- sectional shape corresponds substantially to a cross- sectional shape of the shaft section (8) and is configured in an expanded manner to form the spring elements (10) .

6. The connecting pin (2) according to any one of Claims 1 to

5, wherein the connecting pin (2) has a rounded-off outer cross-sectional shape at least in the region of the spring element ( 6 ) .

7. The connecting pin (2) according to any one of Claims 1 to

6, wherein the at least one shaft section (8) and the spring section (6) of the connecting pin (2) are configured in an integral manner.

8. The connecting pin (2) according to any one of the

preceding claims,

wherein, in the spring section (6), in particular laterally adjoining the material split (32), a first average grain size of a material of the connecting pin is different from a second average grain size of the material in the shaft section (8)

and/or

wherein the material split (32) is formed as a brittle fracture .

9. The connecting pin (2) according to Claim 8, wherein, in the spring section (6), in particular laterally adjoining the material split (32), the first average grain size is 20 percent inclusive to 80 percent inclusive, preferably 30 percent inclusive to 70 percent inclusive, of the second average grain size in the shaft section (8) .

10. A method (18) for manufacturing a connecting pin (2) according to any one of the preceding claims, wherein

- a wire or a profile rod (20) or a contact pin is

provided, - at least two tool sections (40) orientated in the direction of an axis (S) are arranged laterally on at least one section (22) of the provided wire (20),

- the at least two tool sections (40) for forming at least one notch (42) as a weak point (30) are pushed into the wire, profile rod (20) or contact pin radially in the direction of the axis (S) and

- the section (22) for breaking the weak point (30), for forming a material split (32) and for forming the at least two spring elements (10) which are spaced apart from one another by at least the material split (32) is compressed or drawn along the axis (S) .

11. The method according to Claim 10, wherein the provided profile rod or the wire (20) or contact pin for forming a cross-sectional shape in the region of the section (22) is shaped, in particular stamped and/or forged and/or rolled and/or drawn, and the weak point (30) is moulded preferably by means of the shaping.

12. The method according to Claim 11, wherein a first average grain size in the spring section (10), in particular at the material split (32) and/or at the weak point (30), is refined in certain regions by shaping the wire or the profile rod (20) or the contact pin, wherein, preferably after the shaping, a first average grain size is 20 percent inclusive to 80 percent inclusive, in particular 30 percent inclusive to 70 percent inclusive, of a second average grain size of the shaft section (8) .

13. The method according to any one of Claims 10 to 12, wherein the at least two tool sections (40) are twisted about the axis (S) after formation of the weak points (30) .

14. The method according to any one of Claims 10 to 13, wherein, after removal of the tool sections (40), a spring section (6) is formed by compressing or stretching the section (22) between a shaft section (8) and a pin end (16) .

15. The method according to any one of Claims 10 to 14, wherein the wire, profile rod (20) or contact pin is

positioned in a peripherally arranged supporting mould (44) before the at least one notch (42) is made as a weak point (30) by the tool sections (40) .

Description:
Description

Connecting pin and method for manufacturing a connecting pin

The invention relates to a connecting pin for producing an electrical and mechanical connection to a through-contact, having at least a shaft section and a spring section, to a method for manufacturing a connecting pin and to a connecting arrangement .

Contacts configured as plug connectors are already known, which contacts are envisaged for a force-fit mounting in a through-contact of a printed circuit board. Such plug

connectors or connecting pins are also referred to as so- called flexible press-in contacts and have a customarily stamped spring section made from two spring elements

projecting from a shaft section. In an inserted state of the connecting pin, the spring elements exert a force that is directed laterally in relation to the plugging direction and is in opposition to the through-contact, and thereby reduce the electrical transition resistance and enable a mechanical retaining function.

DE 27 42 716 A1 discloses an electrical connection of a structural part to a through-contact of a printed circuit board. The electronic terminals or pins of the structural part are pre-bent to a clamping width of the through-contact and form bent spring sections in a state in which it is inserted into the through-contact.

Owing to the limited number of spring elements and the fact that the rectangular basic shape of the pin contacts differs from a cylindrical receptacle space of the through-contact, the maximum achievable press-on force and the achievable electrical properties of such a connecting arrangement are limited . The problem on which the invention is based can be considered to be that of proposing a connecting pin and a method for manufacturing the connecting pin, which connecting pin has a more uniform distribution of the spring force and a lower electrical transition resistance in relation to a through- contact .

Furthermore, the problem of the invention is to propose a method for manufacturing such a pin contact.

This problem is solved by means of the respective subject- matter of the independent claims. Advantageous configurations of the invention form the subject-matter of respectively dependent subclaims.

According to one aspect of the invention, a connecting pin is provided for producing an electrical and mechanical

connection to a through-contact. For this purpose, the connecting pin has at least a shaft section and a spring section, the spring section having at least two spring elements. Between the at least two spring elements, at least one material split is arranged running in the longitudinal direction of the connecting pin. The spring elements protrude beyond the shaft section radially outwards, at least in certain regions. As a result of the material split, this spaces the at least two spring elements of the spring section from one another and forms a free space for the elastic deformation of the spring elements in the radial direction.

As a result, the spring elements can deform particularly well .

According to a further aspect of the invention, a connecting arrangement is provided, which has at least one through- contact and at least one connecting pin.

Preferably, an outer contour of the spring elements can be rounded off, as a result of which the bearing surface between the spring section and an inner region of the through-contact is enlarged.

The usual flexible press-in contact consists of a spring element the direction of force of which points perpendicular to the stamping direction. The present application enables the moulding of any desired number of planes of spring elements with a spring action. As a result, relatively large forces can be transferred more uniformly and thus more gently over the entire hole diameter of a through-contact.

Owing to the possible increased number of spring elements, such as more than three, of the spring section, the

respective spring elements are shaped to be narrower and are thus adapted geometrically more precisely to the inner region of the through-contact despite an optional rectangular basic shape. The spring section can have at least two spring elements .

As a result of using an increasing number of spring elements of the spring section, the spring force exerted by the spring elements can be distributed evenly onto the through-contact. As a result of this, a mechanically robust connecting

arrangement having an increased frictional force can be implemented. The frictional force or the frictional

engagement of the connecting pin can be heightened further by an increasing number of spring elements.

As a result of an increasing number of spring elements of the spring section, the respective spring elements become

smaller, with the result that there is better fitting

accuracy and a larger contact surface.

In particular, by way of the connecting pin according to the invention, a frictionally engaging connection that has defined plugging forces and defined retaining forces can be produced between the spring section and the through-contact. The respective spring elements of the spring section can be spaced apart from one another in particular by broken-open or split-apart weak points. The weak points are made by notches or an introduced material weakness. As a result of this, a technically simple manufacture of the spring section can be realised .

According to a preferred configuration, the at least two spring elements of the spring section extend in the

longitudinal direction of the connecting pin along an axis. The spring elements preferably have substantially the same radial spacing from the axis. The spring elements are

connected to one another at least at one end on the shaft section, the radial spacing between the spring elements and the axis increasing at least in certain regions starting from the shaft section. Owing to a convex shape of the spring elements, in a pressed-together state the spring elements are lengthened by comparison with an initial and unstressed state of the connecting pin. The spring elements converge at least at one end on the shaft section and adopt an increasingly large radial spacing in relation to one another, up to a defined spacing along the axis. At an opposite end of the spring section to the shaft section, the spring elements can converge radially again or adopt a reduced spacing in

relation to one another. The spring elements can be connected to one another for example by a pin end.

The spring force of the spring section of the connecting pin thus results in a change in length of the spring section and a concomitant change in the spacing between the two shaft sections .

According to an exemplary embodiment, the at least two spring elements of the spring section have the same spacing from one another, the spring elements being connected to one another in the region of the at least one shaft section and being configured to be separate from one another in a region which is at a distance from the shaft section. As a result of this, in a state of the connecting pin in which it is inserted in a through-contact, a symmetrical or uniform force distribution of the spring elements can be realised. Moreover, the spring elements of one or two shaft sections can be stabilised mechanically .

According to a further exemplary embodiment, the at least two spring elements of the spring section project radially beyond an outer edge of the at least one shaft section starting from the axis of the connecting pin running in the longitudinal direction of the connecting pin. In particular, the spring elements can be configured to be convex or bent. As a result of pressing the spring elements together, there then arises a change in length of the spring section, which depends on a pressure or a force acting radially on the spring elements, in defined limits. As a result of this, a spring section can be manufactured which has a precisely adjustable spring force acting radially on the through-contact.

By limiting a possible length extent of the connecting pin, a spring force can thus be adjusted, and the connecting

arrangement can be configured such that it can be adapted to requirements .

According to a further exemplary embodiment, the spring section opens into a pin end at an opposite end to the shaft section, the pin end having a tapering shape. In this way, insertion of the connecting pin in a through-contact of a printed circuit board can be simplified.

In particular, a necessary plugging force for inserting the connecting pin can be adjusted to increase in a defined manner by the shape of the pin end.

According to a further exemplary embodiment, the connecting pin has a cross-sectional shape in the region of the spring section, the cross-sectional shape corresponding substantially to a cross-sectional shape of the shaft section and being configured in an expanded manner to form the spring elements. By this means, the spring section can be configured as a multiplicity of subsections of the basic shape or profile of the shaft sections, which are preferably spaced uniformly apart from one another.

According to a further exemplary embodiment, the connecting pin has a rounded-off outer cross-sectional shape at least in the region of the spring element. The cross-sectional shape preferably corresponds substantially to a profile or cross- sectional profile of the connecting pin. As a result, the cost of shaping during manufacture of the connecting pin can be reduced. The peripheral contour of the cross-sectional shape of the spring section can be rounded off by making the material splits and a corresponding peripheral retention of the other parts.

Owing to the possible cross-sectional shapes, the connecting pin can be shaped with versatility, such that it is adapted to the requirements of its use.

In a technically particularly simple manner, a spring section having four spring elements can be manufactured from a blank with a quadrilateral profile, for example. Here, tool heads or stamping tools can be positioned on each of the four lateral surfaces and pushed radially into the blank, into which they cut until a spacing is produced and spring

elements are formed.

According to a further exemplary embodiment, the at least one shaft section of the connecting pin is configured as a wire or a contact pin or a profile rod. The connecting pin of the connecting arrangement can thus be manufactured inexpensively in an automated process. In particular, the wire or the contact pin or the profile rod can have dimensions which correspond at least in certain regions to the dimensions of the shaft sections. As a result, the cost of subsequent processing can be reduced and the number of steps necessary for the manufacture of the

connecting pin can be minimised.

According to a further exemplary embodiment, the at least one shaft section and the spring section of the connecting pin can be configured in an integral manner. As a result of an integral configuration of the constituents of the connecting pin, it can be configured to be mechanically particularly robust. Furthermore, as a result, further steps which involve subsequent assembly can be omitted. As a result of an

integral configuration of the connecting pin, it can be made in one piece and without connection points.

In a further embodiment, in the spring section in which the material separation is performed by making a targeted split, and in particular laterally adjoining the material split, a first average grain size of a material of the connecting pin is different from a second average grain size of the material in the shaft section. In addition, or as an alternative, the material split is formed as a brittle fracture.

It is particularly advantageous if, in the spring section, in particular laterally adjoining the region in which the material split is introduced, the first average grain size is 20 percent inclusive to 80 percent inclusive, preferably 30 percent inclusive to 70 percent inclusive, of the second average grain size in the shaft section (in the non-deformed region) .

According to a further aspect of the invention, a method for manufacturing a connecting pin is provided.

In one step, a wire or a contact pin or a profile rod is provided. The wire or the contact pin or the profile rod can preferably be configured as a blank. The wire or the contact pin or the profile rod in this case advantageously contain an electrically conductive material.

In at least one section of the provided wire or contact pin or profile rod, a cross-sectional shape of the section can then be changed. This step can also be omitted, depending on a blank and the connecting pin to be manufactured. The step can serve in particular for observing predefined dimensions and for reducing tolerance fluctuations.

At least two tool sections orientated radially in the

direction of an axis are arranged laterally on the at least one section of the provided wire or contact pin or profile rod. The number of tool sections depends in particular on a number of spring elements which are to be manufactured.

Alternatively, or additionally, in the case of a reduced number of tool sections, the spring elements can be formed in a plurality of successive steps.

Then, the at least two tool sections for forming at least one notch as a weak point are pushed into the wire or contact pin or profile rod radially in the direction of the axis.

The section for breaking the weak points, for forming a material split and for forming the at least two spring elements which are spaced apart from one another by the material split is compressed or drawn along the axis. The spring elements are preferably spaced apart from one another by the material split, which runs in the region of the broken weak point.

The tool sections can in particular be tool heads of a stamping and bending machine or of a cutting tool. The tool sections are pressed into the wire or contact pin or profile rod until at least two spring elements which are spaced apart from one another are formed.

It is particularly advantageous if the provided profile rod or the wire or contact pin for forming a cross-sectional shape in the region of the section is shaped, in particular stamped and/or forged and/or rolled and/or drawn, and the weak point is moulded preferably by means of the shaping. By means of the weak point, the material split can be made in the profile rod or the wire or the contact pin in a defined manner by compression or drawing, and the splitting behaviour can be determined in a defined manner.

In a further embodiment, an average grain size in the spring section, in particular in the region of the weak point and/or at the material split, is refined and adjusted in certain regions by shaping the wire or the profile rod or the contact pin, wherein, preferably after the shaping, a first average grain size is 20 percent inclusive to 80 percent inclusive, in particular 30 percent inclusive to 70 percent inclusive, of a second average grain size of the shaft section. In the shaft section, the material has substantially the original, unrefined (second average) grain size.

In one formation of the spring elements, weak points can preferably be made in the form of thin wall thicknesses or material splits, or the tool sections can strike one another in the region of the axis of the connecting pin. The tool sections can strike one another in a centred manner in the axis or in a decentred manner in the region of the axis. The axis can be configured as an axis of symmetry and runs in the longitudinal direction of the connecting pin.

The spring elements can also be formed without the weak points, in which case they have a higher spring force than spring elements which are spaced apart from one another by weak points. As a result of the weak points, a slight compression of the section can lead to the weak points splitting and thus a spacing being produced between the respective spring

elements. As a result, in particular a cutting-open of the section and a subsequent assembly in certain regions can be omitted, with the result that the spring section can be manufactured more quickly and in a technically simpler manner. Furthermore, the material structure is not disrupted by a machine-cutting operation, so the connecting pin is particularly stable.

According to an embodiment of the method, the provided wire or contact pin or profile rod for forming a cross-sectional shape in the region of the section is shaped, in particular stamped and/or rolled and/or compressed and/or forged and/or drawn. As a result, a preparatory step is provided for creating optimum dimensions of the connecting pin which is to be manufactured, which can ensure the dimensional compliance of the connecting pin.

According to a further embodiment of the method, the at least two tool sections are twisted about the axis after formation of the weak points. This produces an additional component of the spring force which can be generated by the spring section and which results from a rotary deformation, at least in certain regions, of the spring elements in the region of the axis. A higher plugging force and/or retaining force can thus be realised.

Furthermore, a homogeneous rise in force can be ensured in a state in which the connecting pin is inserted in a through- contact, by rotating an inner contour of the spring section or of the spring elements. As a result of the additional rotation, at least in certain regions, of the spring

elements, a longer spring travel can be produced, which can compensate manufacturing tolerances of through-contacts. According to a further exemplary embodiment, the wire or contact pin or profile rod is positioned in a peripherally arranged supporting mould before the at least one notch is made as a weak point by the tool sections. Preferably, the supporting mould can have an inner geometric contour which is set up to form a peripheral contour of the spring section by producing the weak point. By pressing the tool sections into the section, the material of the spring section which is to be manufactured is pressed against the supporting mould. As a result, a spring section for example having a rounded outer contour can be manufactured, which permits a larger contact surface in a through-contact.

According to a further embodiment of the method, after removal of the tool sections, the spring section formed between two shaft sections is compressed or stretched in the direction of the axis. As a result, a further processing step for adjusting final dimensions of the spring section can be implemented. By compressing the shaft sections, the spring section can be adapted to through-contacts with a larger diameter. Stretching of the spring sections can be used to reduce a cross-sectional surface or a profile surface.

Preferred exemplary embodiments of the invention are

explained hereinafter in greater detail using greatly

simplified schematic depictions. In the drawings

Fig. 1 shows a schematic depiction of a connecting

arrangement according to an embodiment of the invention,

Fig. 2 shows a schematic depiction of a connecting

arrangement according to a further embodiment of the invention,

Fig. 3 shows a perspective depiction of a connecting pin of the connecting arrangement according to an embodiment of the invention and

Figs. 4-7 show schematic sectional depictions to

illustrate a method for manufacturing a connecting pin from Fig. 2 according to an embodiment of the invention .

Figs. 8-13 show schematic sectional depictions to

illustrate a method for manufacturing a connecting pin according to a further embodiment of the invention .

Figs. 14-17 show schematic sectional depictions B-B from

Fig. 3 to illustrate a method for manufacturing a connecting pin according to a further embodiment of the invention.

Figs. 18-22 show schematic sectional depictions to

illustrate a method for manufacturing a connecting pin according to a further embodiment of the invention .

In the figures, the same structural elements have the same reference numbers in each case.

Figure 1 shows a schematic depiction of a connecting

arrangement 1 according to an embodiment.

The connecting arrangement 1 has a connecting pin 2, which is inserted in a through-contact 4.

The connecting pin 2 has a spring section 6, which is formed between a shaft section 8 and a pin end 16. The spring section 6 has four spring elements 10, according to the exemplary embodiment. The shaft section 8, the spring section 6 and the pin end 16 are arranged in the longitudinal direction along an axis S. The axis S here is configured as an axis of symmetry and runs through a geometric centre point of the connecting pin 2.

The through-contact 4 is made in a printed circuit board 12 and has a cylindrical inner region 14. The cylindrical lateral surface or an inner region 14 serves to receive the connecting pin 2. The through-contact 4 is manufactured from an electrically conductive material, such as copper, silver, gold, an alloy and the like, and electrically connects two opposing sides SI and S2 of the printed circuit board 12 to one another. In this case, the side SI can be configured as an upper side and the side S2 can be configured as a lower side of the printed circuit board 12.

To simplify mounting of the connecting pin 2 in the lateral surface 14 of the through-contact 4, the connecting pin 2 has a pin end 16 at the end. According to the exemplary

embodiment, the pin end 16 tapers conically.

In the state in which it is inserted in the inner region 14 of the through-contact 4, the spring section 6 of the

connecting pin 2 is pressed together radially with respect to the axis S. This produces a compression of the spring

elements 10 in the radial direction with respect to the axis S, which enlarges a spacing between the shaft section 8 and the pin end 16.

The arrows illustrate the longitudinal extent of the

connecting pin 2 in the state in which it is inserted in the lateral surface 14.

Figure 2 shows a schematic depiction of a connecting

arrangement 1 according to a further embodiment. In contrast to the connecting arrangement 1 depicted in Figure 1, here the connecting pin 2 has a spring section 6 with two spring elements 10, which are formed symmetrically relative to the axis S. The shaft section 8 ends on one side in a wider region 9, which can be employed as a soldering surface or crimp section, for example.

Shown in Figure 3 is a perspective depiction of the

connecting pin 2 from the connecting arrangement 1

illustrated in Figure 1, according to an embodiment.

The connecting pin 2 has the spring section 6 with four spring elements 10 of the same shape. The spring elements 10 here are spaced apart from one another in a similar manner and have the same spacing from the axis S of the connecting pin 2. In the peripheral direction, a material split 32, which is formed as a brittle fracture for example, extends in each case in the longitudinal direction between the spring elements 10.

The shaft sections 8, the spring section 6 and the pin end 16 are formed integrally or in one piece of a single material, and preferably consist of a metal. Here, the metal can contain for example copper, silver, aluminium or alloys thereof and the like. A first average grain size, in the spring section 6, in particular adjoining the material split 32, is different from a second average grain size in the shaft section 8. The average grain size can be determined in accordance with EN ISO 2624, for example. In this case, the average grain size can be determined by an intercept method (cf. EN ISO 2624 4.2) or by a planimetric method (cf. EN ISO 2624 4.3).

In this regard, it is particularly advantageous if the spring section 6, in particular directly at the material split 32 and/or at the weak point 30, has the first average grain size of 20 percent inclusive to 80 percent inclusive, preferably 30 percent inclusive to 70 percent inclusive, of the second average grain size in the shaft section 8.

The connecting pin 2 here can be configured in a coated or uncoated manner. A coating can improve the electrical

properties of the connecting pin 2, for example, or can optimise insertion behaviour into the inner region 14 of the through-contact 4. The coating can contain for example gold, silver, tin, zinc and the like.

It is illustrated that the connecting pin 2 has a

substantially rectangular cross-sectional shape with rounded- off corners. As a result of the rounded-off edges, a fit of the connecting pin 2 can be adapted to the cylindrically formed inner region 14, with the result that an electrical transition resistance can be reduced.

The spring elements 10 of the spring section 6 are moulded in a manner projecting laterally transverse to the axis of symmetry S. As a result, the spring elements 10 of the spring section 6 span a larger cross-sectional surface than the shaft sections 8.

In Figures 4-7, schematic sectional depictions for

illustrating a method for manufacturing the connecting pin 2 from Fig. 2 according to an embodiment are depicted. In

Figure 4, a provided blank 20 is arranged between two tool sections 40. The blank 20 can be formed as a wire, wire pin or profile rod. The arrows illustrate the movement or the action of the tool sections 40 on the blank 20, which is formed as a contact pin. The tool sections 40 each produce a notch 42 in the blank 20, with the result that a weak point 30 arises. In particular, the notches 42 in the spring section 6 which is to be manufactured are made in the

material of the blank 20. The tool sections 40 each have a shape which tapers to a point, by way of which the notches 42 are made in the material of the blank 20, in particular pressed, forged, stamped and/or die-stamped. Forging is in particular suitable, as this plasticises the material of the blank 20. As a result of the insertion/shaping, the material is refined in the region of the weak point 30. The weak point 30 produced by the notches 42 separates the spring sections 10 which are to be formed from one another.

Figure 5 shows a cross-section C-C from Figure 4, which has the notches 42 and the spring elements 10 which are to be formed .

The weak point 30 can take the form of a reduced material thickness or a material section with a split, in each case with a refined grain by comparison with the shaft section 8.

Figure 6 shows a further method step in which the weak point 30 is broken. The weak point 30 runs parallel to the axis S in the longitudinal direction of the connecting pin 2. The weak point 30 is split open or broken by compression or drawing or stretching of the connecting pin 2, with the result that the spring elements 10 of the spring section 6 are formed and spaced apart from one another. In particular, the material split 32 arises at the weak point 30 between the two spring elements 10 and spaces the spring elements 10 from one another in at least one direction. As a result of the compression, the material split 32 is widened, with the result that the spacing between the spring elements 10 increases. The corresponding movement sequences are

illustrated by the arrows.

In Figure 7, the cross-section D-D from Figure 6 is shown, in which the produced connecting pin 2 is formed with the spring section 6 having two spring elements 10. Such a connecting pin 2 is also used in Figure 2. The formed material split 32 is illustrated in cross-section in the region of the weak point 30.

Figures 8-13 illustrate, in schematic sectional depictions, the method for manufacturing the connecting pin 2 according to a further embodiment. In a step which is shown in Figure 8, the blank 20 is

provided with a rectangular cross-section and is arranged in a supporting mould 44.

The supporting mould 44 is depicted in Figure 9 and has a rounded inner contour. According to the exemplary embodiment, the supporting mould 44 has two recesses for the guiding of tool sections 40. The tool sections 40 protrude symmetrically from two directions into the blank 20 and cause a material flow and consequently a plastic deformation of the blank 20 in the spring section 6. As a result of the flow process and the plastic deformation, the material of the blank is

displaced and pressed against the supporting mould 44. As a result, the spring elements 10 manufactured in this way can have a rounded-off outer contour, with the result that there is better fitting accuracy and a larger contact surface in the through-contact 4.

The blank 20 with the notches 42 produced by tool sections 40 is shown in Figure 10. The notches 42 form the weak point 30. Then, a compression of the weak point 30 takes place in the region of the spring section 6, with the result that the weak point 30 is broken, and the material split 32 is formed. This step is illustrated as a sectional depiction in Figures 12 and 13. After compression of the spring section 6, the connecting pin 2 is manufactured. Further steps can follow, which, for example, chamfer the connecting pin 2, make a taper in the pin end 16, coat the material and the like.

Schematic sectional depictions B-B from Fig. 3 for

illustrating a method for manufacturing the connecting pin 2 according to an embodiment are shown in Figures 14 to 17.

In Figure 14, a blank 20 is provided as a method step. The blank 20 takes the form of a metal wire with a rectangular profile. The blank 20 can be stretched beforehand such that it runs in a straight line along the axis S. In a further step, which is shown in Figure 15, a cross- section is adapted in the region of the spring section 6 which is to be made. The adapting of the cross-section takes place by pressing the edges of the blank 20 together. The edges are pressed together radially in the direction of the axis S. The arrows illustrate the action of force on the blank 20 by tools. As a result, the section 22 of the blank 20 is produced.

Figure 16 depicts a further step, in which the tool sections 40 (not depicted) are pressed and/or stamped into the processed surfaces or the section 22 of the blank 20.

Alternatively, the tool sections can forge the section 22. Here, the tool sections 40 together deform the material radially in the direction of the axis S and produce notches 42 in the four surfaces of the blank 20 in the region of the spring section 6 which is to be formed. As a result of the tool sections 40 pressing into the material, there is produced a plastic deformation of the sections 24, which are radially spaced apart from one another to form the spring elements 10. As a result of the plastic deformation, the sections 24 can assume a round outer contour. Stamping, pressing in and/or forging have the advantage that no material is removed by cutting, and thus the internal grain structure is not disrupted by the removal of stock.

Furthermore, in this case the grain structure in the plastic deformation is refined by comparison with the shaft section 8. As a result, the connecting pin 2 made by means of the method is particularly strong.

The action of the tools is illustrated by the arrows in Figure 16.

As a result of the action of the four tool sections 40, four fanned-out subregions 24 are produced. In this case, the blank 20 can assume a shape in the manner of a four-leaf clover, as seen in cross-section. As a result of the displacing action of tools, the subregions 24 have a relatively large, rounded-off outer contour, which can be used for making electrical and mechanical contact. As a result of the rounded shape, a contact surface of the spring section 6, in particular in relation to a cylindrical through-contact 4, can be increased in size.

In the further course of the method, the subregions 24 are parted or separated and spaced apart from one another

radially .

A further step for manufacturing the connecting pin 2 is depicted in Figure 17.

In particular, the subregions 24 here are compressed in the combined tangential and radial directions in relation to the axis S. During this, the forces act, laterally past the axis S, on the subregions 24 or the spring elements 10 which are to be formed. The long arrows in Figure 17 illustrate a yield movement (material flow) of the subregions 24, caused by the forces. As a result of the yield movement, the subregions 24 are twisted in a section 25 arranged on the inner side.

In a further step, the blank 20 processed in the region of the spring section 6 can be cut in the axial direction along the axis S at a defined spacing on both sides of the spring section 6 and a connecting pin 2 can be made. At one end, a contact tip or a pin end 16 can be pressed in during this.

Schematic depictions for illustrating a method for

manufacturing a connecting pin 2 according to a further embodiment are shown in Figures 18 to 22.

In Figure 18, a blank 20 is provided with a rectangular cross-section. The cross-section B-B from Figure 3 is shown in Figures 19 and 21. As a result of using four tool sections, four subsections 24 are formed in Figure 19. The subsections 24 are formed by the tool sections that shape the blank 20 in the direction of the axis of symmetry S. This corresponds to the method steps shown in Figures 14-16.

In the region of the axis of symmetry S, the subsections 24 strike one another and are connected to one another at least in certain regions. In this weak point 30, the section 22 or the spring section 6 which is to be formed has thin wall thicknesses, a relatively low average grain size (refined by comparison with the shaft section 8), or already has splits between the subsections 24. The weak point 30 has

considerable material damage, which makes it simple to initiate the split.

In Figures 21 and 22, the blank 20 or the section 22 has been compressed by an extent ST along the axis of symmetry S. As a result of the compression, the subsections 24 are spread in such a way that the weak point 30 splits open in a brittle fracture/separation fracture. As a result, the subsections 24 are separated from one another by the material splits 32 and spring elements 10 are formed. Compression is continued until the material split 32 which separates the spring elements 10 from one another is formed at at least two locations. The opening up or splits 32 in material in each case separate at least two spring elements 10 from one another. As a result of the at least two material splits 32, in this exemplary embodiment four spring elements 10 are produced, spaced apart by splits that are formed. According to the exemplary

embodiment, a compression directed along the axis S is performed to form the spring elements 10. In this regard, the spring elements 10, as depicted in Figure 21, can also be spaced apart from one another unevenly or can have different cross-sectional surface areas.

The steps described in the figures have the effect that, starting from the first average grain size, which is substantially present throughout the blank 20 at the beginning of the steps, refinement is performed to give the second average grain size in the spring section 6. The refinement in this case occurs at least adjoining the material split 32, preferably in the region of the weak point .

The fitting accuracy of the spring elements 10 in the through-contact 4 and the elastic properties of the spring elements 10 can nevertheless be used to make reliable electrical contact.