Devices for the electrical contacting of flat plug connectors

Abstract

Contact spring 1 for contacting a flat plug contact 3, in one piece, which has two pairs of fork legs parallel to each other, wherein two fork legs 4, 5, 6, 7 with each a contact point 14, 15, 16, 17 and a common fastening section 8, 11 form a first pair of fork legs, opposite the fastening section 8, 11 both pairs of fork legs are connected via a bending web 9, 10, characterized in that the two contact points 14, 15 and 16, 17 of a pair of fork legs are set back from the plane E of the fastening section 8, 11.

Description

[0001] The present invention relates to connection technology, in particular devices for the electrical contacting of flat plug contacts.

[0002] In modern electrical engineering, reliable and durable connections between electrical components are crucial. Blade terminals are frequently used to establish a secure electrical connection. In automotive engineering, for example, the electrical interfaces on fuses and switching relays are designed as blade terminals and are contacted using fork contacts. Previous systems that use fork-shaped contact springs often have problems with bare punched edges in the contact area, which can lead to corrosion at the contact points. This can be remedied by applying a complex electroplating surface coating, or by performing costly shearing / bending and / or setting processes to achieve the desired geometry of the contact spring.Another problem with conventional contact springs, fork contacts stamped flat from sheet metal, where the fork legs are formed in the plane of the sheet, is the material thickness. To achieve sufficient contact force while simultaneously not exceeding the elastic deformation limit, greater material thicknesses are often necessary. This then prevents smaller pitches of 2.54 mm or less in the connection area to the circuit board.

[0003] The invention is based on the object of developing a device for contacting components to be plugged in and flat plug contacts with a fork-shaped contact spring made of a surface-coated metal sheet of the type mentioned at the beginning in such a way that, with the same material expenditure, no bare punched edges are created in the area of ​​the contact between the contact spring and the flat plug contact.

[0004] This problem is generally solved by the design features specified in patent claim 1. According to this, the forked legs of the contact spring are arranged in the contact area on the flat plug in such a way that they contact the flat plug at its contact surfaces with the forming edges.

[0005] According to the invention, it was recognized that after punching the metal sheet, the edges of the semi-finished product have a radius on the upper side. Furthermore, it was recognized that with a surface-coated metal sheet, such as pre-tinned strips, a sufficient coating of the punched edges up to one-third of the end face is achieved by the tin indentation during the forming process.

[0006] The semi-finished product of the contact spring is designed in such a way that two opposing forked legs are arranged on a fastening section. At the ends of the forked legs there is a bending web which also represents the mirror axis of the semi-finished product in the middle. Each end of the forked leg also has a widened portion which represents the contacting area. These four contacting areas are set back from the plane of the semi-finished product and, after forming, lie below the surface of the semi-finished product. The semi-finished product is bent downwards by 180° in the middle at the bending web. Due to this forming process, the resulting contact spring, with two parallel forked legs, each has no bare punched edges at the four contact points to the mating connector, such as a flat pin contact.

[0007] Preferably, at least one printed circuit board contact is formed on at least one fastening section. These can be implemented in the form of a flexible press-fit zone, a solid press-fit zone, a solder pin / solder lug, or using SKEDD (direct plug-in technology).

[0008] Further details, features, and advantages of the invention are evident from the patent claims, the wording of which is explained by reference to the content of the description of preferred embodiments of the invention, and from the drawings. Herein: Fig. 1 a perspective view of a contact spring according to the invention with two pairs of fork legs lying parallel to each other for receiving / contacting a flat plug contact. Fig. 2 a top view of the semi-finished product after the punching process with recessed contact points. Fig. 3 a sectional view along the bending line with recessed contact points to the surface of the semi-finished product. Fig. 4 a contact spring in different embodiments of the printed circuit board contact, in a) a solder pin for permanent connection by soldering, in b) a solid press-in pin for permanent connection by pressing in, in c) a flexible press-in pin for permanent connection by pressing in, in d) a direct plug-in pin (SKEDD) for a removable connection, in e) a double direct plug-in pin (SKEDD) for a removable connection, in f) a double flexible press-in pin for permanent connection by pressing in. Fig. 5 a front view of the contact spring with inserted flat plug contact.

[0009] Identical or similar elements in different figures are provided with the same reference numerals. The representations in the figures are schematic and not to scale.

[0010] The Fig. 1 shows a perspective view of a device for contacting a flat plug contact 3 with a fork-shaped contact spring 1 made of sheet metal, each having two parallel pairs of fork legs in the respective plane of the fastening section 8, 11. Each fork leg 4, 5, 6, 7 has a contact point 14, 15, 16, 17 for contacting the contact surface 12 on the flat plug contact 3. The contact points 14, 15, 16, 17 are set back from the plane of the fastening section 8, 11. By setting back the contact points, the upper punched edge 19 rests against the contact surface 12 and thereby securely contacts the pluggable component 2 at its contact surfaces 12. At least one flexible press-in contact 18 is formed on at least one of the two fastening sections 8, 11 for fastening in a plated-through hole in a printed circuit board.

[0011] Fig. 2 shows a top view of the semi-finished product 22, which is advantageously produced from a metal sheet by cutting / punching. The sheet thickness of the metal sheet is preferably between 0.2 mm and 0.5 mm. The contact spring 1 can be produced, for example, from a material such as CuSn6. This material is advantageously pre-tinned by electroplating, so that the upper punched edge 19 has a radius as a result of the punching process, which has a sufficient surface coating due to the tin indentation. It is known that during the punching process at least one-third of the punched surface is provided with the coated surface, thereby ensuring a sufficient coating at the contact points 14, 15, 16, 17 in the area of ​​the upper punched edge 19. This process eliminates any open punched edges in the area of ​​the contact points 14, 15, 16, 17 between the contact spring 1 and the flat plug contact 3, which is advantageous for contact resistance and the longevity of such electrical connections.

[0012] The contact points 14, 15, 16, 17, which are recessed from the surface, the plane E of the semi-finished product 22, ensure that there are no open punched edges in the contact area. This recess of the contact points 14, 15, 16, 17 is Fig. 3 can be seen even more clearly. Fig. 3 shows a sectional view along bending line 21.

[0013] The contact spring 1 takes on its final shape after bending along the bending line 21, so that two fork legs 4, 5, 6, 7 are connected parallel to each other via the two bending webs and each has its own fastening section 8, 11. An insertion radius 13 is formed below the bending web 9, 10 on each fork leg 4, 5, 6, 7. This insertion radius 13 facilitates the insertion of the flat plug contact 3.

[0014] Fig. Figure 4 shows different designs such as a) a solder pin 23 for soldering into a plated-through hole, b) a solid press-in pin 24 and c) a flexible press-in pin 25 for permanent connection by pressing into a plated-through hole, or d) a design as a SKEDD pin 25 (direct plug-in technology) for a removable connection to the circuit board. The advantage of all designs is the low sheet thickness in the connection area to the circuit board, allowing for smallest pitches of < 2.54 mm and minimum drill diameters of < 1.2 mm for the plated-through holes.

[0015] Fig. Figures 4 e) and f) show two further embodiments with printed circuit board contacts implemented on both mounting sections 8, 11, which are inserted together into a single hole in the printed circuit board. As a result, the four contact corners 28, with their edge recess and tin recess, rest against the hole in the printed circuit board. The contact therefore has no bare contact points with the printed circuit board. A further advantage is that the duplicated printed circuit board contacts can be moved relative to each other, thus compensating for any offset or dimensional deviations between themselves and the holes on the printed circuit board.

[0016] Fig. Figure 5 shows a front view of the contact spring 1 with the inserted flat plug contact 3, which rests against the four contact points 14, 15, 16, and 17. The recessed contact points, in conjunction with the radius on the upper punched edge 19, eliminate bare punched edges in the electrical contact area. List of reference symbols 1 contact spring 2 Pluggable component 3 flat plug contacts 4 fork legs 5 fork legs 6 fork legs 7 fork legs 8 Fastening section 9 Bending bar 10 bending bar 11 Fastening section 12 Contact surface 13 Insertion radius 14 Contact point 15 Contact point 16 Contact point 17 Contact point 18 flexible press-in pin 19 upper punching edge 20 lower punching edge 21 Bending line 22 semi-finished products 23 solder pin 24 solid press-in pins 25 SKEDD pin 26 double SKEDD pin 27 double flexible press-in pin 28 contact corners with tin indentation E Exit level

Claims

[1] Contact spring 1 for contacting a flat plug contact 3, one-piece, which has two pairs of fork legs parallel to each other, two fork legs 4, 5, 6, 7 each with a contact point 14, 15, 16, 17 and a common fastening section 8, 11 form a first pair of fork legs, opposite the fastening section 8, 11 both pairs of fork legs are connected via a bending web 9, 10, characterized by that the two contact points 14, 15 and 16, 17 of a pair of fork legs are set back from the plane E of the fastening section 8, 11. [2] Contact spring 1 according to claim 1, characterized by that a semi-finished product 22 has two pairs of fork legs arranged parallel to each other on a bending line 21, resulting in a contact spring 1. [3] Contact spring according to claim 1 or 2, characterized by that the contact points 14, 15, 16, 17 are set back from the plane E of the semi-finished product 22. [4] Contact spring 1 according to one of the preceding claims, characterized by that the semi-finished product 22 is made of a pre-tinned material or has a galvanic surface coating. [5] Contact spring 1 according to one of the preceding claims, characterized by that the four contact points 14, 15, 16, 17 have tin indentation due to the forming process. [6] Contact spring 1 according to one of the preceding claims, characterized by that at least one fastening section 8, 11 has at least one printed circuit board contact such as solder pin 23, solid press-in pin 24, flexible press-in pin 18 or SKEDD pin 25. [7] Contact spring 1 according to one of the preceding claims, characterized by that both fastening sections 8,11 have at least one printed circuit board contact which is jointly inserted or pressed into a plated-through hole in the printed circuit board, such as a double SKEDD pin 26 or a double flexible press-in pin 27. [8] Contact spring 1 according to one of the preceding claims, characterized by that the fastening sections 8, 11 of the fork legs 4, 5 and 6, 7, which are parallel to one another, are arranged at a distance from one another.

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