Contact
The contact design with elongated tips and funnel-shaped guides addresses the issue of non-ideal insertion in flat blade fuses, ensuring reliable high-current transmission by maintaining a defined contact area and multiple insertion options.
Patent Information
- Application Number
- DE102024106526
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-03-07
- Publication Date
- 2026-01-29
- Estimated Expiration
- 2044-03-07
AI Technical Summary
Existing contacts for flat blade fuses, such as those used in motor vehicles, often fail to achieve full contact due to manufacturing and material tolerances, leading to reduced electrical transmission capacity, especially when inserted at angles or offsets, impairing safety and performance, particularly at high currents and temperatures.
The contact design features elongated contact tips forming a cylindrical surface, with flared lip ends creating funnel-shaped insertion guides, allowing for multiple insertion directions and ensuring a defined contact area even in non-ideal orientations, thus enhancing electrical conductivity.
The design guarantees a precise and reliable transmission of high currents up to 50 amperes, even in non-ideal insertion conditions, by maintaining a minimum contact area and accommodating various insertion angles and orientations.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[0001] The invention relates to a contact, - with two opposing side walls, - with a back wall arranged between the side walls, wherein the side walls form a contact cage with the back wall, - with a slot gap, - the plug gap is formed by two opposing contact lips, whereby - each contact lip forms a contact surface, whereby - the contact surfaces of the contact lips are facing each other, whereby - each contact lip is arranged in the contact cage essentially parallel to the side wall, wherein - each contact lip is formed by a side wall section bent into the contact cage, wherein - the side wall section forms a free end facing away from its bending area as well as - with a first insertion direction along which a mating contact can be inserted into the insertion gap, - each contact lip is equipped with at least one contact tip, - the contact tips are facing each other, - the contact tip of each contact lip forms the respective contact surface. - each contact lip extends parallel to the vertex line L of the bending area of the side wall section that is bent into the contact cage to produce the contact lip.
[0002] Contacts of this type are known from the prior art. They typically accommodate flat blade contacts in their slot and are used in particular for the use of blade fuses, as are regularly used in motor vehicles.
[0003] Such contacts are generally manufactured using a stamping and bending process. For example, DE 10 2017 100 724 A1 and DE 699 03 231 T2 disclose contacts of this type.
[0004] The contact lips forming the mating gap are manufactured with a slight taper towards each other in the insertion direction. Ideally, when a mating contact is inserted, the contact lips spread so that they are almost parallel to each other and make full contact with the mating contact, especially the flat blade contact. This ensures a sufficient contact area to transmit adequate current from the contact to the mating contact.
[0005] In reality, the aforementioned ideal state is rarely achieved. Manufacturing tolerances during contact production contribute to this. Material tolerances of the flat blade contact also play a role. Finally, due to specific installation situations, the flat blade contact regularly has to be inserted into the contact with an offset from the center plane of the plug slot, at a certain angle, or even with a certain rotation. This regularly results in both contact lips not making full contact with the inserted flat blade contact.
[0006] In the case of a lateral offset from the center plane of the plug slot, one of the contact lips typically lies flat against the flat blade contact. The other contact lip, however, typically lies with one edge of its free end against the contact blade in a line-like fashion.
[0007] If the flat knife contact is inclined towards the center plane of the slot, a maximum of two diagonally opposite surfaces of the contact lips can be in contact with the flat knife contact, provided the contact lips are appropriately designed. However, in practice, only the edges of the contact lips, which are ideally chamfered during the stamping process, are in contact with the flat knife contact.
[0008] A rotation of the flat knife contact around its vertical axis also precludes full-surface contact of the contact lips on both sides.
[0009] If the contact and its mating contact are inserted in a position that deviates from the ideal orientation, the mutual contact surfaces are reduced, significantly impairing the contact-to-mater contact transfer characteristics. Therefore, in the case of contacts designed according to the state of the art, reductions are made in the theoretical electrical transmission capacity, particularly for high currents, to meet safety requirements.
[0010] The increasing electrification in all areas, for example in the automotive sector through various control units or even battery-electric drive components, and in mechanical and plant engineering through the use of electronic control units and servomotors, increasingly demands the transmission of high currents at sometimes comparatively low voltages in order to provide sufficient energy for the operation of various electrical components.
[0011] It is therefore an object of the invention to optimize the contact between a generic contact and its mating contact in the form of a flat knife contact, in particular the contact of a fuse holder and a flat plug-in fuse, in order to be able to transmit high currents of up to 50 amperes safely, especially at high ambient temperatures.
[0012] The problem is solved by contact with the features of claim 1.
[0013] Since each contact lip is equipped with at least one contact tip, the contact tips are facing each other, and the contact tip of each contact lip forms the respective contact surface.
[0014] The contact tip, which is designed as a bulge extending into the slot, can compensate for the three deviations from the ideal position between the contact and the flat blade contact discussed earlier. The radius of the bulge guarantees a definable minimum contact area for each of the deviations, as well as for the ideal position, so that the transmissible current strengths can be calculated precisely and guaranteed in real-world operation.
[0015] A characteristic feature of the invention is that each contact lip extends parallel to the apex line of the bending area of the side wall section that is bent into the contact cage to produce the contact lip.
[0016] The ideal contact tip for a contact according to the invention is therefore elongated and essentially forms a section of the cylindrical surface. Preferably, the contact tip extends over the entire length or width – depending on the reference direction – of the contact lip. In this way, the contact tip achieves the highest possible contact area with the flat knife contact serving as the mating contact. Additionally, the contact area can be positively influenced by selecting a large radius of curvature for the contact tip.
[0017] This requires that each side wall section has at least one incision parallel to the vertex line and that the contact lip is arranged between this incision and the free end of the side wall section.
[0018] In particular, it is provided that each contact lip forms a lip end in the area of the cut of the associated side wall section, which is flared out along a bending axis running transversely to the apex line, widening the insertion gap, with two opposing lip ends forming a funnel-shaped insertion guide.
[0019] This embodiment offers two advantages. Firstly, it allows for the simplified insertion of a flat blade contact.
[0020] Furthermore, this design of the contact lips is a prerequisite for enabling additional insertion directions for the mating contact, designed as a flat knife contact, beyond the first insertion direction mentioned earlier. This will be discussed in more detail later.
[0021] It is particularly preferred that the respective contact tip extends into the flared end of the lip.
[0022] If the contact tip extends into the flared lip end, the mutual contact surface of the contact and counter-contact can be further improved in arrangements that deviate from the ideal position, especially if the counter-contact is inclined in the plug gap.
[0023] It is particularly preferred that each side wall section has two incisions arranged on a incision line parallel to the vertex line, that each contact lip forms two opposing lip ends, and that the opposing contact lips form two opposing funnel-shaped insertion guides.
[0024] The invention is further characterized by the fact that the insertion gap is arranged opposite the back wall.
[0025] The invention provides that the first insertion direction is perpendicular to the back wall.
[0026] This embodiment has the essential advantage that the curved areas of the side walls, which are created by bending them into the contact cage to form the contact lips, create a first funnel-shaped insertion contour for the mating contact. Therefore, no further insertion guides are required for the first insertion direction.
[0027] Nevertheless, it is possible to align a second insertion direction parallel to the vertex line; in particular, a third insertion direction can also be parallel to the vertex line, but opposite to the second insertion direction.
[0028] These two additional insertion directions can also be achieved, in particular, if the aforementioned funnel-shaped insertion guides are created by extending the ends of the contact lips. This makes it possible to implement up to two further insertion directions in addition to the first, resulting in a very versatile contact.
[0029] The contact according to the invention is designed to be part of a printed circuit board populated with components. Therefore, it is important to ensure that the contact cage has at least one solder connection on its lower side.
[0030] The solder pads can be designed for through-hole plating on the circuit board. It is also possible to design the solder pads as SMD connections and incorporate positioning protrusions on the contact to ensure correct orientation of the contact on the circuit board for component placement.
[0031] In this sense, it is then provided that the second insertion direction is directed towards the underside of the contact cage, and it may additionally be provided that the third insertion direction is directed towards the top of the contact cage.
[0032] Further advantages of the invention, as well as a better understanding of it, will follow from the description of an exemplary embodiment. It will show: Fig. 1: A perspective view of a contact according to the invention looking at the plug gap, Fig. 2: the contact after Fig. 1 in view of its back wall, Fig. 3: contact according to Fig. 1 in view of its side wall according to view arrow III in Fig. 2, Fig. 4: a view of the contact after Fig. 1 according to view arrow IV in Fig. 2, Fig. 5: a view of the contact's slot gap after Fig. 1 according to view arrow V in Fig. 3, Fig. 6: a view according to section line AA in Fig. 5, Fig. 7: a view according to section line BB in Fig. 4, Fig. 8: a view according to section line CC in Fig. 4, Fig. 9: a second embodiment of the contact according to the invention in a perspective view of the plug gap, Fig. 10: a third embodiment of a contact according to the invention in a perspective view of its plug gap.
[0033] In the figures, a contact according to the invention is consistently provided with the reference numeral 10. Since this contact 10, due to its design according to the invention, is intended for the transmission of high currents, it is also referred to as a high-current contact 10.
[0034] In Fig. Figure 1 shows the high-current contact 10 in perspective view. It has a back wall 11, which is arranged between a first side wall 12 and a second side wall 13. The side walls 12 and 13, together with the back wall 11, form a contact cage 14.
[0035] The first side wall 12 has a first side wall section 15, which is bent inwards into the contact cage 14 by approximately 165 to 180 degrees, thus forming a first bending area 16. In this way, the free end of the first side wall section 15 points towards the rear wall 11.
[0036] The second side wall 13 forms a second side wall section 17. This second side wall section 17 is also bent into the contact cage 14 at an angle of approximately 165 to 180 degrees, creating a second bending area 18. Here too, the free end of the second wall section 17 points towards the rear wall 11 of the high-current contact 10.
[0037] The first side wall section 15 of the first side wall 12 forms a first contact lip 19, the second side wall section 17 of the second wall 13 forms a second contact lip 20. Between the contact lips 19, 20 the contact 10 forms a slot gap S.
[0038] Finally, contact 10 in its embodiment according to Fig. 1 via two solder terminals 21 in the form of solder pins 22, which are intended to be inserted into corresponding openings of a circuit board and soldered there.
[0039] Fig. Figure 2 shows a view of the rear wall 11 of contact 10. Using the Fig. 1 it is clear that the back wall is connected to the side walls 12, 13 via a curved section 23 each.
[0040] A support ridge 24 projects from the underside of the contact 10, which carries the solder terminals 21, and which is connected to the support fingers 25 of the side walls 12, 13 (see Fig. 1) unfolds its effects in a manner to be described later.
[0041] Fig. 3 is a side view according to view arrow III in Fig. 2. Here we look at the first side wall 12, and what follows applies equally to the second side wall 13. First, the curved section 23 is also visible here, to which the side wall 12 is attached to a rear wall 11. Fig. Figure 3 also shows the support rib 24 of the back wall 11 and the solder connection 21, which in this embodiment is designed as a solder pin 22. On the front side facing away from the back wall 11, the first bending area 16 is visible, which is created by bending the first side wall section 15 into the contact cage 14.
[0042] The first side wall 12 forms a support finger 25 towards the contact underside. A bending cut B is provided for this purpose, so that the support finger 25 is formed below the bending area 16. The bending cut B is thus located between the first bending area 16 and the support finger 25 and allows the first side wall section 15 to be bent into the contact cage without deformation of the support finger 25.
[0043] Fig. Figure 10 further shows that the support ridge 24 and the support finger 25 terminate in a common support plane A towards the underside of the contact. The top side of the printed circuit board, on which the contact 10 is located, is situated in this plane. The support ridge 24 and the support fingers 25 of the side walls 12, 13 ensure a perpendicular alignment of the contact 10 on the printed circuit board.
[0044] Fig. Figure 4 shows a view of the underside of contact 10 according to view arrow IV in Fig. 2. This figure shows that the side wall sections 15 and 17 are not bent a full 180 degrees into the contact cage 14, but rather have a slightly smaller bending angle, here approximately 175 degrees. This results in a wedge-shaped narrowing of the insertion gap S, which is only widened by the insertion of a mating contact (not shown), in particular a flat blade contact. This ensures contact pressure of the contact lips 19, 20 against the flat blade contact.
[0045] Fig. Figure 4 further shows that both contact lips 19, 20 each form a first contact point 26 and a second contact point 27, respectively. Both contact points 26, 27 point towards each other and further narrow the insertion gap S. They have a curved surface, which can be formed as a section of a cylindrical surface.
[0046] Fig. Figure 5 shows a view of the front side of the contact 10 opposite the rear wall 11. Here, one can see into the insertion gap S, in which the contact tips 26, 27 are formed facing each other on the contact lips 19, 20. The apex lines L are also shown (see also...). Fig. 1), which each represent the apex of the bending regions 16, 18.
[0047] Fig. 8 is a section view according to section line CC in Fig. 4. An interior view of the contact cage 14 is shown, looking at the inner surface of the first side wall 12. It is shown that the first side wall section 15 has two incisions 28. The incisions 28 lie on a cut line Z, which is aligned parallel to the vertex line L. The first incision 28 is made into the first side wall section 15 from the upper contact surface. The second incision 28 is made into the first side wall section 15 from the lower contact surface. A material web 29 remains between the incisions 28. The first contact lip 26 is thus formed between these incisions 28 and the free end of the first side wall section 15.
[0048] The first contact lip 19 forms an upper and lower lip end 30 in the area of each incision 28. Each lip end 30 is flared along a bending axis Y in the direction of the first side wall 12. The bending axis Y runs orthogonally to the vertex line L.
[0049] The second side wall 13 with its second side wall section 17 is designed accordingly.
[0050] Looking back now at Fig. 5, it can be seen that the flared lip ends 30 of the contact lips 19, 20 form a funnel-shaped insertion guide F both from the top and bottom of the contact. This facilitates the insertion of mating contacts, especially flat knife contacts, from both the top and bottom of the contact.
[0051] What to consider when looking at the Fig. 8 and Fig. What is noticeable in 1 as well as 5 and 7 is that the contact tips 26, 27 extend over the entire vertex-parallel length of the contact tips 26, 27, into the flared lip ends 30.
[0052] Fig. Figure 6 shows a cross-section through contact 10 according to section line AA in Fig. 5. This illustration shows how the insertion gap S is narrowed by the contact tips 26 and 27 entering the insertion gap S. It is easy to imagine that, even with a mating contact inserted at an offset, angled, or rotated position, the contact tips 26, 27 are always able to establish a defined contact area and thus reliably ensure the transmission of even high currents.
[0053] Fig. 7 is a longitudinal section according to section line BB in Fig. 4. Here, the view is taken from the rear wall 11 towards the contact front or towards the plug gap S. This illustration also shows how the plug gap S is formed between the contact lips 19, 20, whose lip ends 30, which flare out towards the respective adjacent side walls 12, 13, form an upper and a lower plug guide F.
[0054] In conjunction with the other characters, especially with Fig. 1. It is now clear that a first insertion direction runs orthogonally from the contact front towards the rear wall 11. A flat knife contact can be inserted into the high-current contact 10 along this first insertion direction and is contacted via the contact tips 26, 27.
[0055] A second and a third insertion direction can be defined from the top and bottom of the contact, respectively, i.e., orthogonal to the first insertion direction and parallel to the vertex line L. Flat knife contacts can also be inserted into the high-current contact 10 along these insertion directions.
[0056] A printed circuit board arranged on the underside of the high-current contact 10 can have a hole aligned with the plug gap S so that the flat knife contact can be inserted into the high-current contact 10 through such a printed circuit board.
[0057] Fig. Figure 9 shows a second embodiment of the high-current contact 10 according to the invention. This is largely identical to the high-current contact 10 described above. In particular, there are no significant differences in the area of the contact lips 19 and 20 forming the plug gap S. Instead of the solder pins 22, this embodiment has contact feet 31, which are provided for placement on contact surfaces of a printed circuit board and for soldering thereon. A positioning mandrel 32 extends from the support ridge 24 and positions the high-current contact 10 correctly on the printed circuit board for subsequent soldering of the contact feet 31 to the contact surfaces.
[0058] The third embodiment according to Fig. 10 equal to those of Fig. 9. It should also be noted here that there is no difference whatsoever between the first embodiment and the contact lips 19, 20 and the design of the plug gap. Compared to the high-current contact 10 in Fig. 9 omits the embodiment according to Fig. 10 on the positioning mandrel 32. Reference symbol list 10 Contact / High-current contact 11 Back panel 12 first side wall 13 second side wall 14 contact cages 15 first side wall section 16 first bending area 17 second side wall section 18 second bending area 19 first contact lip 20 second contact lip 21 Solder connection 22 solder pins 23 Curvature section 24 support bridge 25 support fingers 26 first contact point 27 second contact point 28 cut 29 Material bridge 30 Lip end 31 Contact foot 32 Positioning mandrel F Plug guide S slot gap L vertex line B bending cut A support level Z intersection line Y bending axis
Citation Information
Patent Citations
Electrical press-fit contact element
DE102017100724A1
contact part for connecting socket and connector with such a contact part
DE69903231T2