Contact washer for electrically conductive connection

Abstract

The invention relates to a contact washer for electrically conductive connections for arrangement on an electrically conductive counterpart covered with a lacquer layer, in particular a body part of a motor vehicle, comprising an annular, concavely curved washer body, on the washer underside facing the conductor, means for penetrating the lacquer layer are arranged, wherein the washer body has a cross section comprising at least two arc-shaped sections which have a decreasing inclination in the direction of the outer edge of the washer body, and wherein the means are formed by at least one claw projecting in the direction of the outer edge of the curved washer underside.

Description

Technical Field

[0001] The present invention relates to a contact gasket for conductive connection according to the preamble of claim 1. Background Technology

[0002] Contact washers are used in housing and building technology, as well as in motor vehicles and rail vehicles, for grounding applications or overvoltage protection on painted, conductive metal counterparts. These contact washers are toothed, formed by individual teeth arranged at the outer periphery. These teeth cut into the conductive counterpart when the screw is tightened, thereby creating a reliable electrical connection. For example, DE 7220915 U1 describes a contact washer for a vehicle antenna formed of a rigid first metal washer having a spherically pressed neck with three pointed teeth pressed outward at the root of the neck. When the screw connection is tightened, the pointed teeth cut into the vehicle body panels for improved contact.

[0003] A problematic aspect of known contact washers is that they typically only insufficiently penetrate the paint layer on the corresponding conductive counterpart (e.g., body parts), potentially leading to impaired contact. Furthermore, electrical conductivity is limited in known contact washers because the single, few teeth—typically arranged with six forming contact points—account for only a small fraction of the washer's outer diameter. Additionally, cavities can form due to the insufficient penetration of the teeth into the counterpart, allowing water intrusion and posing a risk of corrosion. Moreover, gaps created between the paint and the teeth allow moisture to reach exposed surfaces, increasing the risk of corrosion. In particular, the incomplete penetration of the teeth into the counterpart prevents proper face support of the contact washer, leading to settlement and creep. This can result in loosening and self-detachment, compromising not only the mechanical stability of the helical connection but also its electrical conductivity. Summary of the Invention

[0004] Here, the present invention provides a remedy. The objective of this invention is to provide a contact washer for conductive connections on conductive counterparts covered by a paint layer, particularly on the body parts of motor vehicles, in which reliable electrical contact is ensured and the risk of corrosion is reduced. According to the invention, this objective is achieved by a contact washer having the features of the characteristic portion of claim 1.

[0005] This invention provides a contact washer for conductive connections on conductive counterparts covered by a paint layer, particularly on the body parts of motor vehicles, ensuring reliable electrical contact and preventing cavity formation. Because the washer body has a cross-section comprising at least two arcuate segments with decreasing slopes towards the outer edges of the washer body, movement of the underside of the washer along the conductive counterpart to the surface support is achieved during tightening of the screw connection. Since the device is formed by at least one claw extending towards the outer edge of the arched underside of the washer, a scraping effect is induced during material movement on the underside of the washer, in which the claw cuts through the paint into the conductive counterpart. Here, the paint is scraped away from the counterpart. Direct contact between the claw of the contact washer and the conductive counterpart is achieved.

[0006] In an improved embodiment of the invention, at least two arc-shaped segments are constructed in an arc shape, wherein the radius of the arc-shaped segments decreases towards the outer edge of the washer body. By adjusting the radius, the movement of the lower side of the washer along the conductive counterpart can be adjusted.

[0007] In the design of this invention, at least one claw portion has an arc-shaped, preferably circular, or preferably annular, orientation along the underside of the washer. This allows the claw portion to penetrate the paint layer and make an arc-shaped cut into the corresponding part, thereby improving electrical conductivity.

[0008] In another design of the invention, the washer is constructed eccentrically relative to its center point, following an arcuate path along its underside. This achieves resistance to rotation of the washer when tightening the screw.

[0009] In an improved embodiment of the invention, at least two claw portions with different radii are arranged, each having an arcuate or annular orientation along the underside of the washer. This achieves radially spaced contact lines, thereby further improving the reliability of electrical contact.

[0010] In the design of this invention, at least one claw has a rectangular or triangular cross-section in the extending direction. This achieves sharp edges, thereby supporting the penetration of the coating layer and cutting into the conductive counterpart.

[0011] In another embodiment of the invention, at least one claw is arranged spaced apart from the outer edge of the washer body. This increases the pressing pressure of the claw during screw tightening. The pressing pressure on the claw is generated by compressive stress, which is less than the surface pressure generated by the tightening process because the claw is spaced apart from the screw head. By arranging at least one claw spaced apart from the outer edge of the washer body, the pressing pressure is increased, and thus the penetration depth of the claw is increased. Advantageously, the distance between the at least one claw is at least one-fifth, preferably at least one-quarter, and particularly preferably one-third of the radius of the washer body.

[0012] In another embodiment of the invention, a recessed arch is arranged axially spaced from at least one claw portion in the washer body. This forms a volume for receiving paint material scraped off by the claw portion. By bringing the paint material into the recessed arch, gaps between the washer and the planar conductor due to paint particles are prevented. This also resists corrosion caused by water intrusion. The planar support of the contact washer on the corresponding part, thus ensuring the mechanical stability of the screw connection, is also guaranteed. Furthermore, the paint layer introduced into the recessed arch forms a seal between the contact washer and the planar electrical conductor, thereby further resisting water intrusion.

[0013] In the improved embodiment of the invention, the structure is concave-arched and grooved. This allows the paint layer scraped off by the claws to be "rolled up," thereby improving the sealing effect.

[0014] In the design of this invention, at least one claw's side facing the concave arch is directly connected to the concave arch. This supports the complete transfer of the paint layer scraped off by the claw into the concave arch. The scraped paint layer can slide into the concave arch in a rolled-up manner via the stepless sliding surface of the claw structure and the concave arch. This avoids the peeling of paint particles that could potentially be positioned between the contact washer and the corresponding part, thus potentially leading to cavity formation.

[0015] In another embodiment of the invention, the upper side of the washer facing away from the conductive counterpart has a shaped portion, which is preferably constructed as a V-shaped or S-shaped portion or a scale-like structure. This achieves a locking effect of the helical connection by wedging it against the lower side of the screw head. Alternatively or additionally, the upper side of the washer facing away from the counterpart may also be provided with serrations or protrusions. Attached Figure Description

[0016] Other improvements and designs of the present invention are described in the remaining dependent claims. Embodiments of the present invention are shown in the accompanying drawings and are described in detail below. Wherein: Figure 1 A schematic diagram of a contact washer used for conductive connections is shown; Figure 2A schematic diagram of the conductive connection before the screws are tightened is shown (the vehicle body is shown); Figure 3 It shows Figure 2 Detailed diagram of the contact washer located between the screw head and the vehicle body; and Figure 4 It shows Figure 3 The diagram shows the connecting components, with screws being tightened. Detailed Implementation

[0017] The contact gasket used in this embodiment is made of C60 spring steel and includes a gasket body 1 with a substantially annular structure, having an upper gasket side 11 and a lower gasket side 12. The upper gasket side 11 has a shaped portion—not shown—that is implemented in a scale-like manner in this embodiment. The lower gasket side 12, facing the conductive counterpart 4 (currently formed by the body of a motor vehicle), is arched. Here, the cross-sectional profile of the arched lower gasket side 12 is formed by two intersecting arcuate segments 13, 14, wherein the first inner arcuate segment 13 has a smaller radius than the second outer arcuate segment 14.

[0018] In the transition region between the two arc-shaped sections 13 and 14, the washer body 1 has a claw 2 that annularly surrounds the lower side 12 of the washer, the claw extending at an acute angle toward the outer edge of the lower side 12 of the washer. In this embodiment, the claw 2 has a triangular cross-sectional profile and is arranged at a distance of approximately two-thirds of the radius of the washer body 2 from the outer edge of the contact washer.

[0019] In the washer body 1, an annular, groove-shaped concave arch 3 with a circular arc cross-section is introduced axially spaced from the annular, outwardly extending claw portion 2. The lower side of the claw portion 2 facing the concave arch 3 is directly connected to the concave arch 3, so that the inner circumferential surface of the concave arch 3 and the lower side surface of the claw portion 2 complement each other to form a stepless sliding surface.

[0020] exist Figure 2 The diagram schematically illustrates the arrangement of a contact washer according to the invention for manufacturing a conductive connection. Here, a screw 5 guides through the washer body 1 of the contact washer and the hole 41 of the corresponding member 4 provided with a thin varnish layer 41. The corresponding member 4 with the varnish layer 41 is currently formed from the body of a motor vehicle.

[0021] exist Figure 2In this configuration, screw 5 is not tightened, meaning the contact washer is not tensioned. Here, the contact washer rests on the corresponding part 4 with its outer edge. When screw 5 is tightened, the washer body 1 with the annular claw portion 2 is pressed against the corresponding part 4, wherein the two arc-shaped sections 13, 14 on the lower side of the washer are increasingly flattened. Due to the different radii r1, r2 of the two arc-shaped sections 13, 14, the surface of the lower side 12 of the washer and the claw portion 2 arranged on that surface move outward relative to the corresponding part 4. By selecting the radii r1, r2 of the two sections 13, 14, the outward pointing movement of the lower side 12 of the washer relative to the corresponding part 4 can be adjusted.

[0022] The outwardly moving claw 2 is pressed into the corresponding part 4 after the paint layer 41 is scraped off, thereby establishing electrical contact between the claw 2 and the conductive corresponding part 4 (see [link]). Figure 4 Here, the scraped paint layer 41 is rolled into the grooved arch 3, thereby achieving an O-ring seal. Even if the claw 2 is not fully inserted into the corresponding part 4, the remaining section of the claw 2 is also brought into the grooved arch 3 by the clamping pressure of the screw head 51, thus ensuring that the contact washer fits against the corresponding part 4. The contact area between the claw 2 and the corresponding part 3 is sealed by the scraped paint layer. Cavities are avoided by the fit between the washer lower side 12 of the washer body 1 and the corresponding part 4. This effectively resists the risk of corrosion.

Claims

1. A contact gasket for conductive connection, for placement on a conductive counterpart (4) covered by a paint layer (41), particularly on a vehicle body component, comprising an annular, concave arched gasket body (1), wherein a device for penetrating the paint layer (41) is arranged on the underside (12) of the gasket body facing the counterpart (4), characterized in that, The washer body (1) has a cross-section comprising at least two arcuate segments (13, 14) having a decreasing slope toward the outer edge of the washer body (1), wherein the device is formed by at least one claw (2) extending toward the outer edge of the arched underside (12) of the washer.

2. The contact washer according to claim 1, characterized in that, The at least two arc-shaped segments (13, 14) are constructed in an arc shape, wherein the radius (r1, r2) of the arc-shaped segments (13, 14) decreases toward the outer edge of the washer body (1).

3. The contact washer according to claim 1 or 2, characterized in that, The at least one claw (2) has an arc-shaped, preferably circular, preferably annular orientation along the lower side (12) of the washer.

4. The contact washer according to claim 3, characterized in that, The claw (2) is eccentrically constructed relative to the center point of the washer, along the arc-shaped path of the lower side (12) of the washer.

5. The contact washer according to claim 3 or 4, characterized in that, It is provided with at least two claws (2) having different radii that run along the lower side (12) of the washer in an arc or annular shape.

6. The contact washer according to any one of the preceding claims, characterized in that, The at least one claw (2) has a rectangular or triangular cross-section in the extending direction.

7. The contact washer according to any one of the preceding claims, characterized in that, The at least one claw (2) is arranged spaced apart from the outer edge of the washer body (1), wherein the distance from the outer edge is preferably at least one-fifth, particularly preferably at least one-quarter, of the radius of the washer body (1).

8. The contact washer according to any one of the preceding claims, characterized in that, A concave arch (3) is arranged axially spaced from the at least one claw portion (2) in the washer body (1).

9. The contact washer according to claim 8, characterized in that, The concave arch (3) has a shell-like structure, preferably a trough-like structure.

10. The contact washer according to claim 8 or 9, characterized in that, The side of at least one claw (2) facing the concave arch (3) is directly connected to the concave arch (3).

11. The washer according to any one of the preceding claims, characterized in that, The upper side (11) of the gasket opposite to the corresponding part (4) has a molding part, which is preferably constructed as a V-shaped or S-shaped molding part or a scale-like structure.

12. The washer according to any one of the preceding claims, characterized in that, The upper side (11) of the washer opposite to the corresponding part (4) is provided with sharp teeth or protrusions.

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