Metal protective ground conductor connection device

A ground conductor includes a conductor body formed from a sheet of conductive metal material of a given thickness, the conductor body having a horizontal base portion, and a pair of downwardly extending vertical leg portions that contain opposed mounting rail cavities that terminate at one end in a pair of flange recesses. A vertical tongue portion extends downwardly from the conductor body transversely across the leg portions at the other end of the cavities, the tongue portion having a width that is greater than the thickness of the metal sheet. When the conductor body is mounted on the mounting rail with one flange extending within the recesses, a spring biases the conductor body in a direction to effect electrical engagement between the other rail flange portion and the adjacent surface of the tongue portion.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/EP2009/057018 filed Jun. 8, 2009, which claims priority of German Application No. 20 2008 008 656.6 filed Jun. 27, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

A ground conductor includes a conductor body formed from a sheet of conductive metal material of a given thickness, the conductor body having a horizontal base portion, and a pair of downwardly extending vertical leg portions that contain opposed mounting rail cavities that terminate at one end in a pair of flange recesses. A vertical tongue portion extends downwardly from the conductor body transversely across the leg portions at the other end of the cavities, the tongue portion having a width that is greater than the thickness of the metal sheet. When the conductor body is mounted on the mounting rail with one flange extending within the recesses, a spring biases the conductor body in a direction to effect electrical engagement between the other rail flange portion and the adjacent surface of the tongue portion.

2. Description of Related Art

Grounded conductor wire connection devices are used in various electrical devices, especially in terminal blocks that can be snapped on mounting rails or in electronic housings of some other kind, for example, in switchboards of machines, in order to establish a connection to the mounting rail. The transition resistance to the mounting rail is to be as low as possible, and in case of an error, it should be possible to guarantee a high current conduction.

An example of a typical grounded conductor wire connection device is described in the Follmann et al European patent No. EP 1 182 735 B1, wherein the grounded conductor connection device consists of a sheet metal part with a U-shaped seat for a mounting rail. By way of another feature, it is provided here that only a relatively small cross-section is available for the current conduction of the grounded conductor wire.

SUMMARY OF THE INVENTION

Accordingly, a primary object of the present invention is to provide a ground conductor formed of a conductive metal sheet, the conductor body having a horizontal base portion, and a pair of downwardly extending vertical leg portions that contain opposed mounting rail cavities that terminate at one end in a pair of flange recesses. A vertical tongue portion extends downwardly from the conductor body transversely across the leg portions at the other end of the cavities, the tongue portion having a width that is greater than the thickness of the metal sheet. When the conductor body is mounted on the mounting rail with one flange extending within the recesses, spring means bias the conductor body in a direction to effect electrical engagement between the other rail flange portion and the adjacent surface of the tongue portion.

According to another object of the invention, the spring means comprises a leaf spring mounted between the conductor leg portions, said leaf spring being maintained in a compressed condition with a portion thereof extending adjacent the pair of flange recesses for engagement with the adjacent extremity of the associated mounting rail flange portion, thereby bias the conductor in a direction relative to the rail to effect surface to surface electrical engagement between the extremity of the other rail flange and the tongue portion of the conductor.

A further object of the invention is to provide the ground conductor with a bus bar for connection with the various circuits of the associated electrical component.

According to a more specific object, the basic ground conductor body has a contact tongue—with a line contact area directed toward the mounting rail—which is wider than the material thickness of the conducting material and/or which, in a direction normal to the main longitudinal axis of the mounting rail, has at least the width of the base segment. As a result, one can considerably reduce the danger of a material burn at high current intensities because a large current transmission cross-section is produced that is suitable for high pulse currents. For example, one can transmit brief currents of up to 20 kA.

Another mechanical advantage derives from the fact that, first of all, there is a greater strength due to the U-shaped cross-section of the conductor body, and, besides, more material is available for wear and tear.

In a preferred embodiment, the basic body is made in an easily producible fashion as a flexible stamping part. At the same time, it is advantageous that the contact tongue can be integral with the conductor, which tongue is punched out of the material of the basic body and which is bent over to the desired position.

Another advantage results in the fact that the contact tongue is retained in a stabilized manner between the leg portions of the conductor, as a result of which, the strength of the U-shaped basic body is increased.

In another preferred embodiment, the spring between the leg portions and parts of the basic segment of the basic body is retained in a pre-stressed manner, whereby the necessary retaining segments can be made simultaneously during the punching-bending procedure.

DETAILED DESCRIPTION OF THE INVENTION

Referring first more particularly toFIG. 1, the ground conductor1of the present invention comprises a ground conductor body2that is formed by punching and stamping from a metal conductive sheet material, thereby to define an inverted generally U-shaped configuration, said body including a horizontal base portion4, and a pair of downwardly extending parallel spaced vertical leg portions5and6. As will be described in greater detail below, the conductor body also includes an integral downwardly-extending conductive tongue portion3that is formed by punching and bending from the base portion4.

The lower edge portions of the body leg portions5and6contain opposed rail-receiving cavities C that terminate at their first ends in flange-receiving recesses9. At their other ends9′, the cavities terminate in end walls that support the downwardly bent tongue portion3. Stabilizing tabs5aand6aextend from the cavity end walls into corresponding slots contained in the tongue portion3. It is important to note that the width w of the tongue portion3is greater than the thickness t of the metal sheet from which the conductor body2is formed.

As best shown inFIG. 2, a leaf spring11is mounted in a compressed condition between the body leg portions5and6, said leaf spring having end portions13and15that are retained relative to the conductor body by integral downwardly-bent retaining tab portions7and8. The leaf spring includes a downwardly extending intermediate portion11, and a reversely-bent semi-circular portion14, said spring having a configuration such that a contact portion12thereof extends between the flange recesses9.

An electrical component22, such as a terminal block, relay or the like, is supported by the conductor body2.

Referring now toFIGS. 3-5, the conductor body2is adapted for mounting transversely across a support rail16of the so-called top hat type including outwardly directed flange portions17and18. The flange portion17extends into the two flange recesses9at the right hand ends of the cavities C, and the edge extremity of the flange portion18terminates adjacent the contact surface10of the tongue portion3. The portion12of leaf spring11engages the right hand extremity of the mounting rail flange17to bias the conductor body2to the right relative to the rail16, thereby to effect a tight electrical engagement between the tongue surface10and the adjacent edge of flange18. Owing to the increased width w of the tongue3, a positive electrical ground connection between the tongue3and the mounting rail16is obtained. This facilitates a line contact segment that has a high current transmission capability in cooperation with a mounting rail16.

FIG. 4illustrates that the spring contact portion12is in linear contact with the width of the spring with an edge of the first rail leg17. The second rail leg18lies in a line contact on the contact segment10of the contact loop3. A contact is present on the entire rectangular surface of the contact segment10with the rectangular surface of the second rail leg18, which results in a high current transmission cross-section.

The invention is not confined to the above-described exemplary embodiments. It can be modified in the context of the attached claims. For example, the mounting rail can also have another profile. It is also possible to make the contact segment10wider than the base segment4. Spring11can be arranged and stressed in some other way.

FIG. 6discloses a bus bar conductor connection19is made on the basic conductor body2. In this way, one can in a simple way provide a conductor connection plane that, for example, can be made directly on the basic body2as a punch bending contour or in some other way, for example, as a soldering, riveting, embossing or welding connection. According toFIG. 6, the conductor connection is made as bus bar19that is arranged in a conducting manner on basic body2or that is connected with it integrally, thereby to connect to ground the circuits of the electrical component24.

While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes may be made without deviating from the invention described above.