EP1061325B1 - Glass-metal passages - Google Patents

Abstract

The detonator for inflating a car air bag or releasing a safety belt has two parallel metal rods(1, 2). These are fused at their ends into a glass plug (3). A metal sleeve (4) is fitted on to the plug and a cover plate at the top of the plug surrounds the rods and is in conducting contact with them. It is also sealed to the wall of the sleeve.

Description

The invention relates to a glass-metal bushing according to the preamble of the claim. This means vacuum-tight fusion of glasses in metals. The metals are doing electrical conductors.

US-A-5 345 872 describes a glass-metal bushing according to the Preamble of the claim. Another glass-to-metal bushing is in US-A-3,274,937.

Such bushings are wide in electronics and electrical engineering common. The glass used for melting serves as an insulator. Typical glass-metal bushings are structured as follows: metallic inner conductor melted into a preformed sintered glass part, the sintered glass part being melted into an outer metal part.

Preferred applications of such glass-metal bushings are for example lighters. Such lighters are used for airbags or for belt tensioners in motor vehicles. In this case, the glass-metal bushings Part of an ignition device. The whole Ignition device includes one in addition to the glass-metal bushing Ignition bridge, the explosives and a metal cover that the Ignition mechanism tightly encloses. The implementation plays one important role. It is necessary to control the electrical voltage caused by a or two metallic pins, a housing reliably and insulated supply.

Known glass-metal bushings are structured as follows: a glazed pen is made with conductive epoxy or an electrically conductive adhesive used as ground wire. He poses with it the necessary connection to the metallic housing. This Embodiment is very complex and expensive to manufacture. On serious disadvantage is that the ground connection to the outside Housing is quite unsafe. This can have serious consequences especially in the application examples of the airbag or of the belt tensioner.

The invention has for its object to a glass-metal implementation create a reliable ground connection to the outer metal part guaranteed, even long after installation. The Implementation should also be inexpensive to manufacture.

This object is solved by the features of claim 1. According to a solder-coated cover piece is provided, which on one of the is arranged on both ends of the glass plug and one of the two Conductively encloses metal pins. Such a solder-coated cover piece is inserted into the melting mold when assembling the parts. By the Inserting the cover piece is a safe ground connection to the outside Metal part guaranteed. The application of the lid piece should be during of the glazing process.

• Das Deckelstück kann aufgrund seiner erfindungsgemäßen Gestaltung als Metallscheibe ausgebildet sein, die sich durch Stanzen herstellen läßt und die somit kostengünstig ist.
• Die Metallhülse kann als Abschnitt von einem Rohr abgetrennt werden, und läßt sich somit ebenfalls kostengünstig herstellen.
• Ebenfalls im Sinne einer Fertigungsrationalisierung wirkt sich Merkmal 1.6 des neuen Patentanspruches aus, wonach das Deckelstück zusammen mit den beiden Metallstiften in den Glaspfropfen eingeschmolzen ist.
• Ein Nacharbeiten ist nicht mehr notwendig, schon gar nicht eine Nachbehandlung beim Kunden, der die Glas-Metall-Vorrichtung in eine zugeordnete Einrichtung einbaut, beispielsweise in eine Zündvorrichtung.
• Die Glas-Metall-Durchführung gemäß der Erfindung läßt sich als sogenannte Druckglas-Durchführung herstellen.

The main advantages are as follows:

• Due to its design according to the invention, the cover piece can be designed as a metal disk which can be produced by stamping and which is therefore inexpensive.
• The metal sleeve can be separated as a section from a tube, and can thus also be produced inexpensively.
• Feature 1.6 of the new patent claim also affects the rationalization of production, according to which the cover piece is melted together with the two metal pins in the glass plug.
• Reworking is no longer necessary, and certainly not post-treatment at the customer who installs the glass-metal device in an associated device, for example in an ignition device.
• The glass-metal bushing according to the invention can be produced as a so-called pressure glass bushing.

The glass-metal bushing according to the invention fulfills perfectly their functions. But it is also inexpensive. It will be geometric complex and therefore expensive metal parts are unnecessary.

Figur 1

zeigt in einer perspektivischen Ansicht ein sogenanntes Anzündhütchen, so wie dies beispielsweise für einen Airbag Verwendung findet.

Figur 2

zeigt eine erfindungsgemäße Glas-Metall-Durchführung, die Bestandteil des Anzündhütchens gemäß Figur 1 ist.

Figur 3

veranschaulicht eine Glas-Metall-Durchführung gemäß dem Stande der Technik.

Figur 4

veranschaulicht eine weitere Glas-Metall-Durchführung gemäß dem Stande der Technik.

The invention is explained in more detail with reference to the drawing. The following is shown in detail:

Figure 1

shows in a perspective view a so-called primer, as is used for example for an airbag.

Figure 2

shows a glass-metal bushing according to the invention, which is part of the primer cap according to Figure 1.

Figure 3

illustrates a glass-metal bushing according to the prior art.

Figure 4

illustrates a further glass-metal implementation according to the prior art.

The primer shown in Figure 1 comprises two metal pins 1, 2 as Serve plugs, a glass bushing 3, an ignition charge 4, a Cover 5 and a sleeve 6.

Recognized in the glass-metal bushing according to the invention according to FIG. 2 one again two metal pins 1, 2. These are in a glass plug 3.1 melted down. They protrude on the two faces of the Glass plug 3.1 beyond this, namely on the lower side by one much larger dimension than on the upper side. The two metal pins 1, 2 form the connector.

The glass plug is surrounded by a sleeve 6. As the most important and at the same time element according to the invention can be seen a cover piece 3.2. This is in the glass plug 3.1 together with the two metal pins 1, 2 melted down. It provides a conductive connection between the metal pin 1 and the sleeve 6 ago. On the other hand, it is not more conductive with pin 2 Connection.

In the embodiment according to Figure 3, the prior art heard, you can see the two metal pins 1, 2, the Glass plug 3.1 and the sleeve 6. However, a cover piece 3.2 is missing here.

This is also the case with the previously known embodiment according to FIG. 4. A cover piece is also missing there. Only metal pin 1 is in a glass plug 3.1 melted down.

Claims (1)

1. Glass-metal lead-through, for example for an igniter of an airbag or of a belt tensioner;

   1.1 having two metal pins (1, 2) which are parallel to one another;

   1.2 having a glass plug (3.1) into which the metal pins (1, 2) are fused over part of their length;

   1.3 having a metal sleeve (6) which surrounds the glass plug (3.1);

   1.4 there is a cover piece (3.2) which is arranged on one of the two end sides of the glass plug (3.1), conductively surrounds one (1) of the two metal pins (1, 2) and which furthermore is conductively connected to the metal sleeve (6);

      characterized by the following features:

   1.5 the cover piece (3.2) is fused into the glass plug (3.1) together with the two metal pins (1, 2);

   1.6 the cover piece (3.2) is flush with the associated end face of the glass plug (3.1);

   the metal pins (1, 2) project beyond the end sides of the glass plug (3.1) on both sides.

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