Aktiebolaget Bofors

Sven-Erik Bratt

Olof Nygards

Kurt Nygaard

Kjell Mattsson

Jan-Olov Blix

The present invention relates to an electric igniter of the type which comprises two electrically conducting bodies (8, 9) separated by an electrically insulating body (10). The conductive and insulating bodies define a very smooth common end surface (13) with an interconnecting member (20) for electrically connecting the conductive bodies (8, 9). A pyrotechnic charge (14) is in contact with the interconnecting member (20 ) for ignition when said member is heated by flow of electric current therethrough. The interconnecting member (20) comprises at least one relatively thin metal layer (21, 22) which is bonded to said smooth end surface and a thin inert layer (23) applied directly on the metal layer (22). In addition to said layers the interconnecting member (20) also comprises a metal thin film layer (24) applied directly on the inert layer, the interconnecting member (20) being adjusted to its correct resistance value by means of oxidizing the metal layer (22) adjoining the inert layer (23).

Electric igniter

The present invention relates to an electric connector member to supply electrical energy into an electric igniter of the type which includes a priming charge ignitable by heat generated when feeding an electric current through the resistive element of the igniter and which igniter must be protected against accidental ignition caused by electromagnetic or static electricity which may enter into the igniter through the feed wires. Instead of providing the igniter itself with a high frequency filter, which requires a large space, the connector member is provided with such a filter (16, 17). This makes it possible to reduce the outer dimensions of the igniter to a great extent with the protection against accidental ignition maintained. Further the need to provide each of the igniters with a specific high frequency filter, designed for the expected interference condition in the actual application, does no more exist.

An assembly of an electrical connector and pyrotechnic igniter

The invention comprises an electric igniter comprising a filament (9), a priming charge ignitable by heat generated in the filament by feeding an electric current therethrough, two connection legs (8, 8') for connecting the feed wires (7, 7') to the igniter and the filament and a high frequency filter to protect the igniter against accidental ignition by electromagnetic fields or static electricity. The casing of the igniter comprises a wider part (2), the 'cup', and a narrower part (3) in which narrower part (3) and the connection legs (8, 8') are cast in a material (10) which withstands pressure and high temperatures. The igniter has a simple mechanical design using capacitor and ferrite elements (11, 12) as the high frequency filter which elements are common for the two connection legs. The ferrite element (12) is located in the narrower part (3) of the igniter so that the element together with the material (10) serves as a bushing for the two connection legs.

The present invention relates to an electric igniter of the type comprising two electrically conductive bodies separated by an insulating body. The conductive bodies and said insulating body define a very smooth common surface having a thin connective member electrically connecting the conductive bodies. A pyrotechnic charge is in contact with said thin connective member for ignition when said member is heated by a flow of electric current therethrough. The connective member comprises one or more thin metal layers which are bonded to said smooth surface. In order to give the igniter a somewhat 'slower' electrical response as well as increasing the mechanical strength of the connective member. The connective member also comprises an additional thin layer of inert material, preferably a glass- or SiO.sub.2 -layer, applied directly on the upper metal layer.

Electric igniter with conductive bodies and thin connector

An electric igniter is disclosed which comprises two elements made of electrically conducting material, a body separating the elements and made of electrically insulating material, such as glass or material containing glass, at least one further electrically conducting element arranged on a surface common to the two elements and the body for connecting the two elements electrically, and also a pyrotechnical composition in contact with the surface and the further element. Burning of the composition can be initiated by means of heat developed in the further, initiating element.

Growing community of inventors

Karlskoga, Sweden

Sven-Erik Bratt