Device containing pyrotechnic material and method of manufacturing said device

Abstract

The present invention relates to a device containing pyrotechnic material, having a housing surrounding the pyrotechnic material, the device being wherein the housing is formed entirely from glass and contains at least one metal duct having a spark gap or a heating wire.

What is claimed is:  
     
         1 . A device containing a pyrotechnic material, comprising a housing surrounding the pyrotechnic material, wherein the housing is formed entirely from glass, the housing containing at least one metal duct comprising a spark gap or a heating wire.  
     
     
         2 . The device according to    claim 1   , wherein the device is an igniter for a gas generator.  
     
     
         3 . The device according to    claim 2   , wherein the heating wire or the spark gap is connected with the pyrotechnic material.  
     
     
         4 . The device according to    claim 2   , wherein the pyrotechnic material comprises a primary charge and a booster charge.  
     
     
         5 . The device according to    claim 1   , wherein the device is a gas generator for a safety arrangement in motor vehicles.  
     
     
         6 . The device according to    claim 5   , wherein the safety arrangement is a belt tensioner unit or an airbag module.  
     
     
         7 . The device according to    claim 1   , wherein the pyrotechnic material is solid, liquid or gaseous.  
     
     
         8 . The device according to    claim 1   , wherein the housing has at least one opening which is closed by a sealing means, the sealing means altering its physical condition, its structure or its volume as a result of an action of heat from the exterior below the self-ignition temperature of the pyrotechnic material in such a way that the opening is exposed.  
     
     
         9 . The device according to    claim 8   , wherein the sealing means is a low-melting-point metal alloy or a liquid contained in a closed glass container, the glass container being introduced into the opening.  
     
     
         10 . A method of manufacturing a device containing a pyrotechnic material, wherein the method comprises the steps of: 
 (a) providing a glass bulb having at least one opening;    (b) introducing the pyrotechnic material and at least one metal duct comprising a spark gap or a heating wire into the glass bulb;    (c) closing the opening of the glass bulb forming a glass housing completely surrounding the pyrotechnic material and containing the metal duct comprising the spark gap or the heating wire.    
     
     
         11 . The method according to    claim 10   , wherein the glass bulb is heated in the region of the opening until the glass softens, and the opening is closed by sealingly melting or pressing.  
     
     
         12 . The method according to    claim 11   , wherein the pyrotechnic material is cooled during heating.  
     
     
         13 . The method according to    claim 11   , wherein the heated area of the glass bulb is arranged at a distance from the pyrotechnic material, the distance being selected such that a cooling of the pyrotechnic material may be dispensed with.  
     
     
         14 . The method according to    claim 10   , wherein the glass bulb has a narrowed cross-section in the region of the opening.  
     
     
         15 . The method according to    claim 14   , wherein the glass bulb is heated, pulled apart and sealingly melted in the region of the narrowed cross-sectional portion.  
     
     
         16 . The method according to    claim 10   , wherein prior to introducing the pyrotechnic material, the metal duct comprising the spark gap or the heating wire is introduced into the glass bulb and the glass bulb is closed in the region of the metal duct.  
     
     
         17 . The method according to    claim 10   , wherein at least part of the pyrotechnic material surrounds the spark gap or the heating wire, the metal duct comprising the spark gap or the heating wire and the part of the pyrotechnic material surrounding the spark gap or the heating wire is introduced into the glass bulb and the glass bulb is closed in the region of the metal duct.  
     
     
         18 . The method according to    claim 10   , wherein the pyrotechnic material is introduced into the glass bulb and wherein subsequently the metal duct comprising the spark gap or the heating wire is introduced into the glass bulb and the glass bulb is closed in the region of the metal duct.  
     
     
         19 . The method according to    claim 10   , wherein the glass bulb is a glass tube having a first opening and a second opening located opposite the first opening, wherein the metal duct comprising the spark gap or the heating wire is introduced into the glass tube through the first opening and the glass tube, in the region of the first opening, is heated up to softening and closed and wherein subsequently the pyrotechnic material is introduced into the glass tube through the second opening and the glass tube, in the region of the second opening, is heated up to softening and closed.  
     
     
         20 . The method according to    claim 19   , wherein the narrowed cross-sectional portion is arranged in the region of the second opening.  
     
     
         21 . The method according to    claim 19   , wherein the glass bulb obtainable by introducing the metal ducts and closing the first opening is provided as a prefabricated component.  
     
     
         22 . The method according to    claim 10   , wherein the device containing the pyrotechnic material is an igniter in a gas generator for a safety arrangement in motor vehicles.