Ignition device comprising a predetermined breaking point for the propelling charge of a gas generator associated with a passenger protection device in motor vehicles

Abstract

The invention relates to an ignition device comprising a housing ( 2 ) in which an ignition chamber ( 4 ) for ignition material ( 5 ) is arranged. Said ignition chamber is covered with a flap ( 12 ), the bottom thereof having a predetermined breaking point. The breaking point ( 15 ) extends in an approximately S-shaped pull between opposite edges of the bottom ( 14 ). When the predetermined breaking point is broken by igniting the ignition material ( 5 ), parts ( 14 a, 14 b ) of the bottom ( 14 ) are bent upwards in such a way that the propulsion gases (T) of the ignition materials ( 5 ) are redirected by said parts ( 14 a 14 b ). Said construction enables the ignition device ( 1 ) to have a reduced height, and laterally-arranged propelling charges can be ignited in a reliable manner.

1 . Ignition device for the propellant charge of a gas generator for a passenger protection device in an automobile, for example for an inflatable collision cushion or a seatbelt tightener, with a housing, an ignition chamber in the housing, and ignition material in the ignition chamber, wherein the housing includes a cap covering the ignition chamber having a side wall and a bottom, and with a predetermined breaking point provided in the bottom forming sections by reduction of material, characterized in that the predetermined breaking point ( 15 ) extends in one stroke in an approximately S-shape between opposite edges of the bottom ( 14 ).  
     
     
         2 . Ignition device as in  claim 1 , characterized in that the section ( 15   a ) of the predetermined breaking point ( 15 ) between the edges of the bottom ( 14 ) passes through the center point (M) of the bottom ( 14 ).  
     
     
         3 . Ignition device as in  claim 1  or  2 , characterized in that the sections ( 15   b,    15   c ) of the predetermined breaking point ( 15 ) extend along the edges of the bottom ( 14 ) approximately parallel to the edge of the bottom ( 14 ).  
     
     
         4 . Ignition device according to one of the previous claims, characterized in that the section ( 15   a ) of the predetermined breaking point ( 15 ) between the edges of the bottom ( 14 ) essentially form a straight line.  
     
     
         5 . Ignition device according to one of the previous claims, characterized in that a relatively sharp corner ( 16 ) is provided between the sections ( 15   b,    15   c ) of the predetermined breaking point ( 15 ) positioned along the edges of the bottom ( 14 ) and the section ( 15   a ) between the edges of the bottom ( 14 ).  
     
     
         6 . Ignition device according to one of the previous claims, characterized in that the sections ( 15   b,    15   c ) of the predetermined breaking point ( 15 ) along the edges of the bottom ( 14 ) pass through an arc of a circle with a sector angle α of at least 45° extending outward from the center point (M) of the bottom ( 14 ).  
     
     
         7 . Ignition device as in  claim 6 , characterized in that the sector angle is approximately 90°.