AIRBAG MODULE WITH DEPLOYMENT SENSOR

摘要

A cartridge (36) stores a quantity of string (38), one end of which is attached to the inside surface (42) of an airbag (32). A spool which transitions to a conical member (54) is situated within the cartridge. A narrow gap (50) around the spool forms a string storage space and a similar gap overlies the conical member (54) and leads to an opening (58). Positioned within the body of the cartridge (36) is a light source (68; 94; 110) and a light detector. As string (38) is drawn out of the cartridge, the string traverses between the light sources and a light detector generating a signal directly proportional to the rate at which string is withdrawn. The geometry of the cartridge (36) is arranged to provide friction against the string (38). The friction is created between the string and the junction between the cylindrical spool (48) and the conical member (54) and rapidly overcomes the momentum of the string (38) when the airbag (32) comes to a stop.