Motor vehicle seat belt release mechanism - uses pyrotechnic device enclosing part of seat belt to burn through belt in event of occupant being trapped after accident

摘要

The seat belt release mechanism is intended to function after an impact regardless of the state of the vehicle. The mechanism comprises a box (B) enclosing the seat belt (2), a pyrotechnic compound enclosed inside the box, and a device (12,13,14) for igniting this compound in order to burn through the seat belt. The mechanism is incorporated in the seat belt buckle (4). The pyrotechnic compound is enclosed in a small box (11) which is cut open through a slot (10) in the box, and is ignited by a detonator (18) responding to an electric current supplied from an external source. The current may be switched by a manual switch or an inertia switch. Combustion gas pressure is slowly bled off from the pressure resistant box.