Air Bag Ignition

This is a cut right thru the impact absorber of a steering wheel. Below, the steering wheel rim, embedded in plastic, is visible. Under the folded air cushion the empty gas generator is located. The initiator is inserted in the middle hollow cavity. The ring-shaped channel contains the propellant pressed in tablets from Natriumazid, potassium nitrate and sand. This provides for the quick development of nitrogen gas which inflates the air bag under loss of heat. Consistently the metal grids serve for the cleaning and cooling.
The dismounting of the steering wheel impact absorber requires certain safety measures. These are determined by the vehicle manufacturer. E.g., the bridging of two electric contacts after pulling off of the pins may be necessary. An air bag potentially helps in case of an accident, but it might endanger the mechanic when released in error.