Inspiration of SRS Airbags
Since the inventory of single wheel bicycle, transportation developed by the effort of automobile engineers. Through the ages automobile industry has developed to high performance luxury modern motor cars since the Henry ford's first motor car in 1908. Technology develops for new needs of human beings. Thus speed is not a problem to any modern motor car while they can get needed speed in few seconds. A higher speed increases the likelihood of an accident. Very strong relationships have been established between speed and accident risk. As a safety tip seat belts were introduced by them. But it wasn't a enough solution because number of deaths from road accidents was increased. Most accidents happens in few milliseconds of time. Their problem was how to add a soft pillow between the passenger and the outside when an accident happens. Thus an American inventor, industrial engineer and member of the U.S. Navy called John W. Hetrick was designed this in 1952 and patented in 1953.
This has a interesting mechanism which follows the speed of the vehicle and also moves with the momentum of it. With the speed, vehicle's momentum also increases. To reduce the vehicle's momentum, It requires a force acting over a period of time. When a vehicle crashes, the force required to stop vehicle is very high. Thus the air balloon should release in few milliseconds parallel to the descending momentum of the vehicle. Because the vehicle's momentum can be changed instantly while the passengers and the vehicle parts have large weight and all of them runs in apparent speed. Thus this great inventory introduced as SRS (Supplemental Restraint System) Airbags.
They used two fast reactive compounds called sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas(N3). The first commertial airbag for automobile with introduced in 1998 and since model year 1998, all new cars sold in the USA came with SRS airbags on both driver and passenger sides.
This inventory reduced the number of deaths from road accidents in 30 percent. Then came out seat-mounted and door-mounted side airbags too. Some how, these type malfunctional or high powerful airbags can be harmful to children and older people. Actually, there were some adult deaths and child deaths happened due to malfunctional airbags. NHTSA recorded 238 deaths due to malfunctional airbags between 1990 and 2002.
Thus, In addition, starting from 1999, repair shops and dealers were allowed to install on/off switches that can deactivate airbags. With this effort of engineering, airbags have been credited for saving thousands of lives since the
1990s. And also its a reason for the decrement in number of deaths. Air bags can provide better protection to the passengers. With this inventory the travel and tourism also become more safer than earlier ages. But as the safety tips, people should use seat belts and do their driving in careful while airbags are not a substitute or a life guard for careless drivers.