Petroleum Product of the Week: Seat Belts

Ever since its invention in the mid-19^th century, seat belts have significantly evolved and currently save over 15,000 lives each year.

The piece of fabric found in every vehicle is, at times, a matter of life and death and wearing one increases your chances of surviving a car accident. The National Highway Traffic and Safety Administration assert it reduces the risk of death for someone in the front seat by 50 percent.

A necessary precaution

Seat belts keep car occupants from going through the windshield when the car must come to an abrupt stop or collides with another object.

English engineer George Cayley invented the first version of the device in the mid-1800s. Around the same time, Edward J. Claghorn from New York had secured the first safety-belt patent for tourists, painters, and firemen.

Car manufacturers began installing them in cars more frequently. In the 1930s, physicians tested the seat belts and realized their importance. They recommended the seat belts be installed in all vehicles. The Sports Car Club of America required all competing drivers to wear lap belts in 1954 and the Society of Automotive Engineers (SAE) established a Motor Vehicle Seat Belt Committee.

The three-point design

In 1958, Swedish engineer Nils Bohlin invented the most-advanced version of the device, the three-point seat belt. Volvo hired Bohlin and he designed the seat belts we know today. He received a gold medal from the Royal Swedish Academy of Engineering Science in 1995 and was inducted into the Automotive Hall of Fame in 1999 for the invention.

The belt secures both the upper and lower body. It was simple, efficient, and easily installed in an automobile. The safety provided by the belt transformed the industry. Volvo made the patent open to any car manufacturer.

Early on in seat belt webbing production, nylon made the lap belt and polyester made the diagonal belt.

Engineers conducted research on each of the materials to figure out which was strongest in the early 1970s. They deemed polyester the stronger of the two. It even demonstrated lower extensibility, higher tensile strength, and is good in both low and high temperatures.

Seat belt types

Several other types were invented for different reasons after the invention of the initial lap belt and three-point belt.

Child safety seats and racecars use 4-, 5-, and 6-point seat belts. The 6-point belt became popular in NASCAR after the death of Dale Earnhardt. He wore a 5-point belt at the time of his crash.

Aerobatic aircraft rely on a 7-point harness that has a redundant lap-belt attached to a separate part of the aircraft. It allows the pilot to release harnesses if the pilot must use the parachute.

Sources:

Seat Belt Material Properties

https://www.arnoldclark.com/newsroom/265-why-volvo-gave-away-the-patent-for-their-most-important-invention
https://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/seatbelt.htm