car-seat-us01

A seat belt (also known as a safety belt ) is a vehicle safety device designed to secure the driver or a passenger of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt reduces the likelihood of death or serious injury in a traffic collision by reducing the force of secondary impacts with interior strike hazards, by keeping occupants positioned correctly for maximum effectiveness of the airbag (if equipped) and by preventing occupants being ejected from the vehicle in a crash or if the vehicle rolls over. When in motion, the driver and passengers are traveling at the same speed as the car. If the driver makes the car suddenly stop or crashes it, the driver and passengers continue at the same speed the car was going before it stopped. A seatbelt applies an opposing force to the driver and passengers to prevent them from falling out or making contact with the interior of the car (especially preventing contact with, or going through, the w...

An analysis conducted in the United States in 1984 compared a variety of seat belt types alone and in combination with air bags. The range of fatality reduction for front seat passengers was broad, from 20% to 55%, as was the range of major injury, from 25% to 60%. More recently, the Centers for Disease Control and Prevention has summarized these data by stating "seat belts reduce serious crash-related injuries and deaths by about half." Most seatbelt malfunctions are a result of there being too much slack in the seatbelt at the time of the accident. unreliable source?

Seat belts were invented by English engineer George Cayley to use on his glider, in the mid-19th century. By 1950, almost every race-car driver used safety seat belts. In 1946, Dr. C. Hunter Shelden opened a neurological practice at Huntington Memorial Hospital in Pasadena, California. In the early 1950s, Dr. Shelden made a major contribution to the automotive industry with his idea of retractable seat belts. This came about from his care of the high number of head injuries coming through the emergency room. He investigated the early seat belts whose primitive designs were implicated in these injuries and deaths. To reduce the high level of injuries he was seeing, he proposed, in late 1955, retractable seat belts, recessed steering wheels, reinforced roofs, roll bars, automatic door locks, and passive restraints such as the air bag. Subsequently, in 1966, Congress passed the National Traffic and Motor Vehicle Safety Act requiring all automobiles to comply with certain safety standards....

Two-point edit A 2-point belt attaches at its two endpoints. A simple strap was first used March 12, 1910 by pilot Benjamin Foulois, a pioneering aviator with the Aeronautical Division, U.S. Signal Corps, so he might remain at the controls during turbulence. The Irvin Air Chute Company made the seat belt for use by professional race car driver Barney Oldfield when his team decided the daredevil should have a "safety harness" for the 1923 Indianapolis 500. Lap edit A lap belt is a strap that goes over the waist. This was the most common type of belt prior to legislation requiring three-point belts and is found in older cars. Coaches are equipped with lap belts (although many newer coaches have three-point belts), as are passenger aircraft seats. University of Minnesota Professor James J. (Crash) Ryan was the inventor of and held the patent on the automatic retractable lap safety belt. Ralph Nader cited Ryan's work in Unsafe at Any Speed and in 1966, President Lyndon Johnso...

Locking retractors edit The purpose of locking retractors is to provide the seated occupant the convenience of some free movement of the upper torso within the compartment while providing a method of limiting this movement in the event of a crash. Starting in 1996, all passenger vehicle seatbelts must lock pre-crash meaning they have a locking mechanism in the retractor or in the latchplate. Seat belts are stowed on spring-loaded reels called "retractors" equipped with inertial locking mechanisms that stop the belt from extending off the reel during severe deceleration. There are two main types of inertial seat belt locks. A webbing-sensitive lock is based on a centrifugal clutch activated by the rapid acceleration of the strap (webbing) from the reel. The belt can be pulled from the reel only slowly and gradually, as when the occupant extends the belt to fasten it. A sudden rapid pull of the belt—as in a sudden braking or collision event—causes the reel to lock, restraining ...

Starting in 1971 and ending in 1972, the United States conducted a research project on seat belt effectiveness on a total of 40,000 vehicle occupants using car accident reports collected during that time. Of these 40,000 occupants, 18% were reported wearing lap belts, or two-point safety belts, 2% were reported wearing a three-point safety belt, and the remaining 80% were reported as wearing no safety belt. The results concluded that users of the two-point lap belt had a 73% lower fatality rate, a 53% lower serious injury rate, and a 38% lower injury rate than the occupants that were reported unrestrained. Similarly, users of the three-point safety belt had a 60% lower serious injury rate and a 41% lower rate of all other injuries. Out of the 2% described as wearing a three-point safety belt, no fatalities were reported. This study and others led to the Restraint Systems Evaluation Program (RSEP), started by the NHTSA in 1975 to increase the reliability and authenticity of past studies...

Research and development efforts are ongoing to improve the safety performance of vehicle seatbelts. Some experimental designs include: Criss-cross Experimental safety belt presented in the Volvo SCC. It forms a cross-brace across the chest. 3+2 Point Seatbelt : Experimental safety belt from Autoliv similar to the criss-cross. The 3+2 improves protection against rollovers and side impacts. Four point "belt and suspenders" : An experimental design from Ford where the "suspenders" are attached to the backrest, not to the frame of the car. 3 point Adjustable Seatbelt: Experimental safety belt from GWR Safety Systems that allowed the car Hiriko, designed by MIT, to fold without compromising the safety and comfort of the occupants.