A shock absorber is a device used to smooth jolts or shocks and to disperse kinetic energy. Shock absorbers are crucial in motorcycle and automobile suspension, in landing gear for aircraft and as part of the support systems for industrial machines. A large version of the shock absorber is sometimes used in structural engineering to add stability and lessen damage from earthquakes and other disasters. The shock absorber is usually a cylinder that contains a sliding piston that is cushioned by hydraulic fluid or air.
In 1898, French cyclist J. M. M. Truffault introduced the very first shock absorber on his bicycle. It consisted of front fork suspension with springs and a device that minimized vibrations. The next year, Truffault and American auto enthusiast Edward Harford collaborated on the first adjustable shock absorber. In 1901, M. A. Yeakley built on their efforts with an early independent suspension design in which each wheel was supported independently.
In 1901, C. L. Horock created the first modernized shock absorber and called it the “telescopic shock absorber.” Shock absorbers manufactured today are still based on his initial concept. The next year, hydraulic shock absorbers began to attract the attention of automobile racers, race car builders and mechanics. During the 1902 and 1903 racing seasons, hydraulic suspension was widely used. A number of basic advancements were made to shock absorbers over the next few years, but they were still not widely used. In 1908, Ford launched the Model T with a hybrid suspension system that was made up of traditional leaf suspension combined with two springs mounted on the axles. Later that same year, Frenchman M. Houdaille created the first hydraulic shock absorber that had any real reliability.
From 1909 through the 1920s, there were very advances, despite ongoing work with the new friction systems. In 1932 Packard introduced a shock absorber that could be adjusted by the driver. This was followed closely by Firestone’s experimental car, the Stout-Scarab, which used a pneumatic suspension system of four rubber bellows instead of traditional springs. Air for the system was delivered by compressors that were attached to each bellow.
Over the next 50 years, new systems appeared, like Monroe’s hydraulic shocks, Earl S. MacPherson’s strut suspension and an independent coil system used by General Motors, Hudson Motors and Chrysler. Gradually, most car manufacturers began to rely on hydraulic systems and telescopic shock absorbers. In 1982, the active suspension system was patented, and in 1985, Nissan launched electronically adjustable shock absorbers that automatically responded to speed, driving style and road conditions.