MacPherson strut

The MacPherson strut is a type of car suspension system which uses the top of a telescopic damper as the upper steering pivot. It is widely used in the front suspension of modern vehicles and is named for Earle S. MacPherson, who developed the design.

History

Earle S. MacPherson was appointed the chief engineer of Chevrolet's Light Car project in 1945, to develop new smaller cars for the immediate post-war market. This gave rise to the Chevrolet Cadet. By 1946 three prototypes of the Cadet design had been produced. These incorporated the first MacPherson struts, giving independent suspension both front and rear. The Cadet project was cancelled in 1947 and the disgruntled MacPherson was enticed away to Ford. Patents were filed in both 1947 for GM and 1949 for Ford, the 1949 patent citing designs by Guido Fornaca of FIAT in the mid-1920s. The strut suspension of the pre-war Stout Scarab would also have been a likely influence and like Stout's own influences, the widespread use of long-travel struts in aircraft landing gear was well known by this time. It is possible that MacPherson was inspired by the suspension on the French Cottin-Desgouttes that used the same design, but with leaf springs. Cottin-Desgouttes front suspension was in turn inspired by J. Walter Christie's 1904 design and he was inspired by plants.