A
volute spring is a type of compression spring designed so that when the
spring is compressed, some coils slide inside other coils, providing a large
range of motion. Most people are familiar with a coil spring. Shaped like
cylinder-- or more properly a
helix-- coil springs are probably the most common spring used today. Used in most automobile suspension systems, a coil can compress only until the coils are forced together. A volute spring is shaped like a
cone, with the word coming from the Latin word for
scroll. When compressed a volute spring coils around itself allowing for much greater compression. Volute springs are chosen when a very long
travel is needed. For example, volute springs are common in most
shears and
clippers. Volute springs were also chosen for the
suspension system of most U.S.
armored vehicles designed until the middle of
World War II, including the
M4 Sherman Tank.