Types of spring elements of the suspension. The following spring elements are used for the suspension of modern cars: - metal spring connectors: leaf springs, coil springs and torsion bars, - rubber spring elements (rubber cushions), - pneumatic: spring couplings (air-filled rubber cushions). In trucks, leaf springs are the most frequently used spring elements. Leaf springs consist of a plurality of leaves (steel flat bars) of various lengths and curves. All feathers are held together by a pin, also called a lead screw. In addition, they are tightened with clamps (ferrules), which prevent the feathers from moving sideways, without, however, hindering their sliding along one, the second when bending and straightening the spring. The longest feather, usually the thickest, is called main. The feather has ear-shaped ends at both ends, in which the bearing sleeves are pressed. Under the action of the car's weight, the bent pen straightens and by pressing on the pen lying underneath it also tries to straighten it. The deflection of the leaves also reduces the friction force between the individual leaves when the load changes while driving.