<P> A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles . Originally called a laminated or carriage spring, and sometimes referred to as a semi-elliptical spring or cart spring, it is one of the oldest forms of springing, appearing on carriages in England after 1750 and from there migrating to France and Germany . </P> <P> A leaf spring takes the form of a slender arc - shaped length of spring steel of rectangular cross-section . In the most common configuration, the center of the arc provides location for the axle, while loops formed at either end provide for attaching to the vehicle chassis . For very heavy vehicles, a leaf spring can be made from several leaves stacked on top of each other in several layers, often with progressively shorter leaves . Leaf springs can serve locating and to some extent damping as well as springing functions . While the interleaf friction provides a damping action, it is not well controlled and results in stiction in the motion of the suspension . For this reason, some manufacturers have used mono - leaf springs . </P>

What is the purpose of a leaf spring