The leaf spring allows a relatively simple and reasonable wheel suspension in spite of a large ratio of sprung to non-sprung masses. It is used for truck and occasionally for simpler cross-country vehicles. But this is already often equipped with air suspension. Figure 2 allows an insight into the manufacturing process. After the roller, the spring steel must be hardened before it is assembled and brought in shape. Several layers are connected at their ends with the frame and in the middle with the axis. For safety reasons the second layer is extended towards the mounting points (see figure 1).

Due to the several layers a desired self damping evolves through friction, which in earlier times made dampers obsolete. Without elastic layers in between, the springs must be lubricated regularly. Because engaging the springs changes the length, it is necessary to have accordingly flexible mounting points. Vehicles with large pay loads (figure 1) in proportion to their tare weight need a relatively soft spring suspension without and a hard spring suspension with load. This is possible with a progressive or bended spring characteristic. For this leaf springs with extra layers are necessary, whose spring tension starts later during the engagement process. In figure 3 the second spring leaf from below is heavier than the rest. If the spring is bent further than the middle, this spring leaf increases the effect. 07/12

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