A slab handling apparatus comprising a foundation structure, a plurality of longitudinally spaced buffer members positioned on the foundation structure, and a plurality of longitudinally spaced roller assemblies connected to the respective buffer members with a lost motion connection. The one-way clutch is mounted on one end of a crankshaft, and a sensor of the ignition signal detecting device is positioned radially outside a cylindrical outer wall of a clutch outer component of the one-way clutch. A buried gate electrode is formed at a lower portion of the trench.