A clamp apparatus includes a mounting base, a rotation actuator mounted to the mounting base, a beveled active gear driven by the rotation actuator, and at least two clamp jaws rotatably connected to the mounting base. Each clamp jaw includes a beveled driven gear engaging the beveled active gear of the clamp apparatus and a clamp body connected to the beveled driven gear. When the clamp jaws are rotated together with the beveled driven gear, the clamp bodies are moved toward or away from each other to clamp or release a workpiece, respectively.