Abstract: Power driving apparatus includes a body portion, a power supplying portion, an actuating portion, a drive portion, a biasing portion and a surface contacting portion. The body portion includes a vertically oriented elongated tubular section, the tubular section including a substantially open lower end. The power supplying portion includes a power source affixed to the body portion spaced from the open lower end thereof, the power source including an output shaft member disposed transversely of the body portion. The actuating portion includes a rotatable eccentric supported transversely axially within the body portion, the eccentric being spaced from the open lower body end substantially parallel to the output shaft member. An arm member has one end pivotally connected to the eccentric and extends therefrom downwardly toward the open lower body end. A weighted hammer section is supended from a lower free end of the arm member and disposed within the body portion.