Image Number 3 for United States Patent #5931235.
A cutter head for retrieving earth samples, in particular for taking underwater samples, has, because of frustum-shaped cutting wheels, an approximately round bore cross section. In an associated boring jig, a tube with a cross section corresponding approximately to the bore cross section is placed above the cutter head. With a regrasping system, the tube can be moved vertically relative to a work table lying on the bore surface. The boring jig may be lowered from a ship to the sea bottom to conduct the boring process.