Abstract: The invention relates to a device for affixing cutter drums on an apparatus designed to cut trenches in the ground.The driver includes a revolving plate 4 disposed perpendicular to its axis and to the end of the latter, the plate having on its periphery a convex polygonal shape 9. A cutter drum 8 is provided with a portion 8a including a central hollow of concave polygonal shape 10 corresponding to the convex polygonal shape 9 of the plate 4 and of slightly greater dimensions. Bolts 11 unite the cutter drum 8 to the said plate 4 such that the rotational driving of the cutter drum 8 by the plate is performed through the medium of the aforesaid polygonal surfaces 9, 10 which come into engagement with one another.

Abstract: A cutting machine for cutting trenches in the ground, including a flat bottom face portion for supporting a pair of motor blocks; two motor blocks, with parallel axes, adapted to mount half-drum cutters; each motor block comprising a central vertical keel projecting downwardly from a horizontal top plate; connection means securing each motor block top plate to said bottom face; the inner edge of each top plate being provided with a beveled surface; an abutment member having parallel beveled edges complementary in shape to the beveled edge of each top plate; means mounting said abutment member to the central portions of said bottom surface; locking means urging the beveled edge of each top plate against the beveled edges of said abutment member.

Abstract: A drilling machine for digging trenches in the ground of the type comprising at least one substantially vertical support plate (3) on which are mounted two drilling drums (2) one one each side of it for rotation about an axis (4) substantially perpendicular to the plate.The downwardly facing edge surfaces of said plate have portions (13) inclined relative to the direction perpendicular to said plate.

Abstract: Method of pouring a concrete wall panel directly in the ground, into which two concrete bars (1 and 2) are poured at an interval in such a way that the axis of the future wall will intersect their midpoint at a right angle, characterized by digging a trench extending through the bars, by positioning in the trench a reinforcement (13) with a transverse partition (9) generally along the axis of each bar, and by pouring a concrete panel in the trench between the two transverse partitions.