Abstract: Stamping of a layer (2) of package material, such as cardboard or plastics, for forming one or more bending edges may take place according to the invention by a method wherein a stamping tool (8), which is provided with preferably three ribs (9a, b, c), is pressed down into the layer (2) and thereby forms slots (11a, b, c) in the bending edge in one working cycle. The stamping may take place very precisely, and since the stamping is carried out in one working cycle, an uprecedentedly high production rate may be achieved. Since the stamping tool does not need a lower tool part, but merely a support (10), the stamping may be performed simultaneously with the punching in one and the same working cycle.

Abstract: The ground covering structure comprises a porous and resilient underlayer made of synthetic material forming open meshes or alveoles and which is anchored to the ground, and water-pervious vault forming elements having holes or slots through which water may flow, also made of synthetic material, with the formed vaults having a concavity turned towards the ground. The elements include means for their connection with the underlayer on which they are applied and having a top provided with shags or filaments having free ends, with the free ends of said shags or filaments all ending substantially in the same plane.