Opening formwork for forming cavity e.g. window, in cast concrete wall, has central core grid, and set of transverse crease lines that is formed in blank, where crease lines delimit plane segments which surround central core grid

摘要

The formwork (1) has a central core grid (3) that is formed of a set of central blades with a series of notches. The notches are arranged in a transverse manner with a regular pitch. The central blades are interdigitated to a level of the notches. A frame (2) is formed by a blank. A set of transverse crease lines is formed in the blank, where the crease lines delimit plane segments which surround the central core grid. The frame presents a set of side wings that is delimited by two of the transverse crease lines.