Shrinking core for mold during production of hollow bodies of concrete, has core casing whose opposite longitudinal edge portions is connected with partially elastomeric connecting web in spread position at shear-resistant manner

摘要

The core has a core casing (1) whose opposite longitudinal edge portions (2) are provided with an expanding device (4). The expanding device is acted upon a closure. The opposite longitudinal edge portions of the core casing are connected with a partially elastomeric connecting web (7) in spread position in shear-resistant manner. The connecting web on wedge surfaces is engaged with the opposite longitudinal edges of the core casing. A wedge mechanism (10) adjusts the longitudinal edge portions.