Device for creating ducts in cellar walls and foundations

摘要

In a device for creating ducts in cellar walls and foundations, for domestic connecting pipes to pass through, it is intended to achieve the object of creating a capability for producing ducts with smooth walls in a simple manner, in such a way that they can also be easily closed again. The invention achieves this object by the creation of a conical or truncated-pyramid-shaped body which is provided with a layer of plastic at least on one end side on the conical or pyramid-shaped surfaces. Such a body can easily be built into the cellar masonry and can also easily be cast into foundations. It is removed by its smaller end side being struck, as a result of which this body is knocked out of the cellar masonry or the cellar foundation. The truncated-cone or pyramid shape makes it very easy to knock the body out in this way. Since the plastic layer has smooth surfaces, in general the body moves after the first impact applied to it. If this impact detaches the plastic film from the body, the plastic film can easily be drawn out of the resulting duct. In this way, a duct of the desired shape is produced which has no irregular surfaces, into which, when the duct is subsequently closed, the material used can penetrate only with difficulty. In addition, all the surrounding stones remain firmly seated around the duct and are not loosened, as is otherwise the case when a duct is punched out.