| 摘要 |
The invention concerns a drill for making holes in plasterboard of the type used, for example, in girder walls, which plasterboard consists of a gypsum layer, which is clad on both sides with strong paper or cardboard. When placing through holes in such plasterboard, the inner edges of the hole are usually damaged, making it impossible to use the fastening devices specially developed for mounting in plasterboard. With the drill according to the invention, it is possible to make holes which do not damage the inner edges of the hole, in that the hole is first widened and/or cut clean by removing the drill from the borehole. <IMAGE> |
