| 摘要 |
The procedure and arrangement according to the invention are mainly characterized by the fact that the frames are built up of a moulding (1) which has, on the rear of the frame, at least one groove or tongue in the longitudinal direction and by the fact that the angle unit (2) has at least one corresponding tongue or groove respectively for these and that the frame is jointed by pressing home the angle units (2) from the rear of the frame in each comer of the frame, whereupon the angle units (2) lock the adjacent moulding ends together at right angles with the aid of a tongue-and-groove joint. The angle unit according to the invention is mainly characterized by the fact that it consists of a stiffening plate (5) or the equivalent with at least two straight edges at right angles to each other and at least one tongue (6) along these edges in all essentials at right angles to the plane determined by the stiffening plate (5). |
