Abstract: In an apparatus for the production of articles from a planar web of thermoplastic material, having heating, hot shaping and punching devices, a web conveying mechanism for stepwisely transporting the web along the substantially planar path through the apparatus includes a plurality of driven stationary conveying units arranged at opposite edges of the web along the path thereof, each conveying unit including a driving wheel and a cooperating free wheeling supporting roller arranged opposite to each other and having their axes of rotation extending substantially parallel to each other and to the plane of the web, the driving wheel having a wedge-like converging circumference with a toothed circumferential edge and connected to a driving mechanism which synchronously drives the driving wheels, and the free wheeling supporting roller having a cylindrical circumference supporting the web in an adjustable position relative to the driving wheel, such that the toothed circumferential edge partly penetrates the web a