The invention relates to a film-drawing machine, including a furnace, through which one strand of an endless chain of clamps passes, driven by at least one toothed wheel, characterised in that at least one toothed wheel is inside the furnace, is rotated by its own gear motor surrounded by a casing, placed in the furnace and cooled by cooling means, and is mounted on its own movement device, so as to pass from a withdrawn position, in which it does not mesh with the chain, to a drive position, in which it meshes with the chain. The invention also relates to a method for starting said film-drawing machine.