securingly holding the cops 14 for the tubes 13 which have a substantially lower weight simple arbors 12 are considered to be adequate however as already noted the embodiment of the arbors 11 and 12 is equivalent to their usual embodiment because they can be re used when the transport system is refitted according to the invention as also seen in fig2 a guide track 49 provides exact guidance of the caddies 10 and in particular their base plates 10 39 the guide track 49 extends along the conveyor belts 3 this guide track 49 has an essentially rectangular channel cross section which is open at the top and on the bottom has a groove 49 39 the opening 49 34 on the top serves to allow the passage of the arbors 11 and 12 of the caddies 10 while the groove 49 39 is required for the free passage of the heads of the screws 44 the cover plate of the guide track 49 interrupted by the opening or slit 49 34 serves essentially to prevent tilting of the caddies 10 the parts of the guide track 49 disposed on the underside on either side of the groove 49 39 serve as a bearing surface for the conveyor belt 3 the conveyor belt 3 is deflected by a deflection roller 46 that is driven by a motor 15 fig1 via a drive shaft 47 analogously to the guide track 49 the deflection roller 46 has a groove 48 which permits the free passage of the heads of the screws.