u00b0 and the air permeability of the conveyor belt 20 is below about 10 000 m 3 m 2 h the amounts of air used with a belt 20 of the width of 200 mm are about 50 to 300 l min typically less than 400 l min i e about 2 000 l min width meter and pressures are used to pressures of up to about 2 bar the regulation angle u03b1 of the foil is about 1 to about 10 u00b0 preferably 1 to 5 u00b0 the radius of curvature of the guide plates 12 is about 300 to about 1000 mm preferably 400 to 600 mm in the embodiment example shown in fig3 a and 3b a nozzle 17 extending in the longitudinal direction of the conveyor belt 20 is attached to the device 35 in accordance with the invention from which nozzle blowings p 17 are blown in which connection a longitudinal vacuum effect is achieved which can be enhanced by means of curved guide plates 18 as fig3 a shows the foil ribs 15 can be turned from a cross direction to an oblique position and to a longitudinal position i e as far as the running direction of the belt as desired in order to produce a vacuum effect of a desired type fig4 shows that blowings p 20 can be directed from the foil rib 15 such that the lead in strip can be displaced in a lateral direction on the belt 20 fig5 to 7 schematically show some areas of application where the device 35 in accordance with the invention may be used in conveyance and guidance of a lead in strip the direction of running of the lead in.