with the support arm of the upper left hand support roller 25 is provided with such a mechanical coupling a common control drive for all four support rollers is produced the equidistance of which from an imaginary geometrical roll axis is ensured this roll axis is fixed in relation to the support frame 29 and coincides co axially with the axis of a roll 4 or 5 independently of the diameter thereof as soon as the four support rollers rest on the roll surface a similarly acting coupling of the two scissors like supports may be obtained by hydraulic or pneumatic coupling members by way of the two pusher motors 31 also the use of equivalent electrical coupling members is possible in the given context and similarly to that of hydraulic or pneumatic coupling members is advantageous in particular when only one single carrying scissors bearing is to be coupled to an oppositely disposed support roller and the position of the scissors like support is to be controlled dependently on the position of the oppositely disposed roller in this last mentioned case the auxiliary support comprises a group of three rollers the equidistance of which from an imaginary geometrical roll axis is.