be geared motors with an epicyclic reduction gear and a shaft brake with a considerable reduction ratio or the servo motor 21 can be a spindle motor which drives or holds the shaft extension 20 stationary via a toothed rack and a gear wheel fitted on the shaft extension 20 suitable servo motors are usually geared motors with high gear ratios which have an additional brake in order to hold the driven shaft in a specified position this rotation in the direction of rotation 17 makes it possible to alter the type or size of clothing presented on the carding element 3 additionally the possibility exists for maintaining an unequal clearance between the clothing elements 14 1 to 14 4 and the clothing 12 at the inlet and outlet in the direction of rotation of the roller 1 this means that the clearance a fig1 can be different from the clearance b and the difference between these two clearances can be different from case to case and may be determined empirically similarly with regard to the selection of the clothing to be used to meet particular requirements the partnership between the clothing 12 and the different clothing elements 14 1 to 14 4 as well as the size of.