coincides with the axle of the corresponding guide roller 1 as shown in fig4 referring to fig1 and 2 rigid support members 10 support platforms 11 on which the motors 4 are mounted and are fixed to supports 8 thus the spacing between the grinding cylinders 3 and platforms 10 is fixed during operation and both are simultaneously adjustable in elevation on both sides of the supports 8 opposite arms 9 sectors 12 are fixed sectors 12 are toothed and these teeth mesh with pinions 13 of complementary axles 14 one side of each axle 14 projects from structure a and carries a sprocket 15 which meshes with an endless thread 16 which is controlled by a handwheel 17 each grinding cylinder includes the latter subassembly to vary the height of cylinders 3 individually with reference to the guide rollers 2 and with such height variations the pressure on the fabric being treated and the contact angle of same on cylinders 3 may also be varied the ends of the complementary axles 14 have respective gauges mounted thereon that register the angular displacement of the corresponding quadrants 18 and may be scaled at 19 to read in contact angle or pressure or both the ends of the axles of the grinding cylinders 3 opposite the pulley assemblies 6 each include a shaft extension 20 with an endless thread 21 thread 21 meshes with a gear 22 as shown in fig3 each gear 22 is eccentrically pinned at 23 to the end of rod arm 24 the opposite end of which is at the same time pinned to a point 25 on support 8 the thread 21 and the gear 22 are housed within a housing 26 mounted on bearings 27 through.