Apparatus for removing material from a roll of a fiber processing machine

In a fiber processing machine including

• a clothed roll having a direction of rotation and entraining fiber material thereon;
• a roll cover circumferentially partially surrounding said roll and defining an annular clearance therewith;
• a transfer opening provided in said roll cover for admitting fiber material to said roll;
• a waste discharge opening provided in said roll cover for removing waste from said clearance;
• a fiber removal opening provided in said roll cover downstream of said waste discharge opening as viewed in said direction of rotation;
• and
• first means for generating an air stream for doffing fiber material from said roll and for discharging doffed fiber material through said fiber removal opening;
• the improvement comprising:
• (a) second means for varying a strength of said air stream at said fiber removal opening;
• and
• (b) third means for varying the extent of waste removal through said waste discharge opening.