Method of treating a workpiece

An apparatus comprising:

• a brush rotatable in a direction about an axis and having a multiplicity of radially projecting bristles with tips engageable with a surface of a workpiece to be treated;
• a stop nonrotatable with the brush and in engagement with the bristles radially inward of the stop so as to rearwardly deflect the bristles prior to contact with the workpiece and thereby store kinetic energy in the bristles, whereby as the bristles pass the stop the kinetic energy is released and the bristles spring elastically forward and percussively strike the workpiece surface;
• and
• control means for determining a roughness of the workpiece offset downstream the direction from where the bristles strike the surface and positioning the stop radially relative to the axis or the brush relative to the workpiece at a spacing in accordance with the determined roughness to create a predetermined uniform roughness where the bristles strike the workpiece.

A method of treating a surface of a workpiece using a brush assembly, the method comprising the steps of:

• rotating in a direction about an axis a brush having a multiplicity of radially projecting bristles with tips engaging a surface of a workpiece to be treated;
• positioning a stop nonrotatable with the brush in engagement with the bristles radially inward of the axis of the stop so as to deflect the bristles rearward relative to the direction prior to contact with the workpiece and thereby store kinetic energy in the bristles, whereby as the bristles pass the stop the kinetic energy is released and the bristles spring elastically forward and percussively strike the workpiece surface;
• determining a roughness of the workpiece surface by scanning the surface downstream relative to where the bristles strike the surface in a contactless manner with a laser;
• and
• positioning the stop radially relative to the axis or the brush relative to the workpiece at a spacing in accordance with the determined roughness.