PURPOSE: To prevent a rotary brush from being locked due to entangling of waste thread by a method wherein a thin wall cylindrical part having an outer diameter a little smaller than the rotation locus of a trash scraper is provided on one end of a brush roller, and a large diameter cylindrical part which is loosely fitted in the thin wall cylindrical part is assembled into one piece with a bearing part.

CONSTITUTION: When a motor 40 is put into operation and its rotation is transmitted to a spindle connecting member 28 via a belt 41, a brush roller 26 is revolved at a high speed and blades 34 of the brush roller 26 scrape up trash attached on a carpet, etc. A large diameter cylindrical part 37 provided on a bearing member 31 has a diameter d1 relatively near the rotation locus of the blades 34 as trash scraping members, so that relatively short waste thread is hard to entangle around a bearing member 31 and is prevented from intruding into a clearance 42 between the large diameter cylindrical part 37 and a thin wall cylindrical part 35. As the diameters of a flange 36 and the large diameter cylindrical part 37 are near the diameter of the rotation locus of the blades 34, trash is hard to enter the clearance 42 even when it entangles around the bearing member 31.