Brush for cleaning bottom of blind hole, has sheath with relief, movable along rod between protecting position and withdrawal position such that sheath is cooperated with edge of blind hole during insertion of bristles in blind hole

摘要

The brush has a rod (12) carrying a bundle of bristles at its head. A sheath (16) is movable along the rod between a protecting position in which the sheath surrounds an end part of the bristles and a withdrawal position in which the end part of the bristles projects from the sheath. The sheath has a projecting relief placed on its axial surface, where the sheath has a free end portion with diametrical dimensions that are lower than diametrical dimensions of a rear portion. The sheath is cooperated with an edge (20B) of a blind hole (20) during the insertion of the bristles in the hole.