Patent attributes
A tool holder (1) for a rotary hammer which has a tube like tool holder main body (10) having a side wall formed with through holes (11) for receiving corresponding locking bodies (12) and formed with additional through holes (40). The tool holder includes hardened metal driving ribs (46) each located on an insert (42) and the inserts are fitted within the additional through holes (40) so that the ribs extends axially and radially inwardly of the radially inward facing surface of the holder body. The locking bodies (12) are arranged to releaseably engage a corresponding axial closed groove of a tool or bit inserted within the tool holder and the ribs (46) are arranged to releaseably engaging a corresponding axial rearwardly open driving grooves of a tool or bit inserted within the tool holder. To simplify the process for forming the tool holder body (10) each additional through hole (40) is formed by at least two overlapping axially offset circular cross-sectioned through holes (40a, 40b) and the corresponding insert has a base (44) shaped to fit the through hole (40).
