Patent 7905767 was granted and assigned to Hilti on March, 2011 by the United States Patent and Trademark Office.
A motorized power tool includes an output shaft (11) including a tool receptacle (13) for receiving a disc-shaped tool (7) and having an outer thread with a constant outer diameter (D) and that forms a first securing element (14) for a locking element (8), a centering section (16) adjoining the tool receptacle (13) and extending beyond a radial projection of the tool receptacle, and a second securing element (15) provided at the free end (12) of the output shaft (11) for receiving an attachment element (9) for securing a shaft extension (21) to the output shaft (11).