Patent ID: 8187058

Claim:
A power-driven hand tool comprising: a hollow drive spindle for driving a tool, said drive spindle being configured to move oscillatingly about a longitudinal axis thereof; a split chuck for fixing said tool on a retaining section of said drive spindle, said split chuck being configured for engaging a mounting opening of said tool in a form-locking way and for engaging an inner surface of said drive spindle in a form-locking way; a securing element comprising a clamping shaft configured for insertion through said split chuck into said drive spindle; a displacing assembly for displacing said securing element between a releasing position in which said securing element and said split chuck are free to be released from said drive spindle, and between a clamping position in which said securing element extends through said split chuck and is axially fixed within said drive spindle, said split chuck clamping against said retaining section of said drive spindle for securing said tool therebetween; a spring element biasing said displacing assembly into said clamping position; and a lock assembly received inside said drive spindle between said displacing assembly and said split chuck for locking said clamping shaft against retraction in said clamping position and for releasing said clamping shaft allowing retraction from said drive spindle in said releasing position; wherein said lock assembly further comprises a sleeve and a plurality of clamping pieces held by said sleeve radially displaceably against said clamping shaft and axially displaceably within said drive spindle; wherein said split chuck is releasable from said drive spindle together with said securing element when being in said releasing position.