Hammer drill

摘要

A hammer drill has a movable tool and a driving element substantially coaxial with the tool. The driving element directly transmits axial impact from the same to the tool without transmission of torque. A tool holder surrounds proximal end portions of the driving element and the tool and transmits torque from the former to the latter without transmission of axial impact. Drive means are provided for selectively imparting torque and/or axial impact to the driving element. The tool holder comprises a sleeve which surrounds the proximal end portions. The sleeve is axially movable relative to the driving element and the tool and, at the same time, are connected with them for joint rotation therewith. An additional sleeve is provided surrounding the sleeve and enabling an operator to hold and to guide the hammer drill.