Jackhammer with striker action - uses adjustable ratchets on spindle for striker control and locking

摘要

The jackhammer has a free moving striker acting directly or indirectly on the tool steel in response to a medium controlled by a drive to provide two way striker movement. A twist sleeve rotates the spindle. The ratchet wheel associated with the spindle adjusts axially via a sleeve and relatively free bush and engages a fixed counterpart ratchet mounted on the spindle itself. When engaged, the ratchet wheels form an axial end-stop which de-activates the striker. The movable ratchet disc is self-locking in the setting for percussive drilling.