Impact wrench

摘要

An impact wrench comprising a drive shaft, an anvil with impact cams, a striker having a flywheel mass connected to the drive shaft and impact cams connected to the flywheel mass so as to rotate therewith and move axially in relation thereto. The impact wrench includes a device designed for preventing the striker impact cams from interaction with the anvil impact cams until the striker attains a pre-set rotational speed. According to the invention, the flywheel mass and the anvil are immobile axially, whereas the striker impact cams are adapted to move axially in relation to the striker flywheel mass during striker acceleration. The device for preventing interaction of the striker and anvil impact cams is made in the form of a movable abutment arranged to limit the axial movement of the striker impact cams and located between the striker impact cams and the anvil impact cams in such a manner that during acceleration of the striker flywheel mass the abutment is in engagement with the striker impact cams and moves therewith, limiting their axial movement and preventing them from interaction with the anvil impact cams, and disengages from the striker impact cams for said cams to move further and interact with the anvil impact cams after the abutment interacts with the anvil.