Hammer-tool, particularly for driving bolts and like fasteners

摘要

A pneumatic hammer-tool designed for driving fastener bolts, in which a piston within a cylinder is charged with compressed air and progressively accelerated in order to drive a fastener bolt, is constructed in such a way that the wall of the cylinder is interrupted by windows on the retracted side of the piston. The axial extension of the windows is less than that of the piston. The cylinder is surrounded by a housing which is connected to a compressed air supply. As the piston is advanced forwardly from its rest position it opens the windows in the cylinder in such a way that compressed air can flow into the cylinder from the surrounding housing and charge and accelerate the piston. In this way much greater kinetic energy is produced. Unintentional actuation of the hammer tool is safely and reliably prevented by a mechanical and a pneumatic safety device.