Explosive powder charge actuated fastening element driving device

Abstract

An explosive powder charge actuated fastening element driving device includes a driving piston mounted within a guide bore in an axially extending piston guide for displacement between a firing position and a driving position where the fastening element is driven into a receiving material. After driving a fastening element, the driving piston is returned toward the firing position by exhaust gases generated when a charge is fired. A channel laterally encloses the piston guide with a first and a second aperture, spaced apart in the axial direction, extending through the piston guide communicating between the guide bore and the channel. A blocking slide movable relative to the piston guide is located within the channel. The exhaust gases can flow through the first aperture into the channel and, when the blocking slide is displaced relative to the piston guide, entrapped in a storage space within the channel so that the exhaust gases flow through the second aperture into the guide bore and return the driving piston toward the firing position.