Air-powered driving tool, having a pilot piston and cylinder

摘要

An air-powered driving tool for returning the working piston to its driving position by way of an auxiliary piston and valve arrangement. After the fastener is driven, the auxiliary piston is operated to engage the working piston to move it to its driving position after which the auxiliary piston is moved to an inoperative position. A valve is operated to direct high-pressure air to the auxiliary piston to move it to a working piston engaging position and then the air is released to allow it to return to its inoperative position. Thus, there is no force opposing the working piston when the driving tool is operated to drive a fastener into a workpiece.