Patent attributes
A pneumatic tool (20) for impacting a workpiece (22) is provided. The tool (20) comprises a casing (42) defining a chamber (48). A piston (54) is slidable within the chamber (48) along an operational axis (A). An exhaust valve (100) controlled by a pilot valve (200) slides the piston (54) by selectively introducing and releasing pressurized fluid into and out from the chamber (48). The pilot valve (200) includes a valve housing (202) defining a pilot chamber (204) with a plunger (206) slidable in the pilot chamber (204). The pilot valve (200) actuates the tool (20) by quickly releasing pressurized fluid from the exhaust valve (100) to atmosphere. The pilot valve (200) includes a spring-biased annular seal (214) that is releasable from a poppet seat (222) to perform this function.