Pneumatic hammer

摘要

A hand held impact tool is disclosed which employs an impact piston reciprocated by means of fluid pressure to impact a working tool. Fluid pressure is continually supplied to a pressure chamber forwardly of the impact piston such that a fluid cushion is established between the forward end of the piston and a piston stop surface resulting in substantial noise reduction. The working tool is biased outwardly of the tool housing by fluid pressure such that the working tool must be placed against an external object and moved axially inwardly to effect impact with the piston, whereby accidental ejection or unintentional operating movement of the working tool is prevented.