A reversible impact-operated pneumatic boring tool for reversing the direction of operation of the tool is disclosed. The tool includes two fluid supply lines, a striker and a non-mechanically biased directional control sleeve. The primary fluid supply line provides pressurized fluid for striker reciprocation...http://www.google.com/patents/US6467554?utm_source=gb-gplus-sharePatent US6467554 - Quick reverse mechanism for pneumatic boring tool
