Air pressure reused pneumatic hammer drill

An air pressure reused pneumatic hammer drill, comprising:

• a rotary driven head which is driven to rotate by an external force and run through by a second stone and air discharge duct and includes an air intake duct;
• a housing which encases the rotary driven head and includes an air inlet communicating with the air intake duct, a transitional space formed therein and communicating with the second stone and air discharge duct, and a stone and air discharge outlet communicating with the transitional space;
• and
• a ground entry and operation unit which is driven by the rotary driven head and includes a guide duct communicating with the air intake duct, a pneumatic hammer duct which communicates with the guide duct and holds a hollow pneumatic hammer piston and a drill partly extended outside thereof to receive striking of the pneumatic hammer piston, an integrated hood which includes an air cycling chamber and is fastened to the pneumatic hammer duct and communicates therewith, a stone discharge duct which is fastened to the integrated hood and juxtaposed with the pneumatic hammer duct and includes a discharge stone inlet at a lower side leading to the exterior and a first stone and air discharge duct at an upper side communicating therewith and communicating with the second stone and air discharge duct, a discharge air inlet running through the integrated hood and communicating with the air cycling chamber, and an air discharge duct communicating with the discharge air inlet and the first stone and air discharge duct, the discharge air inlet and the air discharge duct being interposed by a check valve.