Patent ID: 7198116

Claim:
A wholly air-controlled impact mechanism consisting of a pressure container containing a flying hammer and a pressure impulse generator, with a driving shaft and an anvil shaft penetrating said pressure container; said pressure container forming a high-pressure chamber with its volume unoccupied by said flying hammer and said pressure impulse generator and capable of withstanding the pressure variations of the controlling air and serving as a part of the controlling air flow path; said flying hammer comprising a flywheel characterized by two cavities which contain an eccentric pilot valve and an impact pin, and also characterized by seven air-passages to control the movement of said pilot valve and said impact pin; said pilot valve characterized by an annular plenum and four air-passages for switching controlling air directions; said impact pin imposing impact torque on said anvil shaft during stretching out and switching air-passages by the movement of its piston; said pressure impulse generator including a part integrated with and situated on the end surface of said anvil shaft and periodically interfering in the controlling air flow path and thus generating pressure impulses to affect the movement of said pilot valve with rotation of said flying hammer; said driving shaft, penetrating one end of said pressure container to drive said flying hammer into rotation, with an air-inlet bore along its axle for supplying fresh controlling air to said wholly air-controlled impact mechanism; said anvil shaft, penetrating another end of said pressure container to transmit impact torque, with an air-outlet bore along its axle for discharging exhausted controlling air into atmosphere.