| 摘要 |
<p>A safety system for preventing serious accidents, which system is associated with a pneumatic hammering tool for fitting a fastener. Particularly, this system completely eliminates serious accidents resulting in injury or death which can at the moment when the pneumatic hammering tool is connected to a compressed air source, and possesses a safety valve (25) arranged between a first control air passage (12) communicating with a control chamber (11) formed at the upper side of a head valve piston (10) and a second control air passage (14) communicating with a trigger valve (15). The safety valve (25) interrupts the communication between the passage (12) and the passage (14) in its operating state and communicates the passage (12) with a compressed air storage chamber (7), and vice versa in its non-operating state. The system is so constructed as to automatically operate when the hammering tool is disconnected from the compressed air source. Thus, the fastener fitting work cannot be conducted unless the safety valve (25) is manually switched to its non-operating state. </p> |
