| 摘要 |
An impact device using a gas as its medium is formed of an air pump and an impact cylinder. The air pump and the impact cylinder are respectively divided by a pump piston and a hammer piston into upper and lower chambers which intercommunicate upper with upper and lower with lower through valves which regulate the flow of high and negative pressure gas causing the downward impact stroke of the hammer piston onto the tool at the lower end of the impact cylinder and the downward stroke of the pump piston to begin simultaneously after the pump piston has reached its top dead point compressing the air in the upper chamber to the maximum and generating the maximum negative pressure in the lower chamber. There are further provided means for communicating the upper and lower chambers of the pump cylinder when the pump piston has reached the lower dead point and means for communicating the upper chamber of the impact cylinder with the means for connecting the lower chambers of the two cylinders. |
