Date:2015-12-8   8:30

As the development of drifters and the increase of long-hole drilling projects, people noticed high impact energy consumption at the connection of drill rods in the long-hole drilling projects and proposed to deliver drifters to the bottom of holes for drilling. American Ingersoll Land Industrial Technologies Company firstly got the patent in 1932, but the technique was not used in mines until the end of 1940s because of limitations. A DTH hammer which structure is really similar to modern DTH hammers was designed and manufactured in 1951 by Belgian engineer Andrea, not only reducing energy transmission loss, but also reducing noise level. After that, DTH drills were constantly improved and applied in underground mining and open mining. The air pressure is increased from 0.5~0.6MPa to 1.4~1.75MPa at the beginning of 1970s，and to 2.1~2.46MPa at the end of 1970s.