Jackhammer
A pneumatic hammer ( colloquially jackhammer, called Ruhr mining also "Boxer ") is a mobile machine, in which a piston driven by air a pulse on a tool, the chisel, transfers. The compressed air generated by a motor-driven compressor and fed to the hammer via a connecting hose. Pneumatic hammers are available in different designs, from one-handed lightweight device over heavy, two-handed guided equipment to devices that are attached to excavators.
In addition to pneumatic hammers there are also electric and gasoline-powered breakers.
Function
If the compressor is started, the compressed air flows through the rugged hose for pneumatic hammers. Here, the hammer is set in motion via a hand operated valve. The compressed air flows in operation through a valve mechanism in the working cylinder of the device. A piston is accelerated by the air flowing in the direction of the chisel point where it meets a striking piece. Due to the rapid deceleration of the pulse is transmitted. The impact energy passes through the hammer on the chisel. The return of the piston is controlled by air or a return spring to the starting position. The combination of high pulse, small chisel tip and the two-handed application of the tool results in an enormous power that makes the jackhammer about the road ( breaking up of existing roads ) or the demolition of buildings has become an indispensable tool.
Health effects
By pneumatic hammers in the body initiated vibrations can lead to an occupational disease ( vibration-induced vasospastisches syndrome). Also, does the air that escapes from the hammer rhythmically, this tool is one of the loudest in the construction and civil engineering. Several manufacturers offer both a vibration and a noise attenuation. Nevertheless, you should be sure to use ear protection and safety glasses. Especially when chiselling of concrete fragments may meet the eye.
Development
First jackhammers were there in mining and foundry technology, where already compressed air was available, example Hammers. During construction of the Mont Cenis tunnel in Europe (1857-1870) operated by compressed air hammer drills were used for the first time. The drill was a development of Germain Sommeiller, an Italian engineer. Several rotary hammers have been as common practice later, mounted in parallel on a drill mast mounted on a track. Compared to the previously applied by hand percussion drilling the holes for receiving the explosives could thus be produced in a fraction of the time.
Similar drills in 1866 was used in the construction of the Hoosac Tunnel in the United States. The model used there were initially very susceptible to interference. Thus while in 4 months from tunneling over 1000 devices. To use 5-6 hammering at the same time, 40 units were needed. The price of $ 400 for a hammer was huge (a good revolver cost under $ 10). The situation has been improved by a new, enhanced model, which was launched on October 31, 1866 on the market. For a given power, the failure rate was significantly lower. Thus, only 2 to 3 machines have been required to ensure continuous use of a hammer.
Another patent for jackhammers in 1904 granted the company Herner Flottmann. The Flottmann rotary hammers were first introduced in the mining industry of the Ruhr used and increased the capacity of the miners - compared with the conventional technique with a hammer and chisel and pickaxe - enormous.
With the development of mobile compressors themselves conquered the pneumatic hammer numerous other applications, especially in construction. The further development of these tools aimed always aim to reduce the burden on people and the environment. Measures were: weight reduction and noise and vibration damping. A variant of pneumatic hammers is the hydraulic hammer. Here, hydraulic oil is used as the carrier medium for energy rather than compressed air.
Others
In the same engineering pneumatic hammers were also used as riveting, as was still warm in the riveted steel and shipbuilding. These hammers were fitted instead of a chisel with the riveting tool.
The pneumatic hammer should not be confused with an air hammer or a vibratory tamper.
Following the same principle as an air hammer pneumatic Adler works.