Jackhammer

Pneumatic tool

A jackhammer (pneumatic drill, breaker, demolition hammer or road hammer in Commonwealth English) is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William McReavy, who then sold the patent to Charles Brady King. Hand-held jackhammers are generally powered by compressed air, but some are also powered by electric motors.

From Wikipedia, under CC BY-SA. More on occurri.