This invention provides a highly breaking efficient, small-sized light-weight concrete breaker designed to break concrete into fine pieces of ballast size.
It comprises a lower jaw 4 tiltably connected to the front end of a swing arm 3, an upper jaw 6 openably and closably connected to the lower jaw 4, a hydraulic cylinder 8 interposed between the upper and lower jaws to open and close the jaws, and a protective cover 11 connected to the lower jaw 4 by a link 12 and to the upper jaw 6 by a pin and adapted to follow the opening and closing movement of the upper jaw 6 while covering the piston rod 10 of the hydraulic cylinder 8. A plurality of straight lower cutting blades formed on the upper surface of the front end of the lower jaw 4 and a plurality of pointed upper cutting blades 7 are formed on the lower surface of the front end of the upper jaw 6. These upper and lower cutting blades are disposed to mesh with each other in zigzags as viewed from the side. When the upper and lower jaws are closed, concrete is finely broken in the clearances G between the upper and lower cutting blades.