Concrete breaker with protective cover

A concrete breaker comprising:

• a lower jaw tiltably pin-connected to a front end of a swing arm extending from a working machine, a plurality of lower cutting blades disposed at intervals and projecting from an upper side of a front end portion of said lower jaw,
• an upper jaw pivotably pin-connected to said lower jaw such that a lower side of a front end portion of said upper jaw opposes said upper side of said lower jaw, said upper jaw having a plurality of upper cutting blades disposed at intervals and projecting from the lower side of the front end portion of said upper jaw,
• a hydraulic cylinder comprising a cylinder body connected to a rear end portion of the lower jaw and a piston rod extending from the cylinder body, said piston rod connected at its front end to the upper jaw, an advance and retracting movement of said piston rod pivotably driving said front end portion of said upper jaw toward and away from said front end portion of said lower jaw for closing and opening movement, respectively,
• a protective cover with a link wherein said link has two ends and is pin-connected at one end to the lower jaw and at the other end to a rear end of said protective cover, a front end of said protective cover being pin-connected to the upper jaw such that the protective cover extends along an outer side of the piston rod, said protective cover being swung in conjunction with the upper jaw in the opening and closing direction of the upper jaw at a position where it always covers the outer side of the piston rod.