Gripper portal crane

The utility model provides a grab bucket portal crane which comprises a portal frame, a hoisting trolley arranged on the portal frame and a winding drum set arranged on the hoisting trolley, the winding drum set and a grab bucket are connected through a steel wire rope, the winding drum set comprises a main winding drum and an auxiliary winding drum, and the grab bucket comprises two symmetrically-arranged bucket-shaped jaw plates; a hinged connecting rod is arranged at the upper part of the bucket-shaped jaw plate; a hinged connecting plate is arranged in the middle of the bucket-shaped jaw plate; the upper ends of the hinged connecting rods are hinged with the upper cross beam; the hinge connecting plate is hinged with the lower cross beam; the upper cross beam comprises a fixed outer frame and a rotating inner frame which are rotationally connected; the lower cross beam comprises a fixed seat and a rotating seat which are rotationally connected; a regulating pulley block is arranged on the upper side of th