Patent ID: 7918354

Claim:
A container crane for hoisting two 40 feet containers at a time, comprising: a first hoisting device having a first head block, a first spreader, a first winding barrel, a first hoisting mechanism motor, a first brake, a first hoisting reduction gear box, a first head block pulley group including at least two first head block pulleys and a first hoisting pulley group including at least two first hoisting pulleys, wherein the first hoisting pulley group is arranged on a trolley, and the first head block pulley group is arranged on the first head block; a second hoisting device having a second head block, a second spreader, a second winding barrel, a second hoisting mechanism motor, a second brake, a second hoisting reduction gear box, a second head block pulley group including at least two second head block pulleys and a second hoisting pulley group including at least two second head block pulleys, wherein the second hoisting pulley group is arranged on the trolley and the second head block pulley group is arranged on the second head block; a connection cylinder for bringing together and separating the first head block and the first spreader mounted thereon and the second head block and the first spreader mounted thereon in a direction perpendicular to length of the containers; and one wire rope winding system, for connecting the first hosting device and the second hoisting device through a first hoisting wire rope and a second hoisting wire rope, wherein the first hoisting device and the second hoisting device work simultaneously; wherein the first hoisting wire rope unwinds from the first winding barrel, turns around a first end pulley, winds the first hoisting pulley group on the trolley, reaches and winds the first head block pulley group and retraces to the first hoisting pulley group, and reaches one end of a main front girder of the container crane and connects to a first turning device, wherein the first turning device comprises a first plurality of pulleys; the second hoisting wire rope unwinds from the second winding barrel, turns around a second end pulley, winds the second hoisting pulley group on the trolley, reaches and winds the second head block pulley group and retraces to the second hoisting pulley group, reaches a second end of the main front girder of the container crane and connects to a second turning device, wherein the second turning device comprises a second plurality of pulleys; and wherein if a weight of two 40 feet container exceeds a predetermined weight, one of the first hoisting device or the second hoisting device are lifted and fixed, and only one of the first hoisting device or the second hoisting device operates; and if a weight of two 40 feet container does not exceed the predetermined weight, both the first hoisting device and the second hoisting device operate.