Derrick Crane has a simple production, easy assembly and disassembly, from the weight (up to 1 000 kN above), limited by the terrain and other characteristics. But its flexibility is poor, the working radius is small, moving more difficult, and need to pull more cable wind rope, it is generally only applicable to the installation of more concentrated engineering projects.
Derrick Crane can be divided into: single-legged rods, rods, cantilever rods and cable-type Derrick Crane.
A single foot
Single-footed by the rod, lifting pulley group, hoist, cable rope and anchor and other components. When used, the rod should be kept at an inclination of not more than 10 "so as not to strike the rod when the component is lifted. The bottom of the rod is set to be dragged to move. The stability of the rod is mainly dependent on the cable rope and the end of the rope is fixed at the top of the mast , The other end fixed on the anchor, the cable rope is generally set to a 4. According to the different production materials, wood alone feet of the rod, steel pipe feet and metal lattice-style single-foot and so on.
The word rod
The word rod is made up of two logs or two steel pipes with wire rope or iron pieces. The two rods intersect at the top into a 200 -300 angle with a drawbar or drawstring at the bottom to balance the horizontal thrust of the lever itself. One of the rods is provided with a guide pulley at the bottom of the rod, which is connected to the hoisting machine and connected to the anchor by a wire rope to ensure that during lifting
Bottom solid. Word rod is lean forward, but the tilt should not exceed 1/10, and in the front, behind the use of two cable wind rope pull knot.
The advantage of the rod is that the lateral stability is better and the cable rope is less. The disadvantage is that the range of activities of the lifting member is small.
For the installation of heavy columns or other heavy components.
3. cantilever rods
In the middle of the middle of the rod or 2/3 height installed on a boom, that is, into the cantilever rod. The lifting rod can be rotated and fluctuated, as shown in Figure 8-9c.
Cantilever rod is characterized by a large lifting height, lifting rod can swing about 1200 -2700, suitable for hoisting high
A larger component.
4. Cable-type Derrick Crane
In the only foot of the lower end of the rod can be installed on a 3600 turn and ups from the lifting rod. It has a large lifting radius, can be suspended components to the effective lifting radius of any position. Grid structure of the Derrick Crane, from the weight of up to 600 kN, lifting height of up to 80 m, the drawback is more cable wind rope.