The structure of grab: the grab is hung on 4 cables, these 4 cables is connected to 2 cable reels, 2 cable reels is put in a roller truck, this truck is moving with carrier. The main structure: the grab body, the right and left rod, the electric hoist, inside the hoist there are the mobile block and stationary block, the mobile block will move up and down following the cable.
While the power is on, the hydraulic brake is opened, engine starts working and transfer the movement to gear box, diving from gear box to cable reel through connecting joint, cable reel rotaries leading the movement of cable.
When the cable is losen then the mobile block moves down, while a connecting shaft between a left grab body and a right grab body will push these 2 bodies separately and the grab opens. While tightening the cable then the mobile block will move up, let 2 grab bodies close, the grab closes at that time.