The correct method of fixing chain hanger screws

　　Generally, chain hoists do not exist in the use of cable-stayed, crooked hanging, twisting chain, overload, sudden force and other illegal operation phenomenon, the chain hoist decoupling, is due to the hook beam fixed ball screw fixation problem.

　　Screw fixing method is to roll the assembly of 13 after the completion of the screwdriver with a screwdriver screwed into the bottom of the screw hole, and then screw the hole outside the riveting punch. Under normal circumstances, the screw and screw hole in the various parts of the normal processing of the size, when the screw is screwed into the bottom of the screw hole, screw head end and the ball should be equal to the distance between the ball and the ball groove gap. When the hook to withstand the force of gravity, the hook ring groove to an outward force to the ball, the ball is forced by the ball to the outside, when the screw hole outside the port is not riveting solid, the screw exit from the screw hole, Under the action of external force, the ball subjected to shear force and friction force will withdraw from the screw hole one after another, and the ball of the hook and the hook is lost, the hook and the hook are displaced relative to each other in the axial direction of the hook Detach, resulting in the accident.

　　To prevent similar accidents, to prevent the screw from the screw hole to exit, in addition to check the screw hole riveting situation, but also can be hook crossbeam screw screw tail space sealed with tin alloy.