The device that links the movable pulley in the lifting pulley block to the hook becomes the hook clamp.
Generally divided into two types: long type and short type. The pulley and hook of the long type hook are respectively installed on the upper and lower shafts.
The hook gauge and the pulley shaft are supported on the pull plate on both sides, and both ends are fixed by the positioning baffle, so that the hook beam cannot be moved axially.
The overall height of this form is larger, which will take up the effective lifting height of the adjacent part when applied, but the horizontal dimension is small.
The clamping sleeve of the short hook is different from the former. The pulley shaft is also the beam of the hook, which saves the drawing board, but the number of pulleys must be even in order to be symmetrical.
In order to move the hook without touching the pulley on either side, the long hook must be used.
Although its shape height is relatively small, can increase effective lift height.
But its beam heavy Russia is big, appearance dimension is big.
Therefore, it is only used for the crane with small lifting capacity, and the long clamps are mostly used for the heavy lifting.
In order to hook, the hook can rotate flexibly around the vertical axis, and there is a thrust rolling bearing between the nut on the tail of the hook and the beam. When the weight of the hook is large, it is better to use the self-position thrust bearing with ball and pad, which not only makes the rotary hook light, but also makes the bearing bear even force.