The four types of wire rope grab buckets with significant structural differences are the double (quadruple) rope long boom double-jaw plate grab bucket, double (four) rope multi-jaw plate grab bucket, hanger-type grab bucket, and scissor-type grab bucket. If each type of wire rope grab bucket is considered applicable to a portion of bulk cargo loading and unloading operations, then these wire rope grab buckets will exhibit their respective advantages and disadvantages in different operational conditions and for other portions of bulk cargo loading and unloading operations.
Double (Four) Rope Long Boom Double-Jaw Plate Grab Bucket
The long boom double-jaw plate grab bucket is the most commonly used, a typical representative of wire rope grab buckets. Currently, the development status of the long boom double-jaw plate grab bucket is as follows:
(1) The self-weight of the grab bucket accounts for 35% to 45% of the lifting capacity of the crane.
(2) To ensure the maximum coverage area when the grab bucket is opened, the ratio of the jaw plate width B to the maximum opening 2Lmax can be as large as 0.7.
(3) Made of high-quality steel to improve the strength of each component of the grab bucket and reduce its self-weight.
(4) In the rope system of the multi-pulley block, a rope compensation device is set to eliminate uneven extension in the length direction of the closed rope branches and reduce rope wear.
(5) Rolling bearings or self-lubricating bushings are installed at the rotating hinge points to reduce the maintenance workload caused by wear.
