Technically exchanging four link type portal crane

Technically exchanging four link type portal crane Overview of Portal Crane Portal crane has various applications, such as loading and unloading at port, materual handing at dockyard, ship building and repairing yard, metalluygy industry. The four link type portal crane jib crane is composed of frame, lifting mechanism, luffing mechanism, slewing mechanism, traveling mechanism, spreader device (grab, container spreader, hook), electrical equipment and other aiding devices for