浮式起重机、安装用门座起重机、塔式起重机、港口装卸起重机等大型起重机对于超负荷安全保护装置的要求越来越迫切。尤其是港湾和近海作业的浮式起重机常常要在深海里进行吊装和打捞作业,吊重量在事先是无法估计的。多年来,国内对于超负荷限制器已作过多 Floating cranes, gantry cranes for installation, tower cranes, port cranes and other large cranes are becoming more and more urgent for overload safety protection devices. Floating cranes, especially for harbor and offshore operations, often require hoisting and retrieval operations in deep sea where the amount of hoisting can not be estimated in advance. Over the years, there have been too many domestic overload limiter