1979年,贵阳钢厂炼钢车间根据历年来多次发生的桥式起重机钩头下落,造成人员伤亡的事故教训,组织有关专业人员从设备状况、机电性能着手,研究此类事故发生的规律。研究认为,造成限位失灵的原因是:1)天车在运行中,吊钩及钢绳经常剧烈地摆动,连接下重锤的钢绳经常缠绕在吊钩钢丝绳中;2)吊钩摆动时,其托板不能准确 In 1979, Guiyang Steel Plant steelmaking plant according to the repeated occurrences over the years the crane crane whereabouts, resulting in casualties accident lessons, organize the relevant professionals from the equipment status, mechanical and electrical properties to study the law of occurrence of such accidents. The research shows that the reasons for the limit failure are as follows: 1) During the operation of the crane, the hook and the steel wire often swing violently, and the steel wire connecting the heavy hammer is often wound around the steel wire rope; 2) , Its pallet can not be accurate