过卷扬限制器的作用是防止起重钩过卷扬造成钢丝绳拉断、钩头落地、挤碎滑轮、折臂或翻车等事故。限制器有三种型式,即重锤式、丝杠式和凸轮式。 重锤式过卷扬限制器是用LX4-31、LX4-32型限位开关,配以一个重锤组成的。早些时候生产的桥式起重机都采用这种类型的过卷扬限制器。 Winch limiter over the role is to prevent the hoisting hook over hoisting wire rope pulled off, hook the ground, crushing pulleys, folding arm or overturn and other accidents. There are three types of limiter, namely hammer type, screw type and cam type. Hammer over winch limiter is LX4-31, LX4-32 type limit switch, together with a heavy hammer. Bridge cranes manufactured earlier have adopted this type of over-hoist limiter.