在水平臂塔机中,变幅小车大部分为矩形单小车方式,其变换起升绳倍率的方法是变换吊钩滑轮组上滑轮架的位置。当其固定于下滑轮架上时起升绳为四倍率,当其固定于小车架上时二倍率。在大型塔机中,有采用双小车变换倍率的,但其小车架也多为矩形结构。 In the horizontal arm tower crane, most of the trolley is a rectangular single trolley, and the method of changing the lifting rope multiplying ratio is to change the position of the trolley on the hook block. When it is fixed to the lower pulley frame hoist rope for four times the rate, when it fixed to the frame when the double rate. In the large tower crane, there is a double car conversion ratio, but the small frame is also mostly rectangular structure.