| 摘要 |
A large electric dragline having a housing (35) and boom (37) is provided wi th spaced apart in-line sheaves (34) and (36) at boom point to separate hoist ropes (31) and (32) which are led to th e front and rear of bucket (30) respectively. Differential hoist rope control allows accurate and continuous adjustment of the bucket carry angle during all modes of operation. Also described is a computer control system giving continuous accurate control of carry ang le by differential hoist rope operation, with manual selection of mode of operation. |
