| 摘要 |
A drawworks having a main drum spool, a main drum shaft which passes through and is rotatably and concentrically supported by the main drum spool, an auxiliary drum spool, respective drum shafts passing through and rotatably and concentrically supported by the drum spools in a manner in which wireline pull from the spools is isolated therefrom, a clutch mechanism rotatably connected to the shafts and brake mechanisms respectively connected to the main drum spool and the auxiliary drum spool outside the working area of the drawworks.
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