| 摘要 |
A pulley of block-and-tackle system of roller drilling machine in the form of a semi-block, on perimeter of which rollers are installed with grooved side for positioning a runner. Furthermore, the rollers are placed between support columns made in the form of parallel plates equipped with open-end holes, in which axles of rollers are installed, and from outer side of the support columns jaws in the form of plates are adjacently located and fastened to them, in which cylindrical grooves are made and the end parts of the axles of rollers are placed. |
