| 摘要 |
1,211,502. Mineral-mining machines. ALLIED CHEMICAL CORP. 13 March, 1969 [9 May, 1968], No. 13412/69. Heading E1F. [Also in Division F2] In a boring machine, outer cylindrical shells 1 carrying roller cutters 2 are rotated in opposite directions relative to inner cylindrical support shells 28, 29 by a drive mechanism including at least two double-acting steam or hydraulic cylinders 4, 5 which cause continuous rotation of a shaft 10 carrying a bevel gear 16 meshing with ring gears 17 secured to the shells 1. The piston of each cylinder 4, 5 is connected to a respective slide 6, 7 having an opening therein formed with parallel toothed racks 13, 14, the shaft 10 extending through the openings and carrying angularly offset pinion sectors 11, 12 which intermittently engage the racks. The ends of the openings are rounded and as a rack of one slide meshes its pinion sector to rotate the shaft 10 the other pinion sector is rotated at an end of its opening to change mesh from one rack to the other. The boring machine is rotatably suspended from a cable 40 and steam or hydraulic fluid reach the cylinders 4, 5 via lines 42, 20, 21, 22, suitable valve gear being provided. |
