GB257578A - Improvement in mining machines - Google Patents

Abstract

257,578. Sullivan Machinery Co., (Assignees of Holmes, M. P.). Aug. 31, 1925, [Convention date]. Coal-cutting machines.-In a longwall mining machine in which a drum &c. hauls in a flexible feed cable &c. to feed the machine or to swing the cutter bar during sumping, the drum &c. being capable of disconnection from its driving means to enable the cable &c. to be paid out rapidly, the drum &c. is driven through two-speed gearing comprising two clutches, which clutches, together with the means for disconnecting the drum from its drive, are controlled by a single member. The machine contains a centrally arranged motor which, through a pinion 16, drives a gear 49 containing a disc clutch 52 through which a shaft 41 may be driven at high speed; the gear 49 constantly drives reducing gearing 60, 61, 64, 65, the gear 65 containing a disc clutch 66 through which the shaft 41 may be driven at low speed. The shaft 41 drives an aligned worm 37 engaging a worm wheel 32 which, by means of a toothed clutch 35, may be connected to a coaxial shaft 28 acting through a pinion 27 and internal gear 26 to drive the feed drum 18. The toothed clutch 35 is controlled by longitudinal movement of a rod 86, acting through a curved link 88 and a yoke 93 pivoted on a shaft 82, a slidable and rotatable sleeve 96 with an eccentric head 97 being provided to lock the rod 86 in its outward position; on rotation of the rod 86, its toothed inner end 85 causes longitudinal movement of a rack bar 82 which, through a pinion, rotates a screw 77 and thereby moves a guided nut 76 which, through a link 75, rocks a yoke 74 which selectively controls the disc clutches 52, 66, of the two speed gearing.