GB647491A - Improvements in mining machines - Google Patents

Abstract

647,491. Mining-machines. MAVOR & COULSON, Ltd. (Vogel, W.). July 31, 1947, No. 20710. [Class 68 (i)] In a machine for mining minerals having a wedge cutter 16, 17, 18 which shears the mineral from a seam, the force exerted by the hydraulic ram 9 acting on the wedge is increased in the direction of shear by a resonant system built within the wedge-carrying body, 4, without, however, any increased reaction on the anchoring jack 12 taking the reaction of the ram 9 as the cutter head advances. The resonant system comprises a heavy block 26 mounted between springs 34 secured to the body 4 and capable of oscillation along guideways 28, the oscillations being due to a rod 30 reciprocated by an eccentric 24, the rod acting on the block 26 through the intermediary of auxiliary springs 29 mounted between the end shoulders of the rod and the block 26. The magnitude of the oscillatory force can be made equal to the thrust of the ram so that the forward thrust on the wedge head ranges from twice the normal thrust of the ram to zero. Since the mass 26 does not oscillate in the cutting plane of the wedge, lateral oscillatory forces are also set up but these forces can be eliminated by incorporating in the wedge a spring-biassed lateral oscillating mass oscillating at right angles to the mass 26. In a modified form the oscillatory force may be augmented by having a series of oscillating blocks; each oscillating at twice the rate of its predecessor. The machine may be double or single ended and consist of an anchorage body 6, Fig. 1a (not shown) and a wedgecarrying body 4, which have movement relative to each other due to a piston cylinder assembly 9 or the wedges may be carried on an endless track chassis.