Abstract: In a mining machine having a power driven cutter including metallic helical blade means having cutting bit means spaced along the exterior periphery thereof, the improvement which comprises the helical blade means having fixedly secured in surface-to-surface contact therewith energy absorbing layer means for dampening vibrations set up in the metal of the helical blade means when the cutter is in power operated cutting relation so as to materially reduce the operating noise level of the cutter within the mine.

Abstract: An improved advancing mechanism for a dual auger continuous miner of the type adapted to be advanced by a pair of anchoring jack assemblies, a pair of cables extending from the anchoring jack assemblies to a pair of winch mechanisms on the sides of the frame. The mechanism includes a mounting arm mounted on each side of the frame for movement about a vertical axis, a telescoping structure extending longitudinally between each mounting arm and the associated anchoring jack assembly and hydraulic piston and cylinder units for effecting the pivotal movement of each arm and the telescoping movement of each telescoping structure.

Abstract: A continuous mining machine comprising a central longitudinally extending conveyor assembly, a pair of cutting and conveying mechanisms mounted on the forward end of the central conveyor assembly for movement between a normal operating position wherein the cutting and conveying mechanisms are in alignment and extend laterally outwardly with respect to the forward receiving end of the conveyor assembly and a transporting position wherein the cutting and conveying mechanisms are in parallel relation alongside the central portion of the conveyor assembly, the cutting and conveying mechanisms having vertically movable endless track assemblies operable to move the continuous mining machine when the cutting and conveying mechanisms are in the transporting position, and a pair of mine floor-to-roof anchoring canopy units for (1) advancing the continuous mining machine so that the cutting and conveying mechanisms are moved inwardly of the working face, (2) facilitating the installation of mine roof bolts at positions

Abstract: An anti-abrasive, flame-resistant, and noise-suppressant laminate suitable for use with underground scraper conveyors or the like comprising two outer layers of ferrous material having an inner layer of styrene butadiene rubber material vulcanized therebetween. The styrene butadiene rubber material has a durometer of the order of 59, a flame spread index of less than 25 according to ASTM-E162 and a thickness of the order of 1/4 inch. One of the outer layers is of abrasive resistant steel and has a thickness of the order of 1/4 inch. The other outer layer is of 1020 steel and has a thickness of 16 gage.