Abstract: Drive gears with unique teeth profiles drivingly couple the output shaft of a drive on a drum-cutter mining machine to a rack extending along the course of travel of the mining machine. A prime mover on the mining machine is coupled to a drive gearwheel having gear teeth with tooth flanks defined by segments of a hypocycloid. These gear teeth mesh with a rack drive gearwheel having gear teeth with tooth flanks defined by segments of an epicycloid. The gear teeth of the rack drive gearwheel have a slender profile to penetrate into the spaces between pins forming part of a guide rail rack.

Abstract: A rack device consisting of movable and immovable rack segments extends along a face conveyor for a mining machine having a drive gear engageable with the rack device to propel the machine along the working face of a mine. Rack holders are fixedly connected to conveyor pan sections joined together for pivotal movement to form the face conveyor. The rack segments are coupled to spaced-apart rack holders by pivot shafts. The immovable rack segments extend along a single conveyor pan section while each movable rack segment bridges a joint between conveyor pan sections. Pivot shafts for the movable rack segments are received in elongated slots in the rack holders whereby the movable rack segments move through a gap distance formed by a clearance between the pivot shaft and the slot. This gap distance is greater in magnitude than the clearance between the joined conveyor pan sections.

Abstract: This disclosure relates to a mining machine of the type having a driven winch which has its drive output sprocket engaging a displaced portion of a chain which normally extends along the entire length of the mine face. The displacement portion of the chain occurs between guide rollers on the mining machine. The chain is secured by a plurality of holding devices such as catches clamps or locking devices which are distributed at closely, spaced-apart locations along the length of the chain. As the mining machine propels itself along the chain, the guide roller or an associated member at the forward end of the mining machine releasably retain the chain in the holding devices until the chain is deflected toward the drive output sprocket of the winch. A guide roller or an associated member at the trailing end of the mining machine engage again the returned portion of the chain with the holding device as the chain is passed from the drive output sprocket.