Abstract: In a rotary table driven hollow auger type sampling device, a rod is mounted at an end above the rotary table to be substantially fixed against rotation, but for axial movement. The rod extends through a hollow spindle driven by the table, and is fixedly mounted below the table to the upper end of a thin wall sampling tube mounted within a hollow auger to project a short distance below the lower end of the auger. The rod, hence the sampling tube, is forced downwardly with the auger, but is positively restrained from rotation.

Abstract: A track and gear rack disposed on one side of a face conveyor for a longwall mining machine and adapted to be engaged by a driving gear and guide wheels on the mining machine, the track and gear rack being of generally L-shaped cross-sectional configuration and having a horizontal arm resting on the mine floor and a vertical arm secured to the face wall of the conveyor. Driving pin extensions extend outwardly from the vertical arm in cantilever beam relationship near the upper edge of the vertical arm and have vertical widths less than the height of the vertical arm. One of the arms of the L-shaped configuration is provided with studs which engage guide block means on the mining machine for guiding it along the track and gear rack. The invention facilitates good guidance of the mining machine along the track and gear rack without impeding the flow of mined material onto the face conveyor.