Abstract: Mining apparatus is disclosed in which a cutting wheel supporting a plurality of roller-cutters rotates about a horizontal axis and is supported on a slewing boom for cutting a tunnel with a flat floor and roof and elliptical walls as it slews across a mining face. The slewing boom is supported on a main beam assembly, the front end of which rests on powered crawler tracks and the rear end of which passes through a gripper assembly which may be clamped between the floor and roof of the tunnel, and against which the main beam assembly may be urged forward for engaging the roller-cutters with the mining face. A preload crawler is urged against the roof of the tunnel above the powered crawler tracks to locate the main beam assembly rigidly relative to the tunnel such that the roller-cutters may cut the rock in the mining face with minimal loss of cutting force due to vibration.

Abstract: A mobile mining machine for cutting a tunnel in rock has a wheel-like cutterhead assembly supported by a pitch boom assembly that causes movement of the cutterhead assembly in the vertical plane. A swing boom assembly supports the pitch boom assembly and is supported by the main frame of the mobile mining machine. In one embodiment the swing boom assembly has a pivot axis that is tilted from vertical and swings the cutterhead and the pitch boom during mining to cut a tunnel having a wide, flat floor. During mining, a gripper assembly having a floor gripper shoe and a roof gripper shoe brace the mobile mining machine in the tunnel. Thrust is provided by thrust cylinders located between the gripper shoes and the main beam. Extension of the thrust cylinders moves the cutterhead assembly, main beam, and rear portion of the mobile mining machine forward relative to the gripper assembly due to slidable engagement of the main beam and gripper assembly.

Abstract: Mining apparatus in which a cutting wheel supporting a plurality of roller-cutters rotates about a horizontal axis and is supported on a slewing boom for cutting a tunnel with a flat floor and roof and elliptical walls as it slews across a mining face. The slewing boom is supported on a main beam assembly, the front end of which rests on powered crawler tracks and the rear end of which passes through a gripper assembly which may be clamped between the floor and roof of the tunnel, and against which the main beam assembly may be urged forward for engaging the roller-cutters with the mining face. A preload crawler is urged against the roof of the tunnel above the powered crawler tracks to locate the main beam assembly rigidly relative to the tunnel such that the roller-cutters may cut the rock in the mining face with minimal loss of cutting force due to vibration.

Abstract: The invention is concerned with a tobacco substitute which is made by subjecting a strand of viscose fibres to a controlled pyrolysis until the organic residue contains at least 90% carbon by weight, and loading the carbon strand with ingredients for smoking.