Abstract: An apparatus for cutting a flat elongated channel, chamber or passage in subterranean strata, e.g. a crosscut between two mine galleries or shafts, which comprises upper and lower shoes or shields which can be spread apart by a fluid-cylinder system and to which a frame is connected by further fluid cylinders, this frame carrying an excavating worm whose flights are formed with picks for removing the face of the channel to be advanced. A conveyor extends past the frame or through the latter to carry rearwardly the detritus excavated by the worm.

Abstract: An excavating mining and conveying apparatus is formed of trough segments or sections with screw sections mounted on the trough sections carrying out the mining and conveying functions. Actuating means are provided to bring the screws successively into inclined contact with the face or seam of coal at an angle of from 5.degree. to 50.degree.. A drive is provided to transmit a torque to drive the conveying and transporting screws.

Abstract: An excavating and/or tunneling machine having a mobile support unit with suitable endless tracks for advancing the unit. The support unit serves as the base or chassis for an excavating screw, impact devices and excavating boom tools which all are cooperatively brought into operation to cut into material to be mined, excavated and/or tunneled.

Abstract: A support displaceable along a tunnel or gallery floor by means of a caterpillar drive is provided with a rotatable milling tool that can be brought into engagement with a lower portion of a face wall and with a reciprocal hammer engageable with an upper portion of the wall. The miller is operated to cut or grind material off the lower portion so as to undercut the wall. Then the hammer is operated to chip or break off the upper portion of the undercut wall. Both the miller and hammer are mounted on adjustable and directable arms. The loosened rock is carried off by a scoop-transport belt arrangement.