Abstract: A continuous mining machine cutting head structure is set forth. The mining machine is of a type having a support member and an elongated mining head member mounted on the forward end of the support member. The head member is powered for rotation about its longitudinal axis. The head member is of the type having axially extensible and retractable end portions. Included within the head member is a hydraulic piston cylinder arrangement for selectively extending and retracting these end portions. At least one latch element is included within each side of the head member and can be moved into locking engagement with the end portions when it is in an extended position thereby preventing retraction thereof. Also included is a mechanism operatively connected to the piston cylinder arrangement which is capable of moving the latch element out of engagement with the end portion thereby permitting retraction thereof.

Abstract: This invention relates to improved traction control means for a mobile vehicle such as a tractor or excavating machine having a pair of laterally spaced, endless crawler tracks, each of which is powered independently by its own traction motor for generally curvilinear travel of the vehicle at variable speeds in either the forward or reverse direction.

Abstract: A continuous mining machine having a rotary cutter drum provided with internal drive motors. The drive motors extend on opposite sides of the support boom for the rotary cutter drum and each motor is within the axial extent of the cutter drum on each side of the support boom.