A conveyor-mounted mining machine incorporates at least two driving units. Each unit comprises a linearly drivable member operatively engaged with a driven wheel coupled by a clutch to a driving wheel drivingly engaged with a stationary part of the conveyor. With the clutch engaged, linear motion of the linearly drivable member imparts rotary drive to the driving wheel so as to propel the machine along the conveyor. The driving units are operated sequentially so that a continuous drive effort ac...

A screw-type cutter drum is provided having helical ribs on the drum body with cutter picks on the ribs and on the end of the drum. The cutter picks at the end of the drum are arranged in sets spaced apart to coincide with the ends of the ribs and the cutter picks of each set are equally spaced apart angularly and placed at different radial distances from the axis which decrease in the direction of rotation.

A looped cable control device for use in guiding a supply cable to a mineral winning machine in a longwall mining installation to reduce the risk of damage, the device being mountable on a spill plate to form an elongate of side wall parallel to the spill plate, a platform being mounted between the spill plate and the goaf side wall, so that a trough is defined for receiving the supply cable, the goaf side wall being pivotally mounted for deflection towards the spill plate under impact, the goaf...

A rock splitter tool is hydraulically actuated by a piston which moves a tapered wedge between feathers mounted at one end in a retaining means. The feathers and wedge, as an assembly, are inserted into a predrilled hole and the wedge is driven forward by the hydraulic piston to move the feathers outwardly to split the rock. The present invention is directed toward providing a hydraulically moved wedge in which the feathers and wear plate portions are retained by a clam shell clamp and retainer ...

A well drilling assembly including a platform adapted to support a person while drilling a well therebeneath through an opening in the platform includes a clamp assembly carried by the platform and mounted for rotation with respect thereto. The clamp assembly includes a pair of open jaws disposed in confronting relatively movable relation and with respect to each other for engaging and for readily releasing a drilling stem so as to be able to support a column of drilling sections as new sections...

A drill bit is disclosed for drilling large diameter shafts. The drill bit comprises a main bit body having a plurality of rolling cutters rotatively mounted thereon. The cutters function to contact and disintegrate the earth formations at the bottom of the shaft thereby creating rock chips or cuttings. Water or drilling mud is pumped down the shaft and across the face of the main bit body for cooling the drill bit and for flushing the chips away from the shaft bottom. An auxiliary flow enhancer...

A bore hole to be deepened far into air-impermeable bedrock has an air-tight lining and an air lock in its upper portion, and it is pressurized below the air lock. A duct comprising endwise connected but disconnectable duct sections extends through the bore hole, its top end open to the atmosphere. A drilling mechanism having a telescoping connection with the bottom of the duct comprises a bit driven by a pneumatic motor that has an exhaust air outlet opening into the duct and a pressure air inl...

This mining system utilizes a row of roof support units in conjunction with a row of conveyor sections and a continuous mining machine which rides on the conveyor sections. Each roof support includes a primary support shield supported on a base by means of jacks and a secondary support shield telescopically mounted to the primary support shield and having a wall engagement portion at the outer end to provide bearing support for the secondary support shield by the wall rather than merely by canti...

An asphalt-paving cutter tool, adapted to be driven by a power-operated hammer mechanism, has an upper shank adapted to be received and held in the socket of the hammer mechanism, and a wide lower cutter portion terminating at the lower end in a chisel-like cutting edge. Intermediate the upper shank and the lower cutter portion is a wedging-and-reaction portion having divergently-upward sidewalls inclined at an angle of the order of 15.degree.-35.degree. relative to the vertical. This portion ha...

An auxiliary device for a longwall mining machine incorporating an underframe, by which it is mounted for movement along the conveyor of the mining machine, and it is coupled to the mining machine. The auxiliary device comprises a rotary breaking or crushing element drivably carried by the underframe and the underframe is provided with a reaction means, preferably a plate, spaced away from an adjacent periphery of the rotary element. In use, material on the moving conveyor passes between the rot...