Abstract: This drillhead unit includes a sealed housing mounting a bevel gear assembly and a bevel drive pinion assembly. The bevel gear assembly includes a hollow shaft providing a chuck for receiving a hollow drill bit and the bevel pinion assembly includes a shaft providing a connection for a hydraulic drive motor. The hollow shaft is connected to a cavity within the housing, which is connected to exhaust passages connected to a vacuum source. A vacuum sealing assembly is provided within the housing between the bevel gear assembly and the housing to eliminate bearing lubrication loss. The unit can also be used for reverse flow positive water pressure in lieu of a vacuum.

Abstract: This vehicle includes a frame having inboard rail bearing wheels and outboard carriages carrying ground bearing wheels. The carriages are mounted to opposite sides of the frame for vertical movement in a guide system provided at each side of the frame and each carriage provides a mounting for fore and aft ground wheels. A counterbalance system is used to facilitate raising the carriages independently of each other from a ground engaging mode to a retracted mode and a latching system holds the carriages in place in each mode.

Abstract: 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 cantilever support. Each support unit is connected to an associated conveyor unit by a ram for moving said units relative to each other. The mining machine includes a kerf cutting member for creating a continuous ledge at the junction of the longwall and roof for supporting the secondary support shield wall engagement portion.

Abstract: This bit holder assembly includes an elongate base member, which is fixedly attached to a mining machine cutter, and a bit-holding block member, which is connected to the base member by means of longitudinally spaced fasteners. The block member and base member each include interface portions engageable when the members are connected. The assembly can be modified to suit different types of cutting bits and the thickness of the base member can be chosen to achieve the correct mounting height for the particular bit used.

Abstract: This dust collector provides a means of removing dust from air ventilation ducts without utilizing water and includes a cylindrical body aligned with the duct and having a bank of venturi tubes mounted between spaced walls within the body. An exhaust blower creates an airflow in the body and dust-laden air passing through the tubes is subjected to centrifugal action so that the dust is concentrated into a relatively small portion of the air, which is diverted transversely through the venturi throats and into a throat chamber defined by the spaced walls. An external conduit system communicating with the throat chamber returns the diverted air into the cylindrical body upstream of the exhaust blower through a return opening, the blower providing negative pressure in the conduit system which results in a portion of the air passing through the cylindrical body being continuously recycled.

Abstract: An adaptor for applying a predetermined amount of torque to a bolt includes a housing having one end engageable with the bolt, and a shaft coaxially mounted within the housing and having an opposite end engageable by a wrench. The shaft and housing are clutch-connected by a spring-loaded friction disc assembly, which is carried by the shaft and adjusted to slip when the torque applied to the bolt reaches a predetermined value. A visual indicator is provided which measures wear of the friction discs. A thrust bearing is provided at the bolt end of the housing to minimize friction loss between the adaptor and the work.