Abstract: A combustion engine having at least one pair of longitudinal opposed cylinder with electricity generating stator means fixed relative thereto and having pistons arranged in the cylinders for cycles of reciprocating compression and power strokes, the pistons being linked together with a linear actuator for movement therewith.

Abstract: A free-piston internal combustion engine comprises at least one pair of longitudinally opposed cylinders (1, 2) with an electricity generating stator (8) fixed thereto. Respective pistons (5, 6) are arranged in the cylinders (1, 2) for cycles of reciprocating compression and power strokes. There are inlet valves (9) for introducing air or fuel mixture into the cylinders (1, 2) prior to the compression stroke. There is an outlet valve (10) for the expulsion of exhaust gas following the power stroke. The pistons (5, 6) are linked together with a linear actuator (7) for movement. During operation of the engine the reciprocating strokes of the pistons (5, 6) and linear actuator (7) with respect to the stator (8) generate useable electrical energy. The inlet valve (9) is located in the pistons (5, 6) and comprise a portion of the piston heads.

Abstract: An articulated train such as a coal haulage system includes first, second, third and fourth vehicles pivotally pinned to one another in end-to-end relationship. In the improvement, the train includes a steering system having first mechanism for selectively securing the second and third vehicles in aligned relationship and second mechanism for selectively securing the third and fourth vehicles in aligned relationship. Turn control mechanism unlocks the first mechanism when the first vehicle turns through a predetermined angle. In an exemplary embodiment, each of the first and second mechanism includes an actuator and a hydraulic valve which coacts with such actuator. The steering system locks those vehicles following the first vehicle in an aligned (i.e.

Abstract: A chain conveyor for a miner in which the chain adjacent the drive sprocket is guided and supported by channels in a casting such that tension in the chain is reacted by the casting and separated from the driving force applied to the chain by the drive sprocket. The casting may be spring loaded away from the idler sprocket at the other end of the conveyor. The pitch of the sprocket teeth is preferably less than the pitch of the chain, allowing for drive sprocket build up from entrained fines.

Abstract: A mining roof bolt drill feed mechanism whereby the drill is supported on a horizontal pylon extending from an elongate slot in a vertical box section inner strut. The inner strut telescopes within an outer box section strut with an aligned elongate slot, and the pylon is supported on the nut of a dual concentric worm and nut drive system located within the telescopic struts. Elastomeric seals are provided over the elongate slots to prevent the ingress of dust from the mining operation.

Abstract: A chain conveyor for a miner in which the chain adjacent the drive sprocket is guided and supported by channels in a casting such that tension in the chain is reacted by the casting and separated from the driving force applied to the chain by the drive sprocket. The casting may be spring loaded away from the idler sprocket at the other end of the conveyor. The pitch of the sprocket teeth is preferably less than the pitch of the chain, allowing for drive sprocket build up from entrained fines.

Abstract: A drive sprocket for a chain conveyor having one or more chains engaged therewith over a predetermined arc, leaving a disengaged arc of the sprocket. A housing is provided adjacent the disengaged arc incorporating a concave arcuate cylindrical surface closely spaced from the line swept by the tips of the sprocket teeth and forming a pumping chamber adapted to remove particulate material from the region of the drive sprocket.

Abstract: A mining roof bolt drill pot drive wherein the drill chuck and the bolt tightening socket are coaxially mounted and permanently coupled to and simultaneously driven by a drive motor. The drill chuck is directly driven by the drive motor and the bolt socket is driven via a reduction planetary gear box giving speed reduction and torque multiplication. An automatic valve for supplying cooling water to the drill during drilling and allowing excess water together with expended sheer pins to be discharged from the base of the drill pot is also described and claimed.

Abstract: A pick holder for a miner comprising a mounting base and a bit holder detachably mounted to the mounting base by way of a substantially vertical join face. The join face incorporates a pair of mating faces on each of the mounting base and bit holder inclined relative to the longitudinal plane of the pick holder and forming an arrowhead formation with a pair of shoulders parallel to the longitudinal plane. The bit holder is secured to the mounting base by a longitudinal bolt a significant length allowing a desired degree of strain to be induced in the bolt during attachment.

Abstract: A conveyor drive transmission for a secondary conveyor system is disclosed. The secondary conveyor system is designed to feed material cut by a mining machine onto a primary conveyor which would convey mine material to the rear of the machine for discharge. The secondary conveyor has a foot shaft adjacent and parallel to one side of the primary conveyor. The transmission for the secondary conveyor includes an input drive shaft aligned with and driven by a transverse shaft on the primary conveyor. A helical worm drive gear mounted on and driven by the input drive shaft is included to engage and drive a worm wheel. The worm wheel then drives a helical worm gear mounted on a shaft in the same plane as the input drive shaft. A set of bevel gears mounted on the same shaft as the helical worm driven gear drives the worm shaft of the secondary conveyor.

Abstract: A maneuverable mining machine is disclosed. The mining machine has a chassis with at least one cutting head mounted on the front of the chassis and adapted to cut into a mine face extending transversely across the front of the machine. The cutting head comprises a cutting drum which is rotatable in a plane parallel to the mine face. The cutting head is mounted on the chassis by way of a support member arranged to effect movement of the cutting drum parallel to the face. A conveying means is mounted on a chassis and is arranged to convey mine material from the front of the chassis to the rear of the chassis.

Abstract: A bit holder for a replaceable bit is disclosed. The bit is of the type having a pointed head portion axially extending from a shaft portion. The bit holder has a holder part for receiving the bit and has a base part for securing to a cutter head. The bit holder part is releaseably secured to the base part for easy replacement. The holder part has at least one reaction surface cooperating with one reaction surface on the base part for counteracting forces arising on the bit while cutting. A bolt extending from the holder part or the base part into a cooperating aperture in the other of the holder part of the base part is utilized to releaseably secure the two pieces together with the reaction surfaces therebetween. The bolt is positioned relative to the reaction surfaces and with respect to the bit so that the gripping force of the bolt counteracts the force of the bending moment created between the bit tip and the reaction surfaces during cutting.