Abstract: This invention relates to an apparatus and method for detecting and measuring the position of a fracture in solid formations, such as for example a grout filled borehole. An electrical element is placed the length of the borehole prior to filling the hole with grout. When the hole is filled and the grout solidified, any fracture in the grout also breaks the electrical element. The element is constructed such that its electrical capacitance is a known function of its length. The element is constructed of easily frangible materials so that it is severed in close proximity to the grout fracture. The capacitance of the element after the fracture can be measured using suitable instrumentation. The position of the break is a function of the capacitance as measured after the break.

Abstract: A centrifuge is disclosed comprising an elongated shaft, rotatable about its longitudinal central axis, a bowl having upper and lower portions secured to axially spaced portions of the shaft forming a centrifuge chamber therein. The shaft has a passageway for receiving a slurry and for discharging the slurry into an axially lower portion of a passageway in the lower portion of the bowl, which passageway includes a portion which imparts a rotational velocity to the slurry flowing therethrough.

Abstract: A hammer or impactor apparatus including improved motive fluid means cooperable with spring bias means to reciprocably drive a hammer element and an improved process of hammer cycling achieved thereby.

Abstract: A mining machine assembly includes bit supports having primary and secondary cutter bits secured thereto. The bit supports may take the form of bit holders. A drum member may have a plurality of bit holders secured thereto. At least some of the bit holders have two cutter bits secured thereto. A primary cutter bit and a secondary cutter bit are secured to such cutter bit holders. The primary and secondary cutter bits are so positioned as to travel in substantially the same orbital path upon rotation of the cutter drum. The primary cutter bit projects radially outwardly farther than the secondary bit.

Abstract: A pneumatic motor for rock drills and the like having a reciprocating piston with valves at its opposite ends for valving motive air to the piston head from both ends of the cylinder. Large receivers are provided near the respective valves to accommodate availability of air on demand from the valves and to dampen pressure fluctuations. One of the receivers is connected to an external source of fluid under pressure; while the two receivers are interconnected by tubing external to the pneumatic motor itself. This permits the cylinder for the piston to comprise a simple tube provided with exhaust ports only. Additionally, exhaust air and oil from an air motor, which rotates the rock drill, are directed into the area between the lower end of the reciprocating piston and a striking bar for the drill rod to lubricate the reciprocating parts.

Abstract: A monorail suspended conveyor system for conveying materials along a curvilinear path has a plurality of tandemly disposed belt supporting carriages, each carriage having a framework which defines an open extent extending longitudinally therethrough and includes a upper elongated tubular link member and a lower pair of transversely spaced apart side members disposed on opposite sides of the open extent. Adjacent carriages are connected by an articulated joint suspended from the overhead rail and provides for universal movement of one carriage relative to another. The ends of adjacent side members are provided with cooperating structures to selectively limit the lateral swing of the carriages transversely with respect to the longitudinal movement thereof along the curvilinear path, thereby maintaining the conveying belt in a generally horizontal operating mode.

Abstract: An apparatus and method of controlling the input power to a drill feed or other hydraulic system in which the hydraulic power source is obtained from a compressed air supply. Wherein, the flow of air is varied in response to a hydraulic signal controlled by the load demand of the hydraulic system. Low and high mode controls are provided to operate hydraulically actuated mechanisms; and a hydraulic absorbing load is imposed to prevent stall or overspeed of the pump and motor during low load conditions.

Abstract: An improved kelly is provided with a drive section which has a uniform cross section defined by three generally flat drive sides alternating with three generally arcuate sides. The three arcuate sides are spaced an equal radii from the central axis of the kelly and the three flat drive sides lie in planes that form an equilateral triangle therebetween.The improved kelly is driven by an improved mating kelly drive bushing which has three rollers positioned so as to evenly transmit torque to the three flat drive sides of the kelly simultaneously.

Abstract: A hydraulic impactor having a reciprocating piston, a liquid coupling having a stepped bore and an actuatable driven member of a configuration to obtain the optimum energy transfer to the driven member.

Abstract: An emergency brake system for mine shuttle cars and the like wherein the brakes are applied by spring pressure and are normally released only when the hydraulic system for the shuttle car is activated. In the present invention, a hand pump is provided for releasing the brakes when the normal hydraulic system is not activated. This facilitates moving the shuttle car when it is not connected to a source of power. When the car is again connected to a power source and its hydraulic system activated, a shuttle valve initially releases the pressure produced by the hand pump and then returns the system to normal operation.

Abstract: A split spring steel ring having a channel-shape cross-sectional configuration is sewn into the bottom cuff of a filter bag. The split ring is placed into the opening in the thimble plate of a plenum chamber by lapping the ring at the split and pushing inward until the diameter is reduced for insertion into the opening. The ring is then allowed to expand until the ends abutt at the split. The ring is maintained in its expanded condition in interlocking engagement with the opening by a thimble extension which extends through the ring below the thimble plate of the plenum chamber.

Abstract: A reciprocating pneumatic motor for rock drills and the like wherein a freely-movable hammer piston repeatedly strikes the end of a drill rod, usually a rotating drill rod. Fluid under pressure enters a single, central inlet port in the wall of a cylinder which houses the piston with alternate cycling ports being incorporated into the piston itself. Also disclosed is a muffler for such a pneumatic motor.

Abstract: An improved discharge electrode having a stiffener centrally of planar side and corona edges in an electrostatic precipitator.

Abstract: A safety device for a drilling rig of the type wherein a drill-carrying cradle is caused to move upwardly or downwardly on a tower by a chain which traverses sprockets at opposite ends of the tower. Shock loads and vibration cause premature failures in the chain when withdrawing a drill string as the cradle is pulled upwardly on the tower. The present invention minimizes shock loads on the chain to minimize the possibility of a chain failure and, at the same time, prevents a fall of the cradle and drill carried thereby if the chain above it should break, this latter function being accomplished with the use of spring-loaded toothed dogs on the cradle which engage the tower and prevent movement of the cradle in the event of a chain failure.

Abstract: An impactor apparatus including novel means for actuation of a motive fluid flow control valve or comparable motive fluid control means.

Abstract: A hydraulically operable hammer and more particularly a hydraulically operable hammer having improved cycling of a hammer piston reciprocable therewithin.

Abstract: Stretching of a conveyor belt to prevent edge spillage during horizontal turns is achieved with a new and improved chain extending longitudinally of the belt intermediate its side edges and secured to the belt. The chain is formed of alternate links, one of which is a C-shaped link secured to the belt and the other of which is a connecting link adapted to be engaged by a twin-drive sprocket. The links are loosely fitted such that the C-shaped links can be secured to the belt with a minimum distance between links and thereafter pulled apart to stretch the belt to which the chain is attached.

Abstract: The hydraulic fluid control apparatus has velocity control means and pressure control means. The apparatus has hydraulic fluid entry means for receiving hydraulic fluid and hydraulic fluid discharge means for supplying pressurized hydraulic fluid to hydraulic power means such as an hydraulically actuated oil well drill string power tong. The velocity control means is operatively associated with the hydraulic fluid entry means and serves to establish a desired predetermined velocity for the hydraulic fluid. The pressure control means is operatively associated with the hydraulic fluid discharge means for selectively limiting the exit pressure of the hydraulic fluid through the discharge means to predetermined levels. The pressure control means includes valve means adapted to divert pressurized fluid from the hydraulic fluid discharge means when the hydraulic fluid pressure exceeds predetermined levels.

Abstract: A conveyor feed apparatus cooperable with a conveying apparatus for controlled feeding of material to the conveying apparatus in a manner that overfilling of the conveyor apparatus is avoided.

Abstract: A percussive rock drill and more particularly a percussive rock drill having improved means for passing a flow of flushing fluid therethrough.