Abstract: In order to prevent freezing of the input lift gas in an oilwell in which gas under pressure is used to lift the well fluids, a heat exchanger is provided which serves to heat the input gas from the warm well fluids. The heat exchanger includes an outer casing and a coaxial tubing which is in line with the well fluid flow. The casing is sealed, and the tubing within the casing is provided with openings which permit the circulation of well fluids in the space between the casing inner wall and the tubing. Relatively small stainless steel tubing is spirally wrapped, in two spaced apart sections, around the tubing within the casing, and access parts are provided to permit the passage of input lift gas through the wrapped tubing prior to its injection into the well. The two wrapped tubing sections are coupled by a gas flow control valve external to the casing.

Abstract: A jar for use in facilitating the removal of stuck objects from wells. The jar has a telescoping assembly held in a collapsed position by a latching means urged into latching position by a resilient means so that the hammer of the jar is spaced from the anvil thereof. The release of the latching means is actuated by a predetermined longitudinal force applied to the upper end of the jar which overcomes the resilient means to cause the hammer to strike the anvil with a sudden impact translated by a connecting means from the jar to the stuck object.

Abstract: A special drive link permits drilling of holes of different diameters with the same drill drive. The drill shaft has a helical pattern of scroll-like projections for removal of cuttings. The drill drive mechanism includes sprockets carrying two chains of drive links which mate with the helical scroll projections to move the drill shaft axially, and projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft. The drill shaft is formed with an elongated axial groove separating the helical projections and defining notch surfaces which mate with projections or tangs extending inwardly from the hollow portion of the drive links where they surround the drill shaft. Rotation of the mechanism results in transferring the rotating force through the sides of the inwardly extending projection of the drive links to the corresponding notch surfaces of the scroll projections.

Abstract: A raise drill is disclosed for enlarging a pilot hole into a large diameter hole by disintegrating the earth formations surrounding the pilot hole. The raise drill includes a bit body having a plurality of roller cutters mounted thereon. The bit body is detachable secured to a drive stem to permit removal and replacement of the stem. A shock absorbing element is interconnected between the drive stem and the bit body to enable the bit body to be flexibly mounted on the drive stem. A central yoke is provided to extend around the drive stem and interconnect the saddles of the two innermost cutters. The central yoke functions to distribute the loading of the inboard cutters. The central yoke can also function as a housing for a packing element.

Abstract: A large diameter drill bit is disclosed that is capable of drilling various size bores. In the preferred embodiment, the drill functions as a raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole. In the primary stage, the raise bit includes a primary body supporting a plurality of yokes positioned at various radial locations thereon. A frusto-conical cutter is rotatively mounted on each yoke for contacting and disintegrating the above-mentioned earth formations, with the outermost cutters forming the gage row. For the second stage, in which larger diameter holes are to be drilled, a plurality of ear assemblies are provided for attachment to the primary body at circumferential locations between the outermost primary cutters. Each ear assembly comprises a unitary support frame having a yoke and cutter mounted thereon. A vertically oriented roller stabilizer is also mounted on each support frame.

Abstract: A coal plane for use against a coal face, comprises a plane body which has a plane guide. A plane chain is arranged in the plane guide and has chain ends engaged on respective sides of the plane body. A bit support is mounted in the plane body for pivotal movement about a vertical axis in a working direction toward the coal face. A horizontal control shaft, mounted orthogonally to the longitudinal direction of the plane chain on the plane body, is provided, to actuate the bit support. A turning head is mounted on a control shaft for rotation therewith and it operates between two spaced apart slide plates. A lever arm is secured to the control shaft for rotation therewith and a control chain mounted for reciprocating motion is engaged with the lever arm and is connected to the ends of the plane chain.

Abstract: A duct section or other load to be moved axially along a bore hole has two reciprocating drivers mounted on it and two sets of gripping elements. Each driver reacts axially between the load and a set of gripping elements to move the gripping elements relative to the load through a defined stroke in each axial direction. An endless cable with axially extending straight stretches has one stretch connected to each driver to constrain the drivers always to move in opposite axial directions and to begin and end their strokes simultaneously. The gripping elements are so formed that when engaged with the surface of a bore hole, increasing axial force on the load in one direction increases the radially outward force under which they bite into the surface.

Abstract: The present invention consists of an under reamer tool for enlarging, scraping or smoothing a well bore. The tool is attached to a conventional drill string above a conventional bit and involves cutting elements that have retractable cutters arranged for extension from the tool to engage the well bore wall, each cutter, when the drill string is turned, being urged outwardly by centrifugal force until it engages the well bore wall, continued turning thereafter, pulling that cutter into its extended cutting attitude, reaming the wall to the desired diameter, cutter retraction involving ceasing turning the drill string and the pulling of the drill string and connected tool from the well bore.

Abstract: Cavity mining minerals from a subsurface deposit by hydraulically jetting and disintegrating a mineral deposit locally, and transporting lumps and particles to the surface via a borehole.

Abstract: A high density perforating gun having series connected multiple gun housings within which a plurality of jet perforating shaped charges are arranged in spaced apart clusters. The charges of each cluster are captured in radially spaced apart symmetrical relationship within a mounting assembly, and each housing includes a plurality of the mounting assemblies which are spaced vertically apart from one another. The charges contained within each mounting assembly are orientated respective to the charges of the remaining mounting assemblies so that any charge located in one mounting assembly is spaced apart both radially and vertically from the nearest adjacent charge of an adjacent mounting assembly. This arrangement permits a maximum number of shaped charges to be placed within a finite volume. All of the charges contained within one housing are simultaneously detonated.

Abstract: A centralizer apparatus for guiding, within a well bore, a tool having a radially outwardly extending member thereon includes a sleeve concentrically disposed about the tool. The sleeve has a downwardly opening, substantially J-shaped groove therein sized to receive the radially outwardly extending member on the tool about which the sleeve is disposed. The J-groove has a first, closed, axially-extending slot portion and a second, axially-extending slot portion opening at the downstring end of the sleeve. The first and second axially extending slot portions of the J-groove are spaced circumferentially apart and communicate through a substantially transverse slot portion. An outer protective jacket is provided about the sleeve. A centralizer guide depends from the lower end of the jacket to contact the walls of the bore and maintain the tool centrally with respect thereto.

Abstract: 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 rotating breaking or crushing element and the reaction plate where the material is broken up or crushed. In this way, it can be ensured that any large lumps of coal or rock on the conveyor can be broken down to a sufficiently small size so as not to become jammed beneath the main frame of the mining machine straddling the conveyor.

Abstract: 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 inlet in the bore hole outside the duct. At intervals along the duct remotely controllable supporting and moving devices are fixed to duct sections, each device having a pneumatic actuator with an inlet opening to the bore hole and an outlet opening to the duct. The devices have gripping elements that frictionally engage the bore hole surface to confine the duct against motion or to move it up or down for raising or lowering the drilling mechanism.

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: 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.

Abstract: 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 side wall having a projecting lever arm, which engages between a stop and a resilient member, so that the resilient member resists deflection and returns the wall to its normal position, risk of damage by the impact being, therefore, reduced.

Abstract: A variable wall mining machine to release coal from a longwall mine face includes an articulated auger assembly made up of a plurality of side-cutting auger sections joined together by universal couplings in an end-to-end relation and coupled to a drive at one end of the assembly. A scavenger plow, supported on the mine floor, consists of sections connected together for articulated movement toward and away from the longwall mine face. Two support arms are journaled by bearings to each auger section and the other ends of the arms are pivotally supported by one of the scavenger power sections. Hydraulic actuators, supported by mine roof supports, move two adjacent scavenger plow sections together with two auger sections as a pair into sumping cuts with the longwall mine face. Other hydraulic actuators supported by the scavenger plow control the elevation of the pivotal arms and, hence, the auger assembly coupled thereto for shear cutting the mine face.

Abstract: 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 are added and also to permit the clamp to rotate while the drilling sections are rotated at a position supported by the clamp to hold the sections in spaced relation from the bottom of the hole being drilled. The method of drilling includes manipulations involved in supporting the sections of pipe spaced from the bottom of the drilled hole while flooding water through the pipe to flush out the opening and also to permit the pipe to be rotatably driven while so held without exerting manual lifting force on the pipe.

Abstract: 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 which are readily separated and removed to enable an inspection and/or replacement of any damaged apparatus. This clam shell clamp enables existing apparatus to be converted. Auxiliary apparatus utilizing a jack hammer device is also shown as is a hydraulic pulsation developing rotary valve which is adapted to cycle the wedge as it is moved forwardly.

Abstract: A method for breaking a hard compact material such as rock or concrete. The method includes drilling a hole into the material, gripping a portion of the wall of the hole by applying a radially outwardly directed force thereto, and applying an axially outwardly directed force to the gripped region in order to cause cracks to arise in the wall of the hole. One of the forces is generated by means of sequentially repeated axially directed impacts. The apparatus for carrying out the method comprises a gripping means and a wedge means slidable relative to the gripping means. The gripping means and the wedge means have cooperating wedge surfaces. A rear extension member having a shoulder is attached to the wedge means. A hammer piston reciprocable in the apparatus housing delivers sequentially repeated axially directed impacts upon the shoulder.