Abstract: The invention relates to a pipe connector with a connecting portion (4) formed by a non-chip producing method. On one pipe end of the pipes. The connecting portion (4) includes an outer conical face (7) and a first conical bore (10). A first connecting element (13) with a conical supporting bore (15) is adapted to contact the outer conical face (7). A second connecting element (17), in the form of a connecting body, is provided to thread onto the first connecting element (13), in the form of a nut. The second connecting element (17) has a counter sealing face (21) in the form of a conical bore. A sealing element (23) cooperates with the first conical bore (10) of the connecting portion (4) and with the counter sealing face (21) in the form of a conical bore of the second connecting element (17). The sealing element (23) has a first outer conical sealing face (25) and a second outer conical sealing face (26).

Abstract: In a hydraulically operated unit, particularly a prop for a support in an underground excavation, a thin-walled tubular jacket is pressed on an inner element which is movable in an outer tubular element so that the tubular jacket has an inner diameter which is determined with a substantial undersizing relative to the outer diameter of the inner element, and the tubular jacket is clamped on the inner element with exceeding of the flow limit of the inner element and only in a plastic expansion condition which exceeds with a reliable distance and elastic deformation region of the tubular jacket and with a sufficient residual springing part.

Abstract: A peripherally flexible arch for propping rock structure for mining tracks, tunnels or the like is comprised of a plurality of partially overlapped elongated segments, each of which has an end portion extended toward the rock structure, a bottom portion opposite to the end portion, and a lateral flange offset from the end portion laterally and in the direction toward the bottom portion. Clamping devices are arranged at the ends of the overlapping regions of the segments to clamp the segments to each other. The end portion of each lower segment is inserted into a groove formed between the end portion and the flange portion of each upper segment at the side of this segment facing away from the rock structure. Each clamping device has a hook engaged in a groove formed between the end portion and the flange of the upper segment at the side of this segment facing toward the rock structure.

Abstract: A method of and an arrangement for loosening, loading and transporting of stratified minerals includes a single continuously rotating and forceably guided pulling organ, a plurality of loosening elements integrated in the pulling organ in its working run extending in a longitudinal direction of a longwall, and a plurality of transporting elements also integrated in the same single pulling organ at its transporting run located behind the working run at a back filling side, wherein the loosening elements perform loosening and loading functions, whereas the transporting elements perform the transporting functions in an opposite longitudinal direction of the longwall.

Abstract: A shut-off valve has a sealing cone which in a closed position of the valve abuts against a conical sealing seat and is formed as a part of a cylindrical throttling piston, a sealing surface of the sealing seat cooperates at its one end with a cylindrical receiving opening for the throttling piston, and the outer diameter of the throttling piston is selected with respect to the inner diameter of the receiving opening so that a throttling gap is formed between the receiving opening and the the throttling piston.

Abstract: A clamping device for connecting a number of shaped, elongated, flanged through sections of a support structure to each other includes an upper stirrup, the flanges of which are supported on the flanges of the upper through section, a lower stirrup positioned to support the flanges of the lower through section, and clamping bolts extended through the openings in the flanges of the stirrups and the through sections and tightened with nuts. The head of each bolt has supporting projections provided with convexly curved portions which are engaged in the flanges of the upper stirrup in a form-locking fashion.

Abstract: An arrangement for supplying consumers, particularly mobile consumers, with pressure fluids such as pressure air or pressure liquid, particularly in underground excavations, has a composite rail track for guiding a pressure fluid, a plurality of nipples arranged at a predetermined distance from one another in the longitudinal direction of the rail track, and at least one fluid withdrawing unit which cooperates with the nipples to open the latter and has a length selected with respect to the distance between two neighboring nipples so that one nipple is always located in the effective region of the withdrawing unit to be opened by the latter.

Abstract: A rock anchoring arrangement for use in tunnel and mine constructions comprises an elongated anchoring rod insertable in a bore formed in a rock formation, and a supporting plate arranged in contact with the rock formation at the open end of the bore. The anchoring rod includes a leading end portion fixable at the bottom of the bore, a trailing end portion fixable at the open end of the bore, and a smooth intermediate portion of a cross-sectional area smaller than those of the trailing end portion and the leading end portion. The anchoring rod is fixable by an adhesive within the bore at the leading end portion and at the trailing end portion whereas the intermediate portion is surrounded by an adhesive-repellent material to prevent the sticking thereof to the adhesive.

Abstract: An hydraulic prop utilized for barricades in blasting operations that affords simplified mounting and dismantling and will have minimal functional inefficiency if deformed by the impact of rocks; and it can be made out of unworked pipe of minimal standards. Two specific guide regions disposed on the piston are spaced large enough from each other that comparatively wide tolerances can be achieved between the piston and the cylinder.

Abstract: A wall element for an underground gallery has a W-shaped member which is symmetrical relative to its y-axis and has an axis of gravity coinciding with its x-axis and lying at approximately the center of its side, wherein the thickness of its lateral flange portions, base portions and connecting web portions are selected so that, in relation to used weight per meter, the W-shaped member has a maximum possible moment of resistance relative to the x-axis and a maximum possible bending load capacity in the plastic deformation range, and the W-shaped member has such a profile and such thicknesses of these portions that it has at least approximately equal bending load capacities in the plastic deformation region in two opposite directions along the y-axis.

Abstract: A rock anchoring arrangement for use especially in tunnel and mine constructions involving considerable convergences comprises an anchoring sleeve having a leading and a trailing end as considered in the direction of introduction of the anchoring arrangement into an anchoring bore in the rock formation, an anchoring rod having a trailing end portion passing through the interior of the anchoring sleeve and a leading end portion which extends beyond the leading end of the sleeve, a mounting plate arranged at the trailing end of the sleeve and engaging the rock formation around the open end of the bore, and a drawing die secured to the sleeve at the leading end. The anchoring sleeve and the anchoring rod are both retained in the bore by a body of a hardenable material, such as an adhesive, in which the sleeve and the leading end portion of the rod are embedded. The leading end portion of the rod has a smaller diameter than the trailing end portion so that a transition region exists between these portions.

Abstract: A chain bucket conveyor for an underground excavation has a substantially U-shaped forward conveyor part at the side of the sole and open toward a roof, a return conveyor part at the side of backfilling and closed in a substantially channel-like manner, wherein the return conveyor part is normal to the forward conveyor part, and means for transporting the chain from one to the other of the conveyor parts and including actuating stations, a rotary chain wheel having chain pockets and arranged at the actuating stations rotatable about an axis which extends toward the roof and backfilling and is located in a vertical plane transverse to the longitudinal direction of the conveyor, and a conical surface narrowing toward the roof and having an axis coinciding with the axis of rotation of the chain wheel.

Abstract: An arrangement for erecting a columnar supporting element of a hardenable flowable material, for a roof of an underground excavation, has a hollow casing for filling with a hardenable flowable material and is composed of two telescopable casing portions each composed of two open-end semi-circular sections, an element for holding the upper casing portion in contact with the roof of an underground excavation and arranged adjacent to the casing, and elements for connecting the semi-circular sections of at least the lower prop casing portions with one another so as to be pivotable about a longitudinal pivot axis which is parallel to the longitudinal axis of the prop casing, and locking the same with one another.

Abstract: A method and a system are disclosed for supporting an overburden. A single-section or telescoped multi-section longitudinally slit prop casing of light sheet material such as cardboard or metal has a fabric bag installed in it. When the casing is erected the bag is filled with a slurry of hardenable substance which, upon hardening, forms in the bag a column which supports the overburden. The casing may be left in place or it may be removed for re-use.

Abstract: Roofs of underground excavations are supported by forming sheet-material elements into tubes whose diameter can be varied by changing the overlap between the longitudinal edges of the rolled-up sheet material, standing the tubes upright to bear against the roof and the floor of the excavation, and filling them with hardenable material in flowable condition which, after hardening, will form a roof-supporting column.

Abstract: A method for mechanically advancing clean cut underground mining galleries of various profiles, in which during a primary phase of the operation a pilot excavation of circular cross-section smaller than the final desired cross-section of the mining gallery is carried out and in which during a secondary phase of the operation, overlapping in time with the primary phase, the pilot excavation is widened to the desired finished cross-section of the mining gallery; and a machine for carrying out the method.

Abstract: A walking mine support includes a roadway support unit and a face-gallery support unit laterally of the same. The two units are linked by one or more four-pivot couplings whose members can tilt both lengthwise and transversely of the elongation of the roadway and permit walking movements of the units with reference to one another without interfering with proper support of either the roadway or the face-gallery.

Abstract: A walking mine support unit has a pair of adjacent supporting frames each having a multi-partite sole plate and a multi-partite roof shield. The sole plate and roof shield of each frame are connected only at their respective leading and trailing ends, by hydraulic rams which permit the roof shields to be raised and lowered relative to the sole plates, and by four-bar linkages which permit length-wise displacement of the roof shields parallel and relative to the sole plates. A multi-section overshield is located above each of the roof shields and connected thereto by adjustable supports. An arrangement is provided for advancing the unit in stepwise manner.

Abstract: In longwall mining wherein a mine roof is normally supported by a succession of arches each in turn supported at one mine wall on a respective leg, a plurality of vertically expensible holders are pressed up against a plurality of respective adjacent arches with a common first beam, and legs of the thus-supported arches are removed so that the mine wall can be worked at this location. For advancing along the longwall all of the holders except the holder at one end of the row of holders are pressed upwardly against the respective arches with a second beam. The leg of the arch of the end holder is replaced and then the first beam is dropped down away from the row of holders. The end holder is then displaced to the opposite end of the row and the first beam is advanced toward this other end and the end holder is positioned under the arch immediately adjacent the other end.

Abstract: In a longwall mining operation the roof of the breast extending laterally from a heading or gangway is supported by at least two pairs of pit props. Each pair is substantially identical, having an elongated upper part and an elongated lower part displaceable away from each other by hydraulic rams. In addition a shield is provided extending vertically between the upper and lower parts of each prop at the upstream end of the prop turned toward the stowage area. In addition the props furthest from the mine are substantially longer than the props closest to the mine and are provided at their ends turned toward the stowage area with side shields forming a closed chamber so as carefully to segregate the gob from the breast. The upper parts of the props are formed of several articulated sections so as to allow these upper parts to conform to the shape of the roof.