Abstract: A walking mining prop has a skid-lifting assembly in the region of the ram which braces the roof cap with respect to the skid formed by a bridge from which lifting cylinders are articulated and suspended. The pistons of these lifting cylinders are articulated to a pressure plate which at least partly surrounds the guide rods of a guide-rod assembly on which the skid is guided, a mechanism being provided to advance the skid relative to the guide-rod assembly.

Abstract: An adustable cap unit for a mine support frame including a main cap, an adjustable cap connected to the main cap with a hinge-type connection, an adjusting cylinder mechanism extending within the widths of the main cap and the adjustable cap, and a guide for guiding a portion of the adjusting cylinder mechanism in a restrictive manner. The adjusting cylinder mechanism is provided either in the main cap or in the adjustable cap and an end portion of the adjusting cylinder mechanism is hinged to a bearing member provided at the bottom edges of the main cap or the adjustable cap adjacent the hinge-type connection. The adjustable cap unit can be used in extremely small seam thicknesses of as little as approximately 500 mm, while the contact pressure available at the front end of the adjustable cap is sufficient.

Abstract: A trough-shaped travelling bracket of a retracting and guiding arrangement of a mine roof support has fixing elements at its mine-face end for releasably coupling with an abutment, wherein the fixing elements are exchangeable, but fixedly connectable with a web of the travelling bracket.

Abstract: A mine roof support has two sole-sliding elements, a bridge element connecting the sole-sliding elements with one another at the mine face ends of the latter, a roof supporting element supported on the sole-sliding elements, props supporting the roof supporting element on the sole-sliding elements, a displacing arrangement for displacing the sole-sliding elements and connected with the bride element, a guiding arrangement located between the sole-sliding elements and including two laterally spaced guiding rods connected at their mine face ends with a support element and at their backfilling ends with the bridge element via displacing arrangement, wherein a carriage is positively incorporated between the guiding rods of the guiding arrangement. The carriage carries a cylinder-and-piston unit which connects the carriage with the guiding arrangement at the backfilling end of the latter.

Abstract: A walking mine roof support has a roof engaging cap element, two supporting units each including a floor engaging plate member and a prop extending between a respective one of the plate members and the roof supporting cap element so as to support the latter, which floor engaging plate members are displaceable in a first direction toward a mine face and are spaced from one another in a second direction transverse to the first direction, and displacing elements for displacing the floor engaging plate members in the first direction and including two guiding elements spaced from one another in the second direction and two hydraulic cylinder-piston units operative independently of one another. Each of the hydraulic cylinder-piston units connects one of the guiding elements with a respective one of the floor engaging plate members so as to displace the latter relative to but independently of one another in the first direction.

Abstract: A mine roof support for an underground mine gallery comprises a sole plate adapted to rest on the floor of the mine gallery. The sole plate is connected by links to the region of the lower end of a rear shield, and the upper end of the latter is connected by pivot means to a roof shield, between opposite ends of the latter, in such a manner that a portion of the roof shield between the front end thereof and the pivoted means is considerably longer than the portion of the roof shield between the pivot means and the rear end of the roof shield. At least one extensible and collapsible prop extends between the sole plate and the portion of the roof shield which is located forwardly of the pivot means and at least one additional prop extends between the sole plate and the rear shield, so that the roof shield may be pressed against the roof of the mine gallery and be shifted relative to the mine face.

Abstract: An underground excavating system includes a conveyor device which is operative for conveying material away from a mine face, and an excavation roof support device which is operative for supporting the roof of the excavation. A hydraulic cylinder-piston unit is operatively connected to both of the devices and is operative for advancing one of the devices towards the mine face while the other of the devices remains stationary, and vice versa. A guiding arrangement is connected intermediate the control unit and the conveyor device and is operative for guiding the advancing device during its advance towards the mine face. The guiding arrangement includes a pair of elongated support members which are spaced apart of each other and which have one end region located closer to the mine face and another end region located further from the mine face. The guide arrangement further includes a pair of guide sleeve members one at each of the aforementioned end regions.

Abstract: A pit prop assembly has two pit props with parallel laterally spaced bases each having a front end turned toward a face conveyor and a rear end turned away from the face conveyor. A slide has its front end connected via positioning mechanism to the conveyor and its rear end connected via hydraulic ram to the bases. Each of the bases has at its rear end a side turned toward a confronting side on the slide and forming a side pair with this confronting side. One of these sides is formed with a formation that engages over and under another formation on the other side. One of these formations of each of the pairs of formations extends longitudinally toward the face so that the two formations can slide relative to each other. One of these formations may also be a pin whereas the other is a groove, or one may be a pair of facing convex surfaces flanking a straight edge.

Abstract: A pit prop comprises an elongated skid adapted to lie on the floor and having a front end linkable to a support such as a face conveyor. A pair of generally parallel elongated feet flank the skid and each have a front portion which is substantially twice as wide as its rear portion. A slide fluid cylinder has a rear end secured to the rear end of the skid and a front end secured to a cross member attached to the front portions of the feet so that extension or contraction of the slide cylinder displaces the feet relative to the support. A pair of support arms each have a rear end loosely pivoted on the rear portion of the respective foot and a front end carrying a roof-engaging shield. A lift cylinder extends between each foot front portion and the respective front end of the respective arm for pressing the shield against the mine roof and the feet against the mine floor.