Abstract: A portal-shaped installation car picks up at an assembly location remote from the face of the tunnel an upper part of a tunnel-lining arch on a pallet. It then rides along rails secured to the side of the tunnel to the face location and presses this upper part against the tunnel roof, whereupon the lower tunnel-lining arch parts are secured in place. Thereafter the car returns with the empty pallet to the rear end of the tunnel at the assembly location and deposits this empty pallet to pick up a full pallet carrying another upper arch part. The sequence is then repeated. As each upper arch part is being secured at the face of the tunnel another upper arch part is assembled on the previously deposited empty pallet with the help of a portal crane that also rides on the rails along the sides of the tunnel.

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 assembly for use in a mine having a floor, a roof, and a face, comprises a pair of pit props having parallel elongated floor-engaging bases on each of which is pivoted a roof-engaging arm which may be pressed against the roof by means of a hydraulic ram extending vertically between each base and the respective arm. A pair of telescoping elements extend longitudinally between these two bases and one of the elements is pivoted at its front and rear end on respective front and rear end of one of the bases and the other element pivoted at its front and rear end on the respective front and rear end of the other base. A longitudinal-displacement ram is provided between these telescoping elements so that the two pit props can be displaced longitudinally relative to each other. In addition a transverse ram forms the connection between the rear of one of the elements and the corresponding rear of the corresponding base so that transverse displacement or swiveling of the two pit props is also possible.

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.

Abstract: A base has one side facing towards and another side facing away from the face of the excavation. A shield has a first end portion and a second end portion, the latter being adjacent the other side and the shield extending upwardly and towards the one side. A roof-support cap is mounted on the first end portion. A mounting arrangement includes a shaft and mounts the second end portion of the shield on the base for pivoting about a pivot axis. A displacing arrangement serves to selectively displace the pivot axis in direction towards and away from the one side of the base, so as to maintain the cap in engagement with the roof despite different heights of the latter.