Abstract: The invention provides a bag for spacing apart walls in an underground mine working, and including opposed load-bearing walls of flexible sheet material, each defining a substantially centrally located opening and an open-ended radial slot extending between and intersecting the central opening and outer periphery of the load-bearing wall, the openings and slots of the load-bearing walls being in register. There is an intermediate wall of flexible sheet material extending between the load-bearing walls and connected thereto substantially along the entire periphery of each load-bearing wall. A charging connector through the wall is for connection to a source of flowable substance under pressure for charging the bag therewith, to expand the bag by displacing the load-bearing walls away from each other. The invention also provides an installation and method which employ the bag to space the walls apart.

Abstract: This invention relates generally to the field of repair for manholes and other like tubular structures and is more specifically directed to a sectioned panel assembly which is premanufactured for installation within an existing manhole.

Abstract: Methods are provided for translating a face support comprising a plurality of support units arranged side-by-side at an initial position. In the first embodiment, a first pair of alternately positioned support units are moved a predetermined distance from the initial position. Next, a second pair of alternately positioned support units are moved the predetermined distance. One of the support units of the second pair is positioned between the first pair. These moving steps are repeated until the entire plurality of support units is moved the desired distance. In the second embodiment, the first moving step is duplicated. Then, a single support unit located between the first pair is moved the predetermined distance. These two moving steps are repeated until all of the support units are moved.

Abstract: Coal in the roof of a seam being mined by the long wall method is recovered by supporting an elongated area of the seam roof using a plurality of cradle supports, the front cradles being moved forward stepwise parallel to the long wall to form a passage with cantilevered roof supporting arms of the rear cradles. When the rear cradle at one end of the passage is moved forward into engagement with the front cradles, the coal in the roof is left unsupported, is collapsed, and is removed via a conveyor and a loader in the passage.

Abstract: Conveying apparatus for use in conveying mineral ore employs a curvilinear channel section or pan which joins straight groups of similar channel sections joined end-to-end together. A scraper-chain assembly circulates along the channel sections in upper and lower runs. A unit with a hollow housing is combined with the curvilinear channel section and this unit has an upstanding hollow pillar forming a hub on which two rollers are mounted for independent rotation. The rollers are shaped to engage with the scrapers of the scraper-chain assembly to guide the latter during its passage along the curvilinear channel section. To enable the roof of the mine working to be adequately supported over the zone in which the curvilinear section and unit are installed, a roof support with alternately shiftable hydraulic props is located within the hollow hub of the unit. The props are connected to a multi-part roof bar and extend through an elongate aperture in the housing top wall.

Abstract: A walking roof support unit comprising first and second support assemblies isposed adjacent one another for being selectively spragged and released between the floor and the roof of a structure. Each support assembly includes a base, hydraulically operated first and second props extending vertically from the base in spaced parallel relation thereon and a roof beam supported on the props. The first and second support assemblies are coupled together for longitudinally advancing the assemblies step-wise and in sequence parallel to one another. The coupling between the assemblies includes a guide secured to the props of the first support assembly and a guide shoe slidably mounted on the guide for relative movement in the longitudinal direction. The guide has a longitudinal T-shaped slot and the guide shoe includes a longitudinal T-shaped projection slidably engaged in the slot.

Abstract: A releasable pivot joint for use in underground mining installations comprises first and second connecting members. The first connection member has a width which is greater than its thickness and a reduced portion that reduces its width to a core width. The second connection member is formed with a slot into which is inserted the reduced portion of the first connection member. The width of the slot is greater than the thickness and the core width of the first connection member. The length of the slot is greater than the width of the first connection member. The thickness of the second connection member is smaller than the core width of the first connection member. The width of the first connection member extends transversely of the length of the slot when the connection members are in the connected position.

Abstract: The invention relates to an advance mechanism for a roof support assembly constituted by a plurality of roof support units positioned side-by-side along, for example, a longwall face of a mineral mining working. The advance mechanism comprises a pair of hydraulic advance rams and a pair of resilient, generally parallel guide rods. The guide rods are interconnected at one end by means of a head-piece which is attachable to a conveyor extending along the longwall face. The other end of each guide rod is attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a floor girder of a roof support unit. The hydraulic advance rams are each pivotally attached to one of the slide pieces and to one of said floor girders. The guide rods are provided, adjacent said one end, with outwardly projecting alignment members each of which co-operates with one of said floor girders to align an associated roof support unit during its advance.

Abstract: The invention relates to an advance mechanism for a roof support assembly constituted by a plurality of roof support units positioned side-by-side along, for example, a longwall face of a mineral mining working. The advance mechanism comprises a pair of hydraulic advance rams and a pair of resilient, generally parallel guide rods. The guide rods are interconnected at one end by means of a head-piece which is attachable to a conveyor extending along the longwall face. The other end of each guide rod is attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a floor girder of a roof support unit. The hydraulic advance rams are each pivotally attached to one of the slide pieces and to one of said floor girders. The guide rods are provided, adjacent said one end, with outwardly projecting alignment members each of which co-operates with one of said floor girders to align an associated roof support unit during its advance.