Abstract: A support device (8) for a rib (14) between a floor (18) and a roof (16). The device includes an expansion means (10) and a pair of resilient members (12a, 12b). Each of the resilient members (12a, 12b) have a proximal end (27a, 27b) adapted for connection to the expansion mean (10) and a distal end (28a, 28b) curved away from the expansion means (10) and adapted for engagement with the floor (18) and roof (16) respectively. When the device (8) is positioned towards or against the rib (16) and the expansion means (10) is activated to drive the members (12a, 12b) apart, the member's distal ends (28a, 28b) are driven substantially vertically into engagement with the floor (18) and the roof (16) and a portion of the device (8) is driven substantially laterally (32) into abutment against the rib (14).

Abstract: A mine prop is comprised of an elongate tube having a slenderness ratio that would generally allow buckling or kneeling of the elongate tube when exposed to a sufficient axial force. A plurality of elongate support members having a length less than the elongate tube are attached to the tube to prevent buckling or kneeling of the elongate tube along the portion of the tube to which the elongate support members are attached. The portions of the tube that are unsupported by the elongate support members define one or more yieldable zones proximate at least one end of the tube. A compressible filler material is disposed within at least portion of the tube to support yielding in the yieldable zone.

Abstract: This invention is related to a ground advance shoring system and the construction method using such a system.

Abstract: A mine roof support having means for monitoring the angles made by the canopy 11 and the base 10 with respect to a datum. The angular information may be gathered in a number of different ways and the information used to control subsequent movements of the support.

Abstract: A roof support has a pair of floor sills carrying hydraulic props supporting a roof-engaging structure. The floor sills have guide rails on their adjacent sides which mate with a slidable guide block which connects to a shifting ram and thrust mechanism between the sills. The shifting ram has one of its displaceable parts, i.e. its cylinder or piston rod articulated to a thrust beam or a pair of thrust rods which link with a conveyor in front of the support. The sills are interconnected for relative vertical movement and are coupled to the other displaceable part of the ram. The guide is linked to the thrust beam or thrust rods remote from the conveyor by way of a pivot joint which resists traction but permits pivoting about an axis generally parallel to the ram and which is easily assembled and dismounted.

Abstract: The invention relates to a structural frame for mining operations wherein at least one stabilization element is provided and coupled between the roof of the seam cap and the floor of the seam support base which is pivotable around a pivot axis extending in the longitudinal direction of the truss. In order to prevent damage to the stabilization element or the pivot axis during occuring mountain forces, the stabilization element and/or the guides or links guiding the same are designed as yielding spring elements yieldable against compression and tension forces whose restoring forces are dimensioned so large that the parts which have been released from the bracing between the roof of the seam and the floor of the seam can be adjusted back into the initial position by the effect of the restoring forces.

Abstract: The support assembly is made up of a floor-standing runner member 1, a hydraulically vertically-adjustable prop 2 mounted on the same, a roof canopy 3 supported by the same and a rockfall shield 4 hinged to the same on the backfill side which is guided to be pivotable in a vertical plane by two direction-control members 5 and 6 articulated to the runner member so as to be spaced apart one behind the other. The front direction-control member 6 is constructed as a hydraulic thrust piston mechanism. Via a control circuit 8 the hydraulic control valve 7 of the direction-control member 6 is connected to measuring devices 9 usable to measure the position of at least two mutually variably spaced apart support assembly reference points. If the reference points deviate from the preset normal position of the support assembly, pressure fluid acts on the front direction-control member 6 via the control circuit 8 until the normal position has been regained.

Abstract: A mine roof support comprises a plurality of hydraulically extensible chock legs 5,6, articulated at upper ends thereof to one or more roof beams 3 and at lower ends thereof to one or more base members 1, a shield 9 pivotally connected to a rearward part of the base member 1 and also pivotally connected to a rearward part of the roof beam 3, with permanently pressurized rams 12 both located between a pair of laterally spaced chock legs 6 and one located to each side of the center line 19 of the support, the rams being mutually inclined with respect to the center line 19 and reacting via the shield 9 on the roof beam 3, and a pair of tie bars 11 located one at or towards each side of the support and both connected between the roof beam 3 and the shield 9.

Abstract: A mine roof support comprises a plurality of hydraulically extensible chock legs articulated at upper ends thereof to one or more roof beams and at lower ends thereof to one or more base members, a shield pivotally connected to a rearward part of the base member(s) and also pivotally connected to a rearward part of the roof beam(s) with a permanently loaded force applying means reacting via the shield on the roof beam(s), in such a manner that the force applying means resists displacement of the roof beam(s) and, upon a sufficient fall in pressure in the chock legs, restores any displaced chock legs to a predetermined position.

Abstract: A mine roof support comprises at least one hydraulically extensible chock leg connected at its upper end in articulated manner to a roof beam of the support, and connected at its lower end in articulated manner to a base member of the support, a pair of links each having bearing surfaces adapted either to embrace a common chock leg by bearing on opposite sides thereof or to bear on adjacent sides of a pair of spaced apart chock legs, one end of each link being pivotally attached to the base member at a pivot point located to one side of a diametral plane passing through the longitudinal axis of the chock leg on which the link bears, the other end of the link being located to the other side of that plane and being acted upon by a restoring ram adapted to displace the or each link about it or their respective pivot points, to restore the or each leg to its predetermined position upon release of the support from the roof, and also to resist tendency for the or each leg to become displaced from the predetermined