Abstract: A mine roof support includes a pair of substantially-parallel floor-engaging members, a roof engageable member, a shield pivotally-connected to the floor-engaging members, by at least one pair of parallel links, and pivotally-connected to the roof-engageable member, and prop means carried by the floor-engaging members by which the roof-engageable member can be urged into engagement with a mine roof. A strengthening member connects the pair of parallel links. The strengthening member and the pair of parallel links provide the sole connection between the rear-end portions of the floor-engaging members by which the forces tending to cause relative displacement of those rear-end portions in the vertical direction are substantially resisted.

Abstract: A mine roof support includes a roof-engageable beam which comprises a main portion and a further portion which forms an extension of the main portion. The further portion is hinged to the main portion by a pin-less knuckle joint. The further portion includes a part which projects beyond the knuckle joint and beneath the underside of the main portion with which it is engageable to limit pivotal movement of the further portion about the joint. Retaining means provide security of connection of the further portion to the main portion. Means are provided either beneath the main portion or beneath the further portion which are operative upon the further portion for tilting it about the knuckle joint.

Abstract: A roof support suitable for use in mines includes roof-engageable means provided with a roof-engageable pad which is so mounted with respect to the remainder of the roof-engageable means as to be movable with respect thereto for exerting a thrust on the mine roof. A linkage is pivotally connected between the pad and the remainder of the roof-engageable means. Actuator means is so pivotally connected to and supported by the linkage that when operated it effects movement of the pad with respect to the remainder of the roof-engageable means, being itself constrained, simultaneously upon such movement, to move bodily with the pad.

Abstract: A roof support including a roof-engageable member and a cantilever member, one having parallel elongate compartments with a cover member which has a roof-engageable surface and which overlies the compartments, and the other having parallel and rigid elongate elements slidably fitting into the compartments. The other member also includes a plate, having a roof-engageable surface, which defines the profile in plan of that member and which is so secured to the elements as to be relatively slidable with respect to the roof-engageable surface of the cover member. The transverse widths of the roof-engageable surfaces are such that when the roof-engageable member and the cantilever member are caused by actuator means relatively to slide from a retracted condition to an extended or partially-extended condition one of those surfaces effectively forms a full width extension of the other.