Abstract: Apparatus for mounting ancillary equipment between two relatively movable members of, for example a mine roof support, comprises two substantially parallel arm members pivotally mounted between the two relatively movable members, two rotatable members secured one to each arm member, and at least one cross member pivotally mounted at opposing ends to the rotatable members. The members of the apparatus are arranged so that the axes of rotation of the rotatable members, the axis about which the arms pivot, and the axes about which the cross members pivot, are each transverse to the other two. This arrangement can be used to provide a mine roof support with an operating platform having mountings which have a degree of movement akin to a universal joint.

Abstract: A fluid filtering system including two filter units so arranged in parallel that flow of fluid from a source to a point of usage can take place by way of only one unit at a time. Means is provided which can sense the degree of contamination of whichever one of the units is in service so that when the degree of contamination is such that the said one unit is no longer in a suitable condition for further filtering service, that means causes the by-passing of that unit and the bringing of the other unit into service. The system further includes back-flushing means which is automatically operable upon a filter unit when so by-passed for cleaning that unit. Timing means is also provided for automatically controlling the period of time during which back-flushing operation is permitted to continue.

Abstract: A shield support, suitable for use in mines, comprising a floor-engaging structure, a roof-engageable canopy, extendible and contractible prop means disposed between the floor-engaging structure and the canopy, and a shield assembly pivotally-connected to the canopy at or near its rearward end portion. The shield assembly includes a lazy tongs linkage, one element of which is pivotally-connected directly to the floor-engaging structure and another element of which is pivotally-connected to the floor-engaging structure through the intermediary of a further element.

Abstract: A roof support, suitable for use in mines, includes a roof-engageable canopy which comprises a main portion and an extension portion having a pivotal connection to the main portion. Actuator means is carried by the main portion. A wedge member, which is operable by the actuator means, is disposed between, and is engageable with, the main portion and a part of the extension portion projecting substantially beyond the said pivotal connection towards the actuator means. The wedge member is adapted arcuately to be movable by the actuator means and such arcuate movement effects tilting of the extension portion with respect to said main portion.

Abstract: A shield support, suitable for use in mines, comprising a floor-engaging structure which includes two sledge or like elements disposed side-by-side and spaced apart one from the other, a roof-engageable canopy, a shield mounted for pivotal movement with respect to the canopy and extendable and contractible prop means, carried by said elements, which are operable to adjust the height of the canopy. A pivotal guide linkage for supporting the shield from said elements includes links which are so connected to those elements and to the shield that the elements are rigidly coupled together only through the intermediary of those links and the shield.

Abstract: A roof support, suitable for use in mines, includes a floor-engaging structure, extendible and contractible prop means carried by that structure, and a roof-engageable canopy supported by the prop means. The canopy comprises a main portion and an extension portion, each of which includes a plate member the upper face of which is engageable with the roof. Fastening means, which are provided for rigidly connecting the extension portion and the main portion together, include at least one connecting member adapted to lie within the thickness of the plate members, or substantially so.

Abstract: A mine-roof support has a floor beam, an advancing ram and a relay bar. A bell-crank lever is pivotally-connected to the floor beam and the advancing ram is pivotally-connected to the bell-crank lever. One arm of the bell-crank lever has a member which may be in the form of a ball. The pivotal connections are such that, on extension of the ram, when the relay bar is connected to part of a conveyor, the bell-crank lever is initially urged downwardly from an inoperative position away from contact with the relay bar, into an operative position in contact with the relay bar, thereby to apply an upward thrust to the front end of the support and to maintain an upward thrust during further extension of the ram and consequential advancing movement of the mine-roof support towards the conveyor.

Abstract: A mine roof support system including a relief valve communicable with the props of each roof support through respective control valve means, and a main return pipe for receiving liquid discharged, by way of the relief valve, from the props when liquid at high pressure is no longer supplied thereto and the roof support is being advanced. A movable element of the relief valve comprises at least two relatively-movable and connected parts and is so co-operable with its seating as to ensure that when the support is so advancing a substantially constant predetermined back-pressure is maintained in the props sufficient to maintain the support in contact with the mine roof. If the pressure in the main return pipe exceeds the pressure then subsisting in the control valve means, one of the parts of said element is caused automatically to close onto the seating.

Abstract: A roof support suitable for use in mines comprises a main roof-supporting structure, a cantilever carried by the structure, an actuator and a link member through the intermediary of which the actuator is connected to one end portion of the cantilever for moving the cantilever between retracted and extended positions. The end portion of the cantilever has projections which come into engagement with an abutment when, upon advancing movement of the actuator, the cantilever reaches its fully extended position. The abutment and projections are so shaped that when they are in engagement they form pivot means about which the cantilever can be tilted. The link member is so formed and so connected to the cantilever that upon further advancing movement of the actuator the cantilever is caused to tilt about the pivot means into a roof-supporting position.

Abstract: A roof support, suitable for use in mines, includes a roof-engageable canopy comprising a main portion and an extension portion pivotally-connected to the main portion. Actuator means is carried by the main portion and arranged to effect sliding movement of a wedge member. This member has a wedging face which is co-operable with a complementary face formed on a part of the extension portion which projects substantially beyond the pivotal connection of the extension portion to the main portion and in the direction towards the actuator means. The sliding movement of the wedge member effects tilting of the extension portion with respect to the main portion.

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 self-advancing support, suitable for use in mines, includes a cantilever which is extendible and retractable with respect to a main portion of the support, and a sprag which is so mounted on said cantilever as to be extendible and retractable with respect thereto. Means are provided for advancing the support with respect to a mineral face and further means are provided for ensuring that during advance of the support the sprag is maintained in an extended, mineral-face-engaging, condition while the main portion is moved with respect to the cantilever in the direction towards the face, thereby reducing cantilever extension.

Abstract: A mine roof support includes a first liquid supply means having a first control valve for connecting a source of liquid under pressure to the legs of the support. The support is also provided with a second control valve which is actuatable, when the pressure of the liquid being supplied to the legs attains a value below the setting pressure for the legs, to connect the legs to a source of liquid under pressure by way of a second liquid supply means. Time-delay means is operable on the second control valve to cause it to close when a predetermined time has elapsed after the pressure in the legs has reached the setting pressure.

Abstract: A method of mining a mineral in which a roof is supported by a plurality of mine roof supports of the kind specified, each advanceable by a force applied to a lower part thereof. During advance of the support an upper part thereof can be sufficiently retarded, by hydraulic jacks carried, by each of its adjacent supports, with respect to the advance of its lower part. This causes the support effectively to rotate and to raise the leading end of the lower part away from the ground on which it is advancing.

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: An assembly of mine roof supports each of which has a control member and a hydraulically-operated member, e.g. a cantilever. The cantilevers operate one after the other in a predetermined sequence in response to actuation of one of the control members.Each cantilever is associated with a pressure-operated control valve and two serially-connected control valves which normally prevent operation of a cantilever in response to actuation of a control member unless the next-before cantilever in the series has completed its operation and the control member which caused that next-before cantilever to operate has been actuated.

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.

Abstract: A control means for use in a mining apparatus includes a radiation-emitting device on a cutting machine, a number of receiving devices, one associated with each roof support of the apparatus, for receiving radiation from the radiation-emitting device as the machine passes a receiving device, whereby a main control signal is generated, and advance-initiating means for each roof support, responsive to a command signal. A main conductor is connected to the receiving devices for carrying a main control signal, and disabling means is associated with each advance-initiating means and main conductor for rendering a said advance-initiating means non-responsive to a command signal applied to that means when the main control signal is above a pre-determined value. Attenuating means associated with the main conductor between each pair of roof supports is provided for gradually reducing the main control signal to a value below said pre-determined value.

Abstract: A mine roof support comprising a floor-engageable member, a roof-engageable member such as a canopy extending forwardly of the floor-engaging member, a first extensible leg secured between the floor-engaging member and the canopy, a linkage, which may include a shield, mounted on the floor-engaging member and pivotally connected to the roof-engageable member at its rear end and a second extensible leg secured between the floor-engaging member and the linkage. The linkage is preferably operative to constrain its pivotal connection to the canopy to move upward and downward in a fixed path relative to the floor-engaging member.

Abstract: A mine roof support comprising a floor-engaging member, one or more shielding members above the floor-engaging member, a flap pivotally mounted on the or on a shielding member and a sealing member pivotally mounted on the flap.