Abstract: A typewriter carriage escapement mechanism comprises a rack (10) movable with the typewriter carriage (2) and having two sets of teeth (16 and 18) projecting in opposite directions. An escapement dog (30) has two separate teeth or sets of teeth (44 and 54) arranged to engage the two sets of rack teeth (16 and 18) alternately as the dog (30) moves at right angles to the rack (10), on operation of the keys (90) or space bar (92) of the typewriter. One of the sets of teeth (54) is mounted on a pawl (50) movable relative to the other tooth (44) or set of teeth, to enable both sets of teeth to be disengaged from the rack (10) to release the carriage (2). The pawl (50) is movable against a return spring (70) by means of an actuating rod (80) engaging a lug (62) on the pawl (50). The mechanism of the invention enables a single escapement member (30) to effect both the stepwise movement of the carriage (2) and also the carriage release.

Abstract: A coal cutting machine 13, a conveyor 12 and a plurality of mine roof supports 10 extend along the face 11 of a coal mine. The operation of the hydraulic jacks of the roof supports are controlled by pilot valves which are electrically powered and rotationally driven. For example, motorized or cam operated pilot valves can be used. Such pilot valves use much less energy than valves controlled conventionally by solenoids, and the electricity supply can thus be at an intrinsically safe level.The operation of the pilot valves include unitary operation of a given support, remote operation of one support from another and sequential operation of a series of supports.

Abstract: A valve for use in controlling a plurality of fluid operated functions, for example the functions of a hydraulic mine roof support, comprises a valve body 10, a plurality of valve members 13 each movable independently to carry out a fluid flow control function, a plurality of valve actuating members 21, movable in a direction tending to actuate the valve members 13, and an interposer device 25 movable to prevent at least one of the valve actuating members 21 from actuating its associated valve member 13, thus enabling the valves to be selectively operable.

Abstract: Apparatus for the oral administration of capsules to animals, particularly ruminants such as sheep, comprises a tubular member adapted to be inserted into the animal's mouth so that the tip of the tubular member is near the root of the animal's tongue, means for introducing a capsule into the tubular member and for propelling the capsule to its tip, in which the tip of the tubular member consists of two tip portions extending from the mouth of the tubular member and laterally spaced from one another so as to define a cavity in which a capsule is deposited at the root of the animal's tongue. The top of the tubular member has a convexly curved upper surface adapted to engage the animal's soft palate to encourage a swallowing reaction, and a lower surface shaped to engage and restrain movement of the dorsum and the front part of the animal's tongue.

Abstract: A valve assembly is provided for use with a hydraulic mine roof support, the assembly having uni-directional control means 49 interconnecting first and second pressure sectors of the valve assembly, and further control means 20 embodied in the first pressure sector which further control means is arranged for activation by fluid pressure in the first pressure sector to allow pressure fluid to flow from the second pressure sector to the first pressure sector until the fluid in the first pressure sector is equal to or exceeds the fluid pressure in the second pressure sector.

Abstract: Attachment means are provided for attaching a mine roof support to an abutment, (e.g. a flexible conveyor) the attachment means comprising a ram arrangement in the form of at least two rams 25, 26 operable to effect relative movement between the mine roof support and the abutment. The provision of two or more rams instead of the conventional single ram means that smaller bore rams may be used, for example a 60 mm bore as opposed to 41/4 inch bore and this makes it possible to cover or encase the rams in a protective shield without reducing the vertical space available to a miner underneath the mine roof support.

Abstract: A releasable connection device for coupling a bucket 9 to a vehicle comprises a support 2 attached to the lifting vehicle, the support comprising two arms 4, 6 and a channeled member 8 connected between the two arms. Two plates 14, 16 are attached to the bucket 9 and have a bar 18 connected between them. In use, the bar 18 fits into the channelled member 8 and the bucket 9 and support 2 are secured by two hydraulically operated locking bolts 22 attached to the support 2, which pass through holes 20 in plates 14 and 16. When connected, the bucket and support may be manoeuvred by means of hydraulic rams attached to the support.

Abstract: A valve device is provided for use in a pressurized hydraulic fluid path, for example the hydraulic path of a hydraulic leg of a mine roof support which is required to yield under two different sets of conditions. The valve device has a port 15 for connection to the pressurized hydraulic fluid path, a bleed valve 25 being arranged to permit hydraulic fluid to bleed from the path at a first rate when the pressure in the path exceeds the first limit, for example to permit the hydraulic leg to collapse at a very slow rate, for example as a mine roof converges. There is also a dump valve 20 arranged to permit hydraulic fluid to flow from the path at a second greater rate, for example if a rock burst occurs. Although the dump valve 20 reacts to high pressure surges of fluid, it does not react to low pressure surges because a non-return valve device 30 traps on one side of the dump valve hydraulic fluid which is at a pressure in the region of the first limit.

Abstract: Castings are produced by sandwiching a central mould part 10 between two outer mould parts 36, 38 during the casting process. The central mould part 10 is then transfered sequentially from between the outer mould parts 36, 38 and subsequently re-located between the outer mould parts in a vacant, relatively cool, and dry condition for the production of a further casting. In one embodiment a plurality of central mould parts are transferred sequentially from the outer mould parts to a removal station 45, a quenching station 50, and a drying station 70, before being returned to the central mould parts.

Abstract: A mine roof support has a roof engaging structure 13 and a floor engaging base 14, spaced apart by extensible hydraulic jack means 15 and 16. The roof engaging structure and the base are interconnected by a pivotal linkage device 23, 24 arranged so that, throughout its range of working movement, a pivot point of the linkage performs substantially greater movement in the vertical direction than in the horizontal direction. This reduces the effect of problems arising from the linkage device projecting substantially into the goaf area of a mine working or into the walkway area of the support. In a preferred embodiment the linkage device comprises a parallelogram type linkage.

Abstract: A self-advancing mine-roof-support for use in or aligned with a main roadway or gate has a floor-engaging part and a roof engaging part spaced apart by extensible load-bearing prop or jack means, and engagement means for a face-conveyor and a transversely acting transfer conveyor whereby their relative positions are constrained to facilitate discharge of mineral from one conveyor to the other. The engagement means for the face conveyor comprises sliding anchor beams that assure maintenance of the relative attitudes of the support and the face conveyor and the transfer conveyor is held fore and aft of the support.

Abstract: An underground support, e.g. for the roof of a mine, has a roof engaging canopy 10 which can be raised and lowered in a controlled manner by hydraulic legs 14. Inflatable flexible membrane means, for example in the form of bags 12, are provided on the upper face of the canopy 10, which shape themselves to the mine roof and distribute loading evenly thereto. Inflatable flexible membrane means may also be used to prevent flushing of loose debris between adjacent supports, and on roadway supports.