Abstract: A component 10 for making Al5 Nb.sub.3 Sn superconducting wire is of plane-filling cross-section after removing temporary additions 6, 7. It consists of a central pillar 1 of aluminium (later replaced by tin) surrounded by a two-deep array of polygonal copper columns 2/2a containing niobium rods. Many (e.g. 61) components 10 are stacked together and extruded. The niobium rods adopt and retain a uniform distribution with minimum intervening material. On heat-treatment of the whole, the tin diffuses over a relatively short path and hence consistently into the rods, whereby there is formed a kilofilament Nb.sub.3 Sn wire.

Abstract: A component 10 for making A15 Nb.sub.3 Sn superconducting wire is of plane-filling cross-section after removing temporary additions 6, 7. It consists of a central pillar 1 of aluminium (later replaced by tin) surrounded by a two-deep array of polygonal copper columns 2/2a containing niobium rods. Many (e.g. 61) components 10 are voidlessly stacked together and extruded. The niobium rods adopt and retain a uniform distribution with minimum intervening material. This "sixty-one" member retains its shape during the extrusion and is itself of plane-filling cross-section. Several of them are voidlessly stacked together and on heat-treatment of the whole, the tin diffuses over a relatively short path and hence consistently into the rods, whereby there is formed a kilofilament Nb.sub.3 Sn wire.

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 composite strip for use in the manufacture of superconducting windings consisting of a thin layer of insulating material situated between two layers of metal. The composite strip may be used to form the winding on its own, or it may be used in conjunction with a separate strip conductor. If it is used on its own, one or more of the layers of the composite strip is made to be superconducting. If it is used with a separate superconducting strip, then the metal layers can be made of an alloy such as to assist in thermally stabilizing the superconducting strip. A winding made in such a manner.