Abstract: A composite connector for use with a perforated circuit board is formed from a preform of electrically conductive sheet metal which is folded to form, at one end of the composite connector, a socket which will make a snap fit in a hole in a circuit board and in which a terminal pin of a circuit component can be resiliently gripped and, at the other end of the composite connector, two bifurcated contacts. The bifurcated contacts are transversely spaced apart and are of such a form that when a length of insulated wire is introduced between the limbs of each bifurcated contact, the limbs will cut through the insulating covering of the wire to effect an electrical connection with the wire at two positions spaced along its length.

Abstract: In a method of continuously casting unrefined electrodes in quantity for use in the electrolytic refining of metal in which a metal e.g. copper, strip is continuously cast and cut at spaced positions along its length to form electrodes, a substantial saving in metal is effected by casting the strip in such a way that, in longitudinally spaced minor portions of its length, the strip has at least one hole, recess in at least one of its side edges, or region of substantially reduced thickness as compared with that of the major portion of its length.

Abstract: In an electric and/or optical cable for use suspended under water at depths of at least 1,000 m or for direct burial in the ground, each core is surrounded by a water-impermeable barrier comprising a cushioning layer of elastomeric material and, a longitudinally applied, transversely folded metal tape carrying on its outer surface a plastics coating and an outer plastics sheath is bonded to the plastics coating of the water-impermeable barrier. The metal tape has a helically extending corrugation formed by winding around the folded tape, prior to application of the plastics sheath, a plastics coated terylene filament which is applied under such a tension as to form the helical corrugation and to cause elastomeric material of the cushioning layer to fill the trough of the helical corrugation in the inner surface of the folded tape, the plastics coating on the terylene filament being bonded to the plastics sheath.

Abstract: A simple and inexpensive dead end fitting for securing an overhead conductor loosely housing an optical guide to a tower comprises a sleeve of malleable metal or metal alloy, open at each of its ends, for compression jointing to the conductor; a steel termination in screw threaded engagement with the sleeve and having a clevis for securing the fitting to a tower; and a lug welded to the sleeve for effecting electrical connection to a jumper cable. The lug engages in a notch in the adjacent end of the termination to lock positively the screw threaded engagement between the sleeve and termination.

Abstract: In an inexpensive and simple method of effecting a joint between two overhead electric conductors incorporating optical fibres or between an overhead electric conductor incorporating an optical fibre and an optical cable extending to a sub-station or other location, at least a part of each or the overhead conductor is introduced into a metal sleeve extending from a wall of a metal housing and the sleeve is compression jointed to the conductor to effect a mechanical and electrical joint between the conductor and the housing. The part of the conductor protruding into the housing is cut back and a joint is effected between the optical fibres of the two overhead conductors or between the optical fibres of the overhead conductor and the optical cable that has been introduced into the housing. The housing is sealed to render it fluid tight and is preferably filled with petroleum jelly.

Abstract: A flexible stranded body, such as an electric conductor of an overhead electric transmission or distribution system, comprises at least one stranded layer of elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the stranded body and, loosely housed in the elongate compartment, at least one separate optical fibre and/or at least one optical bundle. Preferably, the elongate compartment extends within a circumferentially rigid central core which is surrounded by the stranded layer or layers but it may be a bore in an elongate element of a stranded layer or an elongate space bounded by two adjacent elongate elements.

Abstract: A readily strippable electric wiring cable comprises two electrically insulated line conductors arranged substantially parallel to one another and transversely spaced apart within a surrounding extruded insulating sheath and a bare earth conductor which is loosely housed in a bore extending lengthwise within the sheath between and parallel to the insulated line conductors. Preferably, each line conductor is itself loosely housed in a separate bore in the sheath. Double insulation is provided between the earth conductor and each line conductor.

Abstract: In a modified "Conform" machine for continuous friction-actuated extrusion of metals, especially particulate copper, the abutment at the outlet end of the working passageway does not fully block the end of the wheel groove. Instead a substantial clearance is left, and metal extruding through it adheres to the wheel to re-enter the working passageway at the entry end. Preferably the abutment is of semicircular cross-section. For a given output rate, a significant reduction in torque, and working stresses, is obtained.

Abstract: Apparatus for detecting and locating a fault in an electric cable using a pulse-echo technique comprises means for injecting step function or single pulses into a cable, means for digitizing and storing the pulse-echo signal obtained under two different conditions of the cable, and means for retrieving the signals obtained under the two said conditions, comparing them and thus locating the position of the fault. Preferably, the apparatus also includes means for detecting whether the cable is "live and healthy" or "live and faulty" by obtaining a digital pulse signal indicating that a voltage is present on the cable, obtaining a second digital pulse signal indicating by a series of pulses when the current in the cable is above the normal load current and gating these two signals in a NAND gate to obtain a signal representing the state of the cable.

Abstract: In continuous friction-actuated extrusion, especially Conform extrusion of copper, at least part of the tooling is made from aged nickel-chromium base alloy (which is preferably cold-worked before aging to give a yield strength of at least 1500 MN/m.sup.2 at 20.degree. C.) and which is capable of sustaining an adherent oxide film. The preferred alloy is "Inconel Alloy 718". Despite lower hardness, the tooling has better service life than conventional special-steel tooling.

Abstract: A wire or other core is enclosed by two concentric extruded layers, at least one of which is of crystallizable polymeric material, by extruding the layers in succession around but spaced from the core. The first and second layers are brought into thermal and mechanical engagement with each other before the first contacts the core, and the relative thermal capacities of the parts and the temperatures of the layers as they are brought into engagement are such that as the second layer cools and increases in strength and the first layer is heated by thermal transfer from the second layer and decreases in strength, a region of least overall yield strength is formed at a position where the temperature of at least one of the parts (being made of a crystallizable polymeric material) is at a temperature between its glass transition temperature and its crystalline melting point.

Abstract: In an overhead electric transmission system in which an overhead conductor includes at least one optical fibre constituting part of an optical communication system, there is provided, at a tower along the system, an electrically conductive rod supported by and electrically insulated by an insulator from the cross-arm of the tower but electrically connected to earth through the primary winding of a step-down voltage transformer. The rod is substantially horizontal and substantially parallel to a group of overhead electric conductors suspended from the cross-arm by an insulator. The surface area of the metal rod and its position with respect to the group of current-carrying conductors of the system are such that electrical power for regenerators or other ancillary equipment of the optical communication system is provided across the secondary winding of the transformer, thereby affording simple and inexpensive means of providing such power.

Abstract: A simple and inexpensive skeleton frame for a fabricated structure for housing electrical equipment comprises upstanding legs which are arranged at the corners of the frame and which are secured together at the top and bottom of the frame by endless flexible frame metal bands surrounding the legs and maintained in tension by bracing devices positioned between the legs. Each bracing device comprises a central hub, elongate braces extending outwardly from the hub and each engaging a leg, and screw threaded adjustable means for urging the braces outwardly to maintain the endless band under such a tension that the frame is held rigid. The bottom, sides and top of the frame are clad with sheet metal and a hinged door.

Abstract: An optical cable comprises at least one optical bundle and/or at least one separate optical fibre housed loosely in at least one bore extending lengthwise in an extruded elongate body of rubber or plastics material and, embedded in the extruded elongate body and arranged side by side with the bore or bores, at least one separate elongate reinforcing member. Preferably the bore or bores and the reinforcing member or members extend substantially parallel to the axis of the extruded body and their axes lie in a substantially common plane. Alternatively, a single reinforcing member may extend centrally in the extruded body and a plurality of separate bores be arranged around, preferably helically around, the central reinforcing member.

Abstract: In a continuous friction-actuated extrusion process, such as the Conform process, particulate material is fed into the extrusion passageway at a rate low enough to the rate at which material is extruded from the die orifice to be determined by and substantially equal to the rate of feeding. Feeding can be achieved by a simple hopper feeding through an adjustable constriction, preferably formed by a simple gate valve, or a gravimetric or volumetric controlled rate feed device can be used.

Abstract: A flexible stranded body, such as an electric conductor of an overhead electric transmission or distribution system, comprises at least one stranded layer of elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the stranded body and, loosely housed in the elongate compartment, at least one separate optical fibre and/or at least one optical bundle. Preferably, the elongate compartment extends within a circumferentially rigid central core which is surrounded by the stranded layer or layers but it may be a bore in an elongate element of a stranded layer or an elongate space bounded by two adjacent elongate elements.

Abstract: In an overhead electric transmission system in which the phase conductors incorporate optical fibres, a joint between optical fibres of two phase conductors or between optical fibres of a phase conductor and an optical cable extending to a sub-station is enclosed within a fluid-tight metal housing. The housing is electrically connected to each phase conductor, is electrically insulated from earth, and has an external shape of such a form as to provide effective control of electrical stress. Preferably the metal housing is of hemi-spherical shape and is mounted on top of a porcelain insulator containing oil under pressure. Where an optical fibre connected at the joint is that of an optical cable, it passes into the metal housing through the oil filled porcelain insulator.

Abstract: The invention concerns an overhead electric traction system of the kind in which current is collected from an overhead contact wire by means of a collector carried on the roof of a vehicle and extending transversely of the contact wire. The contact wire is supported, at spaced positions along the route of the system, by an overhead structure comprising two transversely spaced upstanding members, and extending between and connected to the upstanding members, a transversely extending beam. Each of the upstanding members is so installed near its lowermost end as to permit limited pivotal movement of the member at least about an axis extending lengthwise of the route of the system and limited relative movement is permitted between the beam and the upstanding member at least about an axis extending lengthwise of the route of the system, each upstanding member being anchored to the ground by at least one tie connected to the member near its upper-most end.

Abstract: In an optical fiber connector component including a tubular housing and three round rods supported longitudinally side by side within the tubular housing and defining between them an intersticial space for reception of an optical fibre or optical fibres, the tubular housing is of a material having a greater coefficient of thermal expansion than that of the material of the rods. In use, prior to introducing optical fibre into the intersticial space, the tubular housing is heated to cause it to expand radially outwardly to permit radial separation of the rods and introduction of the optical fibre into the intersticial space. The tubular housing is then cooled or permitted to cool to cause the housing to contract radially inwardly to compress the rods inwardly and cause them to grip the optical fiber so that it is aligned axially in the intersticial space.

Abstract: A screw fixing comprising a screw (9) having a nut (1) threaded on it, the screw head and the nut each having a bearing surface facing the other, and a channel (5) having at the free ends of the limbs of the channel inturned flanges (6) directed towards the base (8) of the channel, the flanges defining a slot (10) which is open at both ends, at least one of the flanges having teeth (7) in its free edge directed towards the base of the channel and the bearing surface that engages it having parallel ribs (4) that interlock with the teeth to prevent the screw and nut sliding longitudinally in the channel.