Abstract: A cable connection module comprises a first part that receives a multi-conductor flat cable and that has two pairs of spring loaded insulation piercing teeth. The first part of the module has a channel through which the cable passes and into which the teeth are urged when the first part of the module is screwed into engagement with a second part of the module. The second part of the module has an enclosure formed from metal contact elements that surround the insulation-piercing teeth and provide cam surfaces for urging the teeth through the cable insulation and into engagement with the conductors.

Abstract: A method of making an electrical device comprising two electrodes and a body of a switching material formed by reacting amorphous silicon or silicon compound with a passivating agent to remove or reduce the number of unpaired electrons occuring therein. The method includes a forming step in which a forming current is passed through the amorphous silicon layer so as to form an n- or p- doped amorphous silicon layer adjacent to one of the electrodes. The doped silicon layer extends over part only of the device so that the forming current is at most 400 mA. The device exhibits a voltage controlled negative resistance (VCNR) and may be employed for example for transient protection.

Abstract: An arylene ether ketone copolymer comprising:(a) 99 to 10 mol % of repeat units ##STR1## and (b) 1 to 90 mol % of repeat units --Ar--O--Ar--CO-- (II),wherein each Ar independently is m- or p-phenylene or a di- or poly- m- and/or p-phenylene moiety in which the phenylene rings are linked together by direct bonds or by --O-- or --CO-- groups.Especially preferred are the copolymers wherein ##STR2## and (II) is --Ph--O--Ph--CO--Ph--O--Ph--CO--Ph--CO--, each Ph independently being m- or p-phenylene.

Abstract: A method for the preparation of a variety of engineering polymers and copolymers, in particular aromatic polymers and copolymers which comprises reacting a stannylated reactant containing a first monomeric or polymeric moiety with an electrophilic reactant, usually a di(acid chloride) containing a second monomeric or polymeric moiety. The intermediate and second compound react by way of a condensation reaction to eliminate the tin and polymerise together the first and second moieties. Some novel polymers and copolymers can be prepared using this method.

Abstract: Organic compounds having aromatic ester, thioester, or carbonate groups are prepared by reacting an organometallic reactant where the metal is germanium, tin, lead, gallium, indium, thallium, arsenic, antimony, or bismuth with a suitable second reactant. For example, the ester ##STR1## is prepared by reacting the bis-tri--n-butyl tin derivative of ethyl 4-hydroxybenzoate with 4-phenoxybenzoyl chloride.

Abstract: A dimensionally heat-recoverable article carrying a heat curable adhesive coating on a surface thereof, the adhesive coating comprising (a) a mixture of substantially solid particles of a first reactive component with separate substantially solid particles of at least a second reactive component and (b) a water soluble polymeric binder having substantially no hydroxyl groups, the first and second reactive components being present in the adhesive coating as substantially unreacted separate particles capable of reacting together to effect curing when the article is heated to its heat recovery temperature.

Abstract: A high voltage porcelain insulator has a plurality of sheds extending laterally thereof at spaced apart locations therealong. The creepage path length of the shedded insulator is extended by mounting polymeric insulating creepage extenders on the porcelain sheds. The creepage extenders do not extend completely around the periphery of the sheds but leave a gap. Preferably the gaps of adjacent creepage extenders along the insulator are not aligned.

Abstract: A method for the preparation of a variety of engineering polymers and copolymers, in particular aromatic polymers and copolymers which comprises reacting a stannylated reactant containing a first monomeric or polymeric moiety with an electrophilic reactant, usually a di(acid chloride) containing a second monomeric or polymeric moiety. The intermediate and second compound react by way of a condensation reaction to eliminate the tin and polymerise together the first and second moieties. Some novel polymers and copolymers can be prepared using this method.

Abstract: Partially crystalline polyaryletherketones having improved glass transition temperature without unacceptably high melting temperature are produced by incorporating multi-ring aryl moieties (e.g. terphenyls of naphthyls) in the polymer backbone and mono-substituting those or other moieties in the backbone, or arranging the aryl multi-ring groups asymmetrically so as to kink the backbone.

Abstract: An article of manufacture, for example a conductor for an electrical wire or cable, is provided with a refractory coating preferably formed from a refractory metal or semi-metal oxide or nitride and preferably deposited on the surface of the article by a vacuum deposition process such as a sputter ion plating method. Adhesion of the refractory coating, especially at high temperatures may be improved, and migration of the substrate metal through the coating may be suppressed by varying the stoichiometry of the coating through its thickness and/or by the provision of a metallic or refractory intermediate layer. The articles are particularly suitable for use in circuit and signal integrity cables.The vacuum deposited refractory layer may constitute the sole refractory, or additional refractory layers may be deposited by other methods e.g. a sol-gel method.

Abstract: An arrangement for forming a block in a cable against transmission of fluid along the cable comprises a generally flat blocking array (1) that is formed from a fusible polymeric sealant, e.g. a hot-melt adhesive or a thermosetting adhesive, which has a number of passage ways (2) extending from one end of the array to the other end for receiving wires (4) of the cable. The assembly includes a heat-shrinkable covering that can be positioned around the blocking array (1) in its flat configuration and recovered about the array by application of heat, and the sealant is capable of melting during recovery of the covering and being forced from a generally flat configuration to a generally cylindrical one by recovery of the covering. The invention also includes arrays per se which may be formed from hot-melt adhesives or thermosetting adhesives.

Abstract: The invention provides a high voltage capacitor suitable for measuring the voltage of an overhead power line. The capacitor dielectric is mounted directly on to the power line conductor, which serves as one electrode of the capacitor. The other electrode of the capacitor is mounted on to the outer surface of the dielectric, and is protected at each side by a guard ring. Stress control is provided between the outer capacitor electrode and the guard rings and also at the outer edges of the guard rings. The capacitor may be enclosed in an earthed housing, which can contain one or more current transformers. The apparatus can be used for fault detection and location, and may be used in combination with a power cable or a switch.

Abstract: A method for the preparation of a variety of engineering polymers and copolymers, in particular aromatic polymers and copolymers which comprises reacting a stannylated reactant containing a first monomeric or polymeric moiety with an electrophilic reactant, usually a di(acid chloride) containing a second monomeric or polymeric moiety. The intermediate and second compound react by way of a condensation reaction to eliminate the tin and polymerise together the first and second moieties. Some novel polymers and copolymers can be prepared using this method.

Abstract: A dimensionally heat-recoverable article has on one of its surfaces a heat-curable adhesive coating. The coating has a mixture of substantially solid particles of a first reactive component with separate substantially solid particles of at least a second reactive component, the first and second components being capable of reacting together to effect curing of the coating when the heat-recoverable article is heated to its recovery temperature. The particles have a size distribution in which not more than 40% by weight of the particles are less than 50 micrometers in size and at least 90% by weight of the particles are less than 300 micrometers in size.

Abstract: A circuit protection device for protecting electrical circuits against voltage transients comprises a chip package which includes a threshold switch device formed from an amorphous composition.

Abstract: A circuit protection device for protecting an electrical circuit from a voltage transient, e.g. a voltage transient caused by an electrostatic discharge, lightning or a nuclear electromagnetic pulse, comprises a threshold switching element formed from an amorphous composition comprising arsenic, sulphur, and optionally germanium, and a pair of electrodes in contact with the composition. The devices generally exhibit a good balance of physical properties including switching speed, energy required to latch them in their low resistance state, high resistance state (off) resistance, threshold voltage and capacitance, which enables them to be used successfully to protect electrical circuits from such transients.

Abstract: Friedel Crafts preparation of aryl carbonyl compounds having an exceptionally high degree of isomeric purity and freedom from by-products can be achieved by adding to the Lewis acid reaction system a protic controlling agent selected from ROX, water, RCOOX, RSO.sub.3 X, and ROY, wherein R is organic, X is hydrogen or metal, and Y is metal. Contrary to conventional expectation, the protic agent does not significantly alkylate or acylate the Friedel Crafts reaction product.

Abstract: An arrangement for termination of a screened cable comprises:(a) a termination piece for the screen having a hollow, preferably metal, cable entry portion that can be positioned around the wire(s) of the cable, and(b) a dimensionally recoverable hollow article which can be positioned over at least part of the cable entry portion and the proximal part of the cable extending from the cable entry portion.The cable entry portion is provided with a gripping member, for example a thin annular ridge, for gripping the cable screen, placed around the entry portion. After the cable screen has been positioned over the cable entry portion and gripping member, the recoverable article is positioned over the cable and cable entry portion and is recovered to cause the gripping member to grip the cable screen.

Abstract: Curved composite articles, for example aeronautical radomes, are given a curved surface layer by consolidation under heat and pressure of a fusible polymeric fabric. Polyaryletherketone fabrics are preferred.

Abstract: A circuit protection device for protecting an electrical circuit from a voltage transient, e.g. a voltage transient caused by an electrostatic discharge, lightning or a nuclear electromagnetic pulse, comprises a threshold switching element formed from an amorphous composition comprising germanium, selenium and optionally antimony, and a pair of electrodes in contact with the composition. The devices generally exhibit a good balance of physical properties including switching speed, energy required to latch them in their low resistance state, high resistance state (off) resistance, threshold voltage and capacitance, which enables them to be used successfully to protect electrical circuits from such transients.