摘要:
A support for storage and delivery of coils of wire or like flexible elongate product comprises a first flat member having a length dimension defining the axis of the support and at least one further flat member secured to the first by hinge means so that it may be moved between a storage position in which it lies flat on the first flat member and a working position in which it projects outwardly from it. The first and further flat members have aligned slots extending inwards from the outward edges of the respective members adjacent one (the lower) end thereof. A flat base member has a non-circular aperture with shape and dimensions such that it can be passed freely over the first and further flat members and then rotated with respect to them to to engage in the aligned slots. Preferably there are two of the further flat members, forming an equal-armed cruciform with the first, in which case the aperture in the base is suitably square. The support can be made from plywood, and is lighter than current steel supports besides packing flat for storage or transport when empty.
摘要:
An optical fibre connector-part (1) comprises a housing (2) in which an optical conductor extends between two oppositely disposed ends of the housing, at least one of which ends constitutes a plug or a socket. An integrated optical chip (6) is disposed within the housing and constitutes a part of the optical conductor. Preferably, the housing (2) is a moulded plastics body and the integrated optical chip (6) is at least partially encapsulated in the moulded plastics material. The connector-part provides for ready reconfiguration of modularised optical systems.
摘要:
A cable termination for a mineral insulated electric cable, comprises a tube (21) of flexible electrically insulating material that is slit along its length at at least one position (29) on its circumference to divide the tube into at least two opposed portions (21', 21'') that can be positioned about a cut-back sheath (S) of the cable and brought together to enclose the end region of the sheath. The tube has one end that is closed by an end wall (23) that has one or more throughbores (26) for allowing one or more conductors of the cable to extend through and beyond the termination. The termination also includes a collar (43) that can be located about the tube when, but only when, the opposed portions of the tube have been brought together. The collar (43) ensures that the tube has been correctly closed and that, once installed, the termination cannot be accidentally opened.
摘要:
A method of installing an optical cable in an overhead power transmission line which comprises supporting an optical cable (1), which has an overall protective sheath of electrically insulating material, in long lengths between towers employed to support at least one electric power transmission line (2) which is on load and, after the optical cable (1) has been so installed and while the overhead electric power transmission line is on load, providing on or in the supported optical cable at least one longitudinally continuous path (11) which extends throughout substantially the whole length of the supported optical cable and which is sufficiently electrically conductive to carry along the cable (1) any currents that may be capacitively induced. The method enables a cable that will not be subject to dry-band arcing to be installed without danger to personnel during installation.
摘要:
An electric cable with limited fire survival characteristics comprises at least one insulated conductor insulated with silicone rubber or other organic insulant that leaves an insulating inorganic residue on thermal breakdown and optionally a bare earth wire. A screening layer is formed by a laminate comprising a centre layer of mineral fibre cloth having one face formed by a layer of metal foil and the the other by a layer of organic material infusible below 200°C, preferably regenerated cellulose or cured isophalate polyester film. An extruded sheath of flame-retardant polymeric material contacts, but does not adhere to, the infusible film layer of the laminate. This separation of the screening layer from the sheath ensures that it can be cut back for termination with negligible risk of damage to the conductor insulation and minimal risk of damage to the essential metal layer of the screening laminate. After it has been so cut back, the projecting end of the laminate may be turned back over the cut end of the sheath to expose a metal layer that is sufficiently supported to make an effective screen connection by mechanical means.
摘要:
On réalise un supraconducteur allongé en enfermant des particules anisotropes supraconductrices ou susceptibles d'être converties en une forme supraconductrice par un traitement subséquent dans un tube en un métal malléable, en compactant ledit tube et en le réduisant en une ou plusieurs étapes de réduction en une bande allongée. Au moins une de ces étapes de réduction est réalisée par un processus de laminage rotatif, de préférence avec un équipement dans lequel un des plateaux est stationnaire du moins en rotation alors que le plateau mobile pivote autour d'un premier axe qui est incliné d'un petit angle alpha par rapport à la direction de la force appliquée, et que le premier axe tourne autour d'un second axe coïncidant sensiblement avec la direction de la force appliquée, pour produire un mouvement "vacillant". L'opération de laminage rotatif peut s'effectuer progressivement et par étapes ou être quasi continue. On obtient un alignement sensiblement amélioré des particules supraconductrices en forme de plaques si l'on compare avec les processus de laminage conventionnels, et il en résulte une densité augmentée de courant critique.
摘要:
A device indirectly connects an outlet of a feed chamber of an optical fibre installation unit to an open end of a preformed tube, e.g. one that is pre-installed in a building, in order to enable one or more optical fibres to be introduced into the tube by the viscous drag of a flow of gas. The device comprises a flexible hose (6) one end of which can be connected to the feed chamber outlet, the hose having a number of insulated electrical conductors (36) extending along its length. At the other end of the hose is a coupler (1) which comprises a tubular spigot (8) for forming a spigot and socket connection to a connector associated with the tube, an electric safety switch (28) operatively coupled to the spigot and electrically connected to one of the conductors (36) which can be electrically connected to signal means associated with the feed chamber. The coupler (1) includes at least one electrically operated exhaust valve (30) electrically connected to another of the conductors (36) and can be connected to control means associated with the feed chamber so that when a connection has been made between the coupler (1) and a hose a signal can be sent to the control system to close the valves (30) and to commence introduction of the optical fibre(s). The coupler (1) may be provided with one or more triggers (12,14) to enable disconnection of the spigot (8) from the hose and to actuate an override switch that can override the safety switch (28) so that a further length of fibre can be introduced by the feed chamber once the coupler has been disconnected from the tube, thereby enabling the installed fibre to be terminated.