Abstract: Optical communications fibers extend from a central office to subscribers' premises for carrying signals in both directions between optical transmitters and receivers. Each subscriber's optical receiver continuously reflects back to its fiber, and then to the central office, about 20 percent of the light which it receives. At the central office the reflected light is monitored in turn for each subscriber, and is correlated with the signal transmitted to that subscriber to provide a signal for optical time domain reflectometry of the respective subscriber's fiber connection.

Abstract: A battery powered portable test instrument for detecting whether light is propagating in an optical fiber has a jaw into which the fiber is placed, the jaw being closable to press a section of the fiber into a bend having predetermined radius of curvature. If light is propagating through the fiber it is scattered and detected in a detection circuit. If the detected light is greater than the predetermined threshold, an indicator circuit is energized.

Abstract: A method of sealably encapsulating an article by using, in combination, a plastics heating and pressurizing device and a manually portable accumulator. The device has a chamber to contain plastics material and heat it into a molten state. There is a releasable coupling means to assemble the device and container together to interconnect the chamber with a reservoir inside the accumulator for transfer of the molten plastic material into the reservoir. The accumulator has means for forcing the molten material from the reservoir into a mold cavity when the accumulator has been manually transferred from the device to a mold.

Abstract: A method of sealing an article by heating solid plastic material in a chamber into a flowable state and then forcing the material from the chamber into a reservoir in a manually portable device. While in the reservoir, the material is maintained homogeneously molten and flowable and the material is forced from the reservoir into a mould cavity at a sufficiently fast rate to fill the cavity before flow passages into the cavity become blocked with hardening material.

Abstract: A method of forming an encapsulated splice region between two cable ends in which, after end portions of the core have been exposed beyond the jacket and sheath or shield, the conductors are splayed outwards and the cable end portions are brought close together. Splices are then formed between conductors of the two cables and the conductors are folded over either one cable jacket or the other to locate each splice upon and supported by the jacket. Each splice is individually covered with sealing material and end regions of the cables are encapsulated so as to encapsulate the splices and fluid tightly seal them.

Abstract: A method of moulding by low pressure moulding wherein a passage from the mould cavity is bridged by the molten material during filling and in which the moulding pressure is too low to cause the material to flow down the passage. After the mould is completely filled, the pressure increases to cause penetration of the molten material along the passage to a switch operating position to operate a switch to stop further flow of material into the mould.

Abstract: An optical cable with an axial tensile strength member extending from one cable end beyond the cable jacket, and a pulling attachment secured to the extension of the strength member and does not seal directly around the cable jacket. A moulded plastic encapsulation encapsulates the cable end, an end portion of the jacket and the extension of the strength member to prevent fluid leakage between the exterior and interior of the cable.

Abstract: Moulding apparatus with a passage between mould parts to locate an article extending through the mould parts and into the mould cavity. A device is disposed within the passage for gripping and sealing against the article. This device is resiliently compressible and has gripping and sealing ribs projecting into and spaced along the passage. Parts of the device lying between the ribs define parts of the passage of substantially equal diameters for use with an article, e.g. a cable with an outside diameter which is also substantially equal to the passage diameter at those parts of the passage.