GB255034A - Improvements in or relating to apparatus for feeding oil to high tension cables - Google Patents

Abstract

255,034. Pirelli & Co. July 11, 1925, [Convention date]. Cables, with pressure-controlling means for oil-filling.- Relates to cables of the kind in which passages for oil are provided in the paper or other insulation, and consists in the provision of variable capacity reservoirs for the oil, which are in communication with the passages and are so constructed as to receive oil from or feed it back to the cable automatically under changing temperature conditions, and also to ensure exclusion of air. The reservoir comprises one or more cells b provided with flexible walls, one side of each wall being in contact with air, and the walls being sealed to the sides of a frame a fitted with passages d to permit of oil entering or leaving the reservoir. In a modification a number of cells are contained in a sealed chamber and form containers for air or other gas under pressure, the oil being contained in the spaces between the reservoirs. The interior of the sealed chamber is in communication with the passages in the cable. The Specification as open to inspection under Sect. 91 (3) (a) comprises also detailed constructions of reservoirs. In one construction, Fig. 2 (Cancelled) the reservoir comprises one or more containers, each consisting of a central frame 10, which may be circular, and two flexible diaphragms 11. 12 hermetically sealed to the sides of the frame 10. The outside of the diaphragms is open to the atmosphere and the intervening space containing the supply of oil is in communication with the cable by an outlet 14. When several containers are mounted in one frame, as shown, a common duct 19 communicates with the cable and all the containers. The reservoir filling arrangements consist of a common duct 26 and inlets at the top. The amount of oil in the reservoir is indicated by a lever arm 22 connected by a rod 23 to the diaphragm of one container and moving over a scale provided with maximum and minimum indicators 25. The duct 19 leads to a casing 55, Fig. 9 (Cancelled), which is soldered to the sheath 56 of the cable. In a modification, the elements of the tank are supported in a sealed chamber and form containers for air or other gas under pressure, and the oil is contained in the spaces between the containers. This subject-matter does not appear in the Specification as accepted.