Abstract: A metal end fitting (13) is hermetically sealed to an end fin (4) of an insulator component (1) which includes an insulating rod (2) surrounded by fins (4) of vulcanized elastomer by coating at least one layer of rubber/metal gluing agent on the bottom portion (12) of the metal end fitting (13), then disposing an intermediate washer (10) of raw elastomer between the metal end fitting (13) and the end fin (4), fixing the end fitting (13) to the rod (2) in such a manner that the intermediate washer (10) ring is cmopressed between the end fin (4) and the bottom portion (12) of the end fitting (13), and then vulcanizing the washer (10).

Abstract: Method of welding two hollow ceramic half-components containing an organic binder whereby each half-component is first loaded into a die, the jointing planes of the two half-components are then brought into contact by bringing together the two dies, working pressure is thereafter applied to one of the half-components in a direction perpendicular to the jointing planes and vibration is simultaneously applied to the other half-component in a direction parallel to the jointing planes to effect the welding of the two half-components by interpenetration. The two dies are then separated and the joined monobloc component is removed and sintered without altering the component's monolithic quality.

Abstract: A double molded over method of manufacturing a lightning arrester in which a central core 1 is made of zinc oxide in a first step, then two metal end fittings 5, 6 are molded onto the end faces and over the side thereof, and finally a coating of elastomer material 7 is molded around the side wall of the central core and over side portions of the end fittings. The core may be formed of a plurality of smaller section bars of zinc oxide regularly disposed about a longitudinal axis with the end fittings molded onto the end faces and about the sides of the end bars whose end faces are partially metallized. In a further variant, a stack of zinc oxide based pellets having the same cross-sectional area as the core in the first example, with the stack having the same overall length as the core if stiffened by thermal compression with fusible metal inserted between pairs of pellets. The stack assembly is then compressed mechanically in conjunction with heat treatment to effect very good mechanical bonding.

Abstract: The present invention relates to a method of manufacturing a lightning arrester (100) having two end fittings (2,20) at either end of a substantially cylindrical central core constituted by a stack of pellets (6, 7, 8) made of a varistor-type material and having holes therethrough whereby the pellets are threaded over a central rod (1) made of stratified material. The stack assembly is put into compression against the two facing faces of the end fittings (2, 20) by means of the rod (1), the space between the rod (1) and the pellets (6, 7, 8) is filled by casting or injecting an insulating material, with the assembly obtained in this way being perfectly rigid, and a coating (30) of an elastomer of the EPDM type is molded over the assembly, with the coating adherring perfectly to all of the surfaces of the core and of the end fittings which it covers.

Abstract: A cement for fixing a bone prosthesis, the cement containing:(a) a solid phase comprising firstly polymethylmethacrylate and a copolymer of methyl methacrylate with an acrylate or a methacrylate of another alcohol, both in powder form, and secondly an organic peroxide suitable for generating free radicals; and(b) a liquid phase comprising methyl methacrylate and an accelerator for accelerating decomposition of the organic peroxide.The copolymer is an oligomer, and the liquid phase includes as the accelerator for accelerating decomposition of said organic peroxide an acrylate or a methacrylate carrying a tertiary amine function, and as a cross-linking agent a compound having at least two functions in its molecule suitable for reacting with the reactive functions carried by the polymers of the solid phase, or else a double bond and a function suitable for reacting with the reactive functions carried by the polymers of the solid phase.

Abstract: Rigid electrical insulator including a soda-lime glass dielectric with an average thickness of 10 to 15 mm, exhibiting a substantially parabolic stress curve, wherein the maximum value of the surface compression stresses at any point in the part falls within the range of 30 to 80 MPa, while the maximum value of the internal tensile stresses at any point in the part falls within the range of 15 to 40 MPa.

Abstract: A porous material made from sintered inorganic particles. It has an open pososity of 30% to 40% by volume, a permeability to water at 20.degree. ranging from 0.6 to 60 m.sup.3 /h.m.sup.2.bar for a wall thickness of 2 cm as the average pore diameter varies from 2 to 20 microns and a crushing resistance, measured under conditions of isostatic compression, of 4.times.10.sup.8 to 5.times.10.sup.8 N/m.sup.2.

Abstract: A method of molding the insulating covering of an organic electrical insulator comprising a long central rod (3) having end fittings (5, 6). Retractable supports (11, 12, 21, 22) are disposed at regular intervals along an injection mold for the covering. The covering is injected, and at the end of injection, prior to vulcanization, the supports are retracted. The voids left in the mold (1, 2) by the supports are instantly filled by the injected material. Protective sleeves (24, 25) are interposed between the rod and the said supports.

Abstract: A filter membrane for filtering liquid food stuffs or hot gases and including at least one filter layer. The membrane is constituted by a sintered inorganic material comprising grains which are fixedly connected to one another and the average roughness of the surface of said filter layer over a distance along said surface equal to at least five times the average grain size is less than one fifth of the average grain size in the region in question.

Abstract: Device consists of several gripping modules for gripping sheds on an electrical insulator, said modules being distributed along a moving beam which moves vertically to extract the insulator from the mold. The beam is supported by a moving frame designed to clear the gripper and insulator from the mold. The beam has variable dimensions enabling the number of modules to be varied according to insulator size, especially for long insulators of up to 8 meters.

Abstract: An electrical insulator (1) of the type comprising at least one dielectric (2) and an iron or steel cap (3) fixed axially on the dielectric has a device for protecting the cap against corrosion as well as electric arcs. In one embodiment (FIGS. 1-3), the protection device comprises a zinc or aluminum part (10) shaped as a dish with a center hole (11) and outlet holes (12) for the egress of rainwater. The outside wall (13) of the part (10) curves upwardly toward the cap (3) and a portion of the part (10) is disposed between the base (6) of the cap (3) and the outer surface (7) of the dielectric (2). In another embodiment (FIG. 4), the protection device comprises a solid body of revolution (30) of semi-toroidal shape which is formed of zinc or aluminum and is cast directly around the base (6) of the cap (3) and has a thin flange extending between the base (6 )of the cap (3) and the outer surface (7) of the dielectric (2).

Abstract: The present invention provides a method of fixing a sleeve (3) of malleable metal on a rod (10) of composite material, said sleeve comprising a cylindrical internal housing (6) in which an end (11) of said rod (10) is received. A compression operation is performed causing the sleeve to be stretched in a continuous manner over annular zones of the sleeve substantially from the inlet of the sleeve and substantially up to the end of the rod in such a manner as to cold draw the metal of the sleeve around the rod without stretching the composite material beyond its elastic strain limit.

Abstract: An assembly of a tubular filter member (2) inside an envelope (5) surrounding the member includes a gasket (9) of elastomer or polymer material disposed at at least one of the ends of the filter member and of the envelope in between the outside surface of the filter member and the inside surface of the envelope.The outside surface of the filter member is provided over at least a portion of its surface area facing the gasket with roughnesses (11) or projections or hollows of sufficient size and number to prevent the filter element from sliding longitudinally relative to the gasket.Such an assembly is applicable to microfiltration, ultrafiltration and reverse osmosis.

Abstract: An improved method of manufacturing a composite structure of ceramic material reinforced by refractory fibers is disclosed, whereby the fibers are first embedded in a slip of the ceramic material containing a synthetic resin with good ceramic and fiber wetting properties and a solvent of said resin, the liquid phase is thereafter eliminated from the slip by drying, the synthetic resin is driven from the formed structure by heating, and the fiber-reinforced ceramic material is sintered. The improvement consists in avoiding the use of costly aluminum-nitride powder by initially incorporating an aluminum powder in the slip along with the resin solvent and nitriding the powder in the structure, after drying and firing, but before sintering.

Abstract: In a method of manufacturing parts or powders made of a compound of silicon or of a metal by exothermally reacting parts or powders of silicon or a metal in the solid state with a gas, wherein the differential flow rate or the pressure variation of the reactive gas in contact with the part or the powder is sensed, and the reaction is performed at increasing temperatures as a function of the said differential flow rate or pressure of the reactive gas:the improvement wherein a maximum differential flow rate or a maximum speed of pressure drop of the reactive gas is predetermined as a function of the chemical nature of the parts or powders, and optionally as a function of the density and the size of the parts, and the rise in temperature is suspended when the differential flow rate or the speed of pressure drop of the reactive gas reaches the predetermined maximum value, beyond which the reaction would run away and prevent complete transformation of the parts or the powders being obtained.

Abstract: An electrical insulator offering reduced sensitivity to pollution comprises a body of a glass or porcelain dielectric material with a semiconductor outside coating. This coating mainly consists of zinc oxide with at least one further metal oxide added to it to make its voltage-current characteristic non-linear, such that I=kV.sup..alpha. where I is current, V is voltage, k and .alpha. are coefficients, and the value of .alpha. is between 20 and 50. The coating is between 0.05 and 0.5 mm thick. The further metal oxide is advantageously selected from bismuth, manganese, cobalt, chromium and antimony oxides.

Abstract: The present invention relates to a method of manufacturing a medium for microfiltration, for ultrafiltration, or for reverse osmosis, wherein hydrolysis is performed on an alkoxide, an organo-metallic compound, or a metal salt of an organic or an inorganic acid, optionally dissolved in an anhydrous organic solvent, in order to obtain a sol of particles of the oxide or of the hydroxide of the corresponding chemical element, a thickening agent is added to the sol, and the resulting sol is slip cast onto a support layer having pores which are larger than pores desired for the filter medium, the thin layer deposited on the support medium is then dried, and then heat treated to eliminate the thickening agent and to sinter the particles of the deposited thin layer. The thickening agent is added to the sol in conjunction with a strong acid whose anion does not form a complex with ions of the oxide or hydroxide metal, and the slip casting is performed by mere putting into contact without filtering.

Abstract: A titanium or titanium alloy pin for cement-free fixing in a long bone for a joint prosthesis or for bone repair is surrounded by a lattice of titanium wire with a mesh size of at least 0.3 mm. The central part of the pin and the lattice are coated with a coating of titanium oxide which protects them against long-term corrosion. The lattice is further coated with a biodegradable and biocompatible material having a low modulus of elasticity.

Abstract: A composite type stay insulator comprises a central mandrel (4) made of insulating foam and having its ends (5) glued at (6) to two metal end pieces (1). The glue may be optionally conductive or semiconductive. A skein winding (8) of insulating resin-impregnated fibers is made around the end piece and mandrel assembly to transmit traction forces from a shoulder (7) on one of the end pieces to a corresponding shoulder on the other. The winding is then covered with a resilient insulating covering (9) which is optionally fitted with fins.

Abstract: The ends of a fiber-reinforced resin rod are inserted through sealing grommets into cavities of respective end fittings; the end fittings of the assembly are placed in accurately spaced end moulds; the rod is encased in intermediate half shells; an insulator covering is moulded around the rod by filling the half shells; and the end fittings are then fixed to the rod by embedding or swaging.