Abstract: The invention relates to a process for condensing at least one epoxide on at least one cyclic anhydride of a dicarboxylic acid in the presence of a catalyst consisting of at least one titanium peroxidic complex of the peroxo type of the A form ##STR1## Said process allows to obtain a perfectly alternate polyester.

Abstract: A coupling device between a vehicle steerable wheel and a steering control member, the steerable wheel being carried by a single arm, connected to a suspension arm rotatively mounted, at one of its ends, on a transversal axis of the chassis of the vehicle, wherein the single arm comprises a transmission and guiding rod directed eccenteredly upwards and rigidly fixed thereupon and this rod cooperates with a slide bar on which is pivotally connected at one end, at least one link, and the said device being applied to steering couplings for MacPherson type front suspension motorcycles.

Abstract: Valve assembly (22) intended for closing a combustion chamber (14) of an internal-combustion engine and comprising a valve (36) and a valve seat (42), the valve lifting off from its seat in order to open the combustion chamber (14) by moving away from the latter.According to the invention, the valve seat (42) is designed to move relative to the combustion chamber (14) under the effect of the pressure prevailing in this chamber and thereby to reinforce the closing of the valve assembly.

Abstract: The present invention relates to a device for adjusting the camber angle of the wheel of a vehicle, the rotary axle of which is mounted on the hub carrier (12), at least one of the ends of which is movable in terms of a shift relative to a vertical plane passing through the axis of symmetry of the wheel, characterized in that this end is mounted in an eccentric movable in rotation on one of the fastening points of the arm (12) on a suspension device of the wheel (10, 11), the eccentric being driven in rotation as a function of the angle of lock of the wheels or of the suspension height.

Abstract: This invention provides cationic emulsions of bituminous binders of the bitumen/polymer type, formed by a dispersion of an organic phase of the binder in an aqueous phase containing a cationic nitrogenous emulsifier and a mineral or organic acid, the acid being in appropriate quantity so that the pH of the aqueous phase is comprised between 3 and 9. The aqueous phase also contains an agent consisting of at least one water-soluble sequestering salt of phosphonic acid, particularly a salt of alkaline metal or of amine of hydroxyalkyl-1,1-diphosphonic acid, and optionally a water-soluble thickening agent. To obtain the emulsions, which are usable for road applications, the emulsifying agent, the sequestering agent and optionally the thickening agent may be used in the form of a premixture containing the agents and called cationic emulsifying system.

Abstract: The present invention concerns binary zeolitic systems comprising two zeolites A and B having different crystalline structures while having common structural units. The crystals of the zeolite A form a central core surrounded by a crown of crystals of zeolite B, the zeolites A and B being disposed concentrically and following the same longitudinal axis. These systems are formed by the introduction of a nucleation gel containing germs of the zeolite A in a growth gel where the crystallization parameters are favorable to the crystallization of the zeolite B. The binary zeolitic systems are useful as catalysts for transforming hydrocarbons and more especially as cracking catalysts.

Abstract: Copolymers of average number molecular weight from about 300 to 5,000 comprising recurrent units originating (A) from alpha olefins, (B) from .alpha.,.beta. unsaturated .alpha., .gamma. dicarboxylic compounds, (C) from unsaturated acid esters of 1,2-diols, optionally etherified or esterified, and (D) optionally from acrylic esters, the proportions of the recurrent units being 5-60% for (A), 10-70% for (B), 10-60% for (C) and 0-60% for (D), at least one of recurrent units (A), (B) and/or (C) comprising at least 12 carbon atoms, and at least 10% of the recurrent units of said copolymer being (B) recurrent units of N-substituted imide type. These copolymers form additives useful to lower the pour point of middle distillates, particularly of gas-oils. The use of said additives at a concentration from 0.001 to 2% by weight results in a substantial decrease of the pour point of the treated middle distillates.

Abstract: This invention concerns an omega type zeolite of high thermal stability, present in the form of hexagonal prismatic monocrystals having scored or plane faces of 0.1 .mu.m in edge and 0.5 to 5 .mu.m in length, this zeolite being obtained through crystallization from a mother solution containing a silica source, alumina, metallic oxide, an organic cation and water, in which the alumina source is a crystalline aluminosilicate of which at least one part is in suspension in the mother solution. In its acid form this zeolite can be used as catalyst for hydration of olefins and isomeric change of xylenes.

Abstract: The device for the suspension and steering of a vehicle wheel of the type having two arms pivoted, on the one hand, at the stub axle bracket that they support, and on the other hand, at the vehicle body around axes substantially orthogonal to the axial longitudinal plane of symmetry of the vehicle, the stub axle bracket has the general shape of a tetrahedron A'B'C'D', one of the apex D' being a point of the stub axle axis D'D", two apex A'B' defining the steering axis being the centers of pivoting joints with each of the arms AA' and BB' and the fourth apex C' being the center of a pivoting joint with the steering control kinematic train, and applying to improvements to front wheel of land vehicles.

Abstract: A method for treating a fuel comprising a mixture of hydrocarbon(s) and alcohol(s) with a content by volume of alcohol less than 10%, the method comprising placing the fuel mixture in contact with at least one cationic exchange resin capable of strong dissociation into ion form in an aqueous medium, in particular a sulfonic or carboxylic resin which is prepared in potassium or magnesium form for adsorbing at least a portion of the water dissolved in the mixture on the resin so as to prevent segregation of the mixture and so as to stabilize the homogeneity of the fuel.

Abstract: The supporting and attaching device is connected to non-rotating parts of at least one brake caliper or yoke intended to cooperate with a brake disk and it comprises an attaching piece in a generally arcuate form, situated beyond the periphery of the disk and of which at least part of the transversal section is U-shaped with two legs one of which legs constitutes the section of a plate clamped onto a single arm for wheel suspension, while the other leg constitutes the section of at least one tab secured on either side to a brake caliper straddling a brake disk and is applied to double disk brakes for motorcycles.

Abstract: This invention provides cationic emulsions of bituminous binders of the bitumen/polymer type, formed by a dispersion of an organic phase of the binder in an aqueous phase containing a cationic nitrogenous emulsifier and a mineral or organic acid, the acid being in appropriate quantity so that the pH of the aqueous phase is comprised between 3 and 9. The aqueous phase also contains an agent consisting of at least one water-soluble sequestering salt of phosphonic acid, particularly a salt of alkaline metal or of amine of hydroxyalkyl-1,1-diphosphonic acid, and optionally a water-soluble thickening agent. To obtain the emulsions, which are usable for road applications, the emulsifying agent, the sequestering agent and optionally the thickening agent may be used in the form of a premixture containing the agents and called cationic emulsifying system.

Abstract: The driving wheel of a vehicle is mounted on one side of an arm and is connected at least in rotation to the other side of the arm having a endless wheel, the arm having, prior to the connection with the arm part disposed transversally, a section of which the outer casing is crossed through by at least one of the two chain strands in a chain channel the walls of which cooperate in increasing the inertia of the arm section, and being applied to a rear arm of a chain driven motorcycle.

Abstract: A method of transmission of information or measuring data and devices for using the method, wherein information or measuring data is transmitted from a local measuring device, located at a remote site, to a central interrogation station located at a central site where the data is processed, using a common carrier network while permitting the normal use of the telephone line. The data is transmitted from the local station to the central interrogation station by sending of a first call from the central station to the local station over the telephone line, the ringer of the called set being temporarily rendered inoperative, repetition, after a certain period has passed, of the call by central station, tying up of the line by the local station, and execution of the transmission procedure.

Abstract: A device for improving the feed of diesel engines at low temperatures, particularly at temperatures less than the cloud point of gas oils, without modifying the specific chemical characteristics of the gas oil by recycling the scavenging flow from the injection pump, characterized in that recycling takes place either upstream of the fuel filter and is associated with recirculation towards the reservoir of the gas oil coming from the reservoir through a heat exchanger or directly in the direction of the reservoir with direct feed of the filter by the reservoir.

Abstract: The present invention concerns binary zeolitic systems comprising two zeolites A and B having different crystalline structures while having common structural units. The crystals of the zeolite A form a central core surrounded by a crown of crystals of zeolite B, the zeolites A and B being disposed concentrically and following the same longitudinal axis. These systems are formed by the introduction of a nucleation gel containing seeds of the zeolite A in a growth gel where the crystallization parameters are favorable to the crystallization of the zeolite B. The binary zeolitic systems are useful as catalysts for transforming hydrocarbons and more especially as cracking catalysts.

Abstract: Process for manufacturing methyl tert-butyl ether (MTBE) by reacting methanol with isobutene-containing hydrocarbons in a reaction zone comprising alternate beds of sulfonated resin catalyst and catalyst-free distillation zones, said zones also comprising liquid redistribution plates.

Abstract: The invention concerns a process for manufacturing methyl tert-butyl ether (MTBE) by reacting methanol with an isobutene-containing hydrocarbon mixture.This process is characterized by the steps of:introducing the reactants into a reaction-distillation zone containing at least two superposed and non-contiguous fixed beds (2a, 2b) of catalyst of the sulfonated resin type, wherein passage-ways are provided for a vapor phase, at least one distillation tray (4a), at least one liquid redistribution tray (5),maintaining distillation conditions in said zone so as to have a descending liquid phase and an ascending vapor phase,maintaining a continuous liquid phase in the lower part of said beds,discharging a vapor phase containing a high proportion of unconverted hydrocarbons from the top (8) of said zone, andwithdrawing a liquid phase of high MTBE content from the bottom (10) of said zone.

Abstract: A process is provided for protecting metallic surfaces such as stainless steel, against vanadosodic corrosion which utilizes at least one metal such as the alkaline earth metals which oxidizes in situ into a protective layer. The layer forms a compound with vanadium and/or sodium oxide which has a softening point higher than that of the oxide.

Abstract: An oscillating supporting arm assembly for the driving wheel of a motorcycle, includes an arm mounted to oscillate angularly about a connecting shaft of the motorcycle and cooperating with a suspension assembly between the arm and motorcycle, the wheel being removably fixed to a supporting shaft on one side of the free end of the supporting arm, the supporting shaft extending through the arm on two bearings, a wheel driving pinion is fixed to the supporting shaft, on the side of the arm opposite to the wheel and is driven by a chain mechanically connected to the driving assembly of the motorcycle, the supporting arm having the configuration of a U with two legs between which the rim and the tire of the rear wheel are located, one of the legs having hinge connections which cooperate with the connecting shaft of the motorcycle, the wheel has its median plane extending at substantially equal distances from the two hinge connections of the supporting arm, the wheel is rigidly connected to a brake disc cooperating