Abstract: An active suspension apparatus using hydropneumatic springs is disclosed to control damping characteristics in accordance with the vibration state of the passenger compartment of a vehicle during travel. An absolute acceleration of the floor of the passenger's compartment is detected and is compared with a reference value to discriminate the actual vibration state of the passenger compartment. The openings of restrictors arranged between hydropneumatic spring chambers and actuators are controlled in accordance with the discrimination result. In order to accurately detect the vibration state, specific vibration components are extracted by band-pass filters from the absolute acceleration signal.

Abstract: In this system for vehicle roll control, a suspension device or an actuator is provided corresponding to each wheel of a vehicle, and resiliently suspends it from the vehicle body. Each such suspension device can alter its hardness or softness characteristics according to a control signal, while similarly the actuators are adapted to alter the suspended height of their wheels. A vehicle speed detecting device senses road speed, a steering angle detecting device senses steering angle, and a device detects the total vehicle body weight.

Abstract: An active suspension apparatus detects an absolute acceleration Z in a passenger's compartment of a vehicle and a relative displacement X between an axle and a body, calculates an absolute value .vertline.Z.vertline. of the absolute acceleration, an absolute value .vertline.X.vertline. of the relative displacement and an absolute value .vertline.X.vertline. of a rate X of change in relative displacement, multiplies the absolute values .vertline.X.vertline., .vertline.X.vertline., and .vertline.Z.vertline. with coefficients A11, A12 and A13, and adding the resultant product to obtain a sum Y=A11.vertline.X.vertline.+A12.vertline.X.vertline.+A13.vertline.Z.vertlin e., compares the sum Y with a reference value C for evaluating the predetermined movement of the vehicle, and controls the damping forces of the hydropneumatic springs, thereby improving steering stability and riding comfort.

Abstract: In this system for vehicle roll control, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding vehicle wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. A plurality of working fluid supplying and discharging valves are provided corresponding to the actuator assemblies and serve to supply working fluid to the working fluid chambers and to discharge working fluid from the working fluid chambers. A vehicle speed detector senses the road speed of the vehicle, and a steering angle detector senses the steering angle of the vehicle. A control computer computes a steady state roll angle .phi..sub..infin.

Abstract: An active suspension apparatus detects a relative displacement (x) between an axle and a vehicle body, discriminates a road surface state in accordance with the relative displacement and a change rate (x) in unit time which is derived from the relative displacement (x), and optimally controls characteristics of damping forces of hydropneumatic suspensions in accordance with a discrimination result (i.e., a road surface state). This discrimination is performed in accordance with a sum (Ax+Bx) of a signal obtained by multiplying the relative displacement (x) with a predetermined coefficient and a signal obtained by multiplying the change rate (x) with another predetermined coefficient. These coefficients are obtained in accordance with riding comfort against vibrations. The characteristics of the damping force of the hydropneumatic suspension are controlled by controlling the opening of throttle valves disposed between hydropneumatic chambers and actuators.

Abstract: The tire for automobiles being measured is loaded in advance by the load applying means and the drum is driven to rotate the tire. A displacement of the rotatable shaft produced in response to a variation in the radial force acting between the tire and the drum is detected as a displacement of the movable member. The movable member is movable with respect to the drum about a fulcrum which lies in or is located in the vicinity of a plane including a surface in which the drum and the tire are held against each other. Thus any influence by a moment due to a lateral force imposed on the tire can be eliminated, and the apparatus can measure a radial force variation with precision.

Abstract: The automotive tire being measured is loaded in advance by the load applying means, and the drum is driven to rotate the tire. A displacement of the rotatable shaft produced in response to a variation in the radial force acting between the tire and the drum is detected as a displacement of the movable member which is in turn indicated as the radial force variation generated on the tire. Thus, the apparatus can measure a radial force variation with precision under a condition approximating an actual running condition of automobiles.

Abstract: In a process for preparing a carboxylic acid ester from a nitrile, water and an alcohol in the vapor phase, wherein the vapor is brought into contact with a catalyst, the improvement which comprises said catalyst being a titanium containing oxide catalyst which is obtained by hydrolyzing or neutralizing a water soluble titanium salt and subsequently calcining the resulting precipitate at a temperature in a range of about 300.degree. to 750.degree. C. and having the empirical formula Ti.sub.a Me.sub.b X.sub.c O.sub.d, wherein Me represents at least one element selected from the group consisting of Cu, Ag, Au, Mg, Zn, Sn, Pb, Zr, V, Bi, Cr, W, Mo, Mn, Fe, Co and Ni and X represents at least one element selected from the group consisting of Si and Sb and the subscripts a, b, c and d designate the atomic ratio and when a is 1, b is 0.01 to 12, c is 0 to 12 and b+c is 0.01 to 12 and d is the oxygen content of the catalyst formed by the combination of the above components.

Abstract: This disclosure relates to a process for the purification of 2-acrylamido-2-methylpropanesulfonic acid, which comprises dissolving said sulfonic acid in hydrous acetic acid of a water content of 3 to 80% by weight at 60.degree. to 110.degree. C. and subjecting the resulting solution to recrystallization. The purified product thus obtained is useful particularly as a starting material in preparing a high-molecular-weight polymer or copolymer.

Abstract: A process is described for producing N-substituted acrylamide or methacrylamide comprising reacting an acrylic or methacrylic acid ester with an aliphatic or aromatic amine in liquid medium in the presence of a catalytic amount of alkyltin alkoxide.

Abstract: This disclosure relates to a process for preparing highly pure 2-acylamido-2-methylpropanesulfonic acid, which comprises the steps of adding acetic acid to a slurry containing crystals of 2-acrylamido-2-methylpropanesulfonic acid obtained by the reaction of acrylonitrile, isobutene and either conc. sulfuric acid, fuming sulfuric acid or sulfuric anhydride plus water in a solvent, then distilling the resulting mixture to replace the reaction solvent with acetic acid, adding water or hydrous acetic acid to the resulting mixture, heating the mixture to dissolve said crystals, and subjecting the solution to recrystallization.

Abstract: A low noise level, pressure fluid spouting device includes an inlet for introducing a pressure fluid therein at one end thereof; a nozzle connected to the inlet for jetting or emitting the pressure fluid therefrom, the nozzle having an annular inner wall of a predetermined diameter as a nozzle port thereof with an enlarged portion at the other end thereof for spouting the pressure fluid from the nozzle. The enlarged portion has a predetermined length (1.sub.o) from the entrance to the exit or open end thereof, and comprises an annular inner wall of a predetermined diameter (d.sub.2) larger than that of the nozzle means as an enlarged passage communicating with the nozzle port; and an outer wall which is tapered or gradually decreased in width towards the exit or open end portion of the enlarged portion with a predetermined angle of inclination (.theta.). The wall of the enlarged portion has a predetermined thickness (t) at the exit or open end portion of the enlarged portion.