Abstract: Diaryl guanidines can be obtained in a high degree of purity and in high yields from the crude melt obtained from the reaction of arylamines and cyanogen chloride by dissolving the hot melt in water, extracting this solution with a mixture of at least one water insoluble, apolar hydrocarbon and at least one polar organic compound and precipitating the diaryl guanidine from the purified, aqueous solution by the addition of alkali metal hydroxide.

Abstract: There is disclosed a spot-type disc brake having a non-rotating brake carrier to receive the brake torque with brake shoes disposed on both sides of the brake disc. A yoke or frame embraces the disc and is movably guided in the brake carrier and held without clearance by resilient means. The frame transmits the operating force of an actuating device to the brake shoe disposed on the side of the disc remote from the actuating device. The frame is rigidly supported at and movable with respect to three guide points on the brake carrier. A biased spring is disposed between the brake carrier and frame. The spring .[.tensions.]. .Iadd.forces .Iaddend.the frame .[.at.]. .Iadd.against .Iaddend.its guide points and .Iadd.the spring force .Iaddend.acts on the frame at a point distant from the three guide points.