Abstract: A matting agent for plastic compositions comprising either a high molecular weight, gel-containing vinyl chloride polymer with a gel content of 10 to 99% by weight, a maximum mercury porosity of 0.2 cm.sup.3 /g, a maximum plasticizer absorption of 15%, a particle size parameter d' of 10 to 80 .mu.m and a coefficient of uniformity n greater than 3, or a high molecular weight, gel containing copolymer of vinyl chloride and 1 to 40% by weight of comonomer with a gel content of 10 to 99% by weight, a maximum mercury porosity of 0.10 cm.sup.3 /g, a maximum plasticizer absorption of 10%, a particle size parameter d' of 10 to 80 .mu.m and a coefficient of uniformity n greater than 3, plastic articles containing said matting agent and a method of imparting a matt to the surface of plastic articles.

Abstract: A matting agent for plastic compositions comprising either a high molecular weight, gel-containing vinyl chloride polymer with a gel content of 10 to 99% by weight, a maximum mercury porosity of 0.2 cm.sup.3 /g, a maximum plasticizer absorption of 15%, a particle size parameter d' of 10 to 80 .mu.m and a coefficient of uniformity n greater than 3, or a high molecular weight, gel containing copolymer of vinyl chloride and 1 to 40% by weight of comonomer with a gel content of 10 to 99% by weight, a maximum mercury porosity of 0.10 cm.sup.3 /g, a maximum plasticizer absorption of 10%, a particle size parameter d' of 10 to 80 .mu.m and a coefficient of uniformity n greater than 3, plastic articles containing said matting agent and a method of imparting a matt to the surface of plastic articles.

Abstract: In a process of polymerizing ethylenically unsaturated compounds by polymerization of ethylenically unsaturated monomers in the presence of a free radical-forming initiator system and customary protective colloids and/or emulsifiers and optional known additives in a reactor whose surfaces contact the reaction components, the improvement comprising providing the reactor surfaces with a coating that at least suppresses polymer deposit formation without effecting the color and quality of the polymer.

Abstract: In a process of polymerizing ethylenically unsaturated compounds by polymerization of ethylenically unsaturated monomers in the presence of a free radical-forming initiator system and optionally customary protective colloids and/or emulsifiers and optional known additives in a reactor whose surfaces contact the reaction components, the improvement comprising providing the reactor surfaces with a coating that at least suppresses polymer deposit formation without effecting the color and quality of the polymer.

Abstract: An improvement in the process for the polymerization of vinyl halide polymers comprising polymerizing at least one vinyl halide and, optionally, other olefinically-unsaturated monomers copolymerizable with vinyl halides, in an aqueous dispersion in the presence of free-radical-forming polymerization initiators, dispersants and, optionally, other additives in the presence of an inhibitor of polymer deposits and recovering said vinyl halide polymers, the improvement consisting essentially of adding to the reaction mixture from 10 to 1,000 ppm, based on the monomers, of at least one carbonyl compound having the formula: ##STR1## wherein R.sup.1 is selected from the group consisting of hydrogen and a hydrocarbon having from 1 to 9 carbon atoms selected from the group consisting of alkyl, aryl, alkaryl and aralkyl; R.sup.

Abstract: A brake disc connection, especially for rail vehicles, in which the undivided brake ring or the brake ring divided along a radial or axial plane is by a clamping connection which includes a clamping groove and clamping strip clamped therein connected to the hub or wheel. The hub or the wheel as well as the brake ring are each provided with two clamping surfaces defining the clamping groove. These clamping surfaces are in alignment with each other in radial and/or axis parallel direction, and the clamping strip extends into both clamping grooves while being clamped thereinto; at least three pairs of clamping surfaces being provided for each brake ring, so that at least three of the above mentioned connections are provided for each brake ring.

Abstract: A brake disc with improved ventilation cooling means, comprising a brake ring, the interior of which is provided with radially running channels formed by vanes. Cooling air to be conveyed by the vanes enters the channels on the hub side at the inner circumference of the brake ring and exits at the outer circumference of the brake ring. In addition to rib-shaped vanes, the length of which correspond to the entire width of the brake ring, thermal flow vanes are provided. To increase the air turbulence, the width of the base of the thermal flow vanes is more than 60% of the distance from the start of one vane to the start of the next vane, measured along the braking radius, and the width of the base of the thermal flow vanes is between 80 and 100% of the distance between vanes, measured at the inner circumference of the brake ring.

Abstract: A device for controlling the return of the coupling head for central couplings to their central position, especially for use in connection with rail vehicles, in which the coupling head is by means of a coupling rod linked to a housing arranged on a vehicle. A cam operatively connected to the coupling rod extends between two abutments which in the horizontal path of the cam are displaceable hydraulically, electrically or pneumatically. In one end position of the abutments, the full horizontal lateral deviation of the coupling rod is available, whereas in the other end position, the cam is clamped in between the two abutments.

Abstract: A rail vehicle wheel with brake discs, especially for disc brakes, according to which the brake discs, which may be or may not be divided, are arranged on one or both sides of the wheel. That side of the brake discs which faces toward the wheel disc is provided with radially extending cooling fins and by way of cam rests against the wheel disc. The outer and/or inner circumference of the brake discs is or are respectively engaged by preloaded elastic deformable holding members which in their turn are positively or frictionally connected to the wheel.

Abstract: A closure for a brake jaw holder for disc brakes, especially for use in connection with rail vehicles, in which a closure latch extends in a direction transverse to the guiding direction of the brake lining and in which the lining in a closing manner extends from the rear side of the lining carrier into an opening provided therein. At both sides of the opening in the closure latch there is provided an oblong opening extending perpendicularly with regard to the surface of the lining carrier while the pertaining bolt or pin is arranged on the lining carrier. Elastic spring structure is provided for arresting the closure latch when the bolt or pin occupies either one of its end positions in the oblong opening.