Abstract: The invention concerns a method of producing optical elements, in particular filters, with interference layers comprising alternately slightly refractive and highly refractive dielectric layers deposited on a substrate S. The first layer 1 applied to the substrate is Al.sub.2 O.sub.3, constituting a slightly refractive layer, after which further layers 2 to n of ZnS and Al.sub.2 O.sub.3 are applied in an alternating sequence. The last layer n consists of Al.sub.2 O.sub.3. Such layers can be applied, at low temperatures, on flat substrates and, in particular, on sharply curved substrates. Production costs are reduced, and these layers possess the optical properties of known interference layers however resistance to external influences is greatly increased. In the case of mineral substrates, the coatings also offer considerable resistance to boiling.

Abstract: A piece of wood is prepared for impregnation by causing it in steps to be perforated by a plurality of needles which are moved back and forth with the workpiece, and either rotate individually or are subject to additional oscillatory or impact-producing axial movement.

Abstract: This invention relates to an improvement in a spiral grooved bearing for a shaft adapted to travel in the direction of rotation, composed of a stationary bearing part with a hemispherically cup-shaped first sliding surface and a bearing part of the shaft having a spherical second sliding surface with spiral grooves in said second surface adapted to feed a lubricant between said sliding surfaces, the improvement comprising an additional bearing part centered at the hemispherically-shaped bearing part, said additional part having a sliding surface which encloses said second sliding surface up to the vicinity of said shaft, and sleeve means adapted to receive said stationary bearing part and said additional part.

Abstract: A coating of a thermally hardened alloy of nickel and a nickel-phosphorus compound covers the internal face portions of a spinning pot which are engaged by the fibrous material being spun. The alloy produced from an electroless nickel plating solution is rolled to improve surface smoothness and density, and the rolled coating is heat treated to precipitate a portion of the phosphorus present in the form of a finely dispersed nickel-phosphorus compound. Silicon carbide may be dispersed in the coating to further increase its hardness.

Abstract: A bearing arrangement for the pot of a centrifugal yarn spinning unit has a housing in whose cavity a radial bearing and an axial thrust bearing for the shaft of the pot are arranged. The radial bearing is fixedly mounted on a carrier which plugs an opening of the housing. The carrier is sealed to the housing by O-rings, and the shaft journaled in the bearings is received in a passage of the carrier provided with a packing in fixed spatial relationship with the radial bearing. Wear of the packing is minimized by the permanent guidance provided to the shaft by the radial bearing although the shaft may oscillate radially with the carrier during its high-speed rotation.

Abstract: This invention relates to a process for manufacturing an axially symmetrical rotor adapted to rotate about the vertical axis thereof and having a length greater than the diameter thereof which comprises rolling a thin, high-strength steel sheet to form a cylinder having a longitudinally-extending joint,Welding said joint by electron beam welding,Solution-treating the blank thus formed,And bringing the blank to its final dimensions by means of the three-roll press rolling process wherein the blank mounted on a rotating pressure mandrel having a stop is pressed by pressure rollers moving toward the stop while the material of the blank flows counter-currently with respect thereto.

Abstract: This invention relates to a process for producing helical oil grooves in a spherical metallic body, for example for a spiral groove bearing, which comprises exposing a photographic lacquer on the surface of said body to light under a pattern, developing the resulting image, and electrochemically etching and then chemically etching grooves in said body in the non-image areas, whereby pressure-building spiral grooves are produced having a planar groove bottom, straight walls, sharply right-angled edges, and a depth in the range of about 1 to 20 microns.