Abstract: The invention relates to a hip joint prothesis having a metallic prothesis shell (1) with a cavity insert (2) having a spherical recess (3) and with an intermediate element (4) which is made of plastics and arranged between the prothesis shell (1) and the cavity insert (2). In order to avoid osteolysis, it is suggested that the intermediate element (4) consist of an upper portion (5) and a lower portion (6), that it be possible for upper portion (5) and lower portion (6) to be connected to each other, and that the cavity insert (2) be retained between upper portion (5) and lower portion (6).

Abstract: A ceramic socket or ceramic socket insert for a hip joint prosthesis is tested prior to implantation in a human body by subjecting the portions of the interior of the socket or socket insert to a load that generates stresses that are greater than the physiological load. This may be accomplished either by pressing a hemispherically-shaped deformable material such as polymer or plastic into the interior of the socket or socket insert or by exposing the interior of the socket or socket insert to a fluid under pressure. The interior of the socket or socket insert may be sealed off with a test punch that has a supply line for the fluid. To reduce the amount of fluid that is required, the test punch may have a bulge that projects into the interior of the socket or socket insert and leaves only a gap for the fluid.

Abstract: Joint prosthesis (1) with a cup-shaped supporting part (2) in whose interior a ceramic insert (3) is fastened by conical clamping. Clamping surface (6) of insert (3) runs at an angle (.alpha.) to clamping surface (7) of supporting part (2).

Abstract: Zirconium dioxide containing 2 to 40 vol. % of stabilizing oxides is embedded in the matrix material of a sintered molding consisting of an aluminum oxide/chromium oxide mixed crystal. The quantity of stabilizing oxides added is chosen so that the zirconium dioxide is predominantly tetragonal. The molar ratio of the zirconium dioxide containing the stabilizing oxides to the chromium oxide is between 1000:1 and 20:1 and the zirconium dioxide has a maximum particle size of 2 .mu.m.

Abstract: Disclosed is a lathe cutting tool assembly found of a tool holder which has a seat to accommondate a cutter insert, the cutter insert being provided with a clamping groove or bore. The insert is held in the tool holder by a clamping shoe. The clamping shoe is tightly secured to on the tool holder. To protect the clamping shoe and improve the seating of the cutter insert in the tool holder, a clamping plate is secured to the clamping shoe and lies upon the cutter insert. A projection is provided on the bottom of the clamping plate facing the cutter insert and is in clamping contact with the groove or bore. The tool assembly is especially adapted for a turning chisel.

Abstract: Disclosed is an all-ceramic drill bit which combines the positive properties of ceramic with a tool geometry adapted to the special features of the material. The drill bit is formed with a groove for the shavings which extends in the axial direction linearly along a surface line.

Abstract: Disclosed is a fluid delivery supply unit having an internal gear pump as a pump unit, with a bearing race in which a driven inner gear is arranged on a bearing journal and the inner gear rotates with it by way of toothing engagement with an outer gear arranged between the inner gear and the bearing race, and the inner gear has one tooth fewer than the outer gear so that a pumping action is produced. A low noise level, resistance to corrosion, and a reduced weight, are obtained by forming parts of the internal gear pump, such as the bearing race, inner gear or outer gear, of a ceramic material.

Abstract: The invention relates to a hip joint socket for insertion into bone tissue, with an outer metal shell and an inner ceramic shell, the ceramic shell being anchored in the metal shell. To reduce its size while simultaneously reducing the wall thickness of the ceramic shell the inside of the metal shell and the outside of the ceramic shell have a spherical shape accurately fitted to one another and means are disposed for equalizing the transmission of force between the ceramic shell and the metal shell.

Abstract: Disclosed is an improved ring and traveller system for spinning and twisting frames. At least the surface of the ring coming into contact with the traveller consists of a polycrystalline ceramic material and the ceramic surface of the ring has a surface structure with rounded grain boundaries which form a storage volume for a self-generating lubricating film of fibers. The traveller consists of a resilient carrier material, especially metal, and has a metal and/or ceramic surface, the hardness of which is greater than the hardness of the ceramic surface of the ring.

Abstract: A filter element intended for tangential-flow filtration has an elongated support body of porous ceramic material with coaxial channels running through the support body and provided on their surface with a ceramic membrane having a calibrated pore structure. A portion of the fluid flowing through the channels penetrates the membrane and exits as filtrate at the circumferential surface of the support body. The shape of the outwardly facing channel wall is adapted to the external shape of the support body and there it has a uniformly thick wall corresponding to the mechanical stress. The shape of the channel walls is configured such that the webs remaining between the channels flare outwardly wedge-wise. The filter element thus configured has a support body with a reduced resistance to the passage of the filtrate flowing through it.

Abstract: In a valve the sealing disks in contact with one another consist of sintered silicon carbide ceramic and have on their functional surface a profile bearing percentage of at least 75% established by grinding and/or lapping and/or polishing. The mean roughness at the functional surface amounts to 0.01 to 0.1 .mu.m. The construction is especially suitable for a sanitary mixing faucet.

Abstract: A roller for the pressure treatment of webs, especially a roller such as a press or calender roller for the treatment of paper, cardboard and pulp webs in machines of the paper industry, which include a roller shell, roller flange and a roller shaft, one or more elastic, axial or coaxial clamps and elastic or yielding centering structures. The roller shell includes individual rings of sintered ceramic disposed side by side, the rings are clamped positively together by the one or more elastic, axial or coaxial clamps and the rings are aligned concentrically on the roller shaft by means of the elastic or yielding centering structures.