Abstract: A joint prosthesis, especially for a hip joint has a metal shaft receivable in the marrow cavity of the bone, a closure plate at the upper end of the shaft, and a formation adapted to form the ball joint. The underside of the plate and the shaft along its length are provided with a layer of synthetic bone material which is of greater thickness in the region of the plate and adjoining the plate, corresponding to the greater stress region of the bone, than along the shank remote from the plate.

Abstract: A pipe section of an outer metallic pipe and a nonmetallic inner lining is provided so that the lining can be removed. To this end, the lining consists of lining segments, the terminal members of which are braced against the ends of the pipe in a form fitting manner and the successive lining segments can interfit with, for example, complementary frustoconical formations.

Abstract: A joint prosthesis, especially for a hip joint has a metal shaft receivable in the marrow cavity of the bone, a closure plate at the upper end of the shaft, and a formation adapted to form the ball joint. The underside of the plate and the shaft along its length are provided with a layer of synthetic bone material which is of greater thickness in the region of the plate and adjoining the plate, corresponding to the greater stress region of the bone, than along the shank remote from the plate.

Abstract: A joint prosthesis insertable, for example, in the marrow cavity of the femur, has a shaft formed with three longitudinally extending angularly equispaced contact surfaces by reason of a triangular of Y section. A statically determinate engagement of the prosthesis shaft in the bone is thus obtained.

Abstract: A flow-setting valve has a housing, a flow-guiding duct, a ceramic valve ball and a flow-regulating spindle. The flow-regulating spindle has a plurality of form-fitting elements fitting in complementary receptacles of the valve ball. At least the valve ball is made of an engineering ceramic material. The form-fitting elements are located in the vicinity of the outer edge of a disk which is connected with the flow-regulating spindle. The diameter of the disk is approximately half the diameter of the valve ball.

Abstract: A controlling valve, especially a valve ball, for a gaseous and liquid flow material, comprises a housing, two connector pipes, a flow-adjusting component and associated valve seat components. The flow-adjusting component and the valve seat components have corresponding flow ducts, which are provided in a special component made from sintered ceramic material. At least the flow duct of the flow-adjusting component is located in a sintered ceramic sleeve. This sleeve is inserted in a passage in the flow-adjusting component and pressure-relieved in regard to material flow. The sleeve is held under frictional forces or just fits in the passage.