Abstract: A hand-held power tool a percussion mechanism (2) of which includes a percussion piston (4) displaceable by an air spring (3) of the power tool for applying blows to an anvil (5) that is dust-tightly and lubricant-tightly sealed with respect to its guide by two axially offset sealing elements (8) between which a lubricant chamber (9) for receiving a barrier lubricant (10) is formed.

Abstract: A pipe cutting apparatus comprises at least one work-holding fixture and a cutting device pivotable about the axis of the pipe to be cut and having a cutting tool and drive. The cutting device is movable manually and/or by means of at least one transmission gearing for the feed of the tool about the pipe to be cut. The transmission gearing has a spur gear interacting with a crown gear.

Abstract: A pipe cutting apparatus comprises at least one work-holding fixture and a cutting device pivotable about the axis of the pipe to be cut and having a cutting tool and drive. The cutting device is movable manually and/or by means of at least one transmission gearing for the feed of the tool about the pipe to be cut. The transmission gearing has a spur gear interacting with a crown gear.

Abstract: A pipe end machining unit (1) is provided with a housing (2) which is composed of two parts (2a, 2b). The clamping device (13) and the tool support (9) are supported in the upper housing part (2a). The lower housing part (2b) is of modular design and accommodates at least those components (18) which are relevant for controlling the motor. With a pipe end machining unit (1) designed in such a manner, conversion from an electrical drive to a pneumatic drive, or vice versa, is possible in a simple manner and within a very short time. Furthermore, the essential parts can be standardized, which results in major advantages from the manufacturing point of view.

Abstract: There is proposed an apparatus for machining pipe ends having a motor, a gearing assembly, and a clamping means for clamping a pipe end to be machined on the apparatus, the apparatus having a hollow rod, a tool support with a tool holder, characterized by the fact that the motor and the gearing assembly are arranged alongside of each other and that all units with the exception of the tool support are surrounded by a housing and thus form a compact and handy arrangement, and that the housing has a bottom surface which serves as standing surface and simplifies the handling of the device. The tool holder is provided with a cutting plate which is developed as turnable tip which has at least two active cutting edges.

Abstract: A device for manufacturing a welded connection of tubular components of plastics material. The ends of the components to be connected are axially aligned and held to abut with the end surfaces. The ends of the tubular components can be heated by a foldable heating device which surrounds the tubular components. A support device is arranged in the interior of the tubular components. A heating device which can be fastened on a frame in a determined position is provided for each pipe diameter dimensioned to be welded. Electrical contacts are provided for each heating device. A welding program of a program control predetermined for each dimension can be selected by the contacts when the heating device is placed on the frame.

Abstract: A treating device for mechanically treating the outer circumferential surface of tubular components. The treating device includes a grinding tool and is rotatably mounted on an internal chuck. The internal chuck is chucked by means of chuck jaws concentrically relative to the inner diameter of the tubular component. The grinding tool includes a drive shaft and a drive motor and is eccentrically mounted in a bushing which can be swivelled by means of a worm drive. By swivelling the grinding tool, the grinding tool is moved toward the tubular component for the appropriate processing depth. Subsequently, the outer surface of the tubular component is treated by rotating the treating device about the internal chuck.

Abstract: A process for producing phosphorous-doped silicon monocrystals having a select peripheral depletion or enrichment of dopant atoms along the radial direction of such monocrystals comprises providing a silicon monocrystalline rod homogeneously doped with phosphorous, as by neutron doping, and subjecting such homogeneously doped monocrystalline rod to a peripheral zone melt cycle in a select atmosphere such that the peripheral melt zone depth within the monocrystalline rod is controlled so as to be less than the radius of the rod in accordance with the desired peripheral dopant concentration in the ultimately attained rod.