A pneumatically actuatable linear drive for automatic spot welding machines includes a cylinder, a piston rod with segments and pistons and an intermediate bottom between the pistons for dividing the cylinder into pressure chambers. An axial conduit in the segments has a check valve. Radial conduits communicate between the axial conduit and the pressure chambers. Air line connections and a throttle valve lead into the pressure chambers. One piston on one segment moves toward and away from the cl…

An adjusting device has a pneumatically operating piston-cylinder unit pressurizable in an operating function thereof for actuating adjusting elements in a printing press. The piston-cylinder unit includes a cylinder housing formed with a cylinder chamber, a piston displaceable in the cylinder chamber, and an electromagnet for applying an activated holding force to the piston, the piston being subjectible pneumatically to a prepressurizing force in the cylinder chamber opposite to and less than …

A device for drying printed products in a printing machine having a transport device for conveying printed products along a given path includes a radiation device located outside the printing machine for generating radiant energy, and a device for transmitting the radiant energy generated by the radiation device to a surface of the printed product, the transmitting device being disposed at least partly in the printing machine so as to direct the radiant energy simultaneously over a defined width…

An integratable amplitude-regulated oscillator circuit includes a resonator element, a control element having a control input, an inverter having an output and an input coupled to one another through the resonator element and having a quadrature-axis current component being variable by the control element, an amplitude regulating circuit having an input connected to the input of the inverter and an output connected to the control input of the control element, and an output stage having an input …

A method for replacing bolts on core components of nuclear reactors includes machining away a bolt fastened at an installation site in a core component as well as the entire fastening of the bolt with an electroerosion machine. Machined-away bolt material is removed and caught with a filter. The bolt is then ejected from the core component with a closed force system. The installation site of the bolt is remachined with an accurate fit and a new bolt is subsequently inserted. An apparatus for rep…

A once-through stem generator includes a vertical gas flue having a total given height, a bottom, a lower part having a height equal to less than 70% of the total given height, an upper part, and fossil fuel burners disposed on the lower part. The lower and upper parts are formed of gas-tight tube walls with tubes. The tubes of the lower part rise obliquely, while the tubes of the upper part are vertical. The lower part has a lower end limited by the bottom, and the upper part has an upper end l…

A method for A/D conversion, which includes integrating by analog apparatus, amplifying and subsequently quantizing an analog input signal for producing a quantized signal having n bits, wherein n>1, and feeding back the quantized signal to the input signal. The improvement includes integrating digitally the quantized signal by an arrangement of periodic digital summation, converting the quantized signal into an analog signal, and feeding back the analog signal to the input signal. An apparat…

A switched-capacitor sigma-delta modulator includes at least one memory element, at least one comparator, and at least one integrator. The at least one integrator has an input stage including a series circuit of a first switch, a first capacitor and a second switch, a third switch for connecting one of the two terminals of the first capacitor to ground potential, and a fourth switch for connecting the other of the two terminals of the first capacitor to ground potential. A nodal point is connect…

A cam mechanism for periodically swiveling a swivel device includes a rotatable first cam disk carrying a first cam serving as a main cam, a rotatable second cam disk carrying a second cam serving as an auxiliary cam, a first roller engaging the first cam under spring force and rollable on the first cam during rotation of the first cam disk, a second roller engaging the second cam under spring force and rollable on the second cam during rotation of the second cam disk, and a lever arrangement sw…

A weed puller is disclosed having a tubular main body member in one end of which is mounted a piston that is spring-biased toward a released position adjacent the body one end. At its other end, the main body member is provided with a handle arrangement for displacing the piston to a retracted positon within the body member via a piston rod that extends longitudinally through the main body member and projects at its free end therefrom. A drive plate is incrementally displaced by a lever to incre…