Abstract: A wire-unwinding device in which wire can be unwound from a very large wire drum such that the direction of curvature of the wire is maintained and alternating bendings of the wire are avoided. The wire is guided over a stationary first guide pulley, a second guide pulley, which is changeable in position in order to apply an initial tensioning force, and over a further stationary third guide pulley.

Abstract: Known heat treatment apparatus for continuously advanced material, for example for extruded strip to be vulcanized, include an endless transporting element which is in the form of a belt of steel or of coated glass fiber fabric according to the thermal load. Such conveyor belts have an adverse influence on the engaging surface of the extruded strip and cause surfae defects. The invention aims to achieve a largely defect-free end product and it includes a transporting element in which a plurality of rotatably mounted cylindrical rollers are arranged one behind the other between two mutually parallel chains, each roller being rotated by friction forces on at least one stationary strip as the roller is carried along by the chains.

Abstract: An exemplary embodiment comprises a patient support, an x-ray tube supplied by an x-ray generator, an x-ray image intensifier with a series connected television chain, a control loop for the controlling the mean image brightness, a syringe for contrast medium injection, and a program memory for storing several radiographic exposure programs. A time measuring device is present which is started by the syringe and is stopped by an evaluation unit when the mean image brightness varies to a predetermined extent. A computer calculates the contrast medium velocity from the measured time and the distance (x) between the injection location and the measuring location. On the basis of the calculated contrast medium velocity, an optimum program calculation, or program selection, respectively, is possible.

Abstract: In an exemplary embodiment in order to establish the desired relationship between x-ray tube voltage and x-ray tube current, at least one series resistance is connected in the power path between the mains and the x-ray tube. A switching device for by-passing the series resistance is present which is controlled by a comparator for the actual value and setpoint value of the x-ray tube voltage in such a fashion that the series resistance is by-passed at the commencement of a radiograph as long as the actual value is smaller than the setpoint value.

Abstract: A heat exchanger having an openable casing for the removable reception of a fluid carrying coil for a first fluid. The coil includes a straight section surrounded by helical turns. The helical turns contacting the interior surface of the casing to thereby form a complimentary helical fluid flow path for a second fluid. The casing is provided with an inlet and an outlet for the second fluid, the first fluid entering one end of the coil and exiting from the other end of the coil.