Abstract: A variable displacement compressor that decreases displacement to reduce compression load without imbalancing the rotation of the drive shaft when the rotating speed of the compressor's drive shaft exceeds a predetermined limit value. The compressor includes a pressurizing passage connecting a crank chamber to a discharge chamber. A rotated guide rotates integrally with the drive shaft. The pressurizing passage is opened and closed by a valve body. Orbiting balls, which contact the valve body, are arranged about the axis of the drive shaft and the rotated guide. The balls follow the rotation of the rotated guide and orbit about the axis. The orbiting radius of the balls varies. A spring urges the balls in a direction decreasing the orbiting radius of the balls. When the rotating speed of the drive shaft exceeds the limit value, centrifugal force moves the balls against the force of the spring and increases the orbiting diameter of the balls.

Abstract: A thick matter pump, especially a concrete pump, including a material feed container, two conveyor cylinders opening at the front into the inside of the material feed container, a swivelling pipe, one end of which alternately in pulses communicates with the frontal apertures in the conveying cylinder and the other end being connected to a conveyor pipe and with a closable cleaning aperture in the appropriate pipe wall arranged near the end of the conveyor pipe or in a section of the swivelling pipe outside the material feed container. A cleaning cartridge can be connected to the cleaning aperture having a compressed air and/or pressurized water connection while the feed pipe and/or the swivelling pipe can be closed on the conveyor cylinder side by means of a blocking system.