Metering device for granulates - has sliding units for each constituent which engage or disengage common drive shaft

Device for metering separate constituent materials into a mixer comprises a baseplate contg. a number of apertures through which the individual constituents can be discharged into the mixer below. Each metering unit comprises a separate housing contg. a cell wheel, the shaft projecting out of the housing and having mounted on it externally a gear-wheel for engagement into the drive wheel. Each of these metering unit housings is slidable on the baseplate by means of a hydraulic or pneumatic ram, so that the unit can be advanced to engage its pinion with the driving pinion or retracted to disengage the drive. When in the advanced position, the discharge opening from the bottom of the metering unit housing is in alignment with the aperture in the plate below whereas, when the metering unit is out of engagement with the drive pinion, the dischare opening is covered by the solid plate below. All drive pinions are mounted on common drive shaft. The metering units are connected to their guide rails by quick-acting connectors. Pref. each metering cell wheel is mounted overhung on its shaft and keyed to it. Accurate volumetric control is possible. In partic. the sliding action of the housing immediately cuts off the feed when desired without any follow-up flow.