Metering device for bulk materials, more particularly constituents of animal foodstuffs

Apparatus for dispensing mixtures of more than one constituent of bulk material comprising a single elongate mixing and discharge conveyor, a plurality of metering conveyors each comprising a screw conveyor leading from a source of one of the constituents of each mixture and terminating at said mixing and discharge conveyor, a housing surrounding the terminus of each of said metering conveyors and the associated portion of said mixing and discharge conveyor, and means for simultaneously driving said mixing and discharge conveyor and each of said metering conveyors comprising a single motor located adjacent one of said housings and transmission means extending serially into each housing connecting said motor and an adjustable speed variator interposed between the terminus of each of said metering conveyors and said drive transmission means for driving the associated metering conveyor and for continuously and selectively varying, during operation of said mixing and discharge conveyor and the metering conveyors, the speed of said associated metering conveyors independently of the operation of the other metering conveyors, each of said housings supporting the transmission means and speed variator means associated with the respective metering conveyor and being arranged in abutment in line with each other, said discharge conveyor extending in line serially through each of said housings, said speed variator means comprising an adjustable linkage connected at one end to said transmission means and at the other end to a first uni-directional clutch member, said first uni-directional clutch member being secured between the shaft of said screw conveyor and a second uni-directional clutch member mounted on said housing, said adjustable linkage comprising a handle having a regulating crank arm pivotally mounted at one end extending through an arcuate slot in a wall of said housing opposite said screw conveyor, a crank pin movable by said transmission means, a coupling rod rotatably connected at one end to said crank pin, a spindle journalled at the other end of said coupling rod, and a tie rod adjoining said spindle and said regulating crank arm at the axis of said handle, and a connecting rod joining said spindle and said uni-directional clutch member.