Device for the metered filling of bulk material

1. A device for the metered filling of bulk material having a metering screw ( 16 ), which is arranged in a hollow cylinder shaped metering tube ( 12 ) and which can be slid along a longitudinal axis (L) of the metering tube ( 12 ), the metering screw having a closing head ( 18 ) for closing a metering opening ( 14 ), wherein the closing head ( 18 ) has a substantially conical surface ( 20 ), characterized in that said metering tube ( 12 ) transitions after the metering opening ( 14 ) into a hollow cylinder shaped mouthpiece ( 32 ) having a-larger inner diameter (D Mi ) compared to an inner diameter (d Ri ,) of said metering tube ( 12 ), wherein a diameter of the closing head ( 18 ) is substantially the same as the inner diameter (d Ri ,) of the metering tube ( 12 ), wherein a surface (A) of an annular ring ( 42 ) defined by a difference between the inner diameter (D Mi ,) of the mouthpiece ( 32 ) and the inner diameter (d Ri ) of the metering tube ( 12 ) is greater than a metering surface (B) of the metering screw ( 16 ) in an open position, and wherein the mouthpiece ( 32 ) extends along the longitudinal axis (L) over the closing head ( 18 ) to an extent (e) in the open position.

2. The device according to claim 1 , characterized in that a transition from a cylinder shaped inside wall ( 13 ) of the metering tube ( 12 ) to a cylinder shaped inside wall ( 36 ) of the mouthpiece ( 32 ) is a truncated cone-shaped transition surface ( 38 ), wherein an angle of aperture (α 1 ) of the truncated cone-shaped transition surface ( 38 ) is greater than an angle of aperture (α 2 ) of the conical surface ( 20 ) of the closing head ( 18 ).

3. The device according to claim 1 , characterized in that the mouthpiece ( 32 ) is part of an insert ( 28 ) to the metering tube ( 12 ) in a manner allowing the mouthpiece to be exchanged.

4. The device according to claim 3 , characterized in that the metering opening ( 14 ) is a part of the insert ( 28 ).

5. A device for the metered filling of bulk material having a metering screw ( 16 ), which is arranged in a hollow cylinder shaped metering tube ( 12 ) and which can be slid along a longitudinal axis (L) of the metering tube ( 12 ), the metering screw having a closing head ( 18 ) for closing a metering opening ( 14 ), wherein the closing head ( 18 ) has a substantially conical surface ( 20 ), characterized in that said metering tube ( 12 ) transitions after the metering opening ( 14 ) into a mouthpiece ( 32 ), characterized in that a transition from a cylinder shaped inside wall ( 13 ) of the metering tube ( 12 ) to a cylinder shaped inside wall ( 36 ) of the mouthpiece ( 32 ) is a truncated cone-shaped transition surface ( 38 ), wherein a diameter of the closing head 18 is substantially the same as an inner diameter d Ri of the metering tube 12 , wherein a surface A of an annular ring 42 defined b a difference between an inner diameter D Mi of the mouth piece 32 and the inner diameter d Ri of the metering tube 12 is greater than a metering surface (B) of the metering screw ( 16 ) in an open position, and wherein the mouthpiece ( 32 ) extends along the longitudinal axis (L) over the closing head ( 18 ) to an extent (e) in the open position.

6. The device according to claim 5 , characterized in that the mouthpiece ( 32 ) is part of an insert ( 28 ) to the metering tube ( 12 ) in a manner allowing the mouthpiece ( 32 ) to be exchanged.

7. The device according to claim 6 , characterized in that the metering opening ( 14 ) is a part of the insert ( 28 ).

8. The device according to claim 5 , wherein an angle of aperture (α 1 ) of the truncated cone-shaped transition surface ( 38 ) is greater than an angle of aperture (α 2 ) of the conical surface ( 20 ) of the closing head ( 18 ).