Method and device for conveying particulate material during the layer-wise production of patterns

1. An apparatus for the manufacture of a three dimensional object in layers comprising

i) a device for conveying a particulate material during the manufacture of the object in layers, wherein the devise comprises

a) a reservoir,

b) a spreader unit, and

c) a plurality of particulate material conveying systems including a first particulate material conveying system and a second particulate material conveying system; and

ii) a build platform on which the object is built;

wherein

the first particulate material conveying system conveys the particulate material from the reservoir to the spreader;

the spreader is adapted for being filled with the particulate material, releasing the particulate material while moving over the build platform, and spreading the particulate material over the build platform; and

the second particulate material conveying system conveys excess particulate material that was fed to the spreader back to the reservoir;

so that at least the reservoir and the spreader unit are contained in a closed conveying circuit.

2. The apparatus according to claim 1 , wherein provision is furthermore made for an ejection system.

3. The apparatus according to claim 1 , wherein the reservoir is arranged below the spreader unit in a vertical at least during a filling process.

4. The apparatus according to claim 1 , wherein the particulate material conveying system comprises at least one conveyor belt.

5. The apparatus according to claim 1 , wherein the particulate material conveying system comprises screw conveyors.

6. The apparatus according to claim 1 , wherein the particulate material conveying system comprises a suction device for low pressure conveying.

7. The apparatus according to claim 2 wherein the ejection system comprises two covers comprising slits.

8. The apparatus according to claim 2 wherein the ejection system comprises two tubes located within one another and comprising boreholes, which are arranged so as to be offset.

9. The apparatus according to claim 1 , wherein a provision is furthermore made for a junction for introducing a new particulate material into the reservoir.

10. The apparatus according to claim 1 , wherein the reservoir is maintained in a fixed position and the spreader unit is movable relative to the reservoir.

11. The apparatus according to claim 1 , wherein the build platform is movable in the vertical direction.

12. An apparatus for the manufacture of a three dimensional object in layers comprising

i) a first device for conveying a particulate material during the manufacture of the object in layers, wherein the devise comprises

a) a reservoir,

b) a spreader unit, and

c) a plurality of particulate material conveying systems including a first particulate material conveying system and a second particulate material conveying system, wherein the particulate material conveying system comprises screw conveyors; and

ii) a build platform on which the object is built;

the first device includes a junction for introducing new particulate material into the reservoir;

the first particulate material conveying system conveys the particulate material from the reservoir to the spreader;

the spreader is adapted for carrying the particulate material, releasing the particulate material while moving over the build platform, and spreading the particulate material onto the build platform; and

the second particulate material conveying system conveys excess particulate material that was fed to the spreader back to the reservoir;

so that at least the reservoir and the spreader unit are contained in a closed conveying circuit.

13. The apparatus according to claim 12 , wherein

the reservoir is maintained in a fixed position and the spreader unit is movable relative to the reservoir; and

the build platform is movable in the vertical direction.

14. An apparatus for the manufacture of a three dimensional object in layers comprising

i) a first device for conveying a particulate material during the manufacture of the object in layers, wherein the devise comprises

a) a reservoir,

b) a spreader unit, and

c) a plurality of particulate material conveying systems including a first particulate material conveying system and a second particulate material conveying system, wherein the particulate material conveying systems comprises at least one conveyor belt;

ii) a build platform on which the object is built

the first device includes a junction for introducing new particulate material into the reservoir;

the first particulate material conveying system conveys the particulate material from the reservoir to the spreader;

the spreader is adapted for being filled with the particulate material, releasing the particulate material while moving over the build platform, and spreading the particulate material onto the build platform; and

the second particulate material conveying system conveys excess particulate material that was fed to the spreader back to the reservoir;

so that at least the reservoir and the spreader unit are contained in a closed conveying circuit.

15. The apparatus according to claim 14 , wherein

the reservoir is maintained in a fixed position and the spreader unit is movable relative to the reservoir; and

the build platform is movable in the vertical direction.

16. The apparatus of claims 1 , wherein the build platform is movable in the vertical direction by a layer thickness of one of the layers.

17. The apparatus of claim 16 , wherein the apparatus includes an ejection system for evenly refilling the spreader unit with the particulate material.

18. The apparatus of claim 17 , wherein the ejection system includes a pair of tubes that rotate against one another two provide an opening for discharge of the particulate material into the spreader unit.

19. The apparatus of claim 16 , wherein the reservoir is maintained in a fixed position and the spreader unit is movable relative to the reservoir.

20. The apparatus of claim 16 , wherein the apparatus includes an opening for removing the particulate material from the apparatus.

21. The apparatus of claim 16 , wherein the apparatus includes an opening for recovering excess particulate material during a filling of spreader unit.