Assembly for a tabletting press

1. Assembly for fabrication of pellets from a powder material comprising:

a powder distributor,

a table provided with cavities, on which the distributor is capable of moving, said powder distributor comprising a casing comprising a cover provided with means connecting it to at least one powder supply conduit connected to a hopper, two side walls and two end walls, said distributor being capable of moving the powder in a to and fro movement on a plane along a determined displacement direction (X), said assembly comprising

means of guiding the distributor along the displacement direction and means of pressing the distributor in contact with the table, in which said guide means comprise at least two guide rollers installed on each side wall, said guide rollers having rotation axes (Z) perpendicular to a plane of the table, said guide rollers cooperating with a guide running track fixed relative to the table, and in which said pressure means comprise at least two pressure rollers on each side wall, said pressure rollers having rotation axes (Y 1 ) perpendicular to the displacement direction (X) and parallel to the plane of the table, each pressure roller cooperating with a pressure running track fixed relative to the table, said pressure rollers being arranged only between the associated pressure running track and the table, and being capable of moving to and fro relative to the pressure running track, such that the pressure force is increased by moving the pressure rollers towards the associated pressure running track.

2. Assembly according to claim 1 , comprising two rails fixed to the table on each side of the distributor and supporting the pressure running track and the guide running track.

3. Assembly according to claim 2 , in which each rail has a C-shaped cross section open towards the distributor, the cross-section comprising a lower branch for attachment of the rail on the table and an upper branch supporting the pressure running track and the guide running track.

4. Assembly according to claim 1 , comprising an adjuster to adjust the pressure force between the distributor and the table.

5. Assembly according to claim 4 , in which the adjuster comprises an elastic means mounted free to react between two pressure rollers on one side wall and an elastic means mounted free to react between the two pressure rollers on the other side wall and means capable of modifying the preload on each of the elastic means.

6. Assembly according to claim 5 , in which each pressure roller is mounted free to rotate on a part that is itself free to rotate on the side wall about an axis of rotation (Y 2 , Y 3 ) parallel to the axis of rotation (Y 1 ) of the pressure roller and separate from it, each elastic means being mounted bearing between the parts supporting the pressure rollers, variable length connector connecting the two parts to adjust the preload on the elastic means.

7. Assembly according to claim 6 , in which the variable length connector comprises threaded rods connecting the two parts, each elastic means being free to rotate about a threaded rod, said threaded rods cooperating with the parts supporting the rollers by screwing.

8. Assembly according to claim 1 , in which the cover comprises two bevelled end edges, one of the end walls of the distributor comprising at least one bevelled bill under which one of the bevelled end edges of the cover is located and the other end wall comprises a fixed part and a removable part provided with at least one bevelled bill that will bear on the other bevelled end of the cover.

9. Assembly according to claim 8 , in which the fixed part comprises screws and the removable part is provided with U-lags inside which the screws fit.

10. Assembly according to claim 1 , in which the table comprises several cavities and the distributor comprises means of grouping the powder along separate axes approximately parallel to the displacement direction (X), to fill the cavities, each cavity being located along a grouping axis, the grouping means being supported by walls of the casing perpendicular to the displacement direction (X) and having a saw tooth section along a plane parallel to the displacement plane.

11. Assembly according to claim 10 , comprising downstream grouping means and upstream grouping means relative to the displacement direction (X).

12. Assembly according to claim 11 , in which the cavities are arranged in at least one row (R 1 , R 2 ), in which the downstream grouping means are offset transversely from the upstream grouping means by a half tooth width, such that one tooth tip is facing the bottom between two consecutive teeth, and in which the distance separating the cavities is equal to the distance separating the bottoms of the teeth, the distributor being arranged on the table so that when it moves, each bottom between two teeth covers a cavity in the table.

13. Pellet fabrication device comprising an assembly according to claim 1 , a displacement actuator conferring a to and fro movement on the distributor along the first displacement direction (X), a hopper capable of containing a powder material and routing means to move the powder material from the hopper to the distributor.

14. Pellet fabrication device according to claim 13 , in which the actuator is connected to the distributor through a swivel connection.

15. Pellet fabrication device according to claim 13 , in which the powder material routing means comprise at least one supply conduit connected to the cover and to the hopper, the supply conduit comprising a pipe formed from metal turns embedded in a synthetic material, and connectors to each of its ends.

16. Pellet fabrication device according to claim 15 , connectors being fixed to the cover and to the hopper by bolted articulated collars.

17. Pellet fabrication device according to claim 16 , in which the bolted articulated collar fixed to one of the connectors connecting the conduit to the hopper is mounted on an articulated stirrup free to rotate on said connector.

18. Pellet fabrication device according to claim 17 , in which the articulated rotation of the stirrup on said connector comprises a clearance along the axis of the connector and a transverse clearance.

19. Pellet fabrication device according to claim 15 , comprising several supply conduits between the hopper and the distributor.

20. Pellet fabrication device according to claim 13 , for the fabrication of nuclear fuel pellets.