Plant for producing single-dose capsules for preparing beverages

1. A plant for manufacturing single-dose capsules for preparing beverages, comprising:

a conveyor ( 2 ) for advancing impermeable shells ( 101 ) in succession along a production line, the production line comprising:

a first operative station (A) comprising a forming unit ( 3 ) for forming individual beaker-shaped filters ( 105 ) made of a filtering material and a releasing unit for partially inserting each of the formed beaker-shaped filters ( 105 ) inside an impermeable shell ( 101 ); and

a second operative station (B,C) disposed downstream from the first operative station (A) comprising:

a regulating unit ( 59 , 60 ) for regulating a level of each partially inserted beaker-shaped filter ( 105 ) inside the relative impermeable shell ( 101 ) and pushing the beaker-shaped filter ( 105 ) to slide into the shell ( 101 ), said regulating unit being independent from the forming unit; and

a welding unit welding an upper edge of each beaker-shaped filter ( 105 ) to an upper edge of the impermeable shell ( 101 ) in which the beaker-shaped filter ( 105 ) is inserted.

2. The plant of claim 1 , wherein the forming unit ( 3 ) comprises a device causing a tape ( 13 ) of a filtering material to pass onto a forming matrix ( 30 ), a cutting unit ( 42 ), collaborating with the forming matrix ( 30 ), for cutting the tape ( 13 ) along a perimetral edge of the forming matrix ( 30 ) to separate a single portion of the tape ( 13 ) from the tape, and a sliding punch ( 46 ) which pushes the portion of tape ( 13 ) internally of a through-cavity ( 33 ) of the matrix ( 30 ), such as to impart a beaker shape on the portion of tape ( 13 ) and cause the portion of tape ( 13 ) to exit from an opposite end of the cavity ( 33 ), such as to release the portion of tape ( 13 ) internally of a relative impermeable shell ( 101 ).

3. The plant of claim 2 , wherein the sliding punch ( 46 ) and the axial through-cavity ( 33 ) of the forming matrix ( 30 ) are both grooved, such as to give rise to corresponding grooves in a side wall of the beaker-shaped filter ( 105 ).

4. The plant of claim 2 , wherein the cutting unit comprises a blade ( 42 ) having an annular development which is coaxial and which in plan view exhibits a profile which complements a profile of the perimetral edge of the forming matrix ( 30 ), and a first activating unit for obtaining a relative movement of the annular blade ( 42 ) in an axial direction with respect to the forming matrix ( 30 ), with interposing of the tape ( 13 ) of filtering material.

5. The plant of claim 2 , wherein the cutting unit ( 42 ) comprises a tape ring clamp 35 which is coaxial to the forming matrix ( 30 ), and which pushes the tape ( 13 ) of filtering material against a support surface ( 11 ) which surrounds the forming matrix ( 30 ), such as to delimit and block the portion of tape ( 13 ) to be separated on the support surface ( 11 ), and an activating unit for obtaining a relative movement in an axial direction of the tape ring clamp 35 with respect to the support surface ( 11 ).

6. The plant of claim 4 , wherein the annular blade ( 42 ) is attached to a support body ( 43 ), which support body ( 43 ) is coupled to the tape ring clamp ( 35 ) by means which allow relative movements thereof in an axial direction.

7. The plant of claim 6 , wherein the support body ( 43 ) comprises a through hole ( 44 ), a second activating unit for obtaining a relative movement of the sliding punch ( 46 ) in an axial direction with respect to the support body ( 43 ).

8. The plant of claim 6 , wherein the support body ( 43 ) comprises a truncoconical surface which pushes the tape ( 13 ) of filtering material into a truncoconical depression situated at a mouth of the through-cavity ( 33 ) of the forming matrix ( 30 ).

9. The plant of claim 1 , wherein the welding unit comprises at least two welding devices ( 5 , 6 ), which respectively operate in a first welding station (B) of said second stations and a second welding station (C) of said second stations, the second welding device being disposed downstream of the first welding device, each welding device ( 5 , 6 ) welding different portions of the upper edge of the beaker-shaped filter ( 105 ), such as in combination to obtain a complete welding of the edge.

10. The plant of claim 9 , wherein the welding devices ( 5 , 6 ) weld at least partially-overlapping portions of the edge of the beaker-shaped filter ( 105 ).

11. The plant of claim 9 , wherein each welding device ( 5 , 6 ) comprises a plurality of heatable blocks ( 50 ), which are arranged around a central axis (G) of the device, aligned with the axis of the shell ( 101 ) which is situated in the first welding station or the second welding station (B, C) respectively, a third activating unit for obtaining a relative movement of the heatable blocks ( 50 ) in an axial direction with respect to the shell ( 101 ), and a unit for reciprocally distancing the heatable blocks ( 50 ) with respect to the central axis (G), in such a way that each of the heatable blocks ( 50 ) pushes a portion of the beaker-shaped filter ( 105 ) from inside and outwardly against the shell ( 101 ) in which the beaker-shaped filter ( 105 ) is inserted.

12. The plant of claim 11 , wherein each heatable block ( 50 ) exhibits an outwardly-facing contact surface ( 51 ) a cross-section of which is an arc of circumference profile having a radius of curvature substantially equal to a radius of the mouth of the shell ( 101 ).

13. The plant of claim 11 , wherein the heatable blocks ( 50 ) are angularly equidistant with respect to the central axis (G) of the welding device.

14. The plant of claim 11 , wherein the means for distancing are configured in such a way as to move the heatable blocks ( 50 ) while always maintaining the heatable blocks ( 50 ) equidistant from the central axis (G) of the welding device.

15. The plant of claim 11 , wherein the unit for distancing comprise a plurality of support arms ( 53 ), each of which exhibits an end attached to a respective heatable block ( 50 ), and an opposite end hinged to a base ( 54 ) with an axis of hinging which is perpendicular to the central axis (G) of the welding device, and a fourth activating unit to cause the support arms ( 53 ) to oscillate contemporaneously about respective axes of hinging.

16. The plant of claim 15 , wherein the fourth activating unit comprises a plurality of connecting rods ( 58 ), each of which exhibits an end which is hinged to an intermediate point of a respective support arm ( 53 ) and an opposite end which is hinged to a single connecting body ( 57 ), which is activated by an actuator ( 56 ) to move along the central axis (G) of the welding device.

17. The plant of claim 16 , wherein the actuator ( 56 ) comprise a cylinder-piston group ( 56 ).

18. The plant of claim 11 , wherein the unit for adjusting a level of the beaker-shaped filter ( 105 ) are associated to the first welding device ( 5 ) which operates in the first welding station (B), and comprise a levelling ring ( 59 , 60 ) which is solidly attached to the first welding device ( 5 ), and which coaxially surrounds the relative heatable blocks ( 50 ), which levelling ring ( 59 , 60 ) pushes the beaker-shaped filter ( 105 ) internally of the impermeable shell ( 101 ), following a relative movement of the first welding device ( 5 ) in an axial direction with respect to the shell ( 101 ).

19. The plant of claim 5 , wherein the annular blade ( 42 ) is attached to a support body ( 43 ), which support body ( 43 ) is coupled to the tape ring clamp ( 35 ) by means which allow relative movements thereof in an axial direction.

20. The plant of claim 19 , wherein the support body ( 43 ) comprises a through hole ( 44 ), a fifth activating unit for obtaining a relative movement of the sliding punch ( 46 ) in an axial direction with respect to the support body ( 43 ).

21. The plant of claim 19 , wherein the support body ( 43 ) comprises a truncoconical surface which pushes the tape ( 13 ) of filtering material into a truncoconical depression situated at a mouth of the through-cavity ( 33 ) of the forming matrix ( 30 ).