Machine for making cigarette filters and method for making cigarette filters

Patent metadata

Field	Value
Publication number	US-11672274-B2
Application number	US-201716070348-A
Country	US
Kind code	B2
Filing date	Jan 17, 2017
Priority date	Jan 21, 2016
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

A machine for making cigarette filters and which includes a forming beam having an internal channel whose transverse cross section changes shape along the main longitudinal direction of the channel. Porous conveyor means carry the tow along a feed path in the channel complying with the shape thereof and thereby being wrapped around the tow. At least one treatment station located along the feed path includes a nozzle for blowing a flow of steam into the channel. The nozzle includes a plurality of planar sectors positioned transversely to the channel and defining an overall planar flow orifice placed directly in communication with a steam feed duct. Each planar sector defines a respective planar flow orifice and at least two flow orifices have different thicknesses.

First claim

The invention claimed is:

1. A machine for making cigarette filters, comprising:
a forming beam having an internal channel extending along a main longitudinal direction and adapted to receive a tow of filter material impregnated with a plasticizing fluid, wherein the internal channel has a transverse cross section, the transverse cross section including a changing shape along the main longitudinal direction in order to impart a desired shape to the tow to form a continuous rod of filter material;
a porous conveyor belt to slide in the internal channel of the forming beam along the main longitudinal direction and to carry the tow along a feed path, the porous conveyor belt complies with the shape of the transverse cross section of the internal channel and being at least partly wrapped around the tow,
a treatment station located along the feed path and comprising a nozzle to blow a flow of steam into the internal channel transversely thereto,
wherein the nozzle comprises a plurality of planar sectors positioned transversely to the internal channel, the plurality of planar sectors defining a plurality of planar flow orifices, with each of the plurality of planar sectors defining a respective planar flow orifice placed directly in communication between a steam feed duct positioned around the respective planar flow orifice and the internal channel, with at least two of the plurality of planar flow orifices having different thicknesses along the main longitudinal direction, and
wherein the plurality of planar sectors are in mutual communication with each other, defining an uninterrupted planar flow orifice around the internal channel.

2. The machine according to claim 1 , wherein the nozzle comprises:
two lateral planar sectors located laterally of the internal channel relative to an inlet duct of the steam feed duct,
a front planar sector located between the inlet duct of the steam feed duct and the internal channel, and
a rear planar sector located on an opposite side of the internal channel relative to the inlet duct,
wherein the two lateral planar sectors have respective thicknesses which are greater than at least one chosen from a thickness of the front planar sector and a thickness of the rear planar sector.

3. The machine according to claim 2 , wherein the nozzle comprises a compensating planar sector adjacent a portion of the tow not wrapped by the porous conveyor belt, the compensating planar sector having a thickness which is smaller than at least one chosen from the thickness of the front planar sector and the thickness of the rear planar sector.

4. The machine according to claim 3 , wherein the compensating planar sector has a thickness of between 0.20 mm and 0.25 mm.

5. The machine according to claim 3 , wherein the nozzle includes two rear planar sectors and the compensating planar sector is located on the opposite side of the internal channel relative to the inlet duct, at a central position between the two rear planar sectors.

6. The machine according to claim 2 , wherein the two lateral planar sectors have respective thicknesses which are the same and between 0.3 mm and 0.9 mm.

7. The machine according to claim 2 , wherein the front planar sector and the rear planar sector have respective thicknesses which are the same and between 0.25 mm and 0.8 mm.

8. The machine according to claim 1 , wherein the respective planar flow orifice is in communication with the steam feed duct at a lateral section of the steam feed duct.

9. The machine according to claim 1 , wherein the steam feed duct extends along a feed path which is polygonal in shape and wherein the plurality of planar sectors run parallel to one side of the feed path.

10. The machine according to claim 1 , wherein the plurality of planar sectors run parallel to a steam flow direction along the inlet duct of the steam feed duct.

11. The machine according to claim 1 , wherein the nozzle is an insert placed around the internal channel and includes two separate portions.

12. The machine according to claim 11 , wherein the forming beam comprises a base and a cover closable over the base along a plane parallel to the main longitudinal direction to form the internal channel and the two separate portions of the insert are associated with the base and the cover, respectively.

13. The machine according to claim 12 , and further comprising a compensating device interposed between one of the two separate portions of the insert and at least one chosen from the cover and the base, respectively, the compensating device being configured to keep a position of the two separate portions relative to each other unchanged when a working distance between the base and the cover is changed.

14. The machine according to claim 13 , wherein the compensating device comprises at least one elastic element.

15. The machine according to claim 13 , wherein the compensating device comprises a spring.

16. The machine according to claim 11 , wherein the two separate portions of the insert are coupled at a plane parallel to the main longitudinal direction.

17. The machine according to claim 1 , wherein the steam feed duct extends along a feed path which is rectangular in shape and wherein the plurality of planar sectors run parallel to one side of the feed path.

18. The machine according to claim 1 , wherein each planar sector of the plurality of planar sectors has a flat shape extending transversely to the internal channel.

19. The machine according to claim 1 , wherein the plurality of planar sectors laterally merge into each other such that the uninterrupted planar flow orifice extends in a continuous manner around the internal channel and produces a steam blade leading into the internal channel.

20. The machine according to claim 19 , wherein the planar sectors laterally merge upstream from reaching the internal channel.

21. The machine according to claim 1 , wherein each planar sector of the plurality of planar sectors has a flat shape extending perpendicularly to the internal channel.

22. The machine according to claim 1 , wherein each planar sector is delimited by parallel main walls and wherein said main walls extend perpendicularly to the internal channel.

23. The machine according to claim 1 , wherein the plurality of planar sectors are in mutual communication with each other upstream of the internal channel and along a majority length of the planar flow orifices.

Assignees

• Gd Spa

Inventors

• Baldanza Nicola
• Eusepi Ivan
• Stivani Eros
• Sartoni Massimo

Classifications

• A24D3/0279

  with tubes · CPC title

• A24D3/0233 Primary

  by means of a garniture · CPC title

• A24D3/04

  Tobacco smoke filters characterised by their shape or structure · CPC title

• A24D3/02 Primary

  Manufacture of tobacco smoke filters · CPC title