Filter unit for a smoking article

Patent metadata

Field	Value
Publication number	US-11690398-B2
Application number	US-201816648700-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 29, 2017
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

There is provided a filter unit for a smoking article having a tube formed from filter material and the tube having a first portion and a second portion, wherein an inner diameter of the first portion is different from an inner diameter of the second portion. There is also provided a tube having a longitudinal axis, wherein a straight line following at least a portion of an internal or external surface of the tube intersects the longitudinal axis at an angle other than 90°. Also described is a body or tube of filter material having a longitudinal axis, a first end surface and a second end surface, said body or tube formed from a plurality of continuous fibres extending between said first and second end surfaces, wherein the density of said filter material is greater at said first end surface than at said second end surface. A body of filter material is also described having a longitudinal axis and a channel or recess formed in the body of filter material, the shape of said body of filter material having no lines of reflective symmetry, as well as a body formed from filter material, the body having an end surface and a recess formed in the end surface. A smoking article including the filter unit and a kit comprising a smoking article and a filter unit are also described.

First claim

The invention claimed is:

1. A filter unit for a smoking article comprising:
a tube formed from filter material and having a first portion and a second portion,
wherein an inner diameter of the first portion is different from an inner diameter of the second portion,
wherein the second portion is at a distal end of the filter unit, and

wherein the inner diameter of the second portion decreases with distance from the distal end of the filter unit, and
wherein the second portion includes a chamfer resulting in the inner diameter of at least part of the second portion being greater than the inner diameter of the first portion.

2. A filter unit according to claim 1 , wherein an outer diameter of the second portion is substantially the same as an outer diameter of the first portion.

3. A filter unit according to claim 1 ,
wherein each of the first portion and the second portion has a respective first and second end, and
the second end of the first portion adjoins the first end of the second portion and has an inner diameter substantially the same as the first end of the second portion.

4. A filter unit according to claim 1 , further comprising:
a sleeve; and
a cylindrical element,
wherein the sleeve at least partially surrounds each of the tube and the cylindrical element.

5. A filter unit according to claim 4 , wherein the cylindrical element is formed from filter material.

6. A filter unit according to claim 4 , wherein the cylindrical element comprises a body having an end surface adjacent to the tube and a recess formed in the end surface.

7. A filter unit according to claim 1 , wherein a smallest internal diameter of the tube is between about 1 mm and about 5 mm.

8. A filter unit according to claim 1 , arranged to be coupled to a smoking article by a user.

9. A filter unit according to claim 1 , wherein said filter material comprises filter tow with a denier per filament of from 3 to 15 and a total denier of from 15,000 to 40,000.

10. A smoking article comprising a filter unit according to claim 1 .

11. A kit comprising a smoking article and a filter unit according to claim 1 .

Assignees

• British American Tobacco Investments Ltd

Inventors

• Brice Thomas
• Whiffen Samuel
• Richardson John

Classifications

• A24D3/10

  of cellulose or cellulose derivatives · CPC title

• A24D3/063

  of the fibers · CPC title

• A24D3/04 Primary

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

• A24D3/17

  Filters specially adapted for simulated smoking devices · CPC title

• A24D3/16

  of inorganic materials · CPC title