Method for making a hollow filter rod
US4179323A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1977 |
| Grant date | Dec 18, 1979 |
| Priority date | — |
| Expiry date | Feb 17, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/1011
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The apparatus is constructed to produce a hollow filter rod. The apparatus includes a mandrel through which a supplied length of tubing is passed, a nozzle surrounding the mandrel for shaping a stream of fibrous filter material about the mandrel and a forming means for enveloping a web of paper about the fibrous filter material and the tubing to produce the filter rod. The mandrel can be adjusted relative to the forming means to ensure an accurate centering of the tubing within the filter rod. The hollow filter includes a rigid non-deformable tube defining a smoke passage having a draw resistance to control the amount of unfiltered smoke, a concentric layer of filter material and a perforated outer wrap for passage of air into the layer of filter material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.