Optional dry or liquid filter
US3991773A · kind A · utility
Inventor
Key dates
| Filing date | Feb 20, 1975 |
| Grant date | Nov 16, 1976 |
| Priority date | — |
| Expiry date | Feb 20, 1995 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA24D3/048
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A dry or moist filter element for tobacco smoke is described. The filter comprises a resilient liquid-impervious tubular casing with a porous plug of filter material at either end thereof. A chamber is provided within the casing, between the plugs, defined by mutually spaced walls adjacent the inner end of each plug. Each end wall has at least one port therein to allow the passage of smoke therethrough. A liquid containing, frangible or collapsible module is disposed within the chamber. The module is shaped to permit the passage of smoke through the filter, and designed to admit the liquid contained therein, through the ports, into the plugs when the central portion of the casing is compressed. The filter element of this invention then may be used as a dry filter, or if desired, as a moistened or wet filter merely by compressing the casing to rupture or collapse the module. Preferred liquids which may be used in the module include aqueous solutions of starch, glucose, or salt in biologically acceptable concentrations, alcohol to prevent freezing, or an aqueous, buffered solution containing the enzyme amylase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.