The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 1987
Filed:
Oct. 24, 1985
Applicant:
Inventors:
Assignee:
British-American Tobacco Company Limited, London, GB;
Primary Examiner:
Int. Cl.
CPC ...
A24D / ;
U.S. Cl.
CPC ...
131339 ; 131340 ;
Abstract
Cigarette filters comprises a filter element, open for smoke flow at the mouth end, and smoke passage of flow impedance less than that of the filter element. The passage is closed at the downstream end so that smoke is constrained to pass into the element at the downstream end of the passage. The passage may be an annular cross-section duct or grooves at the periphery of the element or may be a bore within the element. The filters provide an increasing degree of filtration as smoking proceeds.