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:
Jan. 20, 1987
Filed:
May. 07, 1981
Richard M Berger, Midlothian, VA (US);
American Filtrona Corporation, Richmond, VA (US);
Abstract
An improved tobacco smoke filter is characterized by longitudinally continuous grooves running from end-to-end in the peripheral surface of a smoke-impervious filter plug wrap. Smoke-impervious tipping surrounds the plug wrap to seal the grooves except for small ventilation holes in the tipping which permit communication between the grooves and the ambient air. In a preferred embodiment, the grooves are restricted toward the mouth end of the filter and the degree of restriction determines the direction of air and smoke flow in the grooves. The grooves are each preferably formed as two longitudinal sections of different cross-section. Apparatus and method for manufacturing the filter are disclosed.