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:
May. 17, 1977
Filed:
Jul. 16, 1975
Ned A Sigmon, Durham, NC (US);
Liggett & Myers Incorporated, Durham, NC (US);
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.