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:
Nov. 22, 1994
Filed:
Oct. 18, 1993
Applicant:
Inventors:
Takeshi Matsumura, Tokyo, JP;
Mikio Komori, Tokyo, JP;
Assignee:
Japan Tobacco Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
21912184 ; 2191217 ; 21912171 ; 21912183 ;
Abstract
In a method of controlling the air permeability of the hole portion of chip paper in which holes are formed by a laser, the flow rate of permeating air from an air permeable portion of a dummy prepared in advance and the flow rate of permeating air from the hole portion are respectively converted to pressures. An output from the laser is controlled such that the pressure difference between the two pressures becomes zero. Then, an influence caused by variations in suction pressure can be prevented. Accordingly, the air permeability can be detected without being influenced by variations in suction pressure.