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:
Jul. 25, 1989
Filed:
Dec. 05, 1988
Applicant:
Inventor:
Grant E Hagan, Surrey, CA;
Assignee:
Sankyo Manufacturing Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F23J / ;
U.S. Cl.
CPC ...
1263 / ; 126297 ; 1221 / ; 138 46 ;
Abstract
A device for adjustably restricting the flow of exhaust gases in a furnace flue to conserve fuel is disclosed. It comprises two interlocking pipe sections and a helical element having one end fixed to the inner surface of each pipe section. The helical element has a circular opening along its central axis. The degree of restriction provided by the device is adjusted by twisting or separating the two pipe sections.