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:
Feb. 20, 1979
Filed:
Sep. 01, 1977
Applicant:
Inventor:
Richard A Carlsen, Somerset, NJ (US);
Assignee:
Egan Machinery Company, Somerville, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29D / ;
U.S. Cl.
CPC ...
425140 ; 264 403 ; 2642 / ; 425 / ; 425149 ; 4253261 ; 4253871 ; 425392 ; 425467 ;
Abstract
Control apparatus for automatically maintaining the desired blown tube diameter in the blown plastic film process where the blown tube is internally cooled by a gas flow into and out of the interior of the tube. A by-pass duct having a by-pass damper is provided on either the inlet or exhaust duct by-passing the inlet or exhaust duct damper respectively and this by-pass damper is controlled by tube diameter sensors. By thus controlling only a small percentage of the inlet or exhaust flow a very fine and stable control is achieved. Control apparatus is also provided to maintain the by-pass damper in its optimum operating range.