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. 05, 1981
Filed:
Jan. 05, 1979
Applicant:
Inventor:
Gerhard Martin, Hanover, DE;
Assignee:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29B / ; B29F / ;
U.S. Cl.
CPC ...
366 79 ; 277-3 ; 366 75 ; 366139 ; 425107 ; 425203 ;
Abstract
A screw extruder for processing thermoplastic materials wherein a vacuum is applied to the feed opening for the material and/or to a filling section of the cylinder for the purpose of reverse degasification, said extruder having a simultaneously rotating pressure piece between a screw and a back pressure bearing and having a stationary end piece disposed on the screw side in front of the rotating pressure piece and sealing means comprising at least two axially spaced radial sealing rings and a vacuum source to apply vacuum to an annular interspace formed between the sealing rings.