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. 22, 2005
Filed:
Mar. 10, 2003
Dieter Schimmel, Roth, DE;
Dieter Schimmel, Roth, DE;
Demag Ergotech GmbH, Schwaig, DE;
Abstract
A backflow prevention device for a plasticizing and injection screw axially movable in a plasticizing cylinder of an injection molding machine, includes a base body having a leading head portion and a trailing neck portion and formed with a channel for passage of plastic melt by the screw to an anterior screw space, whereby a check valve is disposed in the channel. Bearing against an inner wall of the plasticizing cylinder and axially moving between open and closed positions is a locking ring so positioned behind the head portion in the area of the neck portion as to define a gap with the base body. The locking ring has a leading stop surface in sealing contact with a confronting base of the head portion, when the locking ring is in open position, and a trailing stop surface in sealing contact with the pressure ring, when the locking ring is in closed position, wherein the inlet opening of the channel is so disposed in the base body that the leading stop surface of the locking ring is prevented from overlapping the inlet opening, when the locking ring is in open position.