Dynamic seal and sealing method
US5569429A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 5, 1995 |
| Grant date | Oct 29, 1996 |
| Priority date | — |
| Expiry date | May 5, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92876
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus provided for extruding a polymer in an extruder barrel having an upstream portion and a downstream portion with a discharge port. A hopper is positioned for delivering polymer to the upstream portion of the extruder barrel and a screw shaft is mounted for rotational movement in the extruder barrel. A drive means is connected for rotating the screw shaft. The screw shaft has a conveying screw flight and a metering screw flight arranged for conveying and metering the polymer through the barrel. A seal is provided for sealing against polymer flow and includes at least two different passageways positioned between a seal barrel and at least one seal shaft mounted for rotational movement within the seal barrel. The passageways are oriented to urge the polymer toward the screw shaft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.