US3897938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for refining polymeric material
Assignee: Goodrich Corp
•
Filing: 1974-04-24
•
Granted: 1975-08-05
•
Expires: 1994-04-24
Abstract
Abstract An extruder apparatus for working polymeric material having a feed screw with dual flight defining a primary channel and a secondary channel. The primary channel progressively decreases in cross-sectional area while maintaining a constant width in cooperation with the secondary channel that increases in crosssectional area to accommodate all the melt as it changes from a solid phase to a fluent phase. The secondary flight''s height is such as to accommodate the melt as it is formed in the primary channel.
Inventors
- 👤 Heung T Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:53
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/64; B29C48/65; B29C48/53; B29C48/535; B29C48/03
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
118 words
An extruder for processing polymeric material having a cylinder with an inlet opening and a discharge opening; a feed screw rotatable in said cylinder; said feed screw having a primary flight and a secondary flight cooperating to define a primary groove and a secondary groove; said secondary groove progressively increases in cross-sectional area; said primary groove progressively decreases in cross-sectional area; said primary flight providing a greater clearance space between its outer surface and said cylinder than the outer surface of said secondary flight and said cylinder; the depth of said primary groove diminishes in dimension to equal the clearance space between said primary flight and said barrel; and the axial width of said primary groove being constant.
Claim 2
Dependent Claim
118 words
An extruder for processing polymeric material having a cylinder with an inlet opening and a discharge opening; a feed screw rotatable in said cylinder; said feed screw having a primary flight and a secondary flight cooperating to define a primary groove and a secondary groove; said secondary groove progressively increases in cross-sectional area; said primary groove progressively decreases in cross-sectional area; said primary flight providing a greater clearance space between its outer surface and said cylinder than the outer surface of said secondary flight and said cylinder; the depth of said primary groove diminishes in dimension to equal the clearance space between said primary flight and said barrel; and the axial width of said primary groove being constant.
Claim 3
Dependent Claim
212 words
An extruder for processing polymeric material having a cylinder with an inlet opening and a discharge opening; a feed screw rotatable in said cylinder; said feed screw having a feed section, a transition section, and a metering section; said feed section having means for conveying polymeric material to said transition section; said transition section having flights for conveying material to said metering section; said metering section having flights for conveying polymeric material to said discharge opening; said flights of said transition section comprises a primary flight and a secondary flight cooperating to define a primary groove and a secondary groove, said secondary groove progressively increases in cross-sectional area from said feed section to said metering section; said primary groove progressively decreases in cross-sectional area from said feed section to said metering section; the depth of said primary groove closely adjacent to said metering section diminishing in dimension to equal the clearance space between said primary flight and said barrel; and the axial width of said primary groove being constant from said feed section to a point closely adjacent to said metering section, providing a constant amount of surface area exposed to said cylinder for material carried by said primary groove to where said groove terminates at the juncture to said metering section.
Claim 4
Dependent Claim
212 words
An extruder for processing polymeric material having a cylinder with an inlet opening and a discharge opening; a feed screw rotatable in said cylinder; said feed screw having a feed section, a transition section, and a metering section; said feed section having means for conveying polymeric material to said transition section; said transition section having flights for conveying material to said metering section; said metering section having flights for conveying polymeric material to said discharge opening; said flights of said transition section comprises a primary flight and a secondary flight cooperating to define a primary groove and a secondary groove, said secondary groove progressively increases in cross-sectional area from said feed section to said metering section; said primary groove progressively decreases in cross-sectional area from said feed section to said metering section; the depth of said primary groove closely adjacent to said metering section diminishing in dimension to equal the clearance space between said primary flight and said barrel; and the axial width of said primary groove being constant from said feed section to a point closely adjacent to said metering section, providing a constant amount of surface area exposed to said cylinder for material carried by said primary groove to where said groove terminates at the juncture to said metering section.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |