US3850415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw extruder for synthetic plastics material
Assignee: Individual
•
Filing: 1973-03-12
•
Granted: 1974-11-26
•
Expires: 1993-03-12
Abstract
Abstract A screw extruder comprises a body defining a bore in which a screw is mounted for rotation and a filling aperture through which synthetic plastics material is fed into the bore. The section of the bore adjacent the filling aperture is of greater gross sectional area than the remainder of the bore to allow a greater quantity of material to be fed into the housing than would otherwise be the case thus enabling a greater output to be achieved.
Inventors
- 👤 G Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:16
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/68; B29C48/685; B29C48/686; B29C48/501; B29C48/03
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
A screw extruder for plastic comprising a stationary housing having an interior wall defining an axially extending bore, and a screw within said housing said screw and housing having a filling zone, a compression zone and an homogenizing zone; said housing having a filler opening in said filling zone, the inner diameter of said bore being greater along the axial dimension of said filler opening than in the remainder of said bore; the interior wall of said housing defining a substantially continuous conical taper from said greater inner diameter to the adjacent portion of said bore; and an inwardly protruding, generally axially extending rib fixedly attached to the inner wall of said housing at the location of said greater inner diameter, said rib extending into and terminating at said taper, the inner radial limits of said rib being defined by the inner radius of said compression and homogenizing zones.
Claim 2
Dependent Claim
149 words
A screw extruder for plastic comprising a stationary housing having an interior wall defining an axially extending bore, and a screw within said housing said screw and housing having a filling zone, a compression zone and an homogenizing zone; said housing having a filler opening in said filling zone, the inner diameter of said bore being greater along the axial dimension of said filler opening than in the remainder of said bore; the interior wall of said housing defining a substantially continuous conical taper from said greater inner diameter to the adjacent portion of said bore; and an inwardly protruding, generally axially extending rib fixedly attached to the inner wall of said housing at the location of said greater inner diameter, said rib extending into and terminating at said taper, the inner radial limits of said rib being defined by the inner radius of said compression and homogenizing zones.
Claim 3
Dependent Claim
30 words
A screw extruder according to claim 1 wherein the interior wall of said housing further defines a plurality of longitudinal grooves extending from said taper away from said filler opEning.
Claim 4
Dependent Claim
21 words
A screw extruder according to claim 1 wherein a portion of said rib extends across the interior of said filler opening.
Claim 5
Dependent Claim
17 words
A screw extruder according to claim 1 wherein said rib extends in the shape of a helix.
Claim 6
Dependent Claim
26 words
A screw extruder according to claim 1, wherein said housing includes cooling channels located in the region extending from the filler opening to the compression zone.
Claim 7
Dependent Claim
26 words
A screw extruder according to claim 1 wherein said longitudinal grooves are triangular in cross section, one side of the triangle extending in a radial direction.
Claim 8
Dependent Claim
45 words
A screw extruder according to claim 1 wherein the cross-sectional shape of said rib includes an elongated radially extending surface facing opposite the direction of motion of the screw, and a sloping surface joining said radially extending surface and the interior wall of said housing.
Claim 9
Dependent Claim
26 words
A screw extruder according to claim 7 wherein said rib further includes a second radially extending surface on the side opposite said elongated radially extending surface.
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) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |