US3806567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing reinforced, cellular slabs by extrusion
Assignee: Individual
•
Filing: 1971-03-12
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Granted: 1974-04-23
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Expires: 1991-03-12
Abstract
Abstract A thick, foamed plastic slab having a smooth surface, a densified core, and rounded edges is produced by extruding foamable, substantially unplasticized poly(vinyl chloride) in the form of a tube into a region of lower pressure, immediately cooling the outer surface of the tube while allowing entrapped gases to cause formation of a rough-textured inner surface thereon and then compressing the tube at right angles to the direction of extrusion.
Inventors
- 👤 A Graham
- 👤 R Sitler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:25
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/20; B29C44/22; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/507; B29K; B29K2027/00; B29K2027/06; B29K2105/00; B29K2105/04; B29K2105/043; Y; Y10; Y10S; Y10S264/00; Y10S264/14; Y10S264/57; Y10T; Y10T428/00; Y10T428/24; Y10T428/24777; Y10T428/249921; Y10T428/249953; Y10T428/249987; Y10T428/249988; Y10T428/249989
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3094449A
Cited
US3363034A
Cited
US3431163A
Cited
US3426111A
Cited
US3387067A
Cited
US3413388A
Cited
US3413387A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |