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US2676127A
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Method of making a nonporous duct
Assignee: Northrop Grumman Corp
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Filing: 1951-05-08
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Granted: 1954-04-20
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Expires: 1971-05-08
Abstract
No abstract record available.
Inventors
- 👤 Otto A Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:47
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
THE METHOD OF MAKING A NON-POROUS DUCT FOR COVEYING HOT AIR UNDER PRESSURE, WHICH COMPRRISES WRAPPING A FIRST LAYER OF UNCURED PHENOLIC RESIN IMPREGNATED GLASS FABRIC AROUND A DESIRED FORM, SPIRALLY WRAPPING VULCANIZABLE NON-POROUS, NEOPRENE TAPE AROUND SAID FIRST LAYER, EACH COMPLETE TURN OF SAID TAPE OVERLAPPING THE PRECEDING TURN BY AT LEAST ONE HALF THE WIDTH THEREOF, WRAPPING AN OUTER LAYER OF UNCURED PHENOLIC RESIN IMPREGNATED GLASS FABRIC AROUND SAID SPIRALLY WRAPPED LAYER OF NON-POROUS TAPE, SUBJECTING SAID LAYERS OF MATERIALS ON SAID FORM TO PRESSURE, BAKING SAID MATERIALS UNDER SAID PRESSURE TO CURE SAID RESIN AND VULCANIZE SAID NEOPRENE TAPE, AND REMOVING SAID MATERIALS AS A WHOLE FROM SAID FORM.
Claim 2
Independent Claim
112 words
THE METHOD OF MAKING A NON-POROUS DUCT FOR COVEYING HOT AIR UNDER PRESSURE, WHICH COMPRRISES WRAPPING A FIRST LAYER OF UNCURED PHENOLIC RESIN IMPREGNATED GLASS FABRIC AROUND A DESIRED FORM, SPIRALLY WRAPPING VULCANIZABLE NON-POROUS, NEOPRENE TAPE AROUND SAID FIRST LAYER, EACH COMPLETE TURN OF SAID TAPE OVERLAPPING THE PRECEDING TURN BY AT LEAST ONE HALF THE WIDTH THEREOF, WRAPPING AN OUTER LAYER OF UNCURED PHENOLIC RESIN IMPREGNATED GLASS FABRIC AROUND SAID SPIRALLY WRAPPED LAYER OF NON-POROUS TAPE, SUBJECTING SAID LAYERS OF MATERIALS ON SAID FORM TO PRESSURE, BAKING SAID MATERIALS UNDER SAID PRESSURE TO CURE SAID RESIN AND VULCANIZE SAID NEOPRENE TAPE, AND REMOVING SAID MATERIALS AS A WHOLE FROM SAID FORM.
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) | 1957-04-19 | 1957-10-19 | 1958-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-19 | 1961-10-19 | 1962-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-19 | 1965-10-19 | 1966-04-20 | $7700.00 | Window Closed / Lapsed |