Patent US3216459A successfully refreshed from Google Patents.
US3216459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible insulated duct
Assignee: PPG Industries Inc
•
Filing: 1963-02-08
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Granted: 1965-11-09
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Expires: 1983-02-08
Abstract
No abstract record available.
Inventors
- 👤 Clifford A Schroeder
- 👤 Quentin L Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:47
CPC Classifications
F; F24; F24F; F24F13/00; F24F13/02; F24F13/0218; F16; F16L; F16L11/00; F16L11/02; F16L59/00; F16L59/14; F16L59/153; F24F13/0263
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
IN A DUCT THE COMBINATION OF: A CONTINUOUS WIRE FORMING A HELIX HAVING SPACED CONVOLUTIONS, A TUBULAR MEMBER OF POROUS COMPRESSIBLE INSULATING MATERIAL ENCIRCLING SAID WIRE HELIX WITH SUBSTANTIALLY THE ENTIRE INNER SURFACE EXPOSED AS THE INNER SURFACE OF THE DUCT, MEANS FOR MAINTAINING THE WIRE CONVOLUTION IN SPACED RELATION TO EACH OTHER, AND A SLEEVE ENCIRCLING SAID MEMBER, SAID SLEEVE HAVING A NORMAL INSIDE DIAMETER RELATIVE TO THE OUTSIDE DIAMETER OF THE HELIX AND TO THE NORMAL INSIDE AND OUTER DIAMETERS OF THE TUBULAR MEMBER AND SAID SLEEVE BEING OF A FIRMNESS ONLY SUFFICIENT TO PROVIDE NO MORE THAN SLIGHT RADIAL COMPRESSION OF THE INSULATION MATERIAL AGAINST THE CONVOLUTIONS OF THE WIRE HELIX THEREBY PERMITTING THE THICKNESS OF THE TUBULAR MEMBER TO REMAIN SUBSTANTIALLY CONSTANT ALONG THE LENGTH OF THE DUCT.
Claim 2
Dependent Claim
132 words
IN A DUCT THE COMBINATION OF: A CONTINUOUS WIRE FORMING A HELIX HAVING SPACED CONVOLUTIONS, A TUBULAR MEMBER OF POROUS COMPRESSIBLE INSULATING MATERIAL ENCIRCLING SAID WIRE HELIX WITH SUBSTANTIALLY THE ENTIRE INNER SURFACE EXPOSED AS THE INNER SURFACE OF THE DUCT, MEANS FOR MAINTAINING THE WIRE CONVOLUTION IN SPACED RELATION TO EACH OTHER, AND A SLEEVE ENCIRCLING SAID MEMBER, SAID SLEEVE HAVING A NORMAL INSIDE DIAMETER RELATIVE TO THE OUTSIDE DIAMETER OF THE HELIX AND TO THE NORMAL INSIDE AND OUTER DIAMETERS OF THE TUBULAR MEMBER AND SAID SLEEVE BEING OF A FIRMNESS ONLY SUFFICIENT TO PROVIDE NO MORE THAN SLIGHT RADIAL COMPRESSION OF THE INSULATION MATERIAL AGAINST THE CONVOLUTIONS OF THE WIRE HELIX THEREBY PERMITTING THE THICKNESS OF THE TUBULAR MEMBER TO REMAIN SUBSTANTIALLY CONSTANT ALONG THE LENGTH OF THE DUCT.
References Cited (Backward Citations)
US1009465A
Cited
US1872540A
Cited
US2050023A
Cited
US2011781A
Cited
US2330966A
Cited
US2312282A
Cited
US2226523A
Cited
US2580872A
Cited
US2597806A
Cited
US2790464A
Cited
US2858854A
Cited
US2949133A
Cited
US2861598A
Cited
US2943644A
Cited
US2980144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-08 | 1969-05-10 | 1969-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-08 | 1973-05-10 | 1973-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-08 | 1977-05-10 | 1977-11-09 | $7700.00 | Window Closed / Lapsed |