US3566925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral multilayer pipe for pressure vessel
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1969-02-12
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Granted: 1971-03-02
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Expires: 1989-02-12
Abstract
Abstract A spiral multilayer pipe for a pressure vessel characterized in that a plurality of steel sheets which are thinner than a hoop steel constituting the main spiral body and are different in length, said steel sheets being secured to at least one of the hoop steel ends so as to form the end into wedged shape.
Inventors
- 👤 Hideo Sagara
- 👤 Tomoyuki Mashimo
- 👤 Takeshi Kifune
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:19
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/02; F16L9/04; F16L9/16; F16L9/165
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
56 words
A spiral multilayer pipe for a pressure vessel comprising a hoop steel main spiral body, a plurality of short steel sheets secured to and extending from at least one end of said spiral body, said steel sheets being of different lengths, whereby said one end of the spiral body presents a wedge shape overlying said hoop.
Claim 2
Dependent Claim
56 words
A spiral multilayer pipe for a pressure vessel comprising a hoop steel main spiral body, a plurality of short steel sheets secured to and extending from at least one end of said spiral body, said steel sheets being of different lengths, whereby said one end of the spiral body presents a wedge shape overlying said hoop.
Claim 3
Dependent Claim
22 words
A spiral multilayer pipe for a pressure vessel according to claim 1 wherein said steel sheets have a beveled or rounded edge.
Claim 4
Dependent Claim
33 words
A spiral multilayer pipe for a pressure vessel according to claim 1 wherein said steel sheets are laminated stepwise and in such a manner that shorter sheets thereof may lie between longer sheets.
Claim 5
Dependent Claim
20 words
A spiral multilayer pipe for a pressure vessel according to claim 1 wherein the outermost steel sheet is the longest.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |