US4040327A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High fatigue screw threads
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1975-09-19
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Granted: 1977-08-09
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Expires: 1995-09-19
Abstract
Abstract A symmetric screw thread system including external threads each profiled to have a flank angle of (70 ± 2)° and a flat root located at (0.27 ± 0.02)H from an intersecting point of two lines extended from opposing flanks of two adjacent threads and connected to said opposing flanks through arcs of a radius (0.15 ± 0.02)p where H is the depth and p is the pitch of the threads. Alternatively, the system may include external threads configured to have a flank angle of (106 ± 5)° and connected by a root having a radius of (0.30 ± 0.01)p.
Inventors
- 👤 Hideyuki Otaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:47
CPC Classifications
F; F16; F16B; F16B33/00; F16B33/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
71 words
A substantially symmetric screw thread system including external threads each profiled to have a flank angle of (70 ± 2)° and a flat root located at (0.27 ± 0.02)H from an intersecting point of two lines extended from opposing flanks of two adjacent threads and connected to said opposing flanks through arcs of a radius (0.15 ± 0.02)p where H is the depth and p is the pitch of the threads.
Claim 2
Dependent Claim
71 words
A substantially symmetric screw thread system including external threads each profiled to have a flank angle of (70 ± 2)° and a flat root located at (0.27 ± 0.02)H from an intersecting point of two lines extended from opposing flanks of two adjacent threads and connected to said opposing flanks through arcs of a radius (0.15 ± 0.02)p where H is the depth and p is the pitch of the threads.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |