US3748949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thread system
Assignee: Robertson Manufacturing Co Ltd
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Filing: 1971-10-19
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Granted: 1973-07-31
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Expires: 1991-10-19
Abstract
Abstract A threaded member capable of being driven into low density materials has a sharp thread with its leading angle substantially larger than its trailing angle.
Inventors
- 👤 G Dreger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:44
CPC Classifications
F; F16; F16B; F16B25/00; F16B25/0036; F16B25/0042; F16B25/0047; F16B25/001; F16B25/0015
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
A screw threaded member for use with materials having a density in the range from about 15 to about 60 pounds per cubic foot comprising a root portion of predetermined diameter, a single continuous external sharp-edged thread portion having a leading angle of 30* and a trailing angle of 15*, the depth of said thread portion being from 30 to 40 percent of the diameter of said root portion, and the spacing between threads being from 2.2 to 3 times as great as said thread depth.
Claim 2
Dependent Claim
86 words
A screw threaded member for use with materials having a density in the range from about 15 to about 60 pounds per cubic foot comprising a root portion of predetermined diameter, a single continuous external sharp-edged thread portion having a leading angle of 30* and a trailing angle of 15*, the depth of said thread portion being from 30 to 40 percent of the diameter of said root portion, and the spacing between threads being from 2.2 to 3 times as great as said thread depth.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |