Patent US1902986A successfully refreshed from Google Patents.
US4545104A
Expired / Lapsed
US
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Method of forming a fatigue resistant threaded connection
Assignee: Individual
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Filing: 1982-05-20
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Granted: 1985-10-08
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Expires: 2002-05-20
Abstract
Abstract A fatigue resistant threaded connection includes a nut having two threads which are aligned axially but turned relative to one another about their common axis through an angle great enough to cause development of large axial forces between the screw and nut threads when they are connected together, resulting in improved distribution of load forces between the two threads of the nut and improved resistance of the screw and nut to fatigue and tensile failures.
Inventors
- 👤 Mark Hattan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:55
CPC Classifications
F; F16; F16B; F16B39/00; F16B39/22; F16B39/28; F16B39/38; B; B23; B23K; B23K15/00; B23K15/0006; B25; B25H; B25H7/00; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49947; Y10T29/49948
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
215 words
The method of forming a fatigue resistant threaded connection that comprises: connecting together a screw having an external thread and a nut having two aligned internal threads of a common pitch engaging said external thread at different locations, with said two internal threads being secured together before engagement with the screw in fixed relative positions in which one internal thread is not a true helical continuation of the other, and in which portions of the two internal threads lying in a common axial plane are spread slightly farther apart axially than if the internal threads were true helical continuations of one another; initially applying force to said external thread of the screw by each of said two internal threads of the nut in a direction axially away from the other internal thread of the nut by virtue of said slightly spread condition of the internal threads; then tightening said screw and nut threadedly relative to one another against the resistance of engaged stop shoulder surfaces to a preloaded condition stretching said screw axially relative to said nut; and in said preloaded condition applying force to said external thread of the screw by said two internal threads of the nut in a common axially outer direction rather than in opposite directions axially away from one another.
Claim 2
Independent Claim
215 words
The method of forming a fatigue resistant threaded connection that comprises: connecting together a screw having an external thread and a nut having two aligned internal threads of a common pitch engaging said external thread at different locations, with said two internal threads being secured together before engagement with the screw in fixed relative positions in which one internal thread is not a true helical continuation of the other, and in which portions of the two internal threads lying in a common axial plane are spread slightly farther apart axially than if the internal threads were true helical continuations of one another; initially applying force to said external thread of the screw by each of said two internal threads of the nut in a direction axially away from the other internal thread of the nut by virtue of said slightly spread condition of the internal threads; then tightening said screw and nut threadedly relative to one another against the resistance of engaged stop shoulder surfaces to a preloaded condition stretching said screw axially relative to said nut; and in said preloaded condition applying force to said external thread of the screw by said two internal threads of the nut in a common axially outer direction rather than in opposite directions axially away from one another.
Claim 3
Dependent Claim
35 words
The method as recited in claim 1, in which, in said preloaded condition, said two internal threads of said nut apply approximately equal force in said axially outer direction to said thread of the screw.
Claim 4
Dependent Claim
68 words
The method as recited in claim 1, in which said force applied to opposite axial directions to said thread of the screw by said threads of the nut prior to tightening of the screw and nut against the resistance of said stop shoulder surfaces is equal to at least about twenty percent of the ultimate tensile load of said screw at which the screw will fail in tension.
Claim 5
Dependent Claim
69 words
The method as recited in claim 1, in which said force applied in opposite axial directions to said thread of the screw by said threads of the nut prior to tightening of the screw and nut against the resistance of said stop shoulder surfaces is equal to between about twenty-seven and forty percent of the ultimate tensile load of said screw at which the screw will fail in tension.
Claim 6
Dependent Claim
45 words
The method as recited in claim 1, in which said nut has at least one additional internal thread aligned with said two first mentioned internal threads but turned about said axis relative thereto and engageable with said thread of the screw in an interfering relation.
Claim 7
Dependent Claim
41 words
The method as recited in claim 1, in which said screw and nut in said preloaded condition are tightened enough to assure that all turns of said internal threads apply force to said external thread in said common axially outer direction.
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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |