US4071067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-locking screw threads
Assignee: ATLAS BOLT (DARLASTON)LIMITED PO BOX NO 6 STATION ST DARLASTON WEDNESBURY WEST MIDLANDS SW10 8UL A Co Inc UNDER ENGLAND
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Filing: 1976-04-15
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Granted: 1978-01-31
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Expires: 1996-04-15
Abstract
Abstract A screw threaded member having a thread with at least two portions of different form, one portion being of standard form and the other portion, a locking portion, having its root and crest offset from the standard lead, the offset of the crest being in the same direction as and greater than the offset of the root, the flanks of the locking thread being correspondingly displaced and the flank on the side of the thread which is displaced away from the standard pitch line being bulged outwardly. The root offset may be between one third and two thirds of the offset of the crest. The offsets may be in either direction but are preferably in that direction which moves the lead flank away from the standard pitch line.
Inventors
- 👤 Richard Charles Goldby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:26
CPC Classifications
F; F16; F16B; F16B39/00; F16B39/22; F16B39/28; F16B39/30; Y; Y10; Y10S; Y10S411/00; Y10S411/924; Y10S411/929; Y10S411/938
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
158 words
A screw threaded member having a first portion of thread of a standard form having constant profile, pitch, root diameter and crest diameter, and a second portion of thread of a locking form continuous with said standard portion of thread and having said constant root diameter and constant crest diameter but having a root lead offset from the standard root lead, a crest lead offset from the standard crest lead, the crest offset being greater than the root offset, the flanks of said locking form of thread being displaced from the position of the flanks of thread of said standard form by an amount corresponding to said root and crest lead offsets, a first of the displaced flanks being bulged outwardly, the bulging being greatest in a central region of the flank and decreasing continuously towards the crest and towards the root thereof, the second of the displaced flanks being offset in the direction of said bulged flank.
Claim 2
Dependent Claim
158 words
A screw threaded member having a first portion of thread of a standard form having constant profile, pitch, root diameter and crest diameter, and a second portion of thread of a locking form continuous with said standard portion of thread and having said constant root diameter and constant crest diameter but having a root lead offset from the standard root lead, a crest lead offset from the standard crest lead, the crest offset being greater than the root offset, the flanks of said locking form of thread being displaced from the position of the flanks of thread of said standard form by an amount corresponding to said root and crest lead offsets, a first of the displaced flanks being bulged outwardly, the bulging being greatest in a central region of the flank and decreasing continuously towards the crest and towards the root thereof, the second of the displaced flanks being offset in the direction of said bulged flank.
Claim 3
Dependent Claim
60 words
A member in accordance with claim 1 where said second of said displaced flanks has an angle altered additionally to compensate for the bulging of said first flank whereby the area of a rib of the profile of said locking thread form is substantially the same as the area of a rib of the profile of said standard thread form.
Claim 4
Dependent Claim
23 words
A member according to claim 1 wherein said root offset is in the range one third to two thirds of said crest offset.
Claim 5
Dependent Claim
18 words
A member in accordance with claim 1 wherein said offsets are in the direction of the lead flank.
Claim 6
Dependent Claim
20 words
A member in accordance with claim 1 wherein the profile of said first flank, which is bulged outwardly, is arcuate.
Claim 7
Dependent Claim
68 words
A member in accordance with claim 1 having a transition zone between said first portion of standard thread form and said second portion of said locking thread form wherein the pitch and profile is continuously varied over a part of one turn and the root radius is varied over the rest of said one turn whereby said offsets between said thread forms is accommodated at said transition zone.
Claim 8
Dependent Claim
19 words
A member in accordance with claim 6 wherein said part of one turn is one twelfth of said turn.
Claim 9
Dependent Claim
32 words
A member in accordance with claim 1 having a plurality of portions of thread of said standard form and arranged alternately therewith a plurality of portions of thread of said locking form.
Claim 10
Dependent Claim
31 words
A member in accordance with claim 8 wherein said portions of locking thread form each comprises two thread turns and said portions of standard thread form each comprises one thread turn.
Claim 11
Dependent Claim
41 words
A member in accordance with claim 1 including a third portion of thread which is of said standard form and has the same lead as said first portion, said second portion being located between said first portion and said third portion.
References Cited (Backward Citations)
US2371365A
Cited
US3459250A
Cited
US3481380A
Cited
US3444916A
Cited
US3523565A
Cited
US3661194A
Cited
US3885613A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |