US3687183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-locking screw threaded fastener
Assignee: TORKON FASTENER CORP
•
Filing: 1970-06-30
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Granted: 1972-08-29
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Expires: 1990-06-30
Abstract
Abstract A self-locking fastener in which a portion of less than 180* circumferential extent of the screw thread of the fastener is changed in pitch diameter to achieve an interference fit. If it is an external screw or male thread, it is increased in pitch diameter; but if it is an internal screw or female thread, it is decreased in pitch diameter. In both instances, the cross sectional width of the screw thread is increased at any given diameter, and the width of the crest of the screw thread is increased without change in the crest diameter of the screw thread. In addition, improved locking is obtained, particularly at relatively high temperatures, by constructing the portion as an insert of a metal having a coefficient of expansion which is substantially the same or higher than the material of the fastener.
Inventors
- 👤 Robert F Rohm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:50
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: 8
Claim 1
Independent Claim
192 words
In a metal fastener having a screw thread to engage a complementary screw thread of a complementary member, the improvement for locking action with the complementary member, comprising: the turns of a portion of the screw thread of the fastener in a region of substantially less than 180* circumferential extent being of metal and having an enlarged cross sectional configuration, a wider crest, and substantially the same crest diameter as the remainder of the screw thread and having a different pitch diameter than the pitch diameter of the remainder of the screw thread, whereby said portion of the screw thread meshes with the complementary screw thread to lesser degree than the remainder of the screw thread to cause relative lateral displacement of the fastener and the complementary member for binding action between the fastener and the complementary member, the lead of the screw thread being constant or without change in phase throughout both said region of the turns of the screw thread and the remainder of the turns of the screw thread, whereby the centers of the crests of the screw thread are uniformly spaced throughout the length of the screw thread.
Claim 2
Dependent Claim
192 words
In a metal fastener having a screw thread to engage a complementary screw thread of a complementary member, the improvement for locking action with the complementary member, comprising: the turns of a portion of the screw thread of the fastener in a region of substantially less than 180* circumferential extent being of metal and having an enlarged cross sectional configuration, a wider crest, and substantially the same crest diameter as the remainder of the screw thread and having a different pitch diameter than the pitch diameter of the remainder of the screw thread, whereby said portion of the screw thread meshes with the complementary screw thread to lesser degree than the remainder of the screw thread to cause relative lateral displacement of the fastener and the complementary member for binding action between the fastener and the complementary member, the lead of the screw thread being constant or without change in phase throughout both said region of the turns of the screw thread and the remainder of the turns of the screw thread, whereby the centers of the crests of the screw thread are uniformly spaced throughout the length of the screw thread.
Claim 3
Dependent Claim
44 words
An improvement as set forth in claim 1 in which in comparison with the remainder of the screw thread, the pitch diameter of said portion of the screw thread is shifted towards the diameter of the crest of the remainder of the screw thread.
Claim 4
Dependent Claim
65 words
An improvement as set forth in claim 1 in which the angle between the sloping sides of said portion is the same as the angle between the sloping sides of the reMainder of the screw thread for extensive surface-to-surface contact between said portion and said complementary screw thread to cause said portion to act as a brake shoe to resist relative rotation of the fastener.
Claim 5
Dependent Claim
35 words
An improvement as set forth in claim 1 in which a recess interrupts the screw thread and a metal insert seated in the recess provides said portion of the screw thread for the locking action.
Claim 6
Dependent Claim
38 words
An improvement as set forth in claim 4, wherein the insert is of a material having a coefficient of expansion which is substantially the same as that of the material of the fastener at relatively high operating temperatures.
Claim 7
Dependent Claim
26 words
An improvement as set forth in claim 4, wherein the coefficient of expansion of the insert is greater than that of the material of the fastener.
Claim 8
Dependent Claim
28 words
An improvement as set forth in claim 4 in which the fastener is made of a stainless metal and the insert is made of an aluminum bronze composition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |