Patent US3781022A successfully refreshed from Google Patents.
US3781022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piston ring and cylinder liner having minute oil-retaining indentation
Assignee: TPR Co Ltd
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Filing: 1970-11-30
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Granted: 1973-12-25
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Expires: 1990-11-30
Abstract
Abstract A piston ring or cylinder liner having on its sliding surface numerous minute indentations in a geometric grid pattern, said indentations being formed by closely spaced continuous helical grooves each formed in said surface with a repetitive depth variation to form thereby closely spaced successive ridges and valleys in each groove and with the spacing between successive of said ridges being less than the groove width.
Inventors
- 👤 J Kumabe
- 👤 K Shimuzu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:46
CPC Classifications
F; F16; F16J; F16J9/00; F16J10/00; F16J10/02; F16J10/04; Y; Y10; Y10S; Y10S277/00; Y10S277/924
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
A metallic part having a cylindrical surface thereof which is adapted to be in sliding, pressured, lubricated contact with a mating metallic element to provide a high-pressure seal therebetween, said cylindrical surface of said part having a myriad of minute indentations which are disposed in a regular, geometric grid pattern, said indentations being defined by closely spaced continuous helical grooves each formed in said surface with a repetitive depth variation to form thereby closely spaced successive ridges and valleys in each groove and with the spacing between successive of said ridges being less than the groove width.
Claim 2
Dependent Claim
97 words
A metallic part having a cylindrical surface thereof which is adapted to be in sliding, pressured, lubricated contact with a mating metallic element to provide a high-pressure seal therebetween, said cylindrical surface of said part having a myriad of minute indentations which are disposed in a regular, geometric grid pattern, said indentations being defined by closely spaced continuous helical grooves each formed in said surface with a repetitive depth variation to form thereby closely spaced successive ridges and valleys in each groove and with the spacing between successive of said ridges being less than the groove width.
Claim 3
Dependent Claim
29 words
The invention as defined in claim 1 wherein said metallic part is a piston ring and said grid pattern is formed on the outer cylindrical surface of said ring.
Claim 4
Dependent Claim
34 words
The invention as defined in claim 2 wherein the width of each helical groove is about 60 microns and the circumferential spacing betwEen successive of said ridges in any groove being about 20 microns.
Claim 5
Dependent Claim
30 words
The invention as defined in claim 1 wherein said metallic part is a cylinder liner and said grid pattern is formed on the inner cylindrical surface of said cylinder liner.
Claim 6
Dependent Claim
34 words
The invention as defined in claim 4 wherein the width of each helical groove is about 800 microns and the circumferential spacing between successive of said ridges in any groove being about 16 microns.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |