US3561087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making piston ring
Assignee: Individual
•
Filing: 1967-10-06
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Granted: 1971-02-09
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Expires: 1987-10-06
Abstract
Abstract A SPLIT PISTON RING OF PRESSED AND SINTERED METAL POWDER AND METHOD OF MAKING THE SAME. THE PISTON RING IS CHARACTERIZED PRIMARILY IN THAT IT HAS A HIGHER DENSITY ON ITS INNER PERIPHERY THAN ON ITS OUTER PERIPHERY, WHILE THE SAME DENSITY AND DISTRIBUTION PREVAIL ON EVERY RADIAL CROSS-SECTIONAL PLANE.
Inventors
- 👤 Max Koehler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:30
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/10; B22F3/11; B22F3/1103; B22F3/1109; B22F5/00; B22F5/02; B23; B23P; B23P15/00; B23P15/06; F; F16; F16J; F16J9/00; F16J9/12; F16J9/26; Y; Y10; Y10S; Y10S277/00; Y10S277/924; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49274; Y10T29/49282; Y10T428/00; Y10T428/12; Y10T428/12229; Y10T428/12236; Y10T428/12243; Y10T428/21; Y10T428/218
Claims Analysis
Total Claims: 0
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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) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |