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US2855659A Expired / Lapsed US ⏱️ 0.0 years remaining

Sintered powdered metal piston ring

Assignee: Motors Liquidation Co
•
Filing: 1954-12-29
•
Granted: 1958-10-14
•
Expires: 1974-12-29
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Abstract

No abstract record available.

Inventors

  • 👤 Robert F Thomson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 23:33
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/006

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 47 words
A POROUS PISTON RING FOR AN INTERNAL COMBUSTION ENGINE, SAID PISTON RING BEING CHARACTERIZED BY HIGH WEAR RESISTANCE AND BEING FORMED OF A SINTERED AND WORKED POWDERED METAL MIX COMPRISING APPROXIMATELY 0.3% TO 3% CARBON, 1.5% TO 6% OF CRYSTALLINE AL2O3, AND THE BALANCE SUBSTANTIALLY ALL IRON.
Claim 2
Dependent Claim 47 words
A POROUS PISTON RING FOR AN INTERNAL COMBUSTION ENGINE, SAID PISTON RING BEING CHARACTERIZED BY HIGH WEAR RESISTANCE AND BEING FORMED OF A SINTERED AND WORKED POWDERED METAL MIX COMPRISING APPROXIMATELY 0.3% TO 3% CARBON, 1.5% TO 6% OF CRYSTALLINE AL2O3, AND THE BALANCE SUBSTANTIALLY ALL IRON.

References Cited (Backward Citations)

US2072070A Cited
US2213523A Cited
US2224595A Cited
US2337588A Cited
DE750430C Cited
US2376757A Cited
DE896363C Cited
US2404598A Cited
DE806360C Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1961-10-13 1962-04-14 1962-10-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1965-10-13 1966-04-14 1966-10-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1969-10-13 1970-04-14 1970-10-14 $7700.00 Window Closed / Lapsed

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