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US3658451A
Expired / Lapsed
US
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Apex seal for rotary piston engine
Assignee: Mazda Motor Corp
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Filing: 1970-09-14
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Granted: 1972-04-25
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Expires: 1990-09-14
Abstract
Abstract An apex seal for a rotary piston engine, the apex seal being made of cast iron and having an elongated shape, a roundish sliding surface, the upper portion (including the sliding surface) with a chilled structure containing a large proportion of cementite and the lower portion with at least one-third of the height of the seal and with no chilled structure; and a method of producing the same.
Inventors
- 👤 Nobuyasu Gomada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:41
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/06; C21D1/09; F; F01; F01C; F01C19/00; F01C19/005; F05; F05C; F05C2201/00; F05C2201/04; F05C2201/0433; F05C2201/0436; F05C2201/0439; F05C2201/0442
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
97 words
An apex seal for a rotary piston engine, which is an integral body made of cast iron or elongated shape and with a rounded sliding top surface and which comprises an upper and a lower portion, the former being a hardened portion including the sliding surface and the latter being a non-hardened portion, the hardened portion having chilled structure with a large proportion of cementite and a Vickers hardness of not less than 550, and the non-hardened portion being at least one-third of the seal in height and having a eVickers hardness of not more than 400.
Claim 2
Dependent Claim
97 words
An apex seal for a rotary piston engine, which is an integral body made of cast iron or elongated shape and with a rounded sliding top surface and which comprises an upper and a lower portion, the former being a hardened portion including the sliding surface and the latter being a non-hardened portion, the hardened portion having chilled structure with a large proportion of cementite and a Vickers hardness of not less than 550, and the non-hardened portion being at least one-third of the seal in height and having a eVickers hardness of not more than 400.
Claim 3
Dependent Claim
15 words
An apex seal according to claim 1 wherein the cast iron is acicular cast iron.
References Cited (Backward Citations)
US3180564A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |