US4742759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic insert cast piston
Assignee: NGK Insulators Ltd
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Filing: 1987-04-22
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Granted: 1988-05-10
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Expires: 2007-04-22
Abstract
Abstract Disclosed herein is a ceramic insert cast piston for an internal combustion engine which includes a head made of ceramic, a metal ring fitted around the peripheral portion of the ceramic head, and a piston body made of a metal by casting a metal around the ceramic head with the metal ring thereon, wherein an air insulating layer in the form of an annular groove is formed at the inner periphery of the metal ring and a buffer member is interposed between the ceramic head and the casting metal piston body.
Inventors
- 👤 Issei Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:33
CPC Classifications
F; F02; F02B; F02B23/00; F02B23/02; F02B23/06; F02B23/0636; F02B23/0603; F02F; F02F3/00; F02F3/10; F02F3/12; F02F7/00; F02F7/0085; F02F7/0087; F02B2023/0612; F05; F05C; F05C2201/00; F05C2201/02; F05C2201/021; F05C2253/00; F05C2253/16; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
196 words
A ceramic insert cast piston for an internal combustion engine, comprising: a ceramic head having an outer peripheral portion; an annular metal ring having an inner peripheral portion and an outer peripheral portion, said inner peripheral portion of the metal ring having at least one annular groove therein and said inner peripheral portion of the metal ring being fitted to the outer peripheral portion of the ceramic head such that at least one annular heat insulating air space is formed between the metal ring and the ceramic head; a cast metal piston body having an inner peripheral portion and an outer peripheral portion, wherein said ceramic head with said metal ring fitted thereto are located within said inner peripheral portion of the metal piston body; and a buffer member located between the ceramic head and the metal piston body, wherein said at least one annular heat insulating air space functions to reduce heat transferred to the ceramic head during casting of the metal piston body therearound, to prevent the ceramic head from being fractured due to thermal shock and to reduce combustion heat transferred to the metal piston body during operation of the internal combustion engine.
Claim 2
Dependent Claim
196 words
A ceramic insert cast piston for an internal combustion engine, comprising: a ceramic head having an outer peripheral portion; an annular metal ring having an inner peripheral portion and an outer peripheral portion, said inner peripheral portion of the metal ring having at least one annular groove therein and said inner peripheral portion of the metal ring being fitted to the outer peripheral portion of the ceramic head such that at least one annular heat insulating air space is formed between the metal ring and the ceramic head; a cast metal piston body having an inner peripheral portion and an outer peripheral portion, wherein said ceramic head with said metal ring fitted thereto are located within said inner peripheral portion of the metal piston body; and a buffer member located between the ceramic head and the metal piston body, wherein said at least one annular heat insulating air space functions to reduce heat transferred to the ceramic head during casting of the metal piston body therearound, to prevent the ceramic head from being fractured due to thermal shock and to reduce combustion heat transferred to the metal piston body during operation of the internal combustion engine.
Claim 3
Dependent Claim
26 words
A ceramic insert cast piston according to claim 1, wherein the inner peripheral portion of the metal ring is inwardly projected at an upper portion thereof.
Claim 4
Dependent Claim
20 words
A ceramic insert cast piston according to claim 1, wherein the metal ring is provided with a rotation restriction means.
Claim 5
Dependent Claim
24 words
A ceramic insert cast piston according to claim 1, wherein a rotation restriction means extends between the ceramic head and the metal piston body.
Claim 6
Dependent Claim
26 words
A ceramic insert cast piston according to claim 1, wherein the ceramic head comprises a material selected from the group consisting of zirconia and silicon nitride.
Claim 7
Dependent Claim
17 words
A ceramic insert cast piston according to claim 1, wherein the buffer member comprises a ceramic fiber.
Claim 8
Dependent Claim
26 words
A ceramic insert cast piston according to claim 6, wherein said ceramic fiber comprises a material selected from the group consisting of SiC, alumina and asbestos.
Claim 9
Dependent Claim
36 words
A ceramic insert cast piston according to claim 1, wherein said metal ring is fitted to the ceramic head by a fitting process selected from the group consisting of press fitting, expansion fitting and shrink fitting.
Claim 10
Dependent Claim
35 words
A ceramic insert cast piston according to claim 1, wherein said metal ring has a coefficient of expansion which is intermediate between a coefficient of expansion of the ceramic head and the metal piston body.
Claim 11
Dependent Claim
28 words
A ceramic insert cast piston according to claim 1, wherein a rotation restriction pin is inserted into said ceramic head, said buffer member and said metal piston body.
Claim 12
Dependent Claim
212 words
A ceramic insert cast piston for an internal combustion engine, comprising: a ceramic head having an outer peripheral portion, a top portion exposed to a combustion chamber and a bottom portion; an annular metal ring having an inner peripheral portion and an outer peripheral portion, said inner peripheral portion of the metal ring having at least one annular groove therein and said inner peripheral portion of the metal ring being fitted to the outer peripheral portion of the ceramic head such that at least one annular heat insulating air space is formed between the metal ring and the ceramic head; a cast metal piston body having an inner peripheral portion and an outer peripheral portion, wherein said ceramic head with said metal ring fitted thereto are located within said inner peripheral portion of the metal piston body; and a buffer member located between said bottom portion of the ceramic head and the metal piston body, wherein said at least one annular heat insulating air space functions to reduce heat transferred to the ceramic head during casting of the metal piston body therearound, to prevent the ceramic head from being fractured due to thermal shock and to reduce combustion heat transferred to the metal piston body during operation of the internal combustion engine.
Claim 13
Dependent Claim
212 words
A ceramic insert cast piston for an internal combustion engine, comprising: a ceramic head having an outer peripheral portion, a top portion exposed to a combustion chamber and a bottom portion; an annular metal ring having an inner peripheral portion and an outer peripheral portion, said inner peripheral portion of the metal ring having at least one annular groove therein and said inner peripheral portion of the metal ring being fitted to the outer peripheral portion of the ceramic head such that at least one annular heat insulating air space is formed between the metal ring and the ceramic head; a cast metal piston body having an inner peripheral portion and an outer peripheral portion, wherein said ceramic head with said metal ring fitted thereto are located within said inner peripheral portion of the metal piston body; and a buffer member located between said bottom portion of the ceramic head and the metal piston body, wherein said at least one annular heat insulating air space functions to reduce heat transferred to the ceramic head during casting of the metal piston body therearound, to prevent the ceramic head from being fractured due to thermal shock and to reduce combustion heat transferred to the metal piston body during operation of the internal combustion engine.
Claim 14
Dependent Claim
26 words
A ceramic insert cast piston according to claim 11, wherein the inner peripheral portion of the metal ring is inwardly projected at an upper portion thereof.
Claim 15
Dependent Claim
20 words
A ceramic insert cast piston according to claim 11, wherein the metal ring is provided with a rotation restriction means.
Claim 16
Dependent Claim
24 words
A ceramic insert cast piston according to claim 11, wherein a rotation restriction means extends between the ceramic head and the metal piston body.
Claim 17
Dependent Claim
26 words
A ceramic insert cast piston according to claim 11, wherein the ceramic head comprises a material selected from the group consisting of zirconia and silicon nitride.
Claim 18
Dependent Claim
17 words
A ceramic insert cast piston according to claim 11, wherein the buffer member comprises a ceramic fiber.
Claim 19
Dependent Claim
36 words
A ceramic insert cast piston according to claim 11, wherein said metal ring is fitted to the ceramic head by a fitting process selected from the group consisting of press fitting, expansion fitting and shrink fitting.
Claim 20
Dependent Claim
35 words
A ceramic insert cast piston according to claim 11, wherein said metal ring has a coefficient of expansion which is intermediate between a coefficient of expansion of the ceramic head and the metal piston body.
Claim 21
Dependent Claim
26 words
A ceramic insert cast piston according to claim 11, wherein said buffer member comprises a material selected from the group consisting of SiC, alumina and asbestos.
Claim 22
Dependent Claim
32 words
A ceramic insert cast piston according to claim 11, wherein a rotation restriction pin is inserted through said bottom portion of the ceramic head, said buffer member and said metal piston body.
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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) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |