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US4829940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piston for two-cycle engines
Assignee: Yamaha Marine Co Ltd
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Filing: 1988-02-01
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Granted: 1989-05-16
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Expires: 2008-02-01
Abstract
Abstract Several embodiments of cooling arrangements for the pistons of an internal combustion engine operating on a two-cycle, crankcase compression principle. The cooling arrangement comprises a passage that is formed in the piston and which communicates the ports of the engine with each other when the piston is in confronting relationship with them so as to effect a cooling air flow across the piston through the communicating passage.
Inventors
- 👤 Masaki Okazaki
- 👤 Kazutoshi Sato
- 👤 Hiroaki Fujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:05
CPC Classifications
F; F01; F01P; F01P1/00; F01P1/04; F02; F02F; F02F3/00; F02F3/24; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/025
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
140 words
In a two-cycle internal combustion engine comprising a cylinder defining a cylinder bore, a crankcase at one end of said cylinder bore, a combustion chamber at the other end of said cylinder bore, a piston reciprocating in said cylinder bore and having a head portion facing said combustion chamber, a pair of circumferentially spaced ports extending through said cylinder for communication with said cylinder bore upon reciprocation of said piston in said cylinder bore at least one of said ports being formed at the end of a passage extending from said crankcase and comprising a scavenge port, the improvement comprising passage means formed in said piston for permitting flow between said scavenge port and another of said ports when said piston is in confronting relationship with said ports for effecting a cooling flow across said piston to dissipate heat therefrom.
Claim 2
Dependent Claim
140 words
In a two-cycle internal combustion engine comprising a cylinder defining a cylinder bore, a crankcase at one end of said cylinder bore, a combustion chamber at the other end of said cylinder bore, a piston reciprocating in said cylinder bore and having a head portion facing said combustion chamber, a pair of circumferentially spaced ports extending through said cylinder for communication with said cylinder bore upon reciprocation of said piston in said cylinder bore at least one of said ports being formed at the end of a passage extending from said crankcase and comprising a scavenge port, the improvement comprising passage means formed in said piston for permitting flow between said scavenge port and another of said ports when said piston is in confronting relationship with said ports for effecting a cooling flow across said piston to dissipate heat therefrom.
Claim 3
Dependent Claim
31 words
In a two-cycle internal combustion engine as set forth in claim 1 wherein the piston is further provided with a piston ring and the passage means lies below the piston ring.
Claim 4
Dependent Claim
33 words
In a two-cycle internal combustion engine as set forth in claim 2 wherein the piston is provided with plural piston rings and the communicating passage means is below all of the piston rings.
Claim 5
Dependent Claim
38 words
In a two-cycle internal combustion engine as set forth in claim 1 wherein the piston is provided with a piston pin for connecting the piston to a crankshaft and wherein the passage means lies above the piston pin.
Claim 6
Dependent Claim
39 words
In a two-cycle internal combustion engine as set forth in claim 2 wherein the passage means comprises a circumferential groove formed in the outer periphery of the piston for effecting a blow-by seal in addition to a flow passage.
Claim 7
Dependent Claim
22 words
In a two-cycle internal combustion engine as set forth in claim 1 wherein the other port comprises at least one exhaust port.
Claim 8
Dependent Claim
17 words
In a two-cycle internal combustion engine as set forth in claim 6 further including further scavenge ports.
Claim 9
Dependent Claim
22 words
In a two-cycle internal combustion engine as set forth in claim 7 wherein the ports are circumferentially spaced relative to each other.
Claim 10
Dependent Claim
24 words
In a two-cycle internal combustion engine as set forth in claim 7 wherein only certain of the scavenge ports communicate with the exhaust port.
Claim 11
Dependent Claim
93 words
In a two-cycle internal combustion engine comprising a cylinder defining a cylinder bore, a piston reciprocating in said cylinder bore and having a head portion facing a combustion chamber, a pair of circumferentially spaced scavenge ports extending through said cylinder for communication with said cylinder bore upon reciprocation of said piston in said cylinder bore, the improvement comprising passage means formed in said piston for permitting flow between said scavenge ports when said piston is in confronting relationship with said ports for effecting a cooling flow across said piston to dissipate heat therefrom.
Claim 12
Dependent Claim
93 words
In a two-cycle internal combustion engine comprising a cylinder defining a cylinder bore, a piston reciprocating in said cylinder bore and having a head portion facing a combustion chamber, a pair of circumferentially spaced scavenge ports extending through said cylinder for communication with said cylinder bore upon reciprocation of said piston in said cylinder bore, the improvement comprising passage means formed in said piston for permitting flow between said scavenge ports when said piston is in confronting relationship with said ports for effecting a cooling flow across said piston to dissipate heat therefrom.
Claim 13
Dependent Claim
28 words
In a two-cycle internal combustion engine as set forth in claim 10 further including an exhaust port, said passage means being out of communication with said exhaust port.
Claim 14
Dependent Claim
24 words
In a two-cycle internal combustion engine as set forth in claim 11 wherein the passage means is formed in the periphery of the piston.
Claim 15
Dependent Claim
31 words
In a two-cycle internal combustion engine as set forth in claim 10 wherein the piston is further provided with a piston ring and the passage means lies below the piston ring.
Claim 16
Dependent Claim
33 words
In a two-cycle internal combustion engine as set forth in claim 13 wherein the piston is provided with plural piston rings and the communicating passage means is below all of the piston rings.
Claim 17
Dependent Claim
38 words
In a two-cycle internal combustion engine as set forth in claim 10 wherein the piston is provided with a piston pin for connecting the piston to a crankshaft and wherein the passage means lies above the piston pin.
Claim 18
Dependent Claim
39 words
In a two-cycle internal combustion engine as set forth in claim 15 wherein the passage means comprises a circumferential groove formed in the outer periphery of the piston for effecting a blow-by seal in addition to a flow passage.
Claim 19
Dependent Claim
24 words
In a two-cycle internal combustion engine as set forth in claim 10 wherein the passage means is formed in the periphery of the piston.
Claim 20
Dependent Claim
31 words
In a two-cycle internal combustion engine as set forth in claim 17 wherein the piston is further provided with a piston ring and the passage means lies below the piston ring.
Claim 21
Dependent Claim
33 words
In a two-cycle internal combustion engine as set forth in claim 18 wherein the piston is provided with plural piston rings and the communicating passage means is below all of the piston rings.
Claim 22
Dependent Claim
38 words
In a two-cycle internal combustion engine as set forth in claim 17 wherein the piston is provided with a piston pin for connecting the piston to a crankshaft and wherein the passage means lies above the piston pin.
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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) | 1992-05-15 | 1992-11-14 | 1993-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-15 | 1996-11-14 | 1997-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-15 | 2000-11-14 | 2001-05-16 | $7700.00 | Window Closed / Lapsed |