US4669369A
Expired / Lapsed
US
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Piston and piston ring assemblies
Assignee: AE PLC
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Filing: 1985-01-14
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Granted: 1987-06-02
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Expires: 2005-01-14
Abstract
Abstract A two ring piston and piston ring assembly has an upper thin steel compression ring and a lower ring which is thicker than the compression ring and which acts both as a compression ring and an oil control ring. The lower piston ring is made of a material which is more conformable than steel, for example a plastics material, which may be reinforced. In this way, effective sealing is provided using only two piston rings, while the frictional forces between the piston and an associated cylinder are reduced.
Inventors
- 👤 Jeremy Holt
- 👤 David A. Parker
- 👤 Brian L. Ruddy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:07
CPC Classifications
F; F02; F02F; F02F3/00; F16; F16J; F16J9/00; F16J9/28; F02F7/00; F02F7/0085; F05; F05C; F05C2201/00; F05C2201/04; F05C2201/0433; F05C2201/0448; F05C2225/00; F05C2225/04; F05C2253/00; F05C2253/16
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
129 words
A piston and piston ring assembly for an internal combustion engine, comprising: a piston, a crown at an upper end of said piston, a ring band extending around said crown of the piston, upper and lower axially spaced piston ring grooves provided in the ring band as the only piston ring grooves, a one-piece relatively thin steel compression ring mounted in said upper piston ring groove, a one-piece combined compression and oil control ring which is mounted in said lower piston ring groove and which is relatively thicker than said steel compression ring, said combined compression and oil control ring being of a material which is more conformable than the material of the steel compression ring, so that said ring acts as a combined compression and oil control ring.
Claim 2
Dependent Claim
129 words
A piston and piston ring assembly for an internal combustion engine, comprising: a piston, a crown at an upper end of said piston, a ring band extending around said crown of the piston, upper and lower axially spaced piston ring grooves provided in the ring band as the only piston ring grooves, a one-piece relatively thin steel compression ring mounted in said upper piston ring groove, a one-piece combined compression and oil control ring which is mounted in said lower piston ring groove and which is relatively thicker than said steel compression ring, said combined compression and oil control ring being of a material which is more conformable than the material of the steel compression ring, so that said ring acts as a combined compression and oil control ring.
Claim 3
Dependent Claim
46 words
A piston and ring assembly according to claim 1, wherein the lower piston ring is made from a conformable non-metallic material such that, in operation, the piston ring has an outward pressure against an associated cylinder or liner of between 0.03 and 0.66 MN/m 2 .
Claim 4
Dependent Claim
17 words
A piston and ring according to claim 2, wherein the outward pressure is 0.13 MN/m 2 .
Claim 5
Dependent Claim
31 words
A piston and ring assembly according to claim 1, wherein all the outward pressure exerted by the lower piston ring is generated by the inherent resilience of the lower piston ring.
Claim 6
Dependent Claim
44 words
A piston and ring assembly according to claim 1, wherein the outward pressure exerted by the lower piston ring is at least partially generated by separate spring means between a radially inner end of the lower piston ring and the associated piston ring groove.
Claim 7
Dependent Claim
25 words
A piston and ring assembly according to claim 1, wherein the lower piston ring is made from a high temperature plastics material known as polyetheretherketone.
Claim 8
Dependent Claim
14 words
A piston and ring assembly according to claim 6, wherein the polyetheretherketone is reinforced.
Claim 9
Dependent Claim
19 words
A piston and ring assembly according to claim 1, wherein the lower piston ring is of generally rectangular cross-section.
Claim 10
Dependent Claim
32 words
A piston and ring assembly according to claim 1, wherein the lower piston ring has a generally rectangular cross-section with the upper and lower projections providing upper and lower circumferential sealing lands.
Claim 11
Dependent Claim
29 words
A piston and ring assembly according to claim 1, wherein the lower piston ring has a generally rectangular cross-section formed with only one projection providing a single sealing land.
Claim 12
Dependent Claim
52 words
A piston and ring assembly according to claim 1, wherein a seal assembly is provided within the piston ring groove accommodating the lower piston ring and between this piston ring groove and the lower piston ring for reducing or preventing fluid flow around the radially inner end of the lower piston ring.
Claim 13
Dependent Claim
53 words
A piston and ring assembly according to claim 11, wherein the piston ring groove and the lower piston ring are provided with respective aligned recesses extending therearound, the seal assembly comprising an annular auxiliary ring having two spaced edges received in the piston ring groove recess and the lower piston ring recess respectively.
Claim 14
Dependent Claim
40 words
A piston and ring assembly according to claim 11, wherein the seal assembly comprises a projecting member extending into a co-operating channel member, one member being provided in the piston ring groove and the other in the lower piston ring.
Claim 15
Dependent Claim
24 words
A piston and ring assembly according to claim 11, wherein the seal assembly provides a radially outwardly directed load on the lower piston ring.
Claim 16
Dependent Claim
50 words
A piston and ring assembly according to claim 1, wherein the piston ring groove accommodating the lower piston ring is provided, on that side of the lower piston ring remote from the crown, with means for conveying to the interior of the piston, oil removed by the lower piston ring.
Claim 17
Dependent Claim
47 words
A piston and ring assembly according to claim 15, wherein said means comprise a chamfer provided between a lower radially extending surface of the lower piston ring groove and the ring band, and holes provided in said chamfer and leading therefrom to an interior of the piston.
Claim 18
Dependent Claim
23 words
A piston and ring assembly according to claim 16, wherein said holes are provided only adjacent thrust and counterthrust sides of the piston.
Claim 19
Dependent Claim
49 words
A piston and ring assembly according to claim 1, wherein the ring band between the upper and lower piston ring grooves, is provided with at least one oil drainage hole leading therefrom to the interior of the piston for increasing the oil pressure drop across the upper piston ring.
Claim 20
Dependent Claim
43 words
A piston and ring assembly according to claim 1, wherein the ring band is of reduced diameter between the piston ring grooves to form, with the associated cylinder, an expansion chamber for reducing the pressure of combustion gases passing the upper piston ring.
Claim 21
Dependent Claim
22 words
A piston and ring assembly according to claim 1, wherein the upper steel ring has a thickness of 1 mm or less.
References Cited (Backward Citations)
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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) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |