US4356800A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid-cooled, composite piston for internal-combustion engines
Assignee: Karl Schmidt GmbH
•
Filing: 1979-07-16
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Granted: 1982-11-02
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Expires: 1999-07-16
Abstract
Abstract In a liquid-cooled, composite piston for internal-combustion engines, particularly for medium-speed diesel engines, comprising a lower part, which made of a material comprising an eutectic aluminum-silicon alloy which lower part is connected to an upper part comprised of a ferrous material, said upper part formed on its underside with a concentric top rib, which rib forces the opposite bearing surface of the lower part and is so arranged that the rib constitutes the radially inner boundary of an annular cooling channel, which is disposed in the upper part behind the top land of the piston and behind at least part of the ring-carrying portion of the piston said rib also defining a central cooling chamber, which is disposed in the upper part and which communicates with the cooling channel by radial coolant bores, the improvement comprising a ring comprised of a ferrous material concentrically disposed and gripped between the bearing surface of the bearing rib and the opposite bearing surface of the lower part of the piston in an arrangement in which the confronting bearing surfaces of the bearing rib and the gripped ring are in peripheral rolling contact with one another.
Inventors
- 👤 Horst Moebus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:23
CPC Classifications
F; F02; F02F; F02F3/00; F02F3/16; F02F3/18; F02F3/20; F02F3/22; F02B; F02B3/00; F02B3/06; F02F2200/00; F02F2200/04; F05; F05C; F05C2201/00; F05C2201/02; F05C2201/021; F05C2201/04; F05C2201/0433; F05C2201/0448
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
215 words
In a liquid-cooled, composite piston for internal-combustion engines, particularly for medium-speed diesel engines, comprising a lower part made of a material comprising an eutectic aluminum-silicon alloy which lower part is connected to an upper part comprised of a ferrous material, said upper part formed on its underside with a concentric rib, which rib faces an opposite top surface of the lower part and is so arranged that the rib constitutes the radially inner boundary of an annular cooling channel, which is disposed in the upper part behind a top land of the piston and behind at least part of a ring-carrying portion of the piston, said rib also defining a central cooling chamber, which is disposed in the upper part and which communicates with the cooling channel by radial coolant bores, the improvement comprising a ring comprised of a ferrous material concentrically disposed and gripped between the surface of said concentric rib and the opposite top surface of the lower part of the piston in an arrangement in which the confronting surfaces of the rib and the gripped ring are in peripheral rolling contact with one another, said ring constituting a portion of the radially inner boundary of said annular cooling channel and a portion of the radially outer boundary of said central cooling chamber.
Claim 2
Dependent Claim
215 words
In a liquid-cooled, composite piston for internal-combustion engines, particularly for medium-speed diesel engines, comprising a lower part made of a material comprising an eutectic aluminum-silicon alloy which lower part is connected to an upper part comprised of a ferrous material, said upper part formed on its underside with a concentric rib, which rib faces an opposite top surface of the lower part and is so arranged that the rib constitutes the radially inner boundary of an annular cooling channel, which is disposed in the upper part behind a top land of the piston and behind at least part of a ring-carrying portion of the piston, said rib also defining a central cooling chamber, which is disposed in the upper part and which communicates with the cooling channel by radial coolant bores, the improvement comprising a ring comprised of a ferrous material concentrically disposed and gripped between the surface of said concentric rib and the opposite top surface of the lower part of the piston in an arrangement in which the confronting surfaces of the rib and the gripped ring are in peripheral rolling contact with one another, said ring constituting a portion of the radially inner boundary of said annular cooling channel and a portion of the radially outer boundary of said central cooling chamber.
Claim 3
Dependent Claim
29 words
A piston according to claim 1 wherein one of the two confronting surfaces of the rib (4, 13) and the gripped ring (7, 15, 19) is arcuately curved outwardly.
Claim 4
Dependent Claim
34 words
A piston according to claim 2 wherein the confronting surface which faces at least one of the outwardly curved confronting surface of the rib (4,13) and the gripped ring (7,15,19) has a corresponding concavity.
Claim 5
Dependent Claim
17 words
A piston according to claim 3 wherein the curvatures of the two confronting surfaces differ in size.
Claim 6
Dependent Claim
26 words
A piston according to claim 1 wherein at least one of the confronting surfaces of the rib and the gripped ring have been surface-treated by hardening.
Claim 7
Dependent Claim
25 words
A piston according to claim 1 wherein the gripped ring is inserted in a concentric turned recess in the lower part (11) of the piston.
Claim 8
Dependent Claim
42 words
A piston according to claim 1 wherein the gripped ring is provided at at least one of its inner and outer, lower edge with a peripheral annular centering nose, which engages a concentric turned recess of the lower part of the piston.
Claim 9
Dependent Claim
27 words
A piston according to claim 1, wherein at least one of the confronting surfaces of the rib in the gripped ring have been surface treated by chromium-plating.
Claim 10
Dependent Claim
27 words
A piston according to claim 1, wherein at least one of the confronting surfaces of the rib and the gripped ring have been surface treated by nitriding.
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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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |