US4120081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of pistons incorporating a thermal barrier
Assignee: Alcan Aluminiumwerk Nuernberg GmbH
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Filing: 1977-05-26
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Granted: 1978-10-17
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Expires: 1997-05-26
Abstract
Abstract A piston incorporating a thermal barrier is produced by first making an annular piston ring carrier insert from steel. The insert comprises an annular body to the upper and lower radially-inner edges of which are secured the upper and lower edges of an annular element which is channel shaped in radial cross-section and the channel in which faces radially outward. The element is soldered or welded to the insert body so that an enclosed annular space is defined between the element and body. The insert thus formed is then heated in molten aluminium to "alfinize" its external surface. The treated insert is subsequently placed in a piston mold and the piston is molded about it from aluminium.
Inventors
- 👤 Fritz Rosch
- 👤 Rudolf Zimmermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:11
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/10; F; F02; F02F; F02F3/00; F02F3/16; F02F3/20; F02F3/22; F02F2200/00; F02F2200/04; F05; F05C; F05C2201/00; F05C2201/02; F05C2201/021; F05C2201/04; F05C2201/0433; F05C2201/0448; Y; Y10; Y10S; Y10S164/00; Y10S164/08; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49249; Y10T29/49256; Y10T29/49258; Y10T29/49261; Y10T29/4998; Y10T29/49988
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
119 words
A method of producing a piston comprising (a) forming a piston ring carrier insert by (i) forming an annular steel member, having two opposite circumferentially extending edges, to be channel-shaped in radial cross-section, the channel facing radially outward, and (ii) securing said opposite circumferentially extending edges of said annular member to axially opposite radially-inner inner edge portions respectively of an annular ferrous metal piston ring carrier body whereby an enclosed annular space is formed between the body and the annular member, (b) treating the assembled insert to form an iron/aluminium alloy at the external surface of the insert, (c) placing the treated assembled insert in a piston mould and (d) casting aluminium in the mould to form the piston.
Claim 2
Independent Claim
119 words
A method of producing a piston comprising (a) forming a piston ring carrier insert by (i) forming an annular steel member, having two opposite circumferentially extending edges, to be channel-shaped in radial cross-section, the channel facing radially outward, and (ii) securing said opposite circumferentially extending edges of said annular member to axially opposite radially-inner inner edge portions respectively of an annular ferrous metal piston ring carrier body whereby an enclosed annular space is formed between the body and the annular member, (b) treating the assembled insert to form an iron/aluminium alloy at the external surface of the insert, (c) placing the treated assembled insert in a piston mould and (d) casting aluminium in the mould to form the piston.
Claim 3
Dependent Claim
16 words
A method as claimed in claim 1, wherein the annular member is made from sheet steel.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 2 wherein the annular member is initially flat and is subsequently formed to be channel-shaped in radial cross-section as aforesaid.
Claim 5
Dependent Claim
28 words
A method as claimed in claim 3, wherein said edge portions of the ring carrier body are formed with rebates to receive said edges of the annular member.
Claim 6
Dependent Claim
48 words
A method as claimed in claim 3 wherein the annular member is, whilst still flat, first secured at its outer edge to the ring carrier body, whereafter the annular member is shaped to its finished channel-section, and then has its other edge secured to the ring carrier body.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 1 wherein the annular member is secured to the ring carrier body by welding.
Claim 8
Dependent Claim
24 words
A method as claimed in claim 1 wherein the annular member is formed from a tubular shape to be channel-shaped in cross-section as aforesaid.
References Cited (Backward Citations)
US1390193A
Cited
FR860716A
Cited
US2865348A
Cited
US2893083A
Cited
FR1162420A
Cited
US3616729A
Cited
US3628511A
Cited
DE2000249A1
Cited
DE2410140A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |