US3805677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-piece oil-cooled piston with thermal expansion control
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1972-03-01
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Granted: 1974-04-23
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Expires: 1992-03-01
Abstract
Abstract A multi-piece piston assembly including a skirt defining portion and a head defining portion which interfit to provide wrist pin bores in registry for receiving a wrist pin, the skirt defining and head defining portions being composed of a metal having good thermal conductivity such as an aluminum alloy, together with a bridge member which is anchored in the skirt defining portion in the region of the thrust faces to provide thermal expansion control at the top of the skirt portion and to provide additional mechanical strength.
Inventors
- 👤 H Clary
- 👤 H Skopin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:48
CPC Classifications
F; F02; F02F; F02F3/00; F02F3/0015; F01; F01M; F01M1/00; F01M1/08; F01M2001/086; F05; F05C; F05C2201/00; F05C2201/02; F05C2201/021; F05C2201/04; F05C2201/0433; F05C2201/0448; F05C2251/00; F05C2251/04; F05C2251/042
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
162 words
A two-piece metal piston assembly comprising a skirt defining portion having opposed thrust faces thereon, a separate head defining portion having a crown and depending wrist pin bosses and having grooves for receiving piston rings, said skirt defining portion and said head defining portion being aligned to provide a wrist pin bore extending through said portions, and a metal bridge member having its ends anchored in said opposed thrust faces, said bridge member having a coefficient of thermal expansion less than that of said skirt defining portion, said bridge member having a large surface area and having oilretaining upturned marginal edges facing said crown and being in closely spaced relation to the crown and to the inner, opposing faces of the wrist pin bosses, the space between the bridge member and the underside of the crown defining a cooling chamber, said bridge member having an aperture therein permitting entry of oil into said cooling chamber upon the downward stroke of said piston.
Claim 2
Dependent Claim
162 words
A two-piece metal piston assembly comprising a skirt defining portion having opposed thrust faces thereon, a separate head defining portion having a crown and depending wrist pin bosses and having grooves for receiving piston rings, said skirt defining portion and said head defining portion being aligned to provide a wrist pin bore extending through said portions, and a metal bridge member having its ends anchored in said opposed thrust faces, said bridge member having a coefficient of thermal expansion less than that of said skirt defining portion, said bridge member having a large surface area and having oilretaining upturned marginal edges facing said crown and being in closely spaced relation to the crown and to the inner, opposing faces of the wrist pin bosses, the space between the bridge member and the underside of the crown defining a cooling chamber, said bridge member having an aperture therein permitting entry of oil into said cooling chamber upon the downward stroke of said piston.
Claim 3
Dependent Claim
28 words
The two-piece metal piston assembly of claim 1 in which said skirt defining portion is composed of an aluminum alloy and said bridge member is composed of steel.
Claim 4
Dependent Claim
27 words
The two-piece metal piston assembly of claim 1 in which the ends of said bridge member have finger portions embedded in the metal of said thrust faces.
References Cited (Backward Citations)
US1548329A
Cited
US1745860A
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US1929831A
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US2110346A
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US2180521A
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US2240967A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |