US4602596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reciprocating piston-internal combustion engine with variable compression ratio
Assignee: Audi AG
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Filing: 1985-02-08
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Granted: 1986-07-29
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Expires: 2005-02-08
Abstract
Abstract For changing the compression ratio of a reciprocating piston internal combustion engine the piston 3 consists of an outer piston part 7 and an inner piston part 10 which are connected with each other by a thread 13,14. By turning the outer piston part 7 by means of a bushing 18 which is axially fixed, but rotatable around piston axis 15 and which is in engagement with the outer piston part 7 by means of a longitudinal gear 19,20, the outer piston part 7 can be turned steplessly during operation with respect to the inner piston part 10, whereby the outer piston part 7 is displaced along the piston axis 15, thus changing the volume of the operating chamber and thereby the compression ratio.
Inventors
- 👤 Anton Kessler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:46
CPC Classifications
F; F02; F02B; F02B75/00; F02B75/04; F02B75/044; F16; F16J; F16J1/00; F16J1/10; F16J1/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
221 words
Reciprocating piston-internal combustion engine with variable compression ratio, wherein for each cylinder a piston is provided which has a longitudinal axis and a piston head limiting a working chamber, and which is in drive connection with a crankshaft by means of a piston rod and which consists of first and second parts being adjustable relative to each other along the longitudinal piston axis, said first piston part being pivotally connected with the piston rod and supporting an outer thread, and said second piston part being provided with the piston head and being provided with an inner thread engaging the outer thread on the first piston part, and with a device for turning the second piston part, the device comprising a bushing which is mounted for rotation about the piston longitudinal axis, but is axially stationary, and which is provided with an inner gear extending parallel to the longitudiinal axis of the piston, said second piston part being non-rotatably but axially displaceably connected to said bushing, characterized in that the bushing (18) is concentrically mounted between an inner tubular segment (12) and an outer tubular segment (8) of said second piston part (7), and that the inner gear (19) of bushing (18) is in engagement with an outer gear (20) of said inner tubular segment (12) of said second piston part (7).
Claim 2
Dependent Claim
221 words
Reciprocating piston-internal combustion engine with variable compression ratio, wherein for each cylinder a piston is provided which has a longitudinal axis and a piston head limiting a working chamber, and which is in drive connection with a crankshaft by means of a piston rod and which consists of first and second parts being adjustable relative to each other along the longitudinal piston axis, said first piston part being pivotally connected with the piston rod and supporting an outer thread, and said second piston part being provided with the piston head and being provided with an inner thread engaging the outer thread on the first piston part, and with a device for turning the second piston part, the device comprising a bushing which is mounted for rotation about the piston longitudinal axis, but is axially stationary, and which is provided with an inner gear extending parallel to the longitudiinal axis of the piston, said second piston part being non-rotatably but axially displaceably connected to said bushing, characterized in that the bushing (18) is concentrically mounted between an inner tubular segment (12) and an outer tubular segment (8) of said second piston part (7), and that the inner gear (19) of bushing (18) is in engagement with an outer gear (20) of said inner tubular segment (12) of said second piston part (7).
Claim 3
Dependent Claim
32 words
Reciprocating piston-internal combustion engine in accordance with claim 1, characterized in that the bushing (18) and the inner tubular segment (12) of said second piston part (7) are provided with apertures (24,26).
Claim 4
Dependent Claim
84 words
Reciprocating piston-internal combustion engine in accordance with claim 1, with an outer gear mounted at the end of said bushing extending from said piston into which a pinion engages being mounted on an adjustment shaft, furthermore with a plurality of cylinders being disposed in series and an adjustment mechanism associated with the piston of one each of said cylinders for changing the compression ratios, characterized in that said outer gear (21) of the bushings (18) of adjacent cylinders are in engagement with each other.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-28 | 1990-01-27 | 1990-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-28 | 1994-01-27 | 1994-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-28 | 1998-01-27 | 1998-07-29 | $7700.00 | Window Closed / Lapsed |