US5020488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve mechanism for an internal combustion engine
Assignee: Subaru Corp
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Filing: 1990-10-12
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Granted: 1991-06-04
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Expires: 2010-10-12
Abstract
Abstract A valve mechanism has a low-speed cam and a high-speed cam, a low-speed rocker arm operatively connected a valve and a high-speed rocker arm. A changeover device is provided for connecting the low-speed and high-speed rocker arm with each other so as to be rocked together by the high-speed cam. A roller follower is rotatably mounted on a shaft provided in the low-speed rocker arm. The high-speed rocker arm has a slipper engaging with the high-speed cam. The changeover device has a piston slidably mounted in the high-speed rocker arm so as to connect the high-speed rocker arm with the low-speed rocker arm.
Inventors
- 👤 Kenzo Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:56
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/26; F01L1/267; Y; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20576; Y10T74/20582; Y10T74/20882
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
199 words
A valve mechanism for an internal combustion engine having at least one intake valve and at least one exhaust valve, a cam shaft having a low-speed cam and a high-speed cam, a low-speed rocker arm operatively connected to said at least one of said valves and a high-speed rocker arm which are rocked by the cams to operate the at least one valve, changeover means for connecting the low-speed rocker arm and the high-speed rocker arm with each other so as to be rocked together by the high-speed cam, an improvement of the mechanism comprises: a base circle of said low-speed cam having a larger diameter than that of the base circle of the high-speed cam; a roller follower rotatably mounted on a shaft provided in the low-speed rocker arm, a part of a peripheral portion of the roller follower being projected from the low-speed rocker arm to be engaged with the low-speed cam; said high-speed rocker arm having a slipper engaging with the high-speed cam; and said changeover means comprising a piston slidably mounted in said high-speed rocker arm and means for pushing the piston so as to connect the high-speed rocker arm with the low-speed rocker arm.
Claim 2
Dependent Claim
199 words
A valve mechanism for an internal combustion engine having at least one intake valve and at least one exhaust valve, a cam shaft having a low-speed cam and a high-speed cam, a low-speed rocker arm operatively connected to said at least one of said valves and a high-speed rocker arm which are rocked by the cams to operate the at least one valve, changeover means for connecting the low-speed rocker arm and the high-speed rocker arm with each other so as to be rocked together by the high-speed cam, an improvement of the mechanism comprises: a base circle of said low-speed cam having a larger diameter than that of the base circle of the high-speed cam; a roller follower rotatably mounted on a shaft provided in the low-speed rocker arm, a part of a peripheral portion of the roller follower being projected from the low-speed rocker arm to be engaged with the low-speed cam; said high-speed rocker arm having a slipper engaging with the high-speed cam; and said changeover means comprising a piston slidably mounted in said high-speed rocker arm and means for pushing the piston so as to connect the high-speed rocker arm with the low-speed rocker arm.
Claim 3
Dependent Claim
23 words
The valve mechanism according to claim 1, wherein said piston is disposed perpendicular to the axis of said shaft for the roller follower.
Claim 4
Dependent Claim
58 words
The valve mechanism according to claim 2, wherein two sets of low-speed cams and low-speed rocker arms are provided for operating two valves, respectively, and said high-speed rocker arm is disposed between the low-speed rocker arms, said piston of said changeover means is so provided as to engage with a common shaft for the respective two roller followers.
Claim 5
Dependent Claim
34 words
The valve mechanism according to claim 2, wherein two sets of the high-speed rocker arms are provided, the low-speed rocker arm is disposed between the high-speed rocker arms and shaped to operate two valves.
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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) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |