Patent US5435276A successfully refreshed from Google Patents.
US5435276A
Expired / Lapsed
US
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Engine cam change-over mechanism
Assignee: Hitachi Ltd
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Filing: 1993-10-06
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Granted: 1995-07-25
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Expires: 2013-10-06
Abstract
Abstract A main rocker arm driven by a first cam, and a sub-rocker arm driven by a second cam larger than the first cam, are supported adjacent to each other. A sliding member which moves together with the sub-rocker arm, and a contact piece which comes into contact with the sliding member according to the slide position of the sliding member, are provided on the main rocker arm. The sliding member moves between a position where it is in contact with the contact piece and a position where it is not in contact with the contact piece according to the engine running conditions. The sliding member and contact member are constructed of iron or an iron alloy, while the main rocker arm is constructed of aluminum or an aluminum alloy. The construction of the cam change-over mechanism is therefore rendered lightweight, and machining of the main rocker arm is rendered facile.
Inventors
- 👤 Makoto Nakamura
- 👤 Siniti Takemura
- 👤 Teturou Goto
- 👤 Shoji Morita
- 👤 Yukio Yamakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:49
CPC Classifications
F; F01; F01L; F01L13/00; F01L13/0015; F01L13/0036; Y; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20576; Y10T74/20882
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
218 words
A cam change-over mechanism for an engine, comprising: a valve, a first cam which opens and closes said valve, a second cam larger than said first cam which opens and closes said valve, a main rocker shaft supported on the engine, a main rocker arm supported free to rotate on the main rocker shaft, said main rocker arm being driven by said first cam so as to transmit the motion of said first cam to said valve, a sub-rocker shaft supported on said main rocker arm such that it is parallel to said main rocker shaft, a sub-rocker arm supported on said sub-rocker shaft such that it is free to rotate, means for elastically maintaining said sub-rocker arm in contact with said second cam, a sliding member provided on said sub-rocker arm such that it slides parallel to said sub-rocker shaft, a contact piece supported on said main rocker arm in contact with said sliding member in a predetermined slide position, and means for driving said sliding member between a position wherein it is in contact and a position wherein it is not in contact with said contact piece, wherein said sliding member and said contact piece are constructed of iron or an iron alloy, and said main rocker arm is constructed of aluminum or an aluminum alloy.
Claim 2
Dependent Claim
218 words
A cam change-over mechanism for an engine, comprising: a valve, a first cam which opens and closes said valve, a second cam larger than said first cam which opens and closes said valve, a main rocker shaft supported on the engine, a main rocker arm supported free to rotate on the main rocker shaft, said main rocker arm being driven by said first cam so as to transmit the motion of said first cam to said valve, a sub-rocker shaft supported on said main rocker arm such that it is parallel to said main rocker shaft, a sub-rocker arm supported on said sub-rocker shaft such that it is free to rotate, means for elastically maintaining said sub-rocker arm in contact with said second cam, a sliding member provided on said sub-rocker arm such that it slides parallel to said sub-rocker shaft, a contact piece supported on said main rocker arm in contact with said sliding member in a predetermined slide position, and means for driving said sliding member between a position wherein it is in contact and a position wherein it is not in contact with said contact piece, wherein said sliding member and said contact piece are constructed of iron or an iron alloy, and said main rocker arm is constructed of aluminum or an aluminum alloy.
Claim 3
Dependent Claim
45 words
A cam change-over mechanism as defined in claim 1, wherein said contact piece is formed in a cylindrical shape, having an outer circumference in the form of a male screw, and said main rocker arm has a screw hole into which said contact piece screws.
Claim 4
Dependent Claim
46 words
A cam change-over mechanism as defined in claim 2, wherein said elastic maintaining mechanism comprises a spring, and a member supported by said spring which is in contact with said sliding member in its non-contact position, said elastic maintaining mechanism being housed in said contact piece.
Claim 5
Dependent Claim
55 words
A cam change-over mechanism as defined in claim 1, wherein said drive memos comprises a plunger inserted in said main rocker arm such that it is free to slide parallel to said sub-rocker shaft, a spring which maintains said sliding member in contact with said plunger, and hydraulic means which causes said plunger to slide.
Claim 6
Dependent Claim
50 words
A cain change-over mechanism as defined in claim 4, wherein said hydraulic means comprises an oil chamber formed in said main rocker arm, a hydraulic passage formed through said main rocker shaft, and a throughhole formed in said main rocker arm which connects said hydraulic passage and said oil chamber.
Claim 7
Dependent Claim
218 words
A cam change-over mechanism for an engine comprising: an intake valve, a first cam which opens and closes said valve, a second cam larger than said first cam which opens and closes said valve, a main rocker shaft supported on the engine, a main rocker arm supported free to rotate on said main rocker shaft, said main rocker arm being driven by said first cam so as to transmit the motion of said first cam to said valve, a sub-rocker shaft supported on said main rocker arm such that it is parallel to said main rocker shaft, a sub-rocker arm supported on said sub-rocker shaft such that it is free to rotate, means for elastically maintaining said sub-rocker arm in contact with said second cam, a sliding member provided on said sub-rocker arm such that it slides parallel to said sub-rocker shaft, a contact piece supported on said main rocker arm in contact with said sliding member in a predetermined slide position, and means for driving said sliding member between a position wherein it is in contact and a position wherein it is not in contact with said contact piece, wherein said sliding member and contact piece are constructed of iron or an iron alloy, and said main rocker arm is constructed of aluminum or an aluminum alloy.
Claim 8
Dependent Claim
218 words
A cam change-over mechanism for an engine comprising: an intake valve, a first cam which opens and closes said valve, a second cam larger than said first cam which opens and closes said valve, a main rocker shaft supported on the engine, a main rocker arm supported free to rotate on said main rocker shaft, said main rocker arm being driven by said first cam so as to transmit the motion of said first cam to said valve, a sub-rocker shaft supported on said main rocker arm such that it is parallel to said main rocker shaft, a sub-rocker arm supported on said sub-rocker shaft such that it is free to rotate, means for elastically maintaining said sub-rocker arm in contact with said second cam, a sliding member provided on said sub-rocker arm such that it slides parallel to said sub-rocker shaft, a contact piece supported on said main rocker arm in contact with said sliding member in a predetermined slide position, and means for driving said sliding member between a position wherein it is in contact and a position wherein it is not in contact with said contact piece, wherein said sliding member and contact piece are constructed of iron or an iron alloy, and said main rocker arm is constructed of aluminum or an aluminum alloy.
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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) | 1998-07-24 | 1999-01-23 | 1999-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-24 | 2003-01-23 | 2003-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-24 | 2007-01-23 | 2007-07-25 | $7700.00 | Window Closed / Lapsed |