Patent EP0442460A1 successfully refreshed from Google Patents.
EP0442460A1
Expired / Lapsed
EP
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Variable timing system, particularly for an internal combustion engine
Assignee: Ferrari SpA
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Filing: 1991-02-13
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Granted: —
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Expires: 2011-02-13
Abstract
Abstract A variable timing system for an internal combustion engine, whereby at least one valve is controlled by a cam (5) via the interposition of a rocker arm (6). The cam presents a first and second profile formed side by side and providing for different lift/rotation strategies, and the rocker arm consists of two side by side, longitudinal elements connected together, a first of which cooperates permanently with the first cam profile (9), and a second of which corresponds with the second cam profile (10) and cooperates with means whereby it is set selectively to a first position, wherein the second element (12) of the rocker arm (6) cooperates with the second cam profile, and a second position wherein the second element of the rocker arm is detached from the cam.
Inventors
- 👤 Riccardo Rosa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:20
CPC Classifications
F; F01; F01L; F01L13/00; F01L13/0015; F01L13/0063; F01L13/0036
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
137 words
A variable timing system, particularly for an internal combustion engine, wherein at least one valve is controlled by a cam via the interposition of a rocker arm; characterised by the fact that said cam is defined laterally by a discrete number of different side by side profiles; and by the fact that said rocker arm consists of a number of side by side, longitudinal elements connected together and equal to the number of different cam profiles; each said longitudinal element of said rocker arm being designed to cooperate with a respective cam profile facing it; and means being provided for selectively displacing said elements of said rocker arm in relation to one another, so as to selectively cause at least one of said elements of said rocker arm to cooperate with the respective cam profile facing it.
Claim 2
Dependent Claim
122 words
A variable timing system as claimed in Claim 1, characterised by the fact that said rocker arm comprises two side by side, longitudinal elements, the respective corresponding ends of which are secured together in scissor formation via a transverse pin; a first of said longitudinal elements pivoting about a fixed point to the side of the cam rotation axis, and cooperating with the stem of said valve; and a second of said longitudinal elements being supported on said first element and moving in relation to the same between two positions, in a first of which said second element is detached from said cam, and in a second of which said second element cooperates with a respective said lateral cam profile facing it.
Claim 3
Dependent Claim
62 words
A variable timing system as claimed in Claim 2, characterised by the fact that said means for relatively displacing said elements of said rocker arm comprise a hydraulic actuator supported on said first element and the mobile element of which cooperates with a second end of said second element of said rocker arm opposite said pin connecting said first and second elements.
Claim 4
Dependent Claim
64 words
A variable timing system as claimed in Claim 3, characterised by the fact that said hydraulic actuator comprises a hollow body formed in one piece with said first element; a push rod sliding in fluidtight manner inside said hollow body and projecting from the same towards said second element; and a hydraulic distributor for selectively feeding and draining pressurized oil into/from said hollow body.
Claim 5
Dependent Claim
166 words
A variable timing system as claimed in Claim 4, characterised by the fact that said hydraulic distributor comprises a hollow rotary shaft selectively connectable to a pressurized oil delivery and drain line, and presenting an assembly portion fitted in idle and fluidtight manner with said first element of said rocker arm and having a discontinuous outer radial projection; and an automatic non-return valve closing a passage between the inside of said hollow body of said hydraulic actuator and the inside of a transverse seat located on said first element and housing said assembly portion of said shaft; said assembly portion also presenting at least one radial hole connecting the inside of said shaft to the inside of said seat and enabling the passage of pressurized oil; and said discontinuous radial projection on said assembly portion being designed, subsequent to predetermined rotation of said shaft, to cooperate selectively with an element closing said automatic valve, so as to open said valve against the action of elastic means.
Claim 6
Dependent Claim
42 words
A variable timing system as claimed in one of the foregoing Claims from 2 to 5, characterised by the fact that said first element of said rocker arm cooperates with said valve stem via the interposition of at least one rolling body.
References Cited (Backward Citations)
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