Patent US4881499A successfully refreshed from Google Patents.
US4881499A
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Hydraulic play compensating element
Assignee: Mercedes Benz Group AG
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Filing: 1989-01-13
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Granted: 1989-11-21
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Expires: 2009-01-13
Abstract
Abstract A hydraulic play compensating element adapted to be positioned in the valve train of an internal-combustion engine is described which comprises a cylinder part closes at one end and a piston part slidable longitudinally in the latter. The piston part contains a supply chamber which is pressurized by lubricating oil from the lubricating oil circuit and which is separated from a pressure chamber by a connecting duct controlled by a valve. In order to switch off the play compensating function of the play compensating element during engine braking service, a shut-off valve is provided in the supply chamber for closing or opening the connecting duct as a function of the lubricating oil pressure in the supply chamber.
Inventors
- 👤 Markus Dietrich
- 👤 Frank Berger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:53
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/20; F01L1/22; F01L1/24; F01L1/245
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
137 words
Hydraulic play compensating element for a valve train of an internal combustion engine comprising: (a) a cylinder part closed at one end; (b) a hollow piston part slidable axially in the cylinder part and having a supply chamber adapted to be pressurized by lubricating oil pressure of the internal combustion engine; (c) a presusre chamber, enclosed by the hollow piston part and the cylinder part, for providing play compensation for the valve train of the internal combustion engine; (d) a compression spring for biasing the cylinder part and the piston part in opposite directions; (e) a connecting duct for connecting the pressure chamber and the supply chamber; (f) a spring biased closure element for opening and closing the connecting duct; and (g) a shut-off valve for opening and closing the connecting duct independently of the closure element.
Claim 2
Dependent Claim
137 words
Hydraulic play compensating element for a valve train of an internal combustion engine comprising: (a) a cylinder part closed at one end; (b) a hollow piston part slidable axially in the cylinder part and having a supply chamber adapted to be pressurized by lubricating oil pressure of the internal combustion engine; (c) a presusre chamber, enclosed by the hollow piston part and the cylinder part, for providing play compensation for the valve train of the internal combustion engine; (d) a compression spring for biasing the cylinder part and the piston part in opposite directions; (e) a connecting duct for connecting the pressure chamber and the supply chamber; (f) a spring biased closure element for opening and closing the connecting duct; and (g) a shut-off valve for opening and closing the connecting duct independently of the closure element.
Claim 3
Dependent Claim
24 words
Hydraulic play compensating element according to claim 1, wherein the shut-off valve is controlled as a function of operating parameters of the internal-combustion engine.
Claim 4
Dependent Claim
26 words
Hydraulic play compensating element according to claim 2, wherein the shut-off valve is controlled as a function of the lubricating oil pressure in the supply chamber.
Claim 5
Dependent Claim
18 words
Hydraulic play compensating element according to claim 3, wherein the shut-off valve is arranged in the supply chamber.
Claim 6
Dependent Claim
70 words
Hydraulic play compensating element according to claim 4, wherein the shut-off valve comprises a stepped piston at least slidable in an axial direction counter to a return spring positioned at a piston wall of the piston part opposite the connecting duct, the stepped piston having a closure member which cooperates with a valve seat surface provided in the region of an orifice of the connecting duct in the supply chamber.
Claim 7
Dependent Claim
61 words
Hydraulic play compensating element according to claim 5, wherein a ring seal, inserted in a groove, is arranged at an outer circumference of the piston part in a region between a connecting bore for the connection of the supply chamber to a lubricating oil circuit of the internal combustion engine and a pressure chamber side end wall of the piston part.
Claim 8
Dependent Claim
29 words
Hydraulic play compensating element according to claim 6, wherein a capillary overflow bore is arranged in the end wall of the piston part between supply chamber and pressure chamber.
Claim 9
Dependent Claim
21 words
Hydraulic play compensating element according to claim 7, wherein the overflow bore leads into the region of the valve seat surface.
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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) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |