Patent US5074272A successfully refreshed from Google Patents.
US5074272A
Expired / Lapsed
US
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Process and apparatus for reducing port fuel injector deposits
Assignee: Ashland LLC
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Filing: 1989-12-07
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Granted: 1991-12-24
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Expires: 2009-12-07
Abstract
Abstract Plugging of fuel injectors for internal combustion engines is reduced by depressurizing the fuel pressure line which feeds the injectors, promptly after shutoff of ignition. Reduction of deposits assists in maintaining drivability and fuel economy.
Inventors
- 👤 Giles L. Bostick
- 👤 Carlton H. Jewitt
- 👤 Victor L. Kersey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:23
CPC Classifications
F; F02; F02M; F02M69/00; F02M69/46; F02M69/462; F02M69/465
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
56 words
A method for reducing the formation of fuel-derived deposits on close tolerance port fuel injector components, which comprises the steps of: (a) sensing shut-off of engine ignition regardless of fuel temperature; and (b) automatically reducing the fuel pressure at the inlet of said injector to a pressure less than about 10 kPa when shut-off is sensed.
Claim 2
Independent Claim
56 words
A method for reducing the formation of fuel-derived deposits on close tolerance port fuel injector components, which comprises the steps of: (a) sensing shut-off of engine ignition regardless of fuel temperature; and (b) automatically reducing the fuel pressure at the inlet of said injector to a pressure less than about 10 kPa when shut-off is sensed.
Claim 3
Dependent Claim
40 words
A method according to claim 1, wherein the injector is located within about 8 centimeters (3 inches) of the combustion chamber of said engine and wherein said fuel line is automatically depressurized to a pressure less than about 5 kPa.
Claim 4
Dependent Claim
47 words
A method according to claim 1, wherein at least a portion of said components of said port fuel injector are subjected to temperatures in excess of 80° C. (176° F.) at some point during the period of shut-off of the engine on which said injectors are mounted.
Claim 5
Dependent Claim
28 words
The method according to claim 2, wherein the fuel pressure is reduced by bypassing a fuel pressure line regulator means, said bypassing being responsive to cut-off of ignition.
Claim 6
Dependent Claim
40 words
A method according to claim 2, wherein said fuel pressure is reduced by actuation of a valved shunt which vents pressure from said fuel pressure line, and wherein said valved shunt is actuated in response to cut-off of engine ignition.
Claim 7
Dependent Claim
21 words
A method according to claim 5, wherein said pressure from said fuel pressure line is vented to a fuel return line.
Claim 8
Dependent Claim
22 words
A method according to claim 4, wherein said pressure from said fuel pressure line is vented to the source of said fuel.
Claim 9
Dependent Claim
48 words
A method according to claim 1, wherein said fuel pressure at the inlet of said injector is automatically reduced in response to shut-off of engine ignition by actuation of a valve which vents said pressure from said fuel pressure line to the source of fuel for said engine.
Claim 10
Dependent Claim
19 words
A method according to claim 8, wherein said source of fuel comprises the fuel tank of a motor vehicle.
Claim 11
Dependent Claim
11 words
A method according to claim 9, wherein said fuel comprises gasoline.
References Cited (Backward Citations)
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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) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |