US3724823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel injection systems
Assignee: ZF International UK Ltd
•
Filing: 1970-07-13
•
Granted: 1973-04-03
•
Expires: 1990-07-13
Abstract
Abstract A fuel injection system for an engine has a metering unit controlled by one of a pair of pressure signals, the signals being selected by a valve arrangement so that when the engine throttle is shut, the signal applied to the metering unit has a predetermined value.
Inventors
- 👤 H Littlehales
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:34
CPC Classifications
F; F02; F02M; F02M69/00; F02M69/12; F02M69/125; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
108 words
A fuel injection system for an internal combustion engine, including an air inlet passage for the engine, a throttle valve within the said passage, a control unit for metering the fuel supplied to the engine, means for applying a first pressure signal derived from the said inlet passage downstream of the throttle valve to the control unit to control the operation of the unit and a valve arrangement including a member operable by closing of the throttle valve to isolate said first pressure signal from the control unit and also operable when the throttle valve is closed to apply a predetermined second pressure signal to the control unit.
Claim 2
Dependent Claim
108 words
A fuel injection system for an internal combustion engine, including an air inlet passage for the engine, a throttle valve within the said passage, a control unit for metering the fuel supplied to the engine, means for applying a first pressure signal derived from the said inlet passage downstream of the throttle valve to the control unit to control the operation of the unit and a valve arrangement including a member operable by closing of the throttle valve to isolate said first pressure signal from the control unit and also operable when the throttle valve is closed to apply a predetermined second pressure signal to the control unit.
Claim 3
Dependent Claim
31 words
A system as claimed in claim 1 which includes an airpressure potentiometer arrangement comprising a pair of flow restrictors in series in a further passage between the inlet passage and atmosphere.
Claim 4
Dependent Claim
32 words
A system as claimed in claim 2 in which the potentiometer arrangement is connected to the inlet passage at a position downstream of the location where said first pressure signal is sensed.
Claim 5
Dependent Claim
34 words
A system as claimed in claim 2 in which the dimensions of the said restrictors are such that air flow therethrough does not significantly affect the air/fuel ration supplied, in use, to the engine.
Claim 6
Dependent Claim
24 words
A system as claimed in claim 4 which includes a bypass passage for the throttle valve and a flow restrictor in the bypass passage.
Claim 7
Dependent Claim
15 words
A system as claimed in claim 2 in which one of said restrictors is variable.
Claim 8
Dependent Claim
39 words
A system as claimed in claim 6 in which the other of said restrictors is defined by a reduced bore in said further passage, a step being defined between said reduced bore and the remainder of said further passage.
Claim 9
Dependent Claim
25 words
A system as claimed in claim 7 in which said valve communicates with said further passage at a location therein immediately downstream of said step.
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |