US3916856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel injection systems for internal combustion engines
Assignee: Petrol Injection Ltd
•
Filing: 1973-12-26
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Granted: 1975-11-04
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Expires: 1993-12-26
Abstract
Abstract A fuel injection system for an internal combustion engine, in which, for the purpose of modifying the fuel/air ratio only under certain engine conditions, the return branch of the fuel circulation system includes a resiliently-biased valve member which functions to maintain the return branch fuel pressure at a value dependent on the resilient bias, and means for varying the resilient bias under the said engine conditions. In an embodiment, the bias on the valve member is increased when intake manifold vacuum drops below a predetermined value, enabling fuel enrichment to be achieved when the engine is developing full power.
Inventors
- 👤 Harold Ernest Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:11
CPC Classifications
F; F02; F02D; F02D3/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
171 words
A fuel injection system for an internal combustion engine, of the type including a fuel circulation conduit system having supply and return branches, at least one injector device connected to receive fuel from the supply branch, a fuel pressurizing device operable to supply fuel under pressure to the supply branch, and valve means including a valve closure member which is connected in the return branch and is resiliently biased towards a closed position, the valve closure member being exposed to the fuel pressure upstream in the return branch and being movable against the said resilient bias by that fuel pressure to an extent sufficient to maintain that fuel pressure at a predetermined value dependent on the said resilient bias, the system being characterized by means exposed to engine intake manifold vacuum and movable, in response to a drop in manifold vacuum to below a predetermined value, into co-operation with the valve closure member to increase the said resilient bias and thereby increase the said fuel pressure upstream in the return branch.
Claim 2
Dependent Claim
171 words
A fuel injection system for an internal combustion engine, of the type including a fuel circulation conduit system having supply and return branches, at least one injector device connected to receive fuel from the supply branch, a fuel pressurizing device operable to supply fuel under pressure to the supply branch, and valve means including a valve closure member which is connected in the return branch and is resiliently biased towards a closed position, the valve closure member being exposed to the fuel pressure upstream in the return branch and being movable against the said resilient bias by that fuel pressure to an extent sufficient to maintain that fuel pressure at a predetermined value dependent on the said resilient bias, the system being characterized by means exposed to engine intake manifold vacuum and movable, in response to a drop in manifold vacuum to below a predetermined value, into co-operation with the valve closure member to increase the said resilient bias and thereby increase the said fuel pressure upstream in the return branch.
Claim 3
Dependent Claim
42 words
A system as claimed in claim 1, in which, when the said means is unoperated, the said resilient bias is substantially constant, the said means being co-operable with the valve closure member to increase the resilient bias continously with decreasing manifold vacuum.
Claim 4
Dependent Claim
24 words
A system as claimed in claim 1, in which the valve closure member is a resilient diaphragm and is resiliently biased by a spring.
Claim 5
Dependent Claim
58 words
A system as claimed in claim 1, in which the valve closure member is a first resilient diaphragm, and said means comprises a second resilient diaphragm which is exposed to engine intake manifold vacuum and a push-rod which is mounted on the second resilient diaphragm and is co-operable with the first diaphragm to increase the said resilient bias.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |