US3768249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel supply systems for gas turbine engines
Assignee: ZF International UK Ltd
•
Filing: 1972-02-10
•
Granted: 1973-10-30
•
Expires: 1992-02-10
Abstract
Abstract A fuel control system for a gas turbine engine includes an injection device which can be charged with fuel and which is operable when the engine is started to deliver this charge of fuel directly to the engine.
Inventors
- 👤 G Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:59
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/26; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2579
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A fuel supply system for a gas turbine engine, comprising a fixed displacement pump, driven in use, at a speed proportional to the engine speed, a valve including a chamber having an inlet connected to the outlet of the pump and first and second outlets and a control element variably positionable between said outlets so as to vary the effective flow area of the two outlets simultaneously, a pressure control unit sensitive to the pressures at said two outlets and arranged to spill sufficient fuel from the first outlet to maintain the ratio of said pressures substantially constant, means for positioning the control element of the valve in accordance with the fuel requirement of the engine, and a fuel injection device including a further chamber, means for charging said further chamber with fuel, and means operable during engine starting, for discharging the contents of said chamber to a position downstream of said second outlet.
Claim 2
Dependent Claim
154 words
A fuel supply system for a gas turbine engine, comprising a fixed displacement pump, driven in use, at a speed proportional to the engine speed, a valve including a chamber having an inlet connected to the outlet of the pump and first and second outlets and a control element variably positionable between said outlets so as to vary the effective flow area of the two outlets simultaneously, a pressure control unit sensitive to the pressures at said two outlets and arranged to spill sufficient fuel from the first outlet to maintain the ratio of said pressures substantially constant, means for positioning the control element of the valve in accordance with the fuel requirement of the engine, and a fuel injection device including a further chamber, means for charging said further chamber with fuel, and means operable during engine starting, for discharging the contents of said chamber to a position downstream of said second outlet.
Claim 3
Dependent Claim
51 words
A system as claimed in claim 1 in which the means for charging the further chamber comprises a passage connecting said further chamber with the upstream side of said pump, and a non-return valve to prevent flow of fuel from said further chamber back to said upstream side of the pump.
Claim 4
Dependent Claim
75 words
A system as claimed in claim 1 in which the means for discharging the contents of said further chamber comprises a diaphragm defining a wall of said further chamber, means for moving said diaphragm to reduce the volume of said further chamber, a further passage connecting said further chamber with said downstream position and a non-return valve associated with said further passage to prevent flow of fuel from said downstream position to said further chamber.
Claim 5
Dependent Claim
34 words
A system as claimed in claim 3 in which the means for moving said diaphragm comprises an arrangement for applying a fluid pressure to the side of said diaphragm remote from said further chamber.
Claim 6
Dependent Claim
42 words
A system as claimed in claim 4 in which said arrangement comprises a fluid pressure source, a control valve between said source and said diaphragm and a fluid flow restrictor through which pressure downstream of said control valve can escape to atmosphere.
Claim 7
Dependent Claim
15 words
A system as claimed in claim 5 in which said control valve is electrically operable.
Claim 8
Dependent Claim
43 words
A system as claimed in claim 1 in which the means for discharging the contents of said further chamber comprises a diaphragm defining a wall of said further chamber and means for moving said diaphragm to reduce the volume of said further chamber.
Claim 9
Dependent Claim
18 words
A system as claimed in claim 7 in which the means for moVing said diaphragm comprises a spring.
Claim 10
Dependent Claim
37 words
A system as claimed in claim 8 which includes latching means for restraining movement of the diaphragm under the influence of said spring, said latching means being operable when the engine is started to release said diaphragm.
Claim 11
Dependent Claim
28 words
A system as claimed in claim 9 in which said latching means comprises a stem secured to the diaphragm and an electromagnetically operable plunger engageable with said stem.
References Cited (Backward Citations)
US2986881A
Cited
US3078670A
Cited
US3151452A
Cited
US3282323A
Cited
US3611717A
Cited
US3593736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |