US4825639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control method for a gas turbine engine
Assignee: RTX Corp
•
Filing: 1987-07-08
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Granted: 1989-05-02
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Expires: 2007-07-08
Abstract
Abstract When a stall is detected during high power operation, the engine is given one chance to recover without a change in bleed schedule. Should a second stall occur within 10 seconds the control system switches to an override bleed schedule for 51/2 minutes, or until throttle is reduced. This supplies a minimum adaquate thrust for a limited time.
Inventors
- 👤 Leon Krukoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:51
CPC Classifications
F; F04; F04D; F04D27/00; F04D27/02; F04D27/0207
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
The method of obtaining acceptable thrust for a limited time from a gas turbine engine damaged by a foreign object comprising: continuously monitoring for the presence of a stall condition whenever the bleed valves are substantially closed; determining the presence of a stall condition; determining a subsequent recovery from the stall condition; monitoring for a second stall within a predetermined time of the recovery; continuing normal unrestricted operation if a second stall does not occur within the predetermined time; and opening bleed valves to a predetermined emergency schedule if a second stall occurs within said predetermined time.
Claim 2
Independent Claim
97 words
The method of obtaining acceptable thrust for a limited time from a gas turbine engine damaged by a foreign object comprising: continuously monitoring for the presence of a stall condition whenever the bleed valves are substantially closed; determining the presence of a stall condition; determining a subsequent recovery from the stall condition; monitoring for a second stall within a predetermined time of the recovery; continuing normal unrestricted operation if a second stall does not occur within the predetermined time; and opening bleed valves to a predetermined emergency schedule if a second stall occurs within said predetermined time.
Claim 3
Dependent Claim
23 words
The method of claim 1 including: maintaining said emergency schedule for a preselected time; and continuing normal unrestricted operation after said preselected time.
Claim 4
Dependent Claim
36 words
The method of claim 2 including: detecting the throttle position; overriding the step of maintaining said emergency schedule whenever the throttle position is set to a pre-established minimum; and continuing normal unrestricted operation after said overriding.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said predetermined time is not greater than 10 seconds.
Claim 6
Dependent Claim
15 words
The method of claim 2 wherein said preselected time is between 4 and 6 minutes.
Claim 7
Dependent Claim
55 words
The method of claim 2 including: detecting the throttle position; overriding the step of maintaining said emergency schedule whenever the throttle position is set to a pre-established minimum; and continuing normal unrestricted operation after said overriding; said predetermined time being not greater than 10 seconds; and said preselected time being between 4 and 6 minutes.
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) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |