Patent US3697731A successfully refreshed from Google Patents.
US3697731A
Expired / Lapsed
US
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Method and apparatus for determining maximum allowable jet engine pressure ratios
Assignee: Lear Siegler Inc
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Filing: 1969-02-17
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Granted: 1972-10-10
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Expires: 1989-02-17
Abstract
Abstract An instrument comprised of inputs for receiving signals proportional to aircraft pressure altitude and compressor inlet temperature, which are coupled to function generators that produce outputs respectively representative of maximum engine pressure ratio at such altitude and at such temperature conditions, comparator means for receiving the functions so generated and selecting the one representative of the lowest allowable engine pressure ratio at such conditions, and a servo drive for a visual readout display of maximum engine pressure ratio. The instrument also includes system inputs for modifying the result to be displayed, in accordance with different flight modes of the aircraft, and also in accordance with compressor bleed air tapped from the engine for use in auxiliary aircraft systems.
Inventors
- 👤 James L Kempema
- 👤 Ralph W Foard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:45
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/48; G06G7/70
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
An engine pressure ratio limit indicator, comprising in combination: means for receiving signals which are proportional as processed by a buffer network to the pressure altitude of an aircraft in flight; means for receiving signals as processed by a bridge network which are proportional to the engine ram air temperature; and means connected to said first and said second mentioned means for producing an electrical output signal which is a function of the maximum allowable engine pressure ratio for the engine powering such aircraft at such pressure altitude and ram air temperature.
Claim 2
Dependent Claim
92 words
An engine pressure ratio limit indicator, comprising in combination: means for receiving signals which are proportional as processed by a buffer network to the pressure altitude of an aircraft in flight; means for receiving signals as processed by a bridge network which are proportional to the engine ram air temperature; and means connected to said first and said second mentioned means for producing an electrical output signal which is a function of the maximum allowable engine pressure ratio for the engine powering such aircraft at such pressure altitude and ram air temperature.
Claim 3
Dependent Claim
59 words
The instrument of claim 1, wherein said means for producing an electrical output signal includes a selectable input means for introducing a signal function from a flight mode selector representative of the flight mode of the aircraft, and wherein said output-producing means is structured to vary its output as a function of the selected flight mode of the aircraft.
Claim 4
Dependent Claim
150 words
An engine pressure ratio limit indicator comprising in combination: first input means for providing a signal proportional to the pressure altitude computed from an air data computer of an aircraft in flight; second input means for providing a signal proportional to engine ram air temperature provided by a ram air probe located near the engine compressor; function generating means for generating a pair of separate output signals from said first and said second input means signals, said output signals being representative of the maximum allowable engine pressure ratios for said engine mounted in said aircraft for the ambient pressure altitude and for the engine ram air temperature; comparator means for receiving said pair of output signals and selecting the signal representative of the lower of the maximum allowable engine pressure ratios, said selected output being coupled to an instrument output driver means for driving a desired display or the like.
Claim 5
Dependent Claim
150 words
An engine pressure ratio limit indicator comprising in combination: first input means for providing a signal proportional to the pressure altitude computed from an air data computer of an aircraft in flight; second input means for providing a signal proportional to engine ram air temperature provided by a ram air probe located near the engine compressor; function generating means for generating a pair of separate output signals from said first and said second input means signals, said output signals being representative of the maximum allowable engine pressure ratios for said engine mounted in said aircraft for the ambient pressure altitude and for the engine ram air temperature; comparator means for receiving said pair of output signals and selecting the signal representative of the lower of the maximum allowable engine pressure ratios, said selected output being coupled to an instrument output driver means for driving a desired display or the like.
Claim 6
Dependent Claim
24 words
The instrument of claim 3, wherein said output driver means includes a visual readout display calibrated in terms of maximum allowable engine pressure ratio.
Claim 7
Dependent Claim
20 words
The instrument of claim 4, wherein said output driver means includes a servo-type drive system for driving said readout display.
Claim 8
Dependent Claim
37 words
The instrument of claim 3, wherein said output driver means includes a pair of visual readout displays, one such display calibrated in terms of maximum allowable engine pressure ratio and the other in terms of air temperature.
Claim 9
Dependent Claim
28 words
The instrument of claim 3, wherein said output driver means includes an auxiliary control means for providing control signals to an automated engine controlling apparatus or the like.
Claim 10
Dependent Claim
28 words
The instrument of claim 3, including control input means for modifying the output signals from said function generating means in accordance with the flight mode of the aircraft.
Claim 11
Dependent Claim
26 words
The instrument of claim 8, wherein said control input means includes a selector switch means for selection of a predetermined one of several aircraft flight modes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |