US5055764A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low voltage aircraft engine starting system
Assignee: Sundstrand Corp
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Filing: 1989-12-11
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Granted: 1991-10-08
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Expires: 2009-12-11
Abstract
Abstract In a system for starting an aircraft turbine from a low voltage direct current power supply, the low voltage power supply is coupled by an invertor to the turbine's a.c. generator. The generator operates as a motor during starting. The invertor is initially coupled directly to the generator during starting, and to the generator via a step-up transformer after the speed of the generator increases. In a preferred embodiment of the invention, the transformer is an autotransformer used to step down the output of the generator when operating as a generator after the turbine has been started.
Inventors
- 👤 Gregory I. Rozman
- 👤 Timothy F. Glennon
- 👤 Alexander Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:27
CPC Classifications
F; F02; F02N; F02N11/00; F02N11/04; F05; F05B; F05B2220/00; F05B2220/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
112 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting, comprising in combination: an invertor having a direct current input coupled to said voltage supply and an alternating current output; a transformer having a starting mode input tap and a starting mode output tap, said transformer coupling a stepped up voltage between said input and output taps; means for coupling said output tap to said generator; and control means for coupling said invertor output initially to said generator during starting and to said input tap after the speed of said generator increases.
Claim 2
Independent Claim
112 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting, comprising in combination: an invertor having a direct current input coupled to said voltage supply and an alternating current output; a transformer having a starting mode input tap and a starting mode output tap, said transformer coupling a stepped up voltage between said input and output taps; means for coupling said output tap to said generator; and control means for coupling said invertor output initially to said generator during starting and to said input tap after the speed of said generator increases.
Claim 3
Independent Claim
113 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting, comprising in combination: an invertor having a direct current input coupled to said low voltage supply and an alternating current output; an autotransformer having a starting mode input tap and a starting mode output tap, said transformer coupling a stepped up voltage between said input and output taps; means for coupling said output tap to said generator; and control means for coupling said invertor output initially to said generator during starting and to said input tap after the speed of said generator increases.
Claim 4
Independent Claim
113 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting, comprising in combination: an invertor having a direct current input coupled to said low voltage supply and an alternating current output; an autotransformer having a starting mode input tap and a starting mode output tap, said transformer coupling a stepped up voltage between said input and output taps; means for coupling said output tap to said generator; and control means for coupling said invertor output initially to said generator during starting and to said input tap after the speed of said generator increases.
Claim 5
Dependent Claim
59 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting as in claim 1 wherein said control means couples said invertor output to said input tap in response to the phase angle of said generator reaching a predetermined limit.
Claim 6
Dependent Claim
59 words
A system for starting an aircraft turbine from a low voltage power supply by energizing a generator coupled to said turbine to operate said generator as a motor during starting as in claim 2 wherein said control means couples said invertor output to said input tap in response to the phase angle of said generator reaching a predetermined limit.
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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) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |