Patent US4979874A successfully refreshed from Google Patents.
US4979874A
Expired / Lapsed
US
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Variable van drive mechanism
Assignee: RTX Corp
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Filing: 1989-06-19
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Granted: 1990-12-25
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Expires: 2009-06-19
Abstract
Abstract Improvements to a mechanism for positioning variable vanes of a gas turbine are disclosed. Various construction details for introducing flexibility into the mechanism and for holding components in a snugly fitting relationship are discussed.
Inventors
- 👤 Steven W. Myers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:53
CPC Classifications
F; F01; F01D; F01D17/00; F01D17/10; F01D17/12; F01D17/14; F01D17/16; F01D17/162; F01D7/00; F05; F05D; F05D2260/00; F05D2260/70; F05D2260/74; F05D2260/76; F05D2260/79
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
In an axial flow gas turbine engine of the type having variable inlet guide vanes operable by rotating a unison ring circumferentially about the engine case, the improvement which comprises: a plurality of flexible drive lever arms extending from the unison ring, one each to a post at the radially outward end of a corresponding inlet guide vane; and means for attaching the drive lever arm to the post which includes a post end having a polyhedral geometry which is tapered to a smaller area cross section at the most outward end thereof, a receptacle on the drive lever arm of a geometry corresponding to the geometry of the post, and a bolt passing through the lever arm into the vane post for holding the lever arm and post in tight engagement to prevent wear under vibratory loading.
Claim 2
Dependent Claim
138 words
In an axial flow gas turbine engine of the type having variable inlet guide vanes operable by rotating a unison ring circumferentially about the engine case, the improvement which comprises: a plurality of flexible drive lever arms extending from the unison ring, one each to a post at the radially outward end of a corresponding inlet guide vane; and means for attaching the drive lever arm to the post which includes a post end having a polyhedral geometry which is tapered to a smaller area cross section at the most outward end thereof, a receptacle on the drive lever arm of a geometry corresponding to the geometry of the post, and a bolt passing through the lever arm into the vane post for holding the lever arm and post in tight engagement to prevent wear under vibratory loading.
Claim 3
Dependent Claim
27 words
The invention according to claim 1 wherein the angle of taper of the polyhedral geometry of the post end is on the order of six (6) degrees.
Claim 4
Dependent Claim
17 words
The invention according to claim 1 wherein the polyhedral post end has a square cross section geometry.
Claim 5
Dependent Claim
36 words
The invention according to claim 1 wherein each of said drive lever arm as has a mid-region of sufficient cross-section geometry between the unison ring end and the vane port end to provide flexibility during operation.
Claim 6
Dependent Claim
36 words
The invention according to claim 4 wherein the mid-region of each of said drive lever arms is fabricated of nickel alloy steel and has a thickness on the order to five hundredths (0.05) of an inch.
Claim 7
Dependent Claim
48 words
The invention according to claim 5 wherein the length of each of said drive lever arms has a length on the order of one and five tenths (1.5) inches and a minimum width at the mid-region on the order of three to four tenths (0.3-0.4) of an inch.
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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) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |