US4714410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trailing edge support for control stage steam turbine blade
Assignee: Westinghouse Electric Corp
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Filing: 1986-08-18
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Granted: 1987-12-22
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Expires: 2006-08-18
Abstract
Abstract A side entry rotatable control stage blade with a wedge shape trailing edge support on the root portion which is formed to have two generally right trapezoidal surfaces which converge and a notch disposed on the opposite side of the platform with a trapezoidal surface which registers with one of the trapezoidal surfaces on the trailing edge support of the adjacent blade when the blades are disposed in a circular array in a steam turbine.
Inventors
- 👤 Bynum V. Hancock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:30
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/30; F01D5/12; F01D5/14; F01D5/141
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
114 words
A rotatable blade for a steam turbine comprising: a root portion; a root platform portion disposed radially outwardly with respect to the root portion; an airfoil portion extending radially outwardly from the root platform portion and having a leading and a trailing edge; said root platform portion having an extension which supports the trailing edge of the airfoil portion; said extension being wedge shaped and having two generally right trapezoidal surfaces and two triangular shaped sides; and said root platform having a notch with a generally right trapezoidal surface which receives and supports the wedge shaped extension of the adjacent blade when the blades are disposed in a circular array on a steam turbine.
Claim 2
Dependent Claim
114 words
A rotatable blade for a steam turbine comprising: a root portion; a root platform portion disposed radially outwardly with respect to the root portion; an airfoil portion extending radially outwardly from the root platform portion and having a leading and a trailing edge; said root platform portion having an extension which supports the trailing edge of the airfoil portion; said extension being wedge shaped and having two generally right trapezoidal surfaces and two triangular shaped sides; and said root platform having a notch with a generally right trapezoidal surface which receives and supports the wedge shaped extension of the adjacent blade when the blades are disposed in a circular array on a steam turbine.
Claim 3
Dependent Claim
23 words
A rotatable blade as set forth in claim 1 and further comprising a shroud platform portion disposed radially outwardly from the airfoil portion.
Claim 4
Dependent Claim
27 words
A rotatable blade as set forth in claim 2, wherein the shroud platform portion has a shroud extension which supports the trailing edge of the airfoil portion.
Claim 5
Dependent Claim
38 words
A rotatable blade as set forth in claim 3, wherein the shroud platform portion has a notch for receiving the shroud extension of the adjacent blade when the blades are disposed in a circular array in the turbine.
Claim 6
Dependent Claim
21 words
A rotatable blade as set forth in claim 4, wherein the shroud platform portion has a tenon extending radially outwardly therefrom.
Claim 7
Dependent Claim
44 words
a rotatable blade as set forth in claim 5, wherein the tenon has a circular cross section and is utilized to attach a shroud ring which joins the blade in groups when the blades are disposed in a circular array in a steam turbine.
Claim 8
Dependent Claim
21 words
A rotatable blade as set forth in claim 6, wherein the root portion has a generally Christmas tree shaped cross section.
Claim 9
Dependent Claim
28 words
A rotatable blade as set forth in claim 7, wherein the thickness of the root platform decreases from the leading to the trailing end of the airfoil portion.
Claim 10
Dependent Claim
31 words
A rotatable blade as set forth in claim 8, wherein the thickness of the shroud platform portion decreases in thickness from the leading to the trailing end of the airfoil portion.
Claim 11
Dependent Claim
34 words
A rotatable blade as set forth in claim 9, wherein the distance between the root platform portion and the shroud platform portion increases from the leading to the trailing edge of the airfoil portion.
Claim 12
Dependent Claim
111 words
A rotatable blade for a steam turbine comprising: a root portion; a root platform portion disposed radially outwardly with respect to the root portion; an airfoil portion extending radially outwardly from the root platform portion and having a leading and a trailing edge; said root platform portion having an extension which supports the trailing edge of the airfoil portion; said extension being wedge shaped and having two generally rectangular surfaces and two triangular shaped sides; and said root platform having a notch with generally rectangular surface which receives and supports the wedge shaped extension of the adjacent blade when the blades are disposed in a circular array on a steam turbine.
Claim 13
Dependent Claim
111 words
A rotatable blade for a steam turbine comprising: a root portion; a root platform portion disposed radially outwardly with respect to the root portion; an airfoil portion extending radially outwardly from the root platform portion and having a leading and a trailing edge; said root platform portion having an extension which supports the trailing edge of the airfoil portion; said extension being wedge shaped and having two generally rectangular surfaces and two triangular shaped sides; and said root platform having a notch with generally rectangular surface which receives and supports the wedge shaped extension of the adjacent blade when the blades are disposed in a circular array on a steam turbine.
Claim 14
Dependent Claim
23 words
A rotatable blade as set forth in claim 11 and further comprising a shroud platform portion disposed radially outwardly from the airfoil portion.
Claim 15
Dependent Claim
27 words
A rotatable blade as set forth in claim 12, wherein the shroud platform portion has a shroud extension which supports the trailing edge of the airfoil portion.
Claim 16
Dependent Claim
38 words
A rotatable blade as set forth in claim 13, wherein the shroud platform portion has a notch for receiving the shroud extension of the adjacent blade when the blades are disposed in a circular array in the turbine.
Claim 17
Dependent Claim
21 words
A rotatable blade as set forth in claim 14, wherein the shroud platform portion has a tenon extending radially outwardly therefrom.
Claim 18
Dependent Claim
44 words
A rotatable blade as set forth in claim 15, wherein the tenon has a circular cross section and is utilized to attach a shroud ring which joins the blade in groups when the blades are disposed in a circular array in a steam turbine.
Claim 19
Dependent Claim
21 words
A rotatable blade as set forth in claim 16, wherein the root portion has a generally Christmas tree shaped cross section.
Claim 20
Dependent Claim
30 words
A rotatable blade as set forth in claim 17, wherein the thickness of the root platform is generally constant from the leading to the trailing end of the airfoil portion.
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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) | 1990-12-21 | 1991-06-22 | 1991-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-21 | 1995-06-22 | 1995-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-21 | 1999-06-22 | 1999-12-22 | $7700.00 | Window Closed / Lapsed |