US3876334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable pitch rate means
Assignee: RTX Corp
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Filing: 1974-04-08
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Granted: 1975-04-08
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Expires: 1994-04-08
Abstract
Abstract The pitch velocity of alternate and individual high solidity variable pitch blades of a bypass fan propulsor vary so as to pass through zero or flat pitch at different intervals, although ending at the same pitch at the extent of their travel.
Inventors
- 👤 Merritt B Andrews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:47
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/34; F04D29/36; F01; F01D; F01D7/00; F04D29/321; F04D29/322; F04D29/323; F05; F05D; F05D2220/00; F05D2220/30; F05D2220/36; F05D2260/00; F05D2260/70; F05D2260/74; F05D2260/76
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
51 words
Pitch change means for a propulsor having a plurality of blades circumferentially supported in a rotatable hub and means, including a pitch change actuator, for varying the pitch thereof, and additional means for varying the rate of change of alternate of said blades and means for imparting motion to said actuator.
Claim 2
Dependent Claim
51 words
Pitch change means for a propulsor having a plurality of blades circumferentially supported in a rotatable hub and means, including a pitch change actuator, for varying the pitch thereof, and additional means for varying the rate of change of alternate of said blades and means for imparting motion to said actuator.
Claim 3
Dependent Claim
16 words
Pitch change means as defined as in claim 1 wherein said pitch change actuator is rotational.
Claim 4
Dependent Claim
19 words
Pitch change means as claimed in claim 1 wherein the blades have a solidity factor of one or greater.
Claim 5
Dependent Claim
73 words
In a propulsor for aircraft having a turbine type of power plant driving a variable pitch fan mounted in a power plant bypass duct, a hub supporting a plurality of fan blades that are so dimensioned that adjacent blades when in a given plane overlap each other, means for varying the rate of change of each and alternate blades so that adjacent blades pass through the plane where interference occurs at different intervals.
Claim 6
Dependent Claim
73 words
In a propulsor for aircraft having a turbine type of power plant driving a variable pitch fan mounted in a power plant bypass duct, a hub supporting a plurality of fan blades that are so dimensioned that adjacent blades when in a given plane overlap each other, means for varying the rate of change of each and alternate blades so that adjacent blades pass through the plane where interference occurs at different intervals.
Claim 7
Dependent Claim
104 words
Pitch change actuating means for a bariable pitch propulsor having a hub supporting a plurality of circumerentially mounted blades for pitch change movement, said means including a ring-like gear having a nonuniform surface, a noncircular gear operatively connected to each of said blades mating with teeth formed in said nonuniform surface such that alternate nonuniform gears are spaced equidistant from a plane taken transverse through the axis of rotation of said ring-like gear and the center of rotation of said noncircular gears, means for imparting rotary motion to said ring-like gear for effectuating pitch change whereby the pitch rate of alternate blades will vary.
Claim 8
Dependent Claim
104 words
Pitch change actuating means for a bariable pitch propulsor having a hub supporting a plurality of circumerentially mounted blades for pitch change movement, said means including a ring-like gear having a nonuniform surface, a noncircular gear operatively connected to each of said blades mating with teeth formed in said nonuniform surface such that alternate nonuniform gears are spaced equidistant from a plane taken transverse through the axis of rotation of said ring-like gear and the center of rotation of said noncircular gears, means for imparting rotary motion to said ring-like gear for effectuating pitch change whereby the pitch rate of alternate blades will vary.
Claim 9
Dependent Claim
15 words
Pitch change actuating means as claimed in claim 5 wherein said noncircular gear is segmented.
Claim 10
Dependent Claim
17 words
Pitch change actuating means as claimed in claim 5 wherein said nonuniform surface takes a sinusoidal shape.
Claim 11
Dependent Claim
17 words
Pitch change actuating means as claimed in claim 5 wherein said blades have solidity greater than one.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |