US3572616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pitch control mechanism for bladed rotor
Assignee: RTX Corp
•
Filing: 1969-09-18
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Granted: 1971-03-30
•
Expires: 1989-09-18
Abstract
Abstract Two Z-crank mechanisms connect at different stations to a rotor swashplate so that translation of the mechanisms causes collective pitch variation of the blades and so that rotation of the mechanisms either together or separately causes cyclic pitch variations of the blades.
Inventors
- 👤 Harold Danford Ulisnik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:09
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/54; B64C27/58; B64C27/59
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
457 words
A pitch control system for a helicopter rotor having a plurality of blades mounted for rotation and blade pitch variation including: a. a first torque tube mounted for rotation about an axis of rotation and having a first end of circular cross section positioned concentrically about a first bearing axis which forms an angle with and intersects said axis of rotation to define a point of intersection therewith; b. a first bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis; c. a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection; d. a swashplate nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins; e. a second torque tube concentric about said axis of rotation with said first torque tube and including a first end of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection; f. a second bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis; g. a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member; h. means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque tube will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cYclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis; i. a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member; and j. means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 2
Dependent Claim
457 words
A pitch control system for a helicopter rotor having a plurality of blades mounted for rotation and blade pitch variation including: a. a first torque tube mounted for rotation about an axis of rotation and having a first end of circular cross section positioned concentrically about a first bearing axis which forms an angle with and intersects said axis of rotation to define a point of intersection therewith; b. a first bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis; c. a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection; d. a swashplate nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins; e. a second torque tube concentric about said axis of rotation with said first torque tube and including a first end of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection; f. a second bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis; g. a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member; h. means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque tube will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cYclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis; i. a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member; and j. means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 3
Dependent Claim
29 words
Apparatus according to claim 1 wherein said rotor has an axis of rotation and wherein said torque tube axis of rotation is coincident with the rotor axis of rotation.
Claim 4
Dependent Claim
21 words
a first bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis,
Claim 5
Dependent Claim
21 words
a first bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis,
Claim 6
Dependent Claim
130 words
a rotatable ring member mounted for rotation and supported from said nonrotatable ring member; f. means to prevent rotation of said nonrotatable ring member so that rotation of said tubular leg of said first Z-crank mechanism will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said tubular leg of said second Z-crank mechanism will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis; and g. means connecting said rotatable swashplate member to each of the blades to cause the blades to change pitch in accordance with swashplate motion.
Claim 7
Dependent Claim
130 words
a rotatable ring member mounted for rotation and supported from said nonrotatable ring member; f. means to prevent rotation of said nonrotatable ring member so that rotation of said tubular leg of said first Z-crank mechanism will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said tubular leg of said second Z-crank mechanism will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis; and g. means connecting said rotatable swashplate member to each of the blades to cause the blades to change pitch in accordance with swashplate motion.
Claim 8
Dependent Claim
20 words
a bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis,
Claim 9
Dependent Claim
20 words
a bearing member enveloping said first end of said first torque tube and positioned concentrically about said first bearing axis,
Claim 10
Dependent Claim
56 words
a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection,
Claim 11
Dependent Claim
56 words
a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection,
Claim 12
Dependent Claim
56 words
a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection,
Claim 13
Dependent Claim
56 words
a first control lever including a circular central portion concentrically enveloping said bearing member to be supported therefrom by said first end of said first torque tube and so as to permit rotation therebetween and including end pins projecting from opposite sides thereof concentrically about a first control lever axis passing through said point of intersection,
Claim 14
Dependent Claim
23 words
Apparatus according to claim 1 and including means to support said torque tubes for translation along and rotation about said axis of rotation.
Claim 15
Dependent Claim
40 words
Apparatus according to claim 3 and including means to cause said torque tubes to translate in unison along said axis of rotation and hence to cause said swashplate to so translate to thereby vary the pitch of said blades collectively.
Claim 16
Dependent Claim
43 words
a swashplate nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins,
Claim 17
Dependent Claim
43 words
a swashplate nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins,
Claim 18
Dependent Claim
43 words
a swashplaTe nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins,
Claim 19
Dependent Claim
43 words
a swashplaTe nonrotating ring including two sets of diametrically opposed apertures spaced perpendicular to one another and with said end pins received in the first of said aperture sets so that said swashplate nonrotatable ring is supported by said control lever end pins,
Claim 20
Dependent Claim
70 words
a second torque tube positioned within said rotor shaft and said first torque tube and concentric about said axis of rotation with said first torque tube and mounted for translation along and rotation about said axis of rotation and including a first end Of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection,
Claim 21
Dependent Claim
70 words
a second torque tube positioned within said rotor shaft and said first torque tube and concentric about said axis of rotation with said first torque tube and mounted for translation along and rotation about said axis of rotation and including a first end Of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection,
Claim 22
Dependent Claim
37 words
Apparatus according to claim 3 and including means to selectively rotate said torque tubes about said axis of rotation individually or in unison to vary the position of said swashplate selectively about each of said tilt axes.
Claim 23
Dependent Claim
62 words
a second torque tube positioned concentrically about said axis of rotation and extending through said first torque tube and mounted for rotation about said axis of rotation and translation therealong and having a first end of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection,
Claim 24
Dependent Claim
62 words
a second torque tube positioned concentrically about said axis of rotation and extending through said first torque tube and mounted for rotation about said axis of rotation and translation therealong and having a first end of circular cross section positioned concentrically about a second bearing axis which forms an angle with said axis of rotation and passes through said point of intersection,
Claim 25
Dependent Claim
20 words
a bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis,
Claim 26
Dependent Claim
20 words
a bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis,
Claim 27
Dependent Claim
37 words
Apparatus according to claim 4 and including means to selectively rotate said torque tubes about said axis of rotation individually or in unison to vary the position of said swashplate selectively about each of said tilt axes.
Claim 28
Dependent Claim
20 words
a bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis,
Claim 29
Dependent Claim
20 words
a bearing member enveloping said first end of said second torque tube and positioned concentrically about said second bearing axis,
Claim 30
Dependent Claim
77 words
a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member,
Claim 31
Dependent Claim
77 words
a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member,
Claim 32
Dependent Claim
177 words
A helicopter having a longitudinal and a transverse axis and: a. a first rotor including a hub mounted for rotation about an axis of rotation and a plurality of blades extending therefrom for rotation therewith and mounted for pitch change motion with respect thereto; b. a second rotor including a hub mounted for rotation about said axis of rotation and including a plurality of blades mounted for rotation therewith and for pitch change motion with respect thereto; c. a rotor drive shaft concentric about said axis of rotation and extending through the hub of said second rotor and connected to the hub of said first rotor; d. means to cause said rotor drive shaft to rotate about said axis of rotation; e. means to cause said second rotor to rotate about said axis of rotation; f. means to cause the blades of said second rotor to vary in pitch with respect to the hub thereof; and g. means to cause blades of said first rotor to vary in pitch with respect to the hub thereof and including;
Claim 33
Dependent Claim
177 words
A helicopter having a longitudinal and a transverse axis and: a. a first rotor including a hub mounted for rotation about an axis of rotation and a plurality of blades extending therefrom for rotation therewith and mounted for pitch change motion with respect thereto; b. a second rotor including a hub mounted for rotation about said axis of rotation and including a plurality of blades mounted for rotation therewith and for pitch change motion with respect thereto; c. a rotor drive shaft concentric about said axis of rotation and extending through the hub of said second rotor and connected to the hub of said first rotor; d. means to cause said rotor drive shaft to rotate about said axis of rotation; e. means to cause said second rotor to rotate about said axis of rotation; f. means to cause the blades of said second rotor to vary in pitch with respect to the hub thereof; and g. means to cause blades of said first rotor to vary in pitch with respect to the hub thereof and including;
Claim 34
Dependent Claim
77 words
a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member,
Claim 35
Dependent Claim
77 words
a second control lever having a circular central opening enveloping said second bearing member so that said second control lever is supported through said second bearing unit by said second torque tube first end and including end pins projecting from the opposite ends thereof concentrically about a second control lever axis which is perpendicular to said first control lever axis and with said end pins received in the second set of apertures of said nonrotatable swashplate member,
Claim 36
Dependent Claim
81 words
means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis,
Claim 37
Dependent Claim
81 words
means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque will cause said nonrotatable swashplate member to tilt about a first tilt axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and thereby vary blade pitch cyclically about said second tilt axis,
Claim 38
Dependent Claim
90 words
Apparatus according to claim 7 and wherein said second rotor blades have pitch change horns projecting therefrom and including means to change the pitch of the blades of said second rotor including: a. a swashplate mounted for translation and tilting with respect to said axis of rotation; b. means connecting said swashplate to said pitch change horns; and c. and servo means in the form of hydraulic cylinder piston units connected to said swashplate to cause said swashplate to translate along and tilt with respect to said axis of rotation.
Claim 39
Dependent Claim
138 words
means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque tube will cause said nonrotatable swashplate member to tilt about a first tilt axis which passes through said point of intersection and which is perpendicular to said axis of rotation when at zero pitch setting, said first bearing axis and said first control lever axis and which is parallel to said helicopter longitudinal axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and is coincident with said first control lever axis and parallel to said helicopter lateral axis and thereby vary blade pitch cyclically about said second tilt axis,
Claim 40
Dependent Claim
138 words
means to prevent said nonrotatable swashplate member from rotating so that rotation of said first torque tube will cause said nonrotatable swashplate member to tilt about a first tilt axis which passes through said point of intersection and which is perpendicular to said axis of rotation when at zero pitch setting, said first bearing axis and said first control lever axis and which is parallel to said helicopter longitudinal axis and thereby vary blade pitch cyclically about said first tilt axis and so that rotation of said second torque tube will cause said nonrotatable swashplate member to tilt about a second tilt axis which is perpendicular to said first tilt axis and is coincident with said first control lever axis and parallel to said helicopter lateral axis and thereby vary blade pitch cyclically about said second tilt axis,
Claim 41
Dependent Claim
16 words
a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member, and
Claim 42
Dependent Claim
16 words
a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member, and
Claim 43
Dependent Claim
82 words
A helicopter including: a. a helicopter rotor including a hub mounted for rotation about an axis of rotation and including a plurality of blades extending radially therefrom for rotation therewith and mounted for pitch change motion with respect thereto; b. a transmission unit located in said helicopter and positioned adjacent said rotor; c. a rotor drive shaft connecting said transmission unit to said helicopter rotor; d. pitch control means positioned on the opposite side of the rotor from the transmission and including:
Claim 44
Dependent Claim
82 words
A helicopter including: a. a helicopter rotor including a hub mounted for rotation about an axis of rotation and including a plurality of blades extending radially therefrom for rotation therewith and mounted for pitch change motion with respect thereto; b. a transmission unit located in said helicopter and positioned adjacent said rotor; c. a rotor drive shaft connecting said transmission unit to said helicopter rotor; d. pitch control means positioned on the opposite side of the rotor from the transmission and including:
Claim 45
Dependent Claim
16 words
a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member, and
Claim 46
Dependent Claim
16 words
a rotatable swashplate member supported by and rotatable with respect to said nonrotatable swashplate member, and
Claim 47
Dependent Claim
29 words
Apparatus according to claim 9 wherein said first ends of said torque tubes, said control levers, and said swashplate are in substantially radial alignment with said axis of rotation.
Claim 48
Dependent Claim
17 words
means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 49
Dependent Claim
17 words
means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 50
Dependent Claim
17 words
means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 51
Dependent Claim
17 words
means connecting said rotatable swashplate member to the blades of the rotor for pitch change motion therewith.
Claim 52
Dependent Claim
257 words
Blade pitch control mechanism for a multibladed rotor of the helicopter-type including: a. a first Z-crank mechanism having a tubular center leg mounted for translation along and rotation about an axis of rotation and further having a first end of circular cross section concentric about a first bearing axis forming an angle with said axis of rotation and intersecting the axis of rotation to form a point of intersection; b. a first control lever having a circular center aperture in the interior thereof and mounted around said first end of said first Z-crank mechanism to permit relative rotation between said first control lever and said first Z-crank mechanism first end and having end pins projecting from the opposite ends thereof and positioned concentrically about a first control lever axis passing through said point of intersection; c. a second Z-crank mechanism including a tubular central leg mounted concentrically with said tubular central leg of said first Z-crank mechanism for translation along and rotation about said axis of rotation and having a first end of circular cross section positioned concentrically about a second bearing axis forming an angle with said axis of rotation and passing through said point of intersection; d. a second control lever having a circular aperture in the interior thereof and mounted about said first end of said second Z-crank mechanism to permit relative rotation therebetween and including end pins projecting from the opposite ends thereof and positioned concentrically about a second control lever axis passing through said point of intersection; e. a swashplate assembly including:
Claim 53
Dependent Claim
257 words
Blade pitch control mechanism for a multibladed rotor of the helicopter-type including: a. a first Z-crank mechanism having a tubular center leg mounted for translation along and rotation about an axis of rotation and further having a first end of circular cross section concentric about a first bearing axis forming an angle with said axis of rotation and intersecting the axis of rotation to form a point of intersection; b. a first control lever having a circular center aperture in the interior thereof and mounted around said first end of said first Z-crank mechanism to permit relative rotation between said first control lever and said first Z-crank mechanism first end and having end pins projecting from the opposite ends thereof and positioned concentrically about a first control lever axis passing through said point of intersection; c. a second Z-crank mechanism including a tubular central leg mounted concentrically with said tubular central leg of said first Z-crank mechanism for translation along and rotation about said axis of rotation and having a first end of circular cross section positioned concentrically about a second bearing axis forming an angle with said axis of rotation and passing through said point of intersection; d. a second control lever having a circular aperture in the interior thereof and mounted about said first end of said second Z-crank mechanism to permit relative rotation therebetween and including end pins projecting from the opposite ends thereof and positioned concentrically about a second control lever axis passing through said point of intersection; e. a swashplate assembly including:
Claim 54
Dependent Claim
38 words
Apparatus according to claim 11 and including: a. means to cause said Z-crank mechanisms to translate in unison along said axis of rotation; and b. means to cause said Z-crank mechanisms to rotate about said axis of rotation.
Claim 55
Dependent Claim
37 words
Apparatus according to claim 12 wherein said Z-crank mechanisms rotating means includes means to rotate said first Z-crank mechanism and means independent thereof to rotate said second Z-crank mechanism to thereby accomplish universal blade cyclic pitch variation.
References Cited (Backward Citations)
GB591982A
Cited
US3448810A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |