US3765794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter blade pitch lock
Assignee: RTX Corp
•
Filing: 1972-02-18
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Granted: 1973-10-16
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Expires: 1992-02-18
Abstract
Abstract A helicopter blade pitch lock in which the movable and stationary portions of the pitch change servos carry over-lapping concentric sleeve members with aligned apertures therein to receive pitch lock pins equidistant on opposite sides of the servo-axis. There is a sequencing arrangement wherein the unlocked pitch lock pins are locked out of pitch lock position, and wherein the pins can sequentially be freed for pitch locking when desired, actuated to their pitch lock position, and locked in their pitch locked position when pitch locking is desired, and wherein the pins can sequentially be freed in their pitch lock position, withdrawn from their pitch lock position, and locked out of their pitch lock position when pitch lock is not desired.
Inventors
- 👤 G Kudasch
- 👤 K Wallischeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:30
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473; B64C27/50; B64C27/54
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
149 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 a servo mechanism comprising stationary and movable parts and with at least one movable part connected to said swashplate to cause swashplate motion, 3 a sleeve member projecting from a movable part of said servo mechanism and having opposed apertures therein, 4 a sleeve member projecting from a stationary part of said servo mechanism and having opposed apertures therein adapted to be aligned with said opposed apertures of said movable part sleeve member, and 5 locking pins actuatable to pass through the corresponding aligned holes of said movable and stationary sleeve members to thereby prevent blade pitch change.
Claim 2
Dependent Claim
149 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 a servo mechanism comprising stationary and movable parts and with at least one movable part connected to said swashplate to cause swashplate motion, 3 a sleeve member projecting from a movable part of said servo mechanism and having opposed apertures therein, 4 a sleeve member projecting from a stationary part of said servo mechanism and having opposed apertures therein adapted to be aligned with said opposed apertures of said movable part sleeve member, and 5 locking pins actuatable to pass through the corresponding aligned holes of said movable and stationary sleeve members to thereby prevent blade pitch change.
Claim 3
Dependent Claim
34 words
A rotor according to claim 1 wherein said servo mechanism comprises at least one power piston-cylinder mechanism mounted for relative motion about an axis and wherein said sleeve members are concentric about said axis.
Claim 4
Dependent Claim
21 words
A rotor according to claim 2 wherein said servo mechanism includes three power cylinder-piston mechanisms positioned circumferentially about said swashplate assembly.
Claim 5
Dependent Claim
50 words
A rotor according to claim 1 and including: A means responsive to the location of said one movable servo mechanism part to actuate said lock pins, B means to lock said lock pins in pitch locking position, and C means to lock said lock pins out of pitch locking position.
Claim 6
Dependent Claim
37 words
A rotor according to claim 1 and including means to prevent said sleeve members froM rotating relative to one another to thereby prevent said aligned apertures from moving out of alignment due to a relative rotary motion.
Claim 7
Dependent Claim
38 words
A rotor according to claim 1 wherein said servo mechanism comprises three hydraulic or pneumatic cylinder-piston mechanisms positioned circumferentially about the swashpalte and with the pistons mounted for motion within stationary cylinders and connected to the swashplate assembly.
Claim 8
Dependent Claim
125 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 at least one power piston-cylinder assembly having the movable portion thereof connected to said swashplate assembly to cause swashplate motion, and having overlapping concentric sleeve members projecting from the movable and stationary portions thereof and having substantially diametrically opposed aligned apertures in said concentric sleeves, 3 lock pins actuatable to pass through the respective aligned apertures to lock the movable and stationary portions of the power piston-cylinder assembly to thereby prevent blade pitch change.
Claim 9
Dependent Claim
125 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 at least one power piston-cylinder assembly having the movable portion thereof connected to said swashplate assembly to cause swashplate motion, and having overlapping concentric sleeve members projecting from the movable and stationary portions thereof and having substantially diametrically opposed aligned apertures in said concentric sleeves, 3 lock pins actuatable to pass through the respective aligned apertures to lock the movable and stationary portions of the power piston-cylinder assembly to thereby prevent blade pitch change.
Claim 10
Dependent Claim
98 words
A rotor according to claim 7 wherein the piston is the movable part of the power piston-cylinder assembly and wherein the cylinder is the stationary portion of the power piston-cylinder assembly and including: A means to actuate said piston with respect to said cylinder to thereby move said swashplate assembly and produce pitch change motion, B means responsive to the location of said piston with respect to said cylinder to actuate said lock pins, C means to lock said lock pins in pitch locked position, and D means to lock said lock pins out of pitch locked position.
Claim 11
Dependent Claim
62 words
A rotor according to claim 7 wherein the piston is the movable portion of the power piston-cylinder assembly and is received in the stationary cylinder to reciprocate along the axis thereof and wherein said concentric sleeve members are concentric about said cylinder and piston axis and wherein there are two sets of diametrically opposed lock pin receiving apertures in said sleeve members.
Claim 12
Dependent Claim
132 words
A rotor according to claim 7 wherein said lock pins are actuatable between a locked position and a retracted position and including: A means to sequentially actuate said lock pins from said retracted position to said locked position including: 1 means to free said lock pins in said retracted position, 2 means to actuate said lock pins from said retracted position to said locked position, and 3 means to lock said lock pins in said locked position, B means to sequentially actuate said lock pins from said locked position to said retracted position including: 1 means to free said lock pins in said locked position, 2 means to move said lock pins from said locked position to said retracted position, and 3 means to lock said lock pins in said retracted position.
Claim 13
Dependent Claim
57 words
A rotor according to claim 10 wherein said sequential mechanism to bring said lock pins to said locked position is responsive to the movement of said sleeve member of said piston-cylinder assembly movable portion moving into a position relative to said sleeve member of said piston-cylinder assembly stationary portion so as to bring said apertures into alignment.
Claim 14
Dependent Claim
34 words
A rotor according to claim 10 wherein said pitch lock actuating means and said pitch lock locking means are power piston members, and including means to signal the location of said power piston members.
Claim 15
Dependent Claim
116 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 at least one servo mechanism having a movable portion and a stationary portion mounted for relative motion along an axis and with the movable portion thereof connected to said swashplate assembly to cause swashplate motion, and C means to connect said movable portion to said stationary portion of said power piston-cylinder assembly at at least two stations located equidistant on opposite sides of said axis.
Claim 16
Dependent Claim
116 words
A helicopter rotor having: A a plurality of blades mounted for rotation about an axis and for pitch change motion, B means to vary blade pitch including: 1 a swashplate assembly mounted to be movable relative to said blades and connected thereto so that swashplate motion causes blade pitch change, 2 at least one servo mechanism having a movable portion and a stationary portion mounted for relative motion along an axis and with the movable portion thereof connected to said swashplate assembly to cause swashplate motion, and C means to connect said movable portion to said stationary portion of said power piston-cylinder assembly at at least two stations located equidistant on opposite sides of said axis.
Claim 17
Dependent Claim
28 words
A rotor according to claim 13 and including three power piston-cylinder assemblies positioned circumferentially about said swashplate assembly and having the movable portions thereof connected to said swashplate.
Claim 18
Dependent Claim
132 words
A rotor according to claim 1 wherein said lock pins are actuatable between a locked position and a retracted position and including: A means to sequentially actuate said lock pins from said retracted position to said locked position including: 1 means to free said lock pins in said retracted position, 2 means to actuate said lock pins from said retracted position to said locked position, and 3 means to lock said lock pins in said locked position, B means to sequentially actuate said lock pins from said locked position to said retracted position including: 1 means to free said lock pins in said locked position, 2 means to move said lock pins from said locked position to said retracted position, and 3 means to lock said lock pins in said retracted position.
Claim 19
Dependent Claim
57 words
A rotor according to claim 15 wherein said sequential mechanism to bring said lock pins to said locked position is responsive to the movement of said sleeve member of said piston-cylinder assembly movable portion moving into a position relative to said sleeve member of said piston-cylinder assembly stationary portion so as to bring said apertures into alignment.
Claim 20
Dependent Claim
34 words
A rotor according to claim 16 wherein said pitch lock actuating means and said pitch lock locking means are power piston members, and including means to signal the location of said power piston members.
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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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |